The North American Plate The Eurasian Plate The Philippine Sea Plate The Pacific Plate.
Japan lies over 4 tectonic plates. These are: The North American Plate The Eurasian Plate The Philippine Sea Plate The Pacific Plate. + 5 others found this useful. Nathaniel Preece. Japan lies on the North American, Eurasian and Pacific plates, and is close to the Phillipine plate. Tokyo and Sendai, for example are on the North American plate. The March 11 earthquake in Japan was caused by movement of two of the Earth's tectonic plates against each other.The Pacific plate (underlying the Pacific Ocean) is colliding with the Okhotsk plate (under Japan) at around 9 cm every year. Most of the world's earthquakes occur at the boundaries between tectonic plates. The largest earthquakes are found at plate boundaries where the plates are colliding with each other, and one plate is diving down into the earth. These are called subduction zones, and there is one just off the east coast of Japan. Friday's temblor struck 231 miles (373 kilometers) northeast of Tokyo and 80 miles (130 km) east of Sendai, Honshu, in the Pacific Ocean near the Japan Trench. The Japan Trench, a subduction zone, is where the Pacific plate beneath the Pacific Ocean dives underneath North American plate beneath Japan. This violent movement, called thrust faulting, forced the North American plate upward in this latest quake. More recently, a 6.8 magnitude earthquake struck the city of Kobe in 1995, killing more than 6,000 people. Japan has such a large potential for earthquakes and disaster because the nation sits atop four huge slabs of the Earth's crust, called tectonic plates. The epicenter of the earthquake is on the offshore shelf, and not in the trench. Earthquakes are caused by breaking and movement of rocks along the faultline where the two plates collide. In cross-section the convergent margin would look something like this: Diagram showing the tectonic plate movement beneath Japan. Note the location of the earthquake is beneath the offshore shelf and not in the trench. The shaking of the sea-floor from the earthquake creates the tsunamis. Note that most of the earthquakes occur around the edge of the Pacific Ocean (and the Pacific Plate). Based on our studies of plate tectonics, we can see why Japan is so prone to earthquakes, and we can also see why the earthquake occurred exactly where it did. Japan's Earthquake Research Committee said the earthquake forced the North American plate eastward by about 66 feet (20 meters), reported Japan's national broadcast agency, NHK. The entire island of Honshu was moved about 8 feet (2.4 m) east, according to USGS scientists. More recently, a 6.8 magnitude earthquake struck the city of Kobe in 1995, killing more than 6,000 people. Japan has such a large potential for earthquakes and disaster because the nation sits atop four huge slabs of the Earth's crust, called tectonic plates. Japan’s 2011 Tohoku Earthquake is located at the boundary between the Pacific plate and the North American plate (this is not a typo!). These plates are converging at about 8 cm/year. The rectangle in the figure shows the location and length of the rupture zone. The red star indicates the epicenter.  Japan's tectonic shuffle. Earthquakes typically occur along faults, which are breaks in the rocky plates of the Earth's crust. These faults accumulate strain over the years as two plates butt heads. Japan's stretch of the Ring of Fire is where the North American, Pacific, Eurasian and Philippine plates come together. More recently, a 6.8 magnitude earthquake struck the city of Kobe in 1995, killing more than 6,000 people. Japan has such a large potential for earthquakes and disaster because the nation sits atop four huge slabs of the Earth's crust, called tectonic plates. The 8.9-magnitude earthquake that struck coastal Japan on Friday, devastating large swaths of the coast and spawning a powerful tsunami, was caused by the Pacific tectonic plate thrusting underneath the country, and forcing the seabed and ocean water upward.  The Pacific plate is moving westward and being subducted beneath the northern part of Japan, which is on the Okhotsk Plate. The tectonic plates and their boundaries surrounding Japan. The epicenter of the earthquake is along the convergent margin where the Pacific Plate is being subducted beneath the Okhotsk Plate. Note that most of the earthquakes occur around the edge of the Pacific Ocean (and the Pacific Plate). Based on our studies of plate tectonics, we can see why Japan is so prone to earthquakes, and we can also see why the earthquake occurred exactly where it did. Why is Japan so unstable. Japan lies at the meeting point of several of the world's major tectonic plates. This means that there is an everpresent threat from a range of natural hazards earthquakes,volcanoes and tsunami. The map shows the Philippine and Pacific Plates which are slowly moving north west towards Japan. 
http://www.answers.com/Q/How_many_tectonic_plates_are_under_Japan http://scienceline.ucsb.edu/getkey.php?key=2695 http://www.livescience.com/30226-japan-tectonics-explosive-geology-ring-of-fire-110314.html http://montessorimuddle.org/2011/03/11/plate-tectonics-and-the-earthquake-in-japan/ http://www.livescience.com/30226-japan-tectonics-explosive-geology-ring-of-fire-110314.html http://www.tectonics.caltech.edu/outreach/highlights/japan/ http://www.livescience.com/30226-japan-tectonics-explosive-geology-ring-of-fire-110314.html http://www.pbs.org/newshour/rundown/japans-earthquake-and-tsunami-how-they-happened/ http://montessorimuddle.org/2011/03/11/plate-tectonics-and-the-earthquake-in-japan/ http://www.emu.org.uk/Curriculum/Projects/Japan/ASPECTS/EARTHQUAKE/PLATEB/Plate.html
what tectonic plate is japan on