Discussion
Ask a question about 'Boso Triple Junction' Start a new discussion about 'Boso Triple Junction' Answer questions from other users |
Boso Triple Junction is a
triple junctionA triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction a boundary will be one of 3 types - a ridge, trench or transform fault - and triple junctions can be described according to the types of plate margin that meet at them...
off the coast of Japan; it is the only example of a Triple Trench Junction (Trench, Trench, Trench) on earth.
Formation
It is formed from the junction of the
Izu-Bonin-Mariana ArcThe Izu-Bonin-Mariana arc system is an outstanding example of a plate tectonic convergent boundary. IBM extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, Bonin Islands, and Mariana Islands; much more of the IBM arc system is submerged below sealevel...
where the Izu-Bonin Trench meets with the
Japan Trench__notoc__The Japan Trench is an oceanic trench, a part of the Pacific Ring of Fire, in the floor of the northern Pacific Ocean off northeast Japan. It extends from the Kuril Islands to the Bonin Islands and is at its deepest. It is an extension of the Kuril-Kamchatka Trench to the north and the...
and the
Sagami TrenchThe also Sagami Trench, Sagami Megathrust, or Sagami Subduction Zone is a 210-mile long trough where the Kanto earthquakes of 1703 , 1855 and 1923 arose. It stretches from the Boso Triple Junction where it meets the Japan Trench to Sagami Bay. It runs north of the Izu Islands chain and the...
.
Risks
Tokyo, ; officially , is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family...
is some 300 km from the Boso triple junction, and is subject to quakes and tsunamis generated from slips along this junction. However, there is a large populated region along the coast of the main island that would also be subject to damage. This junction likely has the highest associated insurance risk in the world, due to proximity to extensive urban development.
The
2011 Tōhoku earthquake and tsunamiThe 2011 earthquake off the Pacific coast of Tohoku, also known as the 2011 Tohoku earthquake, or the Great East Japan Earthquake, was a magnitude 9.0 undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST on Friday, 11 March 2011, with the epicenter approximately east...
were generated along the Japan trench well to the north of the junction, and did not involve the other trenches, although quakes which may be aftershocks have been observed there.