Disaster Of A Subduction Zone

1507 Words Oct 18th, 2014 7 Pages
1. Introduction On Friday March 11th, 2011 at 2:46 pm, the fifth largest earthquake recorded since 1900 with a magnitude of 9.0, 1.7 Richter scale points greater than the devastating Vancouver Island earthquake of 1946, struck the coast of Japan, 231 miles northeast of Tokyo1, causing a devastating regional and global catastrophe.
1.1 Megathrust Earthquakes Megathrust earthquakes are defined as interplate earthquakes caused by one tectonic plate being forced under another in a subduction zone. During the lifetime of a subduction zone, two plates are constantly moving towards each other, and due to the great amount of friction, these plates get “stuck” in various areas 2 (fig 1). Due to the build-up of stress in these areas, the plates eventually unlock and release a great amount of energy, resulting in a megathrust earthquake2.

1.2 Tsunamis Since these earthquakes are caused by tectonic plate movement therefore displacing the ocean floor they are almost always accompanied by massive ocean waves, sometimes reaching heights of over 100 ft and reaching speeds of 500 mph, known as seismic sea waves or more commonly known as Tsunamis4. Alongside the catastrophic events that megathrust earthquakes ensue on an affected region these colossal Tsunami waves further destruct costal lines in their path, sometimes reaching many miles inland.
1.3 Report Aim This report will outline the environmental and societal impacts of the Tohoku…
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