mid-ocean ridges
Tsunami's can be triggered by earthquakes that happen underneath the ocean floor.
Earthquakes in Japan are caused by the movement of tectonic plates. A tsunami is a large ocean wave that is caused by sudden motion on the ocean floor which can be triggered by earthquakes.
earthquakes under seafloor can lead to tsunamis
tsunami
Slabs of ocean floor return to the mantle in subduction zones
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The expanse of land known as a 'continental shelf' where seawater is shallow, before it drops off into the ocean.
The mid ocean ridge is the area of the ocean floor that is associated with the breaking down of the oceanic crust. This area is known for seafloor spreading.
The ocean floor is irregular as to the land we can see. It has mountains and ridges and plains and valleys and volcanoes. It even has underwater earthquakes, and just about every other land feature you could name.
THE SHELF
shallow areas
Offshore trenches are deep, elongated depressions on the ocean floor formed by the collision of tectonic plates. They are typically associated with subduction zones where one tectonic plate is forced beneath another, creating a trench-like topographic feature. Offshore trenches play a vital role in plate tectonics and are often sites of earthquakes and volcanic activity.
New Zealand experiences about 300 earthquakes of Richter 4 to 4.9 each year, (on average); and an average of two in the range Richter 6 to 6.9.There is a huge difference in the distribution of Deep and Shallow earthquakes, and this is illustrated by graphs in the website of gns.cri.nz.Of course, the shallow earthquakes have a very much greater effect on structures.The very deep earthquakes are commonly in Fiordland, where the population is very low. The deep earthquakes in both islands are strongly associated with the subduction of the Pacific plate under the Australian Plate in the north; and the subduction of the Australian plate under the Pacific Plate in the South.As far as deep earthquakes are concerned, there is a quiet zone where these patterns cross over, and this raises the Southern Alps.New Zealand straddles the boundary between these two plates. The Alpine Fault in the South Island may be an extension of a transcurrent fault associated with the Mid Ocean Ridge sea floor spreading in the south Pacific.This fault continues through New Zealand, emerging as the Hikurangi trench, which becomes the Tonga Trench further north again.
Tsunami's can be triggered by earthquakes that happen underneath the ocean floor.
Earthquake patterns, including their depth and distribution, can provide evidence of sea floor spreading by showing a concentration of earthquakes along mid-ocean ridges where new oceanic crust is being formed. As tectonic plates diverge and new crust is created, stress builds up and is released through earthquakes. The pattern of earthquakes along mid-ocean ridges provides a visual representation of the tectonic activity associated with sea floor spreading.
what other ocean floor feature is fromed by movement of earth's plates
Focus