title: Cartesian product

text: It is possible to define the Cartesian product of an arbitrary (possibly infinite) indexed family of sets. If "I" is any index set, and formula_22 is a family of sets indexed by "I", then the Cartesian product of the sets in formula_22 is defined to be


title: Cartesian product

text: that is, the set of all functions defined on the index set such that the value of the function at a particular index "i" is an element of "X". Even if each of the "X" is nonempty, the Cartesian product may be empty if the axiom of choice, which is equivalent to the statement that every such product is nonempty, is not assumed.


title: Cartesian product

text: is the set of all functions from "I" to "X", and is frequently denoted "X". This case is important in the study of cardinal exponentiation. An important special case is when the index set is formula_28, the natural numbers: this Cartesian product is the set of all infinite sequences with the "i"th term in its corresponding set "X". For example, each element of


title: Cartesian product

text: can be visualized as a vector with countably infinite real number components. This set is frequently denoted formula_30, or formula_31.


title: Cartesian product

text: If several sets are being multiplied together (e.g., "X", "X", "X", …), then some authors choose to abbreviate the Cartesian product as simply ×"X".


title: Cartesian product

text: If "f" is a function from "X" to "A" and "g" is a function from "Y" to "B", then their Cartesian product is a function from to with


title: Cartesian product

text: Let formula_33 be a set and formula_34. Then the "cylinder" of formula_35 with respect to formula_33 is the Cartesian product formula_37 of formula_35 and formula_33.


title: Cartesian product

text: Normally, formula_33 is considered to be the universe of the context and is left away. For example, if formula_35 is a subset of the natural numbers formula_28, then the cylinder of formula_35 is formula_44.


title: Cartesian product

text: Although the Cartesian product is traditionally applied to sets, category theory provides a more general interpretation of the product of mathematical structures. This is distinct from, although related to, the notion of a Cartesian square in category theory, which is a generalization of the fiber product.


title: Cartesian product

text: Exponentiation is the right adjoint of the Cartesian product; thus any category with a Cartesian product (and a final object) is a Cartesian closed category.


title: Cartesian product

text: In graph theory, the Cartesian product of two graphs "G" and "H" is the graph denoted by , whose vertex set is the (ordinary) Cartesian product and such that two vertices ("u","v") and ("u"′,"v"′) are adjacent in , if and only if and "v" is adjacent with "v"′ in "H", "or" and "u" is adjacent with "u"′ in "G". The Cartesian product of graphs is not a product in the sense of category theory. Instead, the categorical product is known as the tensor product of graphs.


title: Kinmen

text: Kinmen, alternatively known as Quemoy, is a group of islands governed as a county by the Republic of China (Taiwan), off the southeastern coast of mainland China. It lies roughly east of the city of Xiamen in Fujian, from which it is separated by Xiamen Bay. Kinmen is located west from the shoreline of the island of Taiwan across the Taiwan Strait.


title: Kinmen

text: The county consists of the major island of Kinmen along with several surrounding islets, as well as Wuqiu Township located to the northeast of the rest of the county. Kinmen is one of two counties that constitutes Fujian Province, the other being Lienchiang County (Matsu).


title: Kinmen

text: Kinmen's strategic location in the Taiwan Strait has led to numerous confrontations, making it a tangible embodiment of political change on Cross-Strait relations. In August 1958, Kinmen was heavily bombarded by the People's Liberation Army during the Second Taiwan Strait Crisis. Travel restrictions between Kinmen and the main island of Taiwan were lifted in 1994 following the end of decades-long military administration over Kinmen. A direct ferry route to Xiamen was inaugurated in January 2001 following the establishment of the Three Links.


title: Kinmen

text: The People's Republic of China (PRC, China) claims Kinmen as part of Fujian Province and considers Wuqiu to be a separate territory of Fujian apart from Kinmen itself; conversely, the ROC claims the Dadeng Islands (Tateng) as part of Kinmen, even though they were effectively transferred to the control of Xiamen by the PRC.


title: Kinmen

text: Kinmen (金門) means 'golden gate'. The name was first recorded in 1387 when the Hongwu Emperor appointed Zhou Dexing to administer the island and protect it from pirate attacks. The spelling "Kinmen" is a postal romanization. This transcription system is a variation of Nanking Syllabary, a system developed by Herbert Giles in 1892. It was adopted by the Chinese Imperial Post, part of the Chinese Maritime Customs Service led by Irishman Robert Hart. It is based on pronunciation in the Southern Mandarin, or Jianghuai, dialect. This dialect is widely spoken in Jiangsu and Anhui provinces, including the city of Nanjing. The Taiwanese Ministry of Foreign Affairs uses "Kinmen," while the United States Board on Geographic Names gives "Kinmen Island."


title: Kinmen

text: Quemoy, pronounced , is a name for the island in English and in other European languages. It may have originated as a Spanish or Portuguese transcription of the Zhangzhou Hokkien pronunciation of the name, "Kim-mûi". This is the most common form of the islands' name in English. For example, works that deal with the First and Second Taiwan Strait Crises (the Quemoy Incident) and the 1960 United States presidential election debates when the islands received prominent worldwide news coverage all use the word Quemoy. In addition, the former National Kinmen Institute of Technology was renamed National Quemoy University in 2010. Kinmen scholar Wei Jian-feng advocates the use of the word Quemoy to better connect the island to "international society or achieve more recognition in the world".


title: Kinmen

text: Jinmen is the island's name both in Tongyong Pinyin and in Hanyu Pinyin. Hanyu Pinyin is the international standard for transliterating Chinese. It was adopted by the Taiwanese government in 2009. Kimoi is a Hokkien-derived spelling also used in the postal romanization system. Chin-men is the Wade–Giles romanization of the island's name.


title: Kinmen

text: Humans have lived on Kinmen for 5,800 to 8,000 years. During the reign of Emperor Yuan (317 CE), the Five Barbarians invasion of China led six extended families to flee south and they settled in Kinmen, then called Wuzhou. More people settled there during the Tang dynasty, changing the name from" Wuzhou" to "Kinmen".


title: Kinmen

text: During the Ming dynasty, more migrants settled in Kinmen. Koxinga used Kinmen as a base to capture Formosa and Penghu from the Dutch. He cut down trees to build his navy, resulting in massive deforestation that made Kinmen vulnerable to soil erosion.


title: Kinmen

text: The Prince of Lu, a member of the Southern Ming dynasty, resisted the invading Manchu Qing dynasty forces. In 1651, he fled to Kinmen, which the Qing dynasty took in 1663. During the Qing Dynasty, the Kinmen area was part of Tungan County.


title: Kinmen

text: After the establishment of the Republic of China (ROC) in 1912, Kinmen became part of Fujian Province. In 1913, the Kinmen area was made part of Siming County. Kinmen County was established in 1914. In 1928, the county came under direct administration of the provincial government.


title: Kinmen

text: The Empire of Japan captured Kinmen in 1937 during the Second Sino-Japanese War. They blockaded the island on September 3 and landed on October 23. Fighting was light with ROC forces fleeing rather than fighting. The only casualty was sustained by a local self-defense unit. Many of the residents fled to the mainland or to Southeast Asia. The purpose of the Japanese seizure of Kinmen was to use it as a position from which to attack the neighboring city of Xiamen which they would seize in May 1938. Following the seizure of Xiamen many of the locals who had fled there returned to Kinmen.


title: Kinmen

text: After the capture of the island the county government went into exile in Dadeng. The Japanese administered Kinmen as a special municipality of Xiamen, the government was composed of locals, people from other parts of occupied China, and Taiwanese.


title: Kinmen

text: A poor harvest in 1938 brought challenges for islanders. The Japanese engaged in economic development of the island including through the use of forced labor. KMT forces engaged in two serious attempts to retake the island and kept up a low level campaign against the Japanese. In 1943 insurgents kidnapped two Taiwanese officials who had been overseeing the salt fields and took them to China before executing them. In retaliation the Japanese authorities rounded up 300 young men from the local community eventually executing four.


title: Kinmen

text: Towards the end of WWII conditions worsened with Japanese authorities conscripting 500 locals (with their mules) into the military and confiscating household goods. The island came under allied bombing including one attack on Aug. 30, 1944 which killed 19 locals.


title: Kinmen

text: WWII ended in Aug. 15, 1945 with the surrender of Japan. Following the end of the war there were attacks by locals against Taiwanese who took shelter with the Japanese garrison. Kinmen was effectively ungoverned until Oct. 3, 1945 when ROC forces landed and installed a new government. A celebration on Oct. 10 marked the end of hostilities. Locals who had survived the war following their conscription by the Japanese were treated as traitors by the KMT occupation authorities.


title: Kinmen

text: After the establishment of the People's Republic of China (PRC) by the Chinese Communists in October 1949, Kinmen County was claimed by both the Nationalists and the Communists. Dadeng, Xiaodeng and Jiaoyu were taken by the Communists on 9 October or 15 October, 1949. While those islands are still claimed by the ROC, they are governed as part of Dadeng Subdistrict, Xiang'an District, Xiamen, Fujian, China.


title: Kinmen

text: On 25 October 1949, People's Liberation Army (PLA) forces landed on Kinmen Island near Guningtou beginning the Battle of Kuningtou. ROC forces successfully defended the island and prevented an attack on Taiwan.


title: Kinmen

text: At the outbreak of the Korean War in 1950, retired Admiral Charles M. Cooke Jr., advisor to President Chiang Kai-shek, opposed withdrawing ROC forces from Quemoy (Kinmen). On 26 July 1950, ROC forces on Dadan Island (Tatan), in total 298 soldiers, repulsed an attack () from a People's Liberation Army force of 700 soldiers that landed on the island. General Douglas MacArthur and other US officials supported ROC efforts to defend the islands.


title: Kinmen

text: The PLA extensively shelled the island during the First and Second Taiwan Strait crises in 1954–1955 and 1958 respectively. In 1954, the United States considered responding by using nuclear weapons against the PRC. Again in 1958, General Nathan Farragut Twining and the Joint Chiefs of Staff believed that the United States should not permit the loss of the islands to the communists and recommended to President Eisenhower the use of whatever force was necessary, including atomic weapons.


title: Kinmen

text: The phrase "Quemoy and Matsu" became part of American political language in the 1960 U.S. presidential election. During the debates, both candidates, Vice-President Richard Nixon and Senator John F. Kennedy, pledged to use American forces if necessary to protect Taiwan from invasion by the PRC, which the United States did not recognize as a legitimate government. But in the second debate on 7 October 1960, the two candidates presented different opinions about whether to use American forces to protect Taiwan's forward positions, Quemoy and Matsu, also. Senator Kennedy stated that these islands – as little as 9 kilometres (5.5 mi) off the coast of China and as much as 170 kilometres (106 mi) from Taiwan – were strategically indefensible and were not essential to the defense of Taiwan. Vice-President Nixon maintained that since Quemoy and Matsu were in the "area of freedom," they should not be surrendered to the Communists as a matter of principle.


title: Kinmen

text: After the third debate on 13 October 1960, Kennedy's advisers spoke with then Secretary of State Herter and said Kennedy was willing to revise his position on the Quemoy and Matsu issue so as not to give the Communists the impression that the USA would not stand united against aggression. Nixon pointed out the change in Kennedy's position but decided not to press the point due to the importance of the USA's role in what was an extremely tense situation. Nixon's polls among Republicans and Democrats showed overwhelming support for Nixon's position on the issue.


title: Kinmen

text: Kinmen was originally a military reserve under the Martial Law curfews, which eventually led to the tragedies of innocent civilian casualties, such as the 1985 Shi Islet Slaughter and 1987 Lieyu massacre. The island was returned to the civilian government in the mid-1990s, after which travel to and from it was allowed. Direct travel between mainland China and Kinmen re-opened in January 2001 under the mini Three Links, and there has been extensive tourism development on the island in anticipation of mainland tourists. Direct travel was suspended in 2003 as a result of the SARS outbreak, but has since resumed.


title: Kinmen

text: Many Taiwanese businessmen use the link through Kinmen to enter the Chinese mainland, seeing it as cheaper and easier than entering through Hong Kong. However, this changed following the 2005 Pan–Blue visits to mainland China and the 2008 presidential and legislative victories of the KMT, that allowed easier cross-Strait relations. Kinmen has experienced a considerable economic boom as businessmen relocate to the island for easier access to the vast markets of the PRC.


title: Kinmen

text: On 30 June 2014, Dadan Island and Erdan Island were handed over from the military to civilians, represented by Kinmen County Government. Since 1 January 2015, tourists from Mainland China could directly apply for the Exit and Entry Permit upon arrival in Kinmen. This privilege also applies to Penghu and Matsu Islands as means to boost tourism in the outlying islands of Taiwan.


title: Kinmen

text: On 23 August 2019, the sixty-first anniversary of the beginning of the Second Taiwan Strait Crisis, President Tsai Ing-wen visited the Taiwushan Martyrs' Shrine () in Mount Taiwu where she placed flowers and offered incense.


title: Kinmen

text: Kinmen, much like the surrounding Chinese mainland, is predominantly composed of Cretaceous aged granite, with lesser amounts of Eocene-Oligocene sandstone, Miocene basalt and Pleistocene-Holocene conglomerate, the thickness of the sediments varies from 150 metres in the west to only a few metres in the east.


title: Kinmen

text: The people of Kinmen see themselves as Kinmenese, "Mínnánrén"/"Mǐnnánrén" (people of Southern Fujian), or Chinese, but not so much as Taiwanese. They do identify as citizens of the ROC, however Kinmen's strong Chinese identity was forged during the period of the ROC's military confrontation with the People's Republic of China (1949–1992) when Kinmen was under military administration. In the 1980s, as the militarization decreased and martial law was ended on Taiwan, the Taiwan independence movement and efforts in de-Sinicization grew in strength on Taiwan. To Kinmenese, however, these developments were viewed with concern and there was a feeling that "Taiwan didn't identify with Kinmen". Many worried that Taiwanese "de jure" independence from China would lead to the severing of ties with Kinmen. These concerns play a strong role in Kinmenese politics as well. Legally speaking, Kinmenese people are not Taiwanese either and have a unique identity from that of the Taiwanese. 'Taiwanization' is sometimes perceived as a threat to the cultural identity of the Kinmenese people.


title: Kinmen

text: Many of the county's inhabitants speak Hokkien; the Quanzhou accent is predominant. Most residents will say they speak Kinmenese, which is mutually intelligible with Taiwanese Hokkien. The residents of Wuchiu Township speak Pu-Xian Min, as opposed to Hokkien for the rest of Kinmen.


title: Kinmen

text: Kinmen is notable for a number of cultural products. Due to the extensive shelling by the People's Liberation Army in the 1950s, Kinmen is famous for its artillery shell knives. Local artisans would collect the vast amounts of exploded ordnance and make high-quality knives which are still sought after by chefs and connoisseurs. Kinmen is also home of the regionally famous Kinmen Kaoliang liquor, a spirit ranging between 38 and 63 percent alcohol, which is highly appreciated by the Taiwanese. Other local culinary specialties include , "" and beef jerky (bakkwa).


title: Kinmen

text: Because of its military importance, development on the island was extremely limited. Only by 2003, Kinmen opened up itself to tourists from Fujian in Mainland China. It is now a popular weekend tourist destination for Taiwanese and is known for its quiet villages, old-style architecture and beaches. Chinese and Taiwanese tour groups also spend a short time touring the island whilst transiting between the ferry and the airport, as an intermediate stop between China and Taiwan. Large parts of Kinmen form the Kinmen National Park which highlights military fortifications and structures, historical dwellings and natural scenery.


title: Kinmen

text: The year 2014 recorded the highest number of passengers traveling by ferry between Kinmen and Fujian ports for as many as 1.5 million people. Since 1 January 2015, Chinese mainland tourists were no longer required to apply for Exit and Entry Permit in advance for visits to Kinmen, Penghu and Matsu Islands. Instead, they can apply for it upon arrival at a cost of NT$600.


title: Kinmen

text: By 2016, two infrastructure projects are expected to boost tourism and meetings, incentives, conferencing, exhibitions visitors to the islands. One includes a yet-to-be-named five-star resort spearheaded by Xiamen property developer, Wu Youhua, president of Xiamen Huatian Group, the first time a Chinese interest has been allowed to invest in the Taiwan hotel sector.


title: Kinmen

text: Tourist-related affairs in Kinmen are governed by Transportation and Tourism Bureau of Kinmen County Government. Major tourist attractions in Kinmen are:


title: Kinmen

text: August 23 Artillery Battle Museum, Guningtou Battle Museum, Hujingtou Battle Museum, Kinmen Ceramics Museum, Landmine Museum, Lieyu Township Culture Museum, Yu Da Wei Xian Sheng Memorial Museum.


title: Kinmen

text: Ci Lake, Gugang Lake, Houhu Seashore Park, Jiangong Islet, Jincheng Seaside Park, Kinmen National Park, Lingshui Lake, Tianpu Reservoir, Zhongzheng Park.


title: Kinmen

text: Beishan Old Western-style House, Chenggong Coastal Defense Tunnel, Chen Shi-yin Western Style House, Deyue Gun Tower, Gulongtou Zhenwei Residence, Jindong Movie Theater, Jinshui Elementary School, Juguang Tower, Kinmen Folk Culture Village, Kinmen Military Headquarters of Qing Dynasty, Mashan Broadcasting and Observation Station, Mofan Street, Qingtian Hall, Qionglin Tunnel, Yannan Academy, Wang Chin-cheng's Western House, Wuqiu Lighthouse and Zhaishan Tunnel.


title: Kinmen

text: Kinmen is famous for the production of Kaoliang liquor, which takes up about 75% of Taiwan's market share, in which it is a strong economic backbone of the county. Traditional industries are also being kept and improved, ranging from agriculture, fishery and livestock. It has a good fishery industry also due to its nature being surrounded by unpolluted sea.


title: Kinmen

text: Kinmen also produces its unique Kinmen knife, in which the raw material used to produce it is taken from the remaining of shells fired by the People's Liberation Army in 1958–1978. The knife was made as gift to the visiting Head of Taiwan Affairs Office Zhang Zhijun to Kinmen on 23–24 May 2015 to symbolize mutual peace between the two sides of the Taiwan Strait and to bury the hatchet left from Chinese Civil War.


title: Kinmen

text: Kinmen often import more goods from Mainland China than Taiwan Island because of lower costs due to the proximity of the county to the mainland. During the campaign for the 2014 county magistrate, all of the magistrate candidates spent their money on campaign materials produced in mainland provinces, such as Guangdong, Zhejiang and Fujian instead of from Taiwan Island.


title: Kinmen

text: The island consistently votes for the Kuomintang (KMT). Until the early 1990s, proponents of Taiwan independence argued that they would consider handing Kinmen over to the PRC in any negotiated settlement. Residents of the island have broadly opposed such measures.


title: Kinmen

text: The Democratic Progressive Party has a minor presence on the island and typically does not present candidates to stand in local elections, although it does hold a single seat in Kinmen County Council from both of the 2009 and 2014 local elections. However, the party occasionally lends support to liberal or center-left candidates.


title: Kinmen

text: On 29 November 2014 however, independent candidate Chen Fu-hai won the county magistrate election and took office as the Magistrate of Kinmen County on 25 December 2014, the first independent candidate to win the office. He replaced Magistrate Lee Wo-shih of the Kuomintang. The 2014 Kinmen County magistrate election consisted of 10 candidates, the highest number of nominated candidates in the electoral history of Taiwan.


title: Kinmen

text: Kinmen County Constituency is represented by a single seat in the Legislative Yuan. The incumbent Magistrate of Kinmen County is Yang Cheng-wu of the Kuomintang.


title: Kinmen

text: Kinmen County is divided into three urban townships and three rural townships. Jincheng Township is the county seat which houses Kinmen County Government and Kinmen County Council. The township also houses the headquarter office of Kinmen-Matsu Joint Services Center. Kinmen County has the fewest rural townships among other counties in Taiwan.


title: Kinmen

text: All those townships on Greater Kinmen Island start their names with "Jin" (i.e., "Kin", lit. "gold"). Lieyu Township encompasses the entire Lesser Kinmen Island, and is the closest to Xiamen. Wuqiu Township comprises Greater Qiu Islet () and Lesser Qiu Islet ().


title: Kinmen

text: Jincheng and Jinsha are the largest of the six townships. Altogether, there are 37 villages in Kinmen County.


title: Kinmen

text: In the controversy regarding the political status of Taiwan, the People's Republic of China (PRC) has continuously claimed the territory of Kinmen County as part of its own Fujian Province, claiming the Kinmen Islands as a county of Quanzhou prefecture-level city. The PRC claims the Wuqiu (Ockseu) Islands as part of Xiuyu District in Putian prefecture-level city. Taiwan (Republic of China) claims the Dadeng (Tateng) Islands in Dadeng Subdistrict, Xiang'an District, Xiamen, Fujian as part of Kinmen County.


title: Kinmen

text: In August 2010, National Quemoy University was established from the predecessor National Kinmen Institute of Technology and Kinmen Division of National Kaohsiung University of Applied Sciences established in 1997. It is located in Jinning Township. The islands also have a satellite campuses of Ming Chuan University and National University of Kaohsiung. Secondary educational institutions include National Kinmen Senior High School and National Kinmen Agricultural and Industrial Vocational Senior High School. In total, there are 24 junior high schools, elementary schools and kindergartens.


title: Kinmen

text: The Kinmen County Government have invested millions in education in Kinmen, with an average of NT$20,000 per student. Schools in the county also accept the growing number of Taiwanese students whose parents are doing business in Fujian. The county government has been striving to encourage universities in Taiwan Island and Mainland China to set up branches in the county, as well as to attract Chinese mainland students to study in Kinmen.


title: Kinmen

text: The Kinmen Power Company was founded in 1967 and gradually built five power plants in the county and is in charge of providing power resources to all residents in Kinmen. It used to rely on light diesel oil which created high cost burden to its management. Since 1992, the ROC central government approved the power company to authorize Taiwan Power Company (Taipower) for five-year management. All of the power development projects were invested by Taipower and helped the region economic development. In July 1997, Kinmen Power Company was officially incorporated to Taipower. In 1999, the diesel-fired Tashan Power Plant was built to supply electricity to Kinmen grid. The other smaller power plants were subsequently discontinued to reduce cost. The county is also powered by its Jinmen Wind wind farm with a capacity of 4 MW and photovoltaic system with a capacity of 9 MW.


title: Kinmen

text: In August 2012, Kinmen and Xiamen established the first submarine telecommunication cable between the two sides. On Taiwan side, the infrastructure was constructed by Chunghwa Telecom, while on mainland China's side was done by China Telecom, China Unicom and China Mobile. The project was initially launched in 1996 and took 16 years to build.


title: Kinmen

text: The telecommunication system consists of two cables, one is an long cable that runs from Kinmen's Lake Tzu and Xiamen's Mount Guanyin, and the other is a long cable that runs from Guningtou on Greater Kinmen Island (ROC) to Dadeng Island (PRC). The system is a non-repeater system with a bilateral transmission capacity of 90 Gbit/s, which might be expanded in the future if demand arises.


title: Kinmen

text: The current daily water demand for Kinmen is 50,000 tonnes, which are used for households, industries and agriculture sectors. One tonne of water produced for Kinmen costs about NT$50–60 and may surge to NT$70 during summer. In extreme drought condition, water shipment from Taiwan Island may cost as much as NT$200 per tonne. Because Kinmen residents pay only NT$10 for each tonne water they use, the cost of water supply has become a heavy burden for the county government.


title: Kinmen

text: For decades, Kinmen has been facing difficulties in water supply to its residents due to its shallow lakes, lack of rainfall and geographical constraints which makes building reservoirs and dams unfeasible. Therefore, Kinmen often overuses its groundwater, causing rising tidal flood and soil salinity.


title: Kinmen

text: In early September 2013, the People's Republic of China government agreed to supply Kinmen with water from Jinjiang City in Fujian due to the ongoing water shortage problem in Kinmen. Kinmen draws more than 8,000 tonnes of groundwater every day and water from its reservoir is barely enough to support the residents during the dry season. The shortage problem will heavily hit the local economy by 2016 if no mitigation plan is enacted. The water supply agreement was officially signed on 20 July 2015 in Kinmen between Kinmen County Waterworks Director Weng Wen-kuei () and Fujian Water Supply Co chairman Zhu Jinliang () witnessed by Kinmen County Magistrate Chen Fu-hai and Fujian Province Governor Su Shulin.


title: Kinmen

text: The water pipeline was officially opened on 5 August 2018 when the first water supply was delivered in a ceremony held in both Kinmen County and Jinjiang City in Mainland China.


title: Kinmen

text: Kinmen is served by Kinmen Airport, a domestic airport located at Jinhu Township, connecting Kinmen with Penghu Airport, Penghu and Taipei Songshan, Kaohsiung, Taichung, Chiayi and Tainan Airport on Taiwan Island.


title: Kinmen

text: People coming from Mainland China can also visit Kinmen using ferry via Fujian from Xiamen at Wutong Ferry Terminal or from Quanzhou arriving at Shuitou Pier in Jincheng Township. Kinmen to Xiamen Ferry, is a popular route between the Chinese Mainland and Taiwanese tourists alike, with brisk connections available between the ferry ports and Kinmen Airport (for Taiwanese destinations) and Xiamen's Airport and Xiamen North Railway Station (for Mainland destinations). The Kinmen-Quanzhou Ferry is only available to local travellers and foreigner passport holders are not permitted to use this service.


title: Kinmen

text: A new commercial port has been built adjacent to the Shuitou Pier on newly reclaimed land. This will handle the majority of sea freight to and from Kinmen. Previously most of this traffic was handled by a smaller port on the South-East corner of the island in Jinhu Township. In the past, due to constant artillery shelling from the Chinese mainland, an underground port was used to supply the island in times of conflict at the Zhaishan Tunnels on the South-Western tip of the island but this has been decommissioned and turned into a tourist attraction.


title: Kinmen

text: Greatly used as a transit route between the Chinese Mainland and Taiwan Island, buses also connect to the ferry terminal to allow for quick transfer to Xiamen.


title: Kinmen

text: A bridge, Kinmen Bridge, connecting Kinmen Island (Greater Kinmen) and Lieyu was completed in October 2022, estimated to cost NT$7.5 billion (US$250 million). It is expected to increase local tourism.


title: Kinmen

text: In October 2019, Mainland China announced a plan to build a bridge linking Xiamen to Kinmen. Taiwan's Mainland Affairs Council (MAC) said that the plans were made unilaterally by China as part of its schemes to absorb Taiwan and divide Taiwanese society and that they see no need for bridges linking either Matsu or Kinmen to China.


title: Daario Naharis

text: Daario Naharis is a fictional character in the "A Song of Ice and Fire" series of fantasy novels by American author George R. R. Martin and its television adaptation "Game of Thrones".


title: Daario Naharis

text: Introduced in "A Storm of Swords" (2000), Daario is the leader of a mercenary group from the continent of Essos called the Stormcrows. He subsequently appeared in Martin's "A Dance with Dragons" (2011).


title: Daario Naharis

text: Daario was portrayed by the English actor Ed Skrein and then by the Dutch actor Michiel Huisman in the HBO television adaptation.


title: Daario Naharis

text: Daario is a confident and seductive handsome and young warrior, and the commander of the Stormcrows, a company of sellswords comprising 500 mounted mercenaries.


title: Daario Naharis

text: Daario Naharis is not a point of view character in the novels, so his actions are witnessed and interpreted through the eyes of other people, especially Daenerys Targaryen. Daario is mostly a background character in the novels.


title: Daario Naharis

text: The Stormcrows are hired by Yunkai to defend the city against Daenerys Targaryen's forces. Daenerys offers the Stormcrows gold if they defect to her. While the Stormcrows deliberate this offer, Daario (having been won over by Daenerys) kills the Stormcrows' captains and pledges the company's support to Daenerys. The Stormcrows aid Daenerys in her subsequent conquests of Yunkai and Meereen.


title: Daario Naharis

text: Following Daenerys' conquest of Meereen, she sends Daario to Lhazar to reopen trade routes between the two regions. After his return, Daenerys takes Daario as a lover but marries the Meereenese nobleman Hizdahr zo Loraq. With Yunkai besieging Meereen, Daenerys offers an exchange of hostages between the two camps to ensure peace, and Daario is amongst those given to Yunkai. However, Daenerys flies away on Drogon, and the Yunkai'i refuse to release Daario until Daenerys' other two dragons are executed.


title: Daario Naharis

text: The television series develops the backstory that Daario's alcoholic mother sold him to the fighting pits when he was a young boy. Daario was trained as a pit fighter and performed so well that he was released from slavery when his master died. After winning his freedom, Daario joined the Second Sons sellsword company.


title: Daario Naharis

text: Under the leadership of Captain Mero and second in command Prendhal na Ghezn, the Second Sons are hired by the slaver city Yunkai to fight against Daenerys' army. Smitten with Daenerys, Daario refuses to obey his superiors when they decide to assassinate her; he instead kills them and presents their severed heads to Daenerys. With the Second Sons under his command, Daario and his men pledge their allegiance to Daenerys. He then assists Jorah Mormont and Grey Worm in opening the gates of Yunkai, allowing Daenerys' forces to conquer the city.


title: Daario Naharis

text: On the march to the neighbouring slaving city of Meereen, Daario unsuccessfully attempts to romance Daenerys. At the gates of Meereen, Daario volunteers to fight Meereen's champion in single combat and swiftly kills him before taunting the Meereenese by urinating in front of the city. After Daenerys conquers the city, Daario persuades her to take him as her lover. When Yunkai begins to rebel against Daenerys' rule, Daenerys sends Daario and the Meereenese nobleman Hizdahr zo Loraq to negotiate with the city's masters.


title: Daario Naharis

text: Daario and Hizdahr are successful in their negotiations with the Yunkish, although the Yunkish insist as part of the agreement upon reopening the city's fighting pits. Daenerys initially refuses, despite Daario's pointing out that his youth as a pit fighter gave him the skills necessary to join the Second Sons and meet her. Daenerys changes her mind after the Meereenese insurgents, the Sons of the Harpy, kill her advisor Ser Barristan Selmy. She takes Hizdahr as her husband but keeps Daario as her consort. After Daenerys flies off on her dragon Drogon during an attack by the Sons at the opening of the fighting pits, Daario and Jorah decide to leave Meereen to find her. Tyrion Lannister tries to join them, but Daario points out Tyrion is better suited to govern Meereen in Daenerys' absence.


title: Daario Naharis

text: Jorah and Daario discover that Daenerys has been captured by the Dothraki, and follow her to the sacred Dothraki city of Vaes Dothrak. They infiltrate the city and meet Daenerys, but she points out that they will be unable to escape the 100,000 Dothraki in the city. Daenerys instead sets fire to the Temple of the Dosh Khaleen, killing the khals but emerges unscathed. Amazed, the Dothraki bow down to Daenerys, and Daario follows suit. While Jorah leaves to find a cure for his greyscale, Daenerys and Daario march on Meereen with the Dothraki. Daenerys flies ahead on Drogon, and Daario arrives at the gates of Meereen. There, he finds the Sons of the Harpy massacring freedmen and leads the Dothraki charge to kill the Sons. With slavery finally abolished in Slaver's Bay, Daenerys decides to return to Westeros and reclaim the Iron Throne. However, she insists that Daario and the Second Sons remain to keep the peace. Daario is dismayed and declares his love for Daenerys, but ultimately agrees, realizing that Tyrion advised her to end their relationship.


title: Daario Naharis

text: In his first three appearances in season 3 of the television adaptation of the books, Daario Naharis is portrayed by the English actor Ed Skrein. Throughout the remainder of the series, he is portrayed by the Dutch actor Michiel Huisman. The reason for the change of actor was initially said to be because Skrein took on a role in the film "The Transporter Refueled". However Skrein subsequently stated that the change was due to "politics".


title: Mukden Incident

text: The Mukden Incident, or Manchurian Incident, known in Chinese as the 9.18 Incident (九・一八), was a false flag event staged by Japanese military personnel as a pretext for the 1931 Japanese invasion of Manchuria.


title: Mukden Incident

text: On September 18, 1931, Lieutenant Suemori Kawamoto of the Independent Garrison Unit of the 29th Japanese Infantry Regiment () detonated a small quantity of dynamite close to a railway line owned by Japan's South Manchuria Railway near Mukden (now Shenyang). The explosion was so weak that it failed to destroy the track, and a train passed over it minutes later. The Imperial Japanese Army accused Chinese dissidents of the act and responded with a full invasion that led to the occupation of Manchuria, in which Japan established its puppet state of Manchukuo six months later. The deception was exposed by the Lytton Report of 1932, leading Japan to diplomatic isolation and its March 1933 withdrawal from the League of Nations.


title: Mukden Incident

text: The bombing act is known as the Liutiao Lake Incident (, Japanese: , "Ryūjōko-jiken"), and the entire episode of events is known in Japan as the Manchurian Incident (Kyūjitai: , Shinjitai: , "Manshū-jihen") and in China as the September 18 Incident ().


title: Mukden Incident

text: Japanese economic presence and political interest in Manchuria had been growing ever since the end of the Russo-Japanese War (1904–1905). The Treaty of Portsmouth that ended the war had granted Japan the lease of the South Manchuria Railway branch (from Changchun to Lüshun) of the China Far East Railway. The Japanese government, however, claimed that this control included all the rights and privileges that China granted to Russia in the 1896 Li–Lobanov Treaty, as enlarged by the Kwantung Lease Agreement of 1898. This included absolute and exclusive administration within the South Manchuria Railway Zone. Japanese railway guards were stationed within the zone to provide security for the trains and tracks; however, these were regular Japanese soldiers, and they frequently carried out maneuvers outside the railway areas.


title: Mukden Incident

text: Meanwhile, the newly formed Chinese government was trying to reassert its authority over the country after over a decade of fragmented warlord dominance. They started to claim that treaties between China and Japan were invalid. China also announced new acts, so the Japanese people (including Koreans and Taiwanese as both regions were under Japanese rule at this time) who had settled frontier lands, opened stores or built their own houses in China were expelled without any compensation. Manchurian warlord Chang Tso-lin tried to deprive Japanese concessions too, but he was assassinated by the Japanese Kwantung Army. Chang Hsueh-liang, Chang Tso-lin's son and successor, joined the Nanjing Government led by Chiang Kai-shek from anti-Japanese sentiment. Official Japanese objections to the oppression against Japanese nationals within China were rejected by the Chinese authorities.


title: Mukden Incident

text: The 1929 Sino-Soviet conflict (July–November) over the Chinese Eastern Railroad (CER) further increased the tensions in the Northeast that would lead to the Mukden Incident. The Soviet Red Army victory over Chang Hsueh-liang's forces not only reasserted Soviet control over the CER in Manchuria but revealed Chinese military weaknesses that Japanese Kwantung Army officers were quick to note.


title: Mukden Incident

text: The Soviet Red Army performance also stunned Japanese officials. Manchuria was central to Japan's East Asia policy. Both the 1921 and 1927 Imperial Eastern Region Conferences reconfirmed Japan's commitment to be the dominant power in Manchuria. The 1929 Red Army victory shook that policy to the core and reopened the Manchurian problem. By 1930, the Kwantung Army realized they faced a Red Army that was only growing stronger. The time to act was drawing near and Japanese plans to conquer the Northeast were accelerated.


title: Mukden Incident

text: In April 1931, a national leadership conference of China was held between Chiang Kai-shek and Chang Hsueh-liang in Nanking. They agreed to put aside their differences and assert China's sovereignty in Manchuria strongly. On the other hand, some officers of the Kwantung Army began to plot to invade Manchuria secretly. There were other officers who wanted to support plotters in Tokyo.


title: Mukden Incident

text: Believing that a conflict in Manchuria would be in the best interests of Japan, Kwantung Army Colonel Seishirō Itagaki and Lieutenant Colonel Kanji Ishiwara independently devised a plan to prompt Japan to invade Manchuria by provoking an incident from Chinese forces stationed nearby. However, after the Japanese Minister of War Jirō Minami dispatched Major General Yoshitsugu Tatekawa to Manchuria for the specific purpose of curbing the insubordination and militarist behavior of the Kwantung Army, Itagaki and Ishiwara knew that they no longer had the luxury of waiting for the Chinese to respond to provocations, but had to stage their own.


title: Mukden Incident

text: Itagaki and Ishiwara chose to sabotage the rail section in an area near Liutiao Lake (; "liǔtiáohú"). The area had no official name and was not militarily important, but it was only eight hundred meters away from the Chinese garrison of Beidaying (; "běidàyíng"), where troops under the command of the "Young Marshal" Chang Hsueh-liang were stationed. The Japanese plan was to attract Chinese troops by an explosion and then blame them for having caused the disturbance in order to provide a pretext for a formal Japanese invasion. In addition, they intended to make the sabotage appear more convincing as a calculated Chinese attack on an essential target, thereby making the expected Japanese reaction appear as a legitimate measure to protect a vital railway of industrial and economic importance. The Japanese press labeled the site "Liǔtiáo Ditch" (; "liǔtiáogōu) or "Liǔtiáo Bridge" (; "liǔtiáoqiáo), when in reality, the site was a small railway section laid on an area of flat land. The choice to place the explosives at this site was to preclude the extensive rebuilding that would have been necessitated had the site actually been a railway bridge.


title: Mukden Incident

text: Colonel Seishirō Itagaki, Lieutenant Colonel Kanji Ishiwara, Colonel Kenji Doihara, and Major Takayoshi Tanaka had completed plans for the incident by May 31, 1931.


title: Mukden Incident

text: The plan was executed when 1st Lieutenant Suemori Komoto of the Independent Garrison Unit (獨立守備隊) of the 29th Infantry Regiment, which guarded the South Manchuria Railway, placed explosives near the tracks, but far enough away to do no real damage. At around 10:20 pm (22:20), September 18, the explosives were detonated. However, the explosion was minor and only a 1.5-meter section on one side of the rail was damaged. In fact, a train from Changchun passed by the site on this damaged track without difficulty and arrived in Shenyang at 10:30 pm (22:30).


title: Mukden Incident

text: On the morning of September 19, two artillery pieces installed at the Mukden officers' club opened fire on the Chinese garrison nearby, in response to the alleged Chinese attack on the railway. Chang Hsueh-liang's small air force was destroyed, and his soldiers fled their destroyed Beidaying barracks, as five hundred Japanese troops attacked the Chinese garrison of around seven thousand. The Chinese troops were no match for the experienced Japanese troops. By the evening, the fighting was over, and the Japanese had occupied Mukden at the cost of five hundred Chinese lives and only two Japanese lives.


title: Mukden Incident

text: At Dalian in the Kwantung Leased Territory, Commander-in-Chief of the Kwantung Army General Shigeru Honjō was at first appalled that the invasion plan was enacted without his permission, but he was eventually convinced by Ishiwara to give his approval after the act. Honjō moved the Kwantung Army headquarters to Mukden and ordered General Senjuro Hayashi of the Chosen Army of Japan in Korea to send in reinforcements. At 04:00 on 19 September, Mukden was declared secure.


title: Mukden Incident

text: Chang Hsueh-liang personally ordered his men not to put up a fight and to store away any weapons when the Japanese invaded. Therefore, the Japanese soldiers proceeded to occupy and garrison the major cities of Changchun and Antung and their surrounding areas with minimal difficulty. However, in November, General Ma Zhanshan, the acting governor of Heilongjiang, began resistance with his provincial army, followed in January by Generals Ting Chao and Li Du with their local Jilin provincial forces. Despite this resistance, within five months of the Mukden Incident, the Imperial Japanese Army had overrun all major towns and cities in the provinces of Liaoning, Jilin, and Heilongjiang.


title: Mukden Incident

text: Chinese public opinion strongly criticized Chang Hsueh-liang for his non-resistance to the Japanese invasion. While the Japanese presented a real threat, the Kuomintang directed most of their efforts towards eradication of the communist party. Many charged that Chang's Northeastern Army of nearly a quarter million could have withstood the Kwantung Army of only 11,000 men. In addition, his arsenal in Manchuria was considered the most modern in China, and his troops had possession of tanks, around 60 combat aircraft, 4000 machine guns, and four artillery battalions.


title: Mukden Incident

text: Chang Hsueh-liang's seemingly superior force was undermined by several factors. The first was that the Kwantung Army had a strong reserve force that could be transported by railway from Korea, which was a Japanese colony, directly adjacent to Manchuria. Secondly, more than half of Chang's troops were stationed south of the Great Wall in Hebei Province, while the troops north of the wall were scattered throughout Manchuria. Therefore, deploying Chang's troops north of the Great Wall meant that they lacked the concentration needed to fight the Japanese effectively. Most of Chang's troops were under-trained, poorly led, poorly fed, and had poor morale and questionable loyalty compared to their Japanese counterparts. Japanese secret agents had permeated Chang's command because of his and his father Chang Tso-lin's past reliance on Japanese military advisers. The Japanese knew the Northeastern Army very well and were able to conduct operations with ease.


title: Mukden Incident

text: The Chinese government was preoccupied with numerous internal problems, including the issue of the newly independent Guangzhou government of Hu Hanmin, Communist Party of China insurrections, and terrible flooding of the Yangtze River that created tens of thousands of refugees. Moreover, Chang himself was not in Manchuria at the time, but was in a hospital in Beijing to raise money for the flood victims. However, in the Chinese newspapers, Chang was ridiculed as "General Nonresistance" ().


title: Mukden Incident

text: Because of these circumstances, the central government turned to the international community for a peaceful resolution. The Chinese Foreign Ministry issued a strong protest to the Japanese government and called for the immediate stop to Japanese military operations in Manchuria, and appealed to the League of Nations, on September 19. On October 24, the League of Nations passed a resolution mandating the withdrawal of Japanese troops, to be completed by 16 November. However, Japan rejected the League of Nations resolution and insisted on direct negotiations with the Chinese government. Negotiations went on intermittently without much result.


title: Mukden Incident

text: On November 20, a conference in the Chinese government was convened, but the Guangzhou faction of the Kuomintang insisted that Chiang Kai-shek step down to take responsibility for the Manchurian debacle. On December 15, Chiang resigned as the Chairman of the Nationalist Government and was replaced as Premier of the Republic of China (head of the Executive Yuan) by Sun Fo, son of Sun Yat-sen. Jinzhou, another city in Liaoning, was lost to the Japanese in early January 1932. As a result, Wang Jingwei replaced Sun Fo as the Premier.


title: Mukden Incident

text: On January 7, 1932, United States Secretary of State Henry Stimson issued his Stimson Doctrine, that the United States would not recognize any government that was established as the result of Japanese actions in Manchuria. On January 14, a League of Nations commission, headed by Victor Bulwer-Lytton, 2nd Earl of Lytton, disembarked at Shanghai to examine the situation. In March, the puppet state of Manchukuo was established, with the former emperor of China, Puyi, installed as head of state.


title: Mukden Incident

text: On October 2, the Lytton Report was published and rejected the Japanese claim that the Manchurian invasion and occupation was an act of self-defense, although it did not assert that the Japanese had perpetrated the initial bombing of the railroad. The report ascertained that Manchukuo was the product of Japanese military aggression in China, while recognizing that Japan had legitimate concerns in Manchuria because of its economic ties there. The League of Nations refused to acknowledge Manchukuo as an independent nation. Japan resigned from the League of Nations in March 1933.


title: Mukden Incident

text: Colonel Kenji Doihara used the Mukden Incident to continue his campaign of disinformation. Since the Chinese troops at Mukden had put up such poor resistance, he told Manchukuo Emperor Puyi that this was proof that the Chinese remained loyal to him. Japanese intelligence used the incident to continue the campaign to discredit the murdered Chang Tso-lin and his son Chang Hsueh-liang for "misgovernment" of Manchuria. In fact, drug trafficking and corruption had largely been suppressed under Chang Tso-lin.


title: Mukden Incident

text: Different opinions still exist as to who caused the explosion on the Japanese railroad at Mukden. Strong evidence points to young officers of the Japanese Kwantung Army having conspired to cause the blast, with or without direct orders from Tokyo. Post-war investigations confirmed that the original bomb planted by the Japanese failed to explode, and a replacement had to be planted. The resulting explosion enabled the Japanese Kwantung Army to accomplish their goal of triggering a conflict with Chinese troops stationed in Manchuria and the subsequent establishment of the puppet state of Manchukuo.


title: Mukden Incident

text: The 9.18 Incident Exhibition Museum (九・一八歷史博物館) at Shenyang, opened by the People's Republic of China on September 18, 1991, takes the position that the explosives were planted by Japan. The Yūshūkan museum, located within Yasukuni Shrine in Tokyo, also places the blame on members of the Kwantung Army.


title: Mukden Incident

text: David Bergamini's book "Japan's Imperial Conspiracy" (1971) has a detailed chronology of events in both Manchuria and Tokyo surrounding the Mukden Incident. Bergamini concludes that the greatest deception was that the Mukden Incident and Japanese invasion were planned by junior or hot-headed officers, without formal approval by the Japanese government. However, historian James Weland has concluded that senior commanders had tacitly allowed field operatives to proceed on their own initiative, then endorsed the result after a positive outcome was assured.


title: Mukden Incident

text: In August 2006, the "Yomiuri Shimbun", Japan's top-selling newspaper, published the results of a year-long research project into the general question of who was responsible for the "Shōwa war". With respect to the Manchurian Incident, the newspaper blamed ambitious Japanese militarists, as well as politicians who were impotent to rein them in or prevent their insubordination.


title: Mukden Incident

text: Debate has also focused on how the incident was handled by the League of Nations and the subsequent Lytton Report. A. J. P. Taylor wrote that "In the face of its first serious challenge", the League buckled and capitulated. The Washington Naval Conference (1921) guaranteed a certain degree of Japanese hegemony in East Asia. Any intervention on the part of America would be a breach of the already mentioned agreement. Furthermore, Britain was in crisis, having been recently forced off the gold standard. Although a power in East Asia at the time, Britain was incapable of decisive action. The only response from these powers was "moral condemnation".


title: Mukden Incident

text: Each year at 10:00 am on 18 September, air-raid sirens sound for several minutes in numerous major cities across China. Provinces include Heilongjiang, Jilin, Liaoning, Hainan, and others.


title: German cruiser Admiral Graf Spee

text: Admiral Graf Spee was a ""Panzerschiff"" (armored ship), nicknamed a "pocket battleship" by the British, which served with the Kriegsmarine of Nazi Germany during World War II. The vessel was named after World War I Admiral Maximilian von Spee, commander of the East Asia Squadron who fought the battles of Coronel and the Falkland Islands, where he was killed in action. She was laid down at the "Reichsmarinewerft" shipyard in Wilhelmshaven in October 1932 and completed by January 1936. The ship was nominally under the limitation on warship size imposed by the Treaty of Versailles, though with a full load displacement of , she significantly exceeded it. Armed with six guns in two triple gun turrets, "Admiral Graf Spee" and her sisters were designed to outgun any cruiser fast enough to catch them. Their top speed of left only the few battlecruisers in the Anglo-French navies fast enough and powerful enough to sink them.


title: German cruiser Admiral Graf Spee

text: The ship conducted five non-intervention patrols during the Spanish Civil War in 1936–1938 and participated in the Coronation Review of King George VI in May 1937. "Admiral Graf Spee" was deployed to the South Atlantic in the weeks before the outbreak of World War II, to be positioned in merchant sea lanes once war was declared. Between September and December 1939, the warship sank nine vessels totaling , before being confronted by three British cruisers at the Battle of the River Plate on 13 December. "Admiral Graf Spee" inflicted heavy damage on the British ships, but she too was damaged and was forced to put into port at Montevideo, Uruguay. Convinced by false reports of superior British naval forces gathering, Hans Langsdorff, commander of the ship, ordered the vessel to be scuttled. The ship was partially broken up "in situ", though part of the ship remained visible above the surface of the water.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee" was long overall and had a beam of and a maximum draft of . The ship had a design displacement of and a full load displacement of , though the ship was officially stated to be within the limit of the Treaty of Versailles. "Admiral Graf Spee" was powered by four sets of MAN 9-cylinder double-acting two-stroke diesel engines. The ship's top speed was , at . At a cruising speed of , the ship had a range of . As designed, her standard complement consisted of 33 officers and 586 enlisted men, though after 1935 this was significantly increased to 30 officers and 921–1,040 sailors.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee"s primary armament was six SK C/28 guns mounted in two triple gun turrets, one forward and one aft of the superstructure. The ship carried a secondary battery of eight SK C/28 guns in single turrets grouped amidships. Her anti-aircraft battery originally consisted of three L/45 guns, though in 1935 these were replaced with six L/78 guns. In 1938, the 8.8 cm guns were removed, and six L/65 guns, four SK C/30 guns, and ten C/30 guns were installed in their place. The ship also carried a pair of quadruple deck-mounted torpedo tubes placed on her stern.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee"s armored belt was thick; her upper deck was thick while the main armored deck was thick. The main battery turrets had thick faces and 80 mm thick sides.


title: German cruiser Admiral Graf Spee

text: The ship was equipped one catapult but had no aircraft hangar. One floatplane was carried on the catapult. The initial Heinkel He 60 was replaced with an Arado Ar 196 before the outbreak of the war.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee" was the first German warship to be equipped with radar. A FMG G(gO) "Seetakt" set was mounted on the foretop range finder.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee" was ordered by the Reichsmarine from the "Reichsmarinewerft" shipyard in Wilhelmshaven. Ordered as "Ersatz Braunschweig", "Admiral Graf Spee" replaced the old pre-dreadnought battleship . Her keel was laid on 1 October 1932, under construction number 125. The ship was launched on 30 June 1934; at her launching, she was christened by the daughter of Admiral Maximilian von Spee, the ship's namesake. She was completed slightly over a year and a half later on 6 January 1936, the day she was commissioned into the German fleet.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee" spent the first three months of her career conducting extensive sea trials to ready the ship for service. The ship's first commander was "Kapitän zur See" ("KzS") Conrad Patzig; he was replaced in 1937 by "KzS" Walter Warzecha. After joining the fleet, "Admiral Graf Spee" became the flagship of the German Navy. In the summer of 1936, following the outbreak of the Spanish Civil War, she deployed to the Atlantic to participate in non-intervention patrols off the Republican-held coast of Spain. Between August 1936 and May 1937, the ship conducted three patrols off Spain. On the return voyage from Spain, "Admiral Graf Spee" stopped in Great Britain to represent Germany in the Coronation Review at Spithead for King George VI on 20 May.


title: German cruiser Admiral Graf Spee

text: After the conclusion of the Review, "Admiral Graf Spee" returned to Spain for a fourth non-intervention patrol. Following fleet maneuvers and a brief visit to Sweden, the ship conducted a fifth and final patrol in February 1938. In 1938, "KzS" Hans Langsdorff took command of the vessel; she conducted a series of goodwill visits to various foreign ports throughout the year. These included cruises into the Atlantic, where she stopped in Tangier and Vigo. She also participated in extensive fleet maneuvers in German waters. She was part of the celebrations for the reintegration of the port of Memel into Germany, and a fleet review in honor of Admiral Miklós Horthy, the Regent of Hungary. Between 18 April and 17 May 1939, she conducted another cruise into the Atlantic, stopping in the ports of Ceuta and Lisbon. On 21 August 1939, "Admiral Graf Spee" departed Wilhelmshaven, bound for the South Atlantic.


title: German cruiser Admiral Graf Spee

text: Following the outbreak of war between Germany and the Allies in September 1939, Adolf Hitler ordered the German Navy to begin commerce raiding against Allied merchant traffic. Hitler nevertheless delayed issuing the order until it became clear that Britain would not countenance a peace treaty following the conquest of Poland. The "Admiral Graf Spee" was instructed to strictly adhere to prize rules, which required raiders to stop and search ships for contraband before sinking them, and to ensure that their crews are safely evacuated. Langsdorff was ordered to avoid combat, even with inferior opponents, and to frequently change position. On 1 September, the cruiser rendezvoused with her supply ship southwest of the Canary Islands. While replenishing his fuel supplies, Langsdorff ordered superfluous equipment transferred to the "Altmark"; this included several of the ship's boats, flammable paint, and two of her ten 2 cm anti-aircraft guns, which were installed on the tanker.


title: German cruiser Admiral Graf Spee

text: On 11 September, while still transferring supplies from "Altmark", "Admiral Graf Spee"s Arado floatplane spotted the British heavy cruiser approaching the two German ships. Langsdorff ordered both vessels to depart at high speed, successfully evading the British cruiser. On 26 September, the ship finally received orders authorizing attacks on Allied merchant shipping. Four days later "Admiral Graf Spee"s Arado located Booth Steam Ship Co's cargo ship off the coast of Brazil. The cargo ship transmitted an "RRR" signal ("I am under attack by a raider") before the cruiser ordered her to stop. "Admiral Graf Spee" took "Clement"s captain and chief engineer prisoner but left the rest of her crew to abandon ship in the lifeboats. The cruiser then fired 30 rounds from her 28 cm and 15 cm guns and two torpedoes at the cargo ship, which broke up and sank. Langsdorff ordered a distress signal sent to the naval station in Pernambuco to ensure the rescue of the ship's crew. The British Admiralty immediately issued a warning to merchant shipping that a German surface raider was in the area. The British crew later reached the Brazilian coast in their lifeboats.


title: German cruiser Admiral Graf Spee

text: On 5 October, the British and French navies formed eight groups to hunt down "Admiral Graf Spee" in the South Atlantic. The British aircraft carriers , , and , the , the British battlecruiser , and French battleships and , and 16 cruisers were committed to the hunt. Force G, commanded by Commodore Henry Harwood and assigned to the east coast of South America, comprised the cruisers "Cumberland" and . Force G was reinforced by the light cruisers and ; Harwood detached "Cumberland" to patrol the area off the Falkland Islands while his other three cruisers patrolled off the River Plate.


title: German cruiser Admiral Graf Spee

text: On the same day as the formation of the Anglo-French hunter groups, "Admiral Graf Spee" captured the steamer "Newton Beech". Two days later, she encountered and sank the merchant ship "Ashlea". On 8 October, the following day, she sank "Newton Beech", which Langsdorff had been using to house prisoners. "Newton Beech" was too slow to keep up with "Admiral Graf Spee", and so the prisoners were transferred to the cruiser. On 10 October, she captured the steamer "Huntsman", the captain of which had not sent a distress signal until the last minute, as he had mistakenly identified "Admiral Graf Spee" as a French warship. Unable to accommodate the crew from "Huntsman", "Admiral Graf Spee" sent the ship to a rendezvous location with a prize crew. On 15 October, "Admiral Graf Spee" rendezvoused with "Altmark" to refuel and transfer prisoners; the following morning, the prize "Huntsman" joined the two ships. The prisoners aboard "Huntsman" were transferred to "Altmark" and Langsdorff then sank "Huntsman" on the night of 17 October.


title: German cruiser Admiral Graf Spee

text: On 22 October, "Admiral Graf Spee" encountered and sank the steamer "Trevanion". At the end of October, Langsdorff sailed his ship into the Indian Ocean south of Madagascar. The purpose of that foray was to divert Allied warships away from the South Atlantic, and to confuse the Allies about his intentions. By this time, "Admiral Graf Spee" had cruised for almost and needed an engine overhaul. On 15 November, the ship sank the tanker , and the following day, she stopped an unidentified Dutch steamer, though did not sink her. "Admiral Graf Spee" returned to the Atlantic between 17 and 26 November to refuel from "Altmark". While replenishing supplies, the crew of "Admiral Graf Spee" built a dummy gun turret on her bridge and erected a dummy second funnel behind the aircraft catapult to alter her silhouette significantly in a bid to confuse allied shipping as to her true identity.


title: German cruiser Admiral Graf Spee

text: "Admiral Graf Spee"s Arado floatplane located the merchant ship : Langsdorff fired a shot across her bow to stop the ship. "Doric Star" was able to send out a distress signal before she was sunk, which prompted Harwood to take his three cruisers to the mouth of the River Plate, which he suspected might be Langsdorff's next target. On 3 December, "Admiral Graf Spee" sank the steamer . On 6 December, she met with "Altmark" and transferred 140 prisoners from "Doric Star" and "Tairoa". "Admiral Graf Spee" encountered her last victim on the evening of 7 December: the freighter "Streonshalh". The prize crew recovered secret documents containing shipping route information. Based on that information, Langsdorff decided to head for the seas off Montevideo. On 12 December, the ship's Arado 196 broke down and could not be repaired, depriving "Graf Spee" of her aerial reconnaissance. The ship's disguise was removed, so it would not hinder the ship in battle.


title: German cruiser Admiral Graf Spee

text: At 05:30 on the morning of 13 December 1939, lookouts spotted a pair of masts off the ship's starboard bow. Langsdorff assumed this to be the escort for a convoy mentioned in the documents recovered from "Tairoa". At 05:52, however, the ship was identified as ; she was accompanied by a pair of smaller warships, initially thought to be destroyers but quickly identified as s. Langsdorff decided not to flee from the British ships, and ordered his ship to battle stations and to close at maximum speed. At 06:08, the British spotted "Admiral Graf Spee"; Harwood divided his ships to split the gunfire of "Admiral Graf Spee"s 28 cm guns. The German ship opened fire with her main battery at "Exeter" and her secondary guns at the flagship at 06:17. At 06:20, "Exeter" returned fire, followed by "Ajax" at 06:21 and at 06:24. In the span of thirty minutes, "Admiral Graf Spee" had hit "Exeter" three times, disabling her two forward turrets, destroying her bridge and her aircraft catapult, and starting major fires. "Ajax" and "Achilles" moved closer to "Admiral Graf Spee" to relieve the pressure on "Exeter".


title: German cruiser Admiral Graf Spee

text: Langsdorff thought the two light cruisers were making a torpedo attack, and turned away under a smokescreen. The respite allowed "Exeter" to withdraw from the action; by now, only one of her gun turrets was still in action, and she had suffered 61 dead and 23 wounded crew members. At around 07:00, "Exeter" returned to the engagement, firing from her stern turret. "Admiral Graf Spee" fired on her again, scored more hits, and forced "Exeter" to withdraw again, this time with a list to port. At 07:25, "Admiral Graf Spee" scored a hit on "Ajax" that disabled her aft turrets. Both sides broke off the action, "Admiral Graf Spee" retreating into the River Plate estuary, while Harwood's battered cruisers remained outside to observe any possible breakout attempts. In the course of the engagement, "Admiral Graf Spee" had been hit approximately 70 times; 36 men were killed and 60 more were wounded, including Langsdorff, who had been wounded twice by splinters while standing on the open bridge.


title: German cruiser Admiral Graf Spee

text: As a result of battle damage and casualties, Langsdorff decided to put into Montevideo, where repairs could be effected and the wounded men could be evacuated from the ship. Most of the hits scored by the British cruisers caused only minor structural and superficial damage, but the oil purification plant, which was required to prepare the diesel fuel for the engines, was destroyed. Her desalination plant and galley were also destroyed, which would have increased the difficulty of a return to Germany. A hit in the bow would also have negatively affected her seaworthiness in the heavy seas of the North Atlantic. "Admiral Graf Spee" had fired much of her ammunition in the engagement with Harwood's cruisers.


title: German cruiser Admiral Graf Spee

text: After arriving in port, the wounded crewmen were taken to local hospitals and the dead were buried with full military honors. Captive Allied seamen, consisting of 6 captains, 9 chief engineers, 25 officers, and 21 seamen still aboard the ship, were released. Repairs necessary to make the ship seaworthy were expected to take up to two weeks. British naval intelligence worked to convince Langsdorff that vastly superior forces were concentrating to destroy his ship, if he attempted to break out of the harbor. The Admiralty broadcast a series of signals, on frequencies known to be intercepted by German intelligence. The closest heavy units—the carrier "Ark Royal" and battlecruiser "Renown"—were some away, much too far to intervene in the situation. Believing the British reports, Langsdorff discussed his options with commanders in Berlin. These were either to break out and seek refuge in Buenos Aires, where the Argentine government would intern the ship, or to scuttle the ship in the Plate estuary.


title: German cruiser Admiral Graf Spee

text: Langsdorff was unwilling to risk the lives of his crew, so he decided to scuttle the ship. He knew that although Uruguay was neutral, the government was on friendly terms with Britain and if he allowed his ship to be interned, the Uruguayan Navy would allow British intelligence officers access to the ship. Under Article 17 of the Hague Convention of 1907, neutrality restrictions limited "Admiral Graf Spee" to a period of 72 hours for repairs in Montevideo, before she would be interned for the duration of the war. On 17 December 1939, Langsdorff ordered the destruction of all important equipment aboard the ship. The ship's remaining ammunition supply was dispersed throughout the ship, in preparation for scuttling. On 17 December, the ship, with only Langsdorff and 40 other men aboard, moved into the outer roadstead to be scuttled. A crowd of 20,000 watched as the scuttling charges were set; the crew was taken off by an Argentine tug and the ship was scuttled at 20:55. The multiple explosions from the munitions sent jets of flame high into the air and created a large cloud of smoke that obscured the ship which burned in the shallow water for the next two days.


title: German cruiser Admiral Graf Spee

text: On 20 December, in his room in a Buenos Aires hotel, Langsdorff shot himself in full dress uniform while lying on the ship's battle ensign. In late January 1940, the neutral American cruiser arrived in Montevideo and the crew was permitted to visit the wreck of "Admiral Graf Spee". The Americans met the German crewmen, who were still in Montevideo. In the aftermath of the scuttling, the ship's crew were taken to Argentina, where they were interned for the remainder of the war.


title: German cruiser Admiral Graf Spee

text: The wreck was partially broken up in situ in 1942–1943, though parts of the ship were visible for some time after; the wreck lies at a depth of only . The salvage rights were purchased from the German Government by a Montevideo engineering company for £14,000, a front for the British. The British had been surprised by the accuracy of the gunnery and expected to find a radar range finder, which they did. They used the knowledge thus acquired to try to develop countermeasures, under the leadership of Fred Hoyle at the British radar project. The Admiralty complained about the large sum paid for the salvage rights.


title: German cruiser Admiral Graf Spee

text: In February 2004, a salvage team began work raising the wreck of "Admiral Graf Spee". The operation was in part being funded by the government of Uruguay, in part by the private sector as the wreck was a hazard to navigation. The first major section—a gunnery rangefinding telemeter—was raised on 25 February. On 10 February 2006, the , eagle and swastika crest of "Admiral Graf Spee" was recovered from the stern of the ship; it was stored in a Uruguayan naval warehouse following German complaints about exhibiting "Nazi paraphernalia".


title: German cruiser Admiral Graf Spee

text: On 2 January 2022, a newspaper in Punta del Este reported that an Argentine Jewish businessman, Daniel Sielecki, had offered to buy the 800-pound eagle and swastika crest from the "Admiral Graf Spee" from the naval warehouse. Sielecki said he wanted to explode the crest into “a thousand pieces" in order to keep it out of the hands of neo-Nazis.


title: Magma

text: Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles.


title: Magma

text: Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a dike, a sill, a laccolith, a pluton, or a batholith.


title: Magma

text: While the study of magma has relied on observing magma after its transition into a lava flow, magma has been encountered in situ three times during geothermal drilling projects, twice in Iceland (see Use in energy production) and once in Hawaii.


title: Magma

text: Magma consists of liquid rock that usually contains suspended solid crystals. As magma approaches the surface and the overburden pressure drops, dissolved gases bubble out of the liquid, so that magma near the surface consists of materials in solid, liquid, and gas phases.


title: Magma

text: Most magma is rich in silica. Rare nonsilicate magma can form by local melting of nonsilicate mineral deposits or by separation of a magma into separate immiscible silicate and nonsilicate liquid phases.


title: Magma

text: Silicate magmas are molten mixtures dominated by oxygen and silicon, the most abundant chemical elements in the Earth's crust, with smaller quantities of aluminium, calcium, magnesium, iron, sodium, and potassium, and minor amounts of many other elements. Petrologists routinely express the composition of a silicate magma in terms of the weight or molar mass fraction of the oxides of the major elements (other than oxygen) present in the magma.


title: Magma

text: Because many of the properties of a magma (such as its viscosity and temperature) are observed to correlate with silica content, silicate magmas are divided into four chemical types based on silica content: "felsic", "intermediate", "mafic", and "ultramafic".


title: Magma

text: "Felsic" or silicic magmas have a silica content greater than 63%. They include rhyolite and dacite magmas. With such a high silica content, these magmas are extremely viscous, ranging from 10 cP (10 Pa⋅s) for hot rhyolite magma at to 10 cP (10 Pa⋅s) for cool rhyolite magma at . For comparison, water has a viscosity of about 1 cP (0.001 Pa⋅s). Because of this very high viscosity, felsic lavas usually erupt explosively to produce pyroclastic (fragmental) deposits. However, rhyolite lavas occasionally erupt effusively to form lava spines, lava domes or "coulees" (which are thick, short lava flows). The lavas typically fragment as they extrude, producing block lava flows. These often contain obsidian.


title: Magma

text: Felsic lavas can erupt at temperatures as low as . Unusually hot (>950 °C; >1,740 °F) rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States.


title: Magma

text: "Intermediate" or andesitic magmas contain 52% to 63% silica, and are lower in aluminium and usually somewhat richer in magnesium and iron than felsic magmas. Intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. They are also commonly hotter, in the range of ). Because of their lower silica content and higher eruptive temperatures, they tend to be much less viscous, with a typical viscosity of 3.5 × 10 cP (3,500 Pa⋅s) at . This is slightly greater than the viscosity of smooth peanut butter. Intermediate magmas show a greater tendency to form phenocrysts, Higher iron and magnesium tends to manifest as a darker groundmass, including amphibole or pyroxene phenocrysts.


title: Magma

text: "Mafic" or basaltic magmas have a silica content of 52% to 45%. They are typified by their high ferromagnesian content, and generally erupt at temperatures of . Viscosities can be relatively low, around 10 to 10 cP (10 to 100 Pa⋅s), although this is still many orders of magnitude higher than water. This viscosity is similar to that of ketchup. Basalt lavas tend to produce low-profile shield volcanoes or flood basalts, because the fluidal lava flows for long distances from the vent. The thickness of a basalt lava, particularly on a low slope, may be much greater than the thickness of the moving lava flow at any one time, because basalt lavas may "inflate" by supply of lava beneath a solidified crust. Most basalt lavas are of "ʻAʻā" or "pāhoehoe" types, rather than block lavas. Underwater, they can form pillow lavas, which are rather similar to entrail-type pahoehoe lavas on land.


title: Magma

text: "Ultramafic" magmas, such as picritic basalt, komatiite, and highly magnesian magmas that form boninite, take the composition and temperatures to the extreme. All have a silica content under 45%. Komatiites contain over 18% magnesium oxide, and are thought to have erupted at temperatures of . At this temperature there is practically no polymerization of the mineral compounds, creating a highly mobile liquid. Viscosities of komatiite magmas are thought to have been as low as 100 to 1000 cP (0.1 to 1 Pa⋅s), similar to that of light motor oil. Most ultramafic lavas are no younger than the Proterozoic, with a few ultramafic magmas known from the Phanerozoic in Central America that are attributed to a hot mantle plume. No modern komatiite lavas are known, as the Earth's mantle has cooled too much to produce highly magnesian magmas.


title: Magma

text: Some silicic magmas have an elevated content of alkali metal oxides (sodium and potassium), particularly in regions of continental rifting, areas overlying deeply subducted plates, or at intraplate hotspots. Their silica content can range from ultramafic (nephelinites, basanites and tephrites) to felsic (trachytes). They are more likely to be generated at greater depths in the mantle than subalkaline magmas. Olivine nephelinite magmas are both ultramafic and highly alkaline, and are thought to have come from much deeper in the mantle of the Earth than other magmas.


title: Magma

text: The concentrations of different gases can vary considerably. Water vapor is typically the most abundant magmatic gas, followed by carbon dioxide and sulfur dioxide. Other principal magmatic gases include hydrogen sulfide, hydrogen chloride, and hydrogen fluoride.


title: Magma

text: The solubility of magmatic gases in magma depends on pressure, magma composition, and temperature. Magma that is extruded as lava is extremely dry, but magma at depth and under great pressure can contain a dissolved water content in excess of 10%. Water is somewhat less soluble in low-silica magma than high-silica magma, so that at 1,100 °C and 0.5 GPa, a basaltic magma can dissolve 8% while a granite pegmatite magma can dissolve 11% . However, magmas are not necessarily saturated under typical conditions.


title: Magma

text: Carbon dioxide is much less soluble in magmas than water, and frequently separates into a distinct fluid phase even at great depth. This explains the presence of carbon dioxide fluid inclusions in crystals formed in magmas at great depth.


title: Magma

text: Viscosity is a key melt property in understanding the behaviour of magmas. Whereas temperatures in common silicate lavas range from about for felsic lavas to for mafic lavas, the viscosity of the same lavas ranges over seven orders of magnitude, from 10 cP (10 Pa⋅s) for mafic lava to 10 cP (10 Pa⋅s) for felsic magmas. The viscosity is mostly determined by composition but is also dependent on temperature. The tendency of felsic lava to be cooler than mafic lava increases the viscosity difference.


title: Magma

text: The silicon ion is small and highly charged, and so it has a strong tendency to coordinate with four oxygen ions, which form a tetrahedral arrangement around the much smaller silicon ion. This is called a "silica tetrahedron". In a magma that is low in silicon, these silica tetrahedra are isolated, but as the silicon content increases, silica tetrahedra begin to partially polymerize, forming chains, sheets, and clumps of silica tetrahedra linked by bridging oxygen ions. These greatly increase the viscosity of the magma.


title: Magma

text: The tendency towards polymerization is expressed as NBO/T, where NBO is the number of non-bridging oxygen ions and T is the number of network-forming ions. Silicon is the main network-forming ion, but in magmas high in sodium, aluminium also acts as a network former, and ferric iron can act as a network former when other network formers are lacking. Most other metallic ions reduce the tendency to polymerize and are described as network modifiers. In a hypothetical magma formed entirely from melted silica, NBO/T would be 0, while in a hypothetical magma so low in network formers that no polymerization takes place, NBO/T would be 4. Neither extreme is common in nature, but basalt magmas typically have NBO/T between 0.6 and 0.9, andesitic magmas have NBO/T of 0.3 to 0.5, and rhyolitic magmas have NBO/T of 0.02 to 0.2. Water acts as a network modifier, and dissolved water drastically reduces melt viscosity. Carbon dioxide neutralizes network modifiers, so dissolved carbon dioxide increases the viscosity. Higher-temperature melts are less viscous, since more thermal energy is available to break bonds between oxygen and network formers.


title: Magma

text: Most magmas contain solid crystals of various minerals, fragments of exotic rocks known as xenoliths and fragments of previously solidified magma. The crystal content of most magmas gives them thixotropic and shear thinning properties. In other words, most magmas do not behave like Newtonian fluids, in which the rate of flow is proportional to the shear stress. Instead, a typical magma is a Bingham fluid, which shows considerable resistance to flow until a stress threshold, called the yield stress, is crossed. This results in plug flow of partially crystalline magma. A familiar example of plug flow is toothpaste squeezed out of a toothpaste tube. The toothpaste comes out as a semisolid plug, because shear is concentrated in a thin layer in the toothpaste next to the tube, and only here does the toothpaste behave as a fluid. Thixotropic behavior also hinders crystals from settling out of the magma. Once the crystal content reaches about 60%, the magma ceases to behave like a fluid and begins to behave like a solid. Such a mixture of crystals with melted rock is sometimes described as "crystal mush".


title: Magma

text: Magma is typically also viscoelastic, meaning it flows like a liquid under low stresses, but once the applied stress exceeds a critical value, the melt cannot dissipate the stress fast enough through relaxation alone, resulting in transient fracture propagation. Once stresses are reduced below the critical threshold, the melt viscously relaxes once more and heals the fracture.


title: Magma

text: Temperatures of lava, which is magma extruded onto the surface, are in the range , but very rare carbonatite magmas may be as cool as , and komatiite magmas may have been as hot as . Magma has occasionally been encountered during drilling in geothermal fields, including drilling in Hawaii that penetrated a dacitic magma body at a depth of . The temperature of this magma was estimated at . Temperatures of deeper magmas must be inferred from theoretical computations and the geothermal gradient.


title: Magma

text: Most magmas contain some solid crystals suspended in the liquid phase. This indicates that the temperature of the magma lies between the solidus, which is defined as the temperature at which the magma completely solidifies, and the liquidus, defined as the temperature at which the magma is completely liquid. Calculations of solidus temperatures at likely depths suggests that magma generated beneath areas of rifting starts at a temperature of about . Magma generated from mantle plumes may be as hot as . The temperature of magma generated in subduction zones, where water vapor lowers the melting temperature, may be as low as .


title: Magma

text: Magma expands slightly at lower pressure or higher temperature. When magma approaches the surface, its dissolved gases begin to bubble out of the liquid. These bubbles had significantly reduced the density of the magma at depth and helped drive it toward the surface in the first place.


title: Magma

text: The temperature within the interior of the earth is described by the geothermal gradient, which is the rate of temperature change with depth. The geothermal gradient is established by the balance between heating through radioactive decay in the Earth's interior and heat loss from the surface of the earth. The geothermal gradient averages about 25 °C/km in the Earth's upper crust, but this varies widely by region, from a low of 5–10 °C/km within oceanic trenches and subduction zones to 30–80 °C/km along mid-ocean ridges or near mantle plumes. The gradient becomes less steep with depth, dropping to just 0.25 to 0.3  °C/km in the mantle, where slow convection efficiently transports heat. The average geothermal gradient is not normally steep enough to bring rocks to their melting point anywhere in the crust or upper mantle, so magma is produced only where the geothermal gradient is unusually steep or the melting point of the rock is unusually low. However, the ascent of magma towards the surface in such settings is the most important process for transporting heat through the crust of the Earth.


title: Magma

text: Rocks may melt in response to a decrease in pressure, to a change in composition (such as an addition of water), to an increase in temperature, or to a combination of these processes. Other mechanisms, such as melting from a meteorite impact, are less important today, but impacts during the accretion of the Earth led to extensive melting, and the outer several hundred kilometers of our early Earth was probably an ocean of magma. Impacts of large meteorites in the last few hundred million years have been proposed as one mechanism responsible for the extensive basalt magmatism of several large igneous provinces.


title: Magma

text: Decompression melting occurs because of a decrease in pressure. It is the most important mechanism for producing magma from the upper mantle.


title: Magma

text: The solidus temperatures of most rocks (the temperatures below which they are completely solid) increase with increasing pressure in the absence of water. Peridotite at depth in the Earth's mantle may be hotter than its solidus temperature at some shallower level. If such rock rises during the convection of solid mantle, it will cool slightly as it expands in an adiabatic process, but the cooling is only about 0.3 °C per kilometer. Experimental studies of appropriate peridotite samples document that the solidus temperatures increase by 3 °C to 4 °C per kilometer. If the rock rises far enough, it will begin to melt. Melt droplets can coalesce into larger volumes and be intruded upwards. This process of melting from the upward movement of solid mantle is critical in the evolution of the Earth.


title: Magma

text: Decompression melting creates the ocean crust at mid-ocean ridges, making it by far the most important source of magma on Earth. It also causes volcanism in intraplate regions, such as Europe, Africa and the Pacific sea floor. Intraplate volcanism is attributed to the rise of mantle plumes or to intraplate extension, with the importance of each mechanism being a topic of continuing research.


title: Magma

text: The change of rock composition most responsible for the creation of magma is the addition of water. Water lowers the solidus temperature of rocks at a given pressure. For example, at a depth of about 100 kilometers, peridotite begins to melt near 800 °C in the presence of excess water, but near 1,500 °C in the absence of water. Water is driven out of the oceanic lithosphere in subduction zones, and it causes melting in the overlying mantle. Hydrous magmas with the composition of basalt or andesite are produced directly and indirectly as results of dehydration during the subduction process. Such magmas, and those derived from them, build up island arcs such as those in the Pacific Ring of Fire. These magmas form rocks of the calc-alkaline series, an important part of the continental crust.


title: Magma

text: The addition of carbon dioxide is relatively a much less important cause of magma formation than the addition of water, but genesis of some silica-undersaturated magmas has been attributed to the dominance of carbon dioxide over water in their mantle source regions. In the presence of carbon dioxide, experiments document that the peridotite solidus temperature decreases by about 200 °C in a narrow pressure interval at pressures corresponding to a depth of about 70 km. At greater depths, carbon dioxide can have more effect: at depths to about 200 km, the temperatures of initial melting of a carbonated peridotite composition were determined to be 450 °C to 600 °C lower than for the same composition with no carbon dioxide. Magmas of rock types such as nephelinite, carbonatite, and kimberlite are among those that may be generated following an influx of carbon dioxide into mantle at depths greater than about 70 km.


title: Magma

text: Increase in temperature is the most typical mechanism for formation of magma within continental crust. Such temperature increases can occur because of the upward intrusion of magma from the mantle. Temperatures can also exceed the solidus of a crustal rock in continental crust thickened by compression at a plate boundary. The plate boundary between the Indian and Asian continental masses provides a well-studied example, as the Tibetan Plateau just north of the boundary has crust about 80 kilometers thick, roughly twice the thickness of normal continental crust. Studies of electrical resistivity deduced from magnetotelluric data have detected a layer that appears to contain silicate melt and that stretches for at least 1,000 kilometers within the middle crust along the southern margin of the Tibetan Plateau. Granite and rhyolite are types of igneous rock commonly interpreted as products of the melting of continental crust because of increases in temperature. Temperature increases also may contribute to the melting of lithosphere dragged down in a subduction zone.


title: Magma

text: When rocks melt, they do so over a range of temperature, because most rocks are made of several minerals, which all have different melting points. The temperature at which the first melt appears (the solidus) is lower than the melting temperature of any one of the pure minerals. This is similar to the lowering of the melting point of ice when it is mixed with salt. The first melt is called the "eutectic" and has a composition that depends on the combination of minerals present.


title: Magma

text: For example, a mixture of anorthite and diopside, which are two of the predominant minerals in basalt, begins to melt at about 1274 °C. This is well below the melting temperatures of 1392 °C for pure diopside and 1553 °C for pure anorthite. The resulting melt is composed of about 43 wt% anorthite. As additional heat is added to the rock, the temperature remains at 1274 °C until either the anorthite or diopside is fully melted. The temperature then rises as the remaining mineral continues to melt, which shifts the melt composition away from the eutectic. For example, if the content of anorthite is greater than 43%, the entire supply of diopside will melt at 1274 °C., along with enough of the anorthite to keep the melt at the eutectic composition. Further heating causes the temperature to slowly rise as the remaining anorthite gradually melts and the melt becomes increasingly rich in anorthite liquid. If the mixture has only a slight excess of anorthite, this will melt before the temperature rises much above 1274 °C. If the mixture is almost all anorthite, the temperature will reach nearly the melting point of pure anorthite before all the anorthite is melted. If the anorthite content of the mixture is less than 43%, then all the anorthite will melt at the eutectic temperature, along with part of the diopside, and the remaining diopside will then gradually melt as the temperature continues to rise.


title: Magma

text: Because of eutectic melting, the composition of the melt can be quite different from the source rock. For example, a mixture of 10% anorthite with diopside could experience about 23% partial melting before the melt deviated from the eutectic, which has the composition of about 43% anorthite. This effect of partial melting is reflected in the compositions of different magmas. A low degree of partial melting of the upper mantle (2% to 4%) can produce highly alkaline magmas such as melilitites, while a greater degree of partial melting (8% to 11%) can produce alkali olivine basalt. Oceanic magmas likely result from partial melting of 3% to 15% of the source rock. Some calk-alkaline granitoids may be produced by a high degree of partial melting, as much as 15% to 30%.


title: Magma

text: High-magnesium magmas, such as komatiite and picrite, may also be the products of a high degree of partial melting of mantle rock.


title: Magma

text: Certain chemical elements, called incompatible elements, have a combination of ionic radius and ionic charge that is unlike that of the more abundant elements in the source rock. The ions of these elements fit rather poorly in the structure of the minerals making up the source rock, and readily leave the solid minerals to become highly concentrated in melts produced by a low degree of partial melting. Incompatible elements commonly include potassium, barium, caesium, and rubidium, which are large and weakly charged (the large-ion lithophile elements, or LILEs), as well as elements whose ions carry a high charge (the high-field-strength elements, or HSFEs), which include such elements as zirconium, niobium, hafnium, tantalum, the rare-earth elements, and the actinides. Potassium can become so enriched in melt produced by a very low degree of partial melting that, when the magma subsequently cools and solidifies, it forms unusual potassic rock such as lamprophyre, lamproite, or kimberlite.


title: Magma

text: When enough rock is melted, the small globules of melt (generally occurring between mineral grains) link up and soften the rock. Under pressure within the earth, as little as a fraction of a percent of partial melting may be sufficient to cause melt to be squeezed from its source. Melt rapidly separates from its source rock once the degree of partial melting exceeds 30%. However, usually much less than 30% of a magma source rock is melted before the heat supply is exhausted.


title: Magma

text: Pegmatite may be produced by low degrees of partial melting of the crust. Some granite-composition magmas are eutectic (or cotectic) melts, and they may be produced by low to high degrees of partial melting of the crust, as well as by fractional crystallization.


title: Magma

text: Most magmas are fully melted only for small parts of their histories. More typically, they are mixes of melt and crystals, and sometimes also of gas bubbles. Melt, crystals, and bubbles usually have different densities, and so they can separate as magmas evolve.


title: Magma

text: As magma cools, minerals typically crystallize from the melt at different temperatures. This resembles the original melting process in reverse. However, because the melt has usually separated from its original source rock and moved to a shallower depth, the reverse process of crystallization is not precisely identical. For example, if a melt was 50% each of diopside and anorthite, then anorthite would begin crystallizing from the melt at a temperature somewhat higher than the eutectic temperature of 1274 °C. This shifts the remaining melt towards its eutectic composition of 43% diopside. The eutectic is reached at 1274 °C, the temperature at which diopside and anorthite begin crystallizing together. If the melt was 90% diopside, the diopside would begin crystallizing first until the eutectic was reached.


title: Magma

text: If the crystals remained suspended in the melt, the crystallization process would not change the overall composition of the melt plus solid minerals. This situation is described as "equillibrium crystallization". However, in a series of experiments culminating in his 1915 paper, "Crystallization-differentiation in silicate liquids", Norman L. Bowen demonstrated that crystals of olivine and diopside that crystallized out of a cooling melt of forsterite, diopside, and silica would sink through the melt on geologically relevant time scales. Geologists subsequently found considerable field evidence of such "fractional crystallization".


title: Magma

text: When crystals separate from a magma, then the residual magma will differ in composition from the parent magma. For instance, a magma of gabbroic composition can produce a residual melt of granitic composition if early formed crystals are separated from the magma. Gabbro may have a liquidus temperature near 1,200 °C, and the derivative granite-composition melt may have a liquidus temperature as low as about 700 °C. Incompatible elements are concentrated in the last residues of magma during fractional crystallization and in the first melts produced during partial melting: either process can form the magma that crystallizes to pegmatite, a rock type commonly enriched in incompatible elements. Bowen's reaction series is important for understanding the idealised sequence of fractional crystallisation of a magma.


title: Magma

text: Magma composition can be determined by processes other than partial melting and fractional crystallization. For instance, magmas commonly interact with rocks they intrude, both by melting those rocks and by reacting with them. Assimilation near the roof of a magma chamber and fractional crystallization near its base can even take place simultaneously. Magmas of different compositions can mix with one another. In rare cases, melts can separate into two immiscible melts of contrasting compositions.