plain plain underwater plain deep ocean floor usually found depths metres metres lying generally foot continental rise mid ocean ridge plains cover earth surface explored regions earth plains key elements oceanic basins elements elevated mid ocean ridge flanking hills addition elements active oceanic basins associated moving plate boundary typically include oceanic trench zone plains recognized distinct features sea floor late 1940s recently studied systematic basis poorly preserved record tend consumed process creation plain end result spreading plate melting lower oceanic crust rises layer upper mantle material reaches surface mid ocean ridges forms new oceanic crust constantly pulled sideways spreading plains result originally uneven surface oceanic crust fine sediments mainly clay sediment deposited currents continental margins submarine deeper water remainder sediment composed chiefly sediments metallic common areas plains varying concentrations metals including iron copper provide significant resource future mining ventures owing vast size plains currently believed major reservoir biodiversity abyss significant influence ocean carbon cycling dissolution calcium atmospheric concentrations years structure function ecosystems strongly influenced rate food composition material factors climate change fishing practices ocean expected substantial effect patterns primary production zone undoubtedly impact organic material abyss similar manner profound effect structure function diversity ecosystems oceanic zones ocean divided zones depending depth presence absence sunlight nearly life forms ocean depend activities marine plants convert carbon dioxide organic carbon basic building block organic matter turn requires energy sunlight drive chemical reactions produce organic carbon water column nearest surface ocean sea level referred zone zone subdivided different vertical regions portion zone adequate light support plants referred zone referred zone surface zone lower portion zone light intensity insufficient called zone means poorly lit greek zone referred zone twilight zone boundary tropics generally lies metres zone somewhat defined extending surface depth light intensity approximately surface sunlight depending season latitude degree water ocean water zone extend depth metres rarely metres dissolved substances solid particles absorb light coastal regions high concentration substances causes light rapidly depth areas zone tens metres deep zone light intensity considerably surface extends base zone metres extending zone zone region perpetual darkness average depth ocean metres zone represents tiny fraction ocean total volume capacity zone greatest biodiversity oceanic zones nearly primary production ocean occurs life forms inhabit zone capable movement upwards water column zone feeding rely material sinking find source energy nutrition occurs found near cold zone subdivided different vertical regions based depth temperature zone extending depth metres metres water temperature decreasing depth increases zone extending depth metres metres final zone includes deep oceanic trenches known zone deepest oceanic zone extends depth metres approximately metres plains typically located zone depths ranging metres table illustrates classification oceanic zones formation oceanic crust forms bedrock plains continuously created mid ocean ridges type boundary process known melting related melting solid mantle responsible creating ocean islands like hawaiian islands ocean crust mid ocean ridges phenomenon common explanation flood oceanic types large provinces melting occurs upper mantle partially melted moves upwards mid ocean ridges convection heat form new oceanic crust occurs mantle added growing edges plate usually associated spreading age oceanic crust function distance mid ocean ridge youngest oceanic crust mid ocean ridges progressively older cooler mid ocean ridges process called mantle convection rides atop divided number plates continuously created consumed opposite plate boundaries oceanic crust plates formed apart mid ocean ridges hills formed stretching oceanic consumption destruction oceanic occurs oceanic trenches type boundary known destructive plate boundary process known oceanic trenches found places oceanic different plates meet older slab begins descend mantle consumption edge plate oceanic trench oceanic contracted dense weight process process older oceanic oceanic crust seldom million years old overall process repeated cycles creation destruction oceanic crust known cycle proposed canadian new oceanic crust closest mid oceanic ridges shallow levels rugged topography topography function rate mid ocean ridge spreading spreading rate spreading rates vary significantly typical values fast spreading ridges greater slow spreading ridges typically studies shown slower spreading rate new oceanic crust vice versa thought phenomenon mid ocean ridge new oceanic crust formed faults oceanic crust hills common features surface earth process spreading helps explain concept continental drift theory plate flat appearance mature plains results originally uneven surface oceanic crust fine sediments mainly clay sediment deposited currents continental margins submarine deeper water remainder sediment comprises chiefly dust clay particles blown sea land remains small marine plants animals sink upper layer ocean known sediments total sediment deposition rate remote areas estimated centimeters thousand years sediment covered plains common pacific_ocean major ocean basins sediments currents trapped oceanic trenches border pacific_ocean plains typically covered deep sea parts crisis mediterranean_sea plain exposed air hot dry salt sink discovery landmark scientific expedition december british_royal_navy survey ship yielded tremendous data confirmed subsequent researchers data obtained course challenger expedition enabled scientists draw maps provided rough outline certain major submarine terrain features edge continental shelves set data points obtained simple technique taking lowering long lines ship challenger expedition followed expedition led united_states navy lieutenant team sailed recorded meteorological astronomical data addition taking ship trapped ice pack near september ultimately crushed sunk june expedition followed arctic expedition norwegian explorer aboard proved deep oceanic basin significant land masses north continent beginning canadian physicist scientists undertook research ultimately led development technology acoustic sounding equipment developed operated rapidly sounding lines enabling german expedition aboard german research vessel frequent east west atlantic maps produced techniques major atlantic basins depth precision early instruments sufficient reveal flat plains technology improved measurement depth latitude precise possible collect continuous sets data points allowed researchers draw accurate detailed maps large areas ocean floor use continuously recording enabled summer identify describe plain plain located south newfoundland known plain following discovery examples found oceans challenger deep deepest surveyed point earth oceans located southern end near group depression named researchers recordings depth march station reported depth meters based separate june mapping challenger deep system aboard indicated maximum depth meters miles system uses phase detection accuracy better water depth error meters depth terrain features rare important terrain feature found zones vent contrast approximately ambient water temperature depths water emerges temperatures ranging high high barometric pressure depths water exist liquid form fluid temperatures barometric pressure critical point water depth meters barometric pressure sea water salt water fresh water depth pressure temperature image increase depth pushes water closer critical point water emerging hottest parts black submarine fluid possessing physical properties gas liquid elevation elevation black category located near presumed active earthquake shook region observed vent phase separated type sustained exit temperatures recorded peak recorded temperature conditions exceed critical point highest temperatures recorded date reported evidence direct interaction slow spreading mid ocean ridge cold unusual feature found zones cold called cold vent area hydrogen rich fluid occurs form deep sea pool cold discovered depth meters gulf_of_mexico cold discovered areas including california pacific_coast costa_rica atlantic coast africa coast alaska ice shelf antarctica biodiversity plains assumed vast desert like habitats research past decade shows wide variety life ecosystem structure function deep historically poorly studied size abyss recent expeditions conducted international group scientists found extremely high level biodiversity plains species bacteria species species invertebrates worms crustaceans typically found single sites new species thousands species collected station highlighting poor understanding diversity evolution richer biodiversity associated areas known input higher organic carbon species family deepest living species fish specimen depth meters animal dead arrival surface observed recorded depth meters date deepest living fish recorded fish zone include fishes family includes fish black members family recorded depths meters scientists demonstrated species cosmopolitan distribution example certain species distributed arctic groups worms crustaceans appear endemic certain specific plains basins apparently unique taxa worms recently discovered plains suggests deep ocean fostered taxonomic composition fauna pacific similar identical north_atlantic list species discovered found described species class live meters species live exclusively zone greatest number eastern pacific_ocean oceanic trenches found species identified indian_ocean known species class species reported live meters restricted plain genetic studies lacking species thought capable living wide range depths having reported occurring depths large number great depths explain difference distribution world oceans crustaceans including known form significant community responsible large food falls sea floor scientists diversity deep atlantic diva expedition cruise german research vessel discovered collected new species benthic plains collected crustaceans species traps deployed found specimens belonged family half species collected depths greater meters remotely operated vehicle collected sediment core challenger deep living specimens soft walled identified sediment samples single construct shells estimated species living organisms collected overwhelming majority sample consisted simple soft shelled representing species complex multi genera overall specimens consisted soft shelled unusual compared samples sediment dwelling organisms deep sea environments percentage organic walled ranges total small organisms hard shells trouble growing extreme depths water depth severely lacking calcium similar known exist shallower oceanic trenches plain discovered challenger deep represent independent taxa shallower ecosystems soft shelled organisms challenger deep result selection pressure millions years ago challenger deep shallower past million years challenger deep grew present depth species present sediment ancient unable adapt increasing water pressure changing environment species able adapt ancestors organisms currently endemic challenger deep occur earth oceans depths forms live near surface deepest oceanic trenches robot ocean probe observed specimen challenger deep described species found nearly marine environment species live ocean temperatures zone found extremely hot waters adjacent zones areas submarine cold far greatest biodiversity unit area fueled chemicals dissolved vent areas home large diverse communities genus arranged large near cold locations bacteria typically form base food chain process entirely support vast ecosystems consisting complex organisms communities characterized species giant tube worms soft crabs shrimp deepest community discovered far located japan trench depth meters probably important ecological characteristic ecosystems energy limitation communities considered food limited benthic production depends input organic material produced zone thousands meters organic arrives rain small particles typically net primary production zone decreases water depth small particle augmented fall larger transport organic material near continental margins exploitation resources addition high biodiversity plains great current future commercial strategic interest example legal illegal disposal large structures ships oil radioactive waste hazardous waste munitions attractive sites deep sea fishing extraction oil gas minerals future deep sea waste disposal activities significant include sewage carbon dioxide disposal fish stocks upper ocean deep sea fisheries increasingly targeted exploitation deep sea fish long lived slow growing deep sea fisheries thought sustainable long term given current management practices changes primary production zone expected alter standing stocks food limited zone exploration deep water occasionally results significant environmental degradation resulting mainly accumulation contaminated drill oil oil involved horizon oil spill gulf_of_mexico originates meters ocean surface illustrates kind environmental disaster result related offshore drilling oil gas sediments certain plains contain abundant mineral resources notably potato sized iron copper distributed depths greater meters significant commercial interest area maximum commercial interest mining called pacific province lies international waters pacific_ocean stretching area million area pacific province currently exploration mineral potential commercial contractors currently licensed organization established organize control mineral related activities international area limits national jurisdiction explore resources test mining techniques claim areas covering mining ultimately begins mining operation projected directly disrupt year benthic fauna area times size suspended sediments year projected duration single mining operation mining severely damage communities areas zone size massachusetts limited knowledge taxonomy natural history deep sea communities prevents accurate assessment risk species large scale mining data acquired north_atlantic suggest deep sea ecosystems adversely affected mining operations time scales aboard operated american mining consortium mining track depth meters fields conducted expedition mining track visible study long term effects physical disturbance sediment benthic fauna samples taken superficial sediment revealed physical chemical properties shown recovery disturbance years earlier hand biological activity measured track instruments aboard manned differ nearby site data suggests benthic fauna nutrient water sediment interface fully recovered list plains
Abyssal plain