A unexampled map of the ocean floor off the coast of Alaska shows geologic features that resemble the area that generated the 2011 Tohoku tsunami in Japan . This recent discovery mean that previous models might have undervalue the tsunami risk in the realm .
The determination , published inNature Geoscience , present how the region , called the Shumagin Gap , is a “ crawl subduction zone ” that load for 145 kilometers ( 90 miles ) parallel to the Alaskan glide . The research squad register a serial publication of small earthquake in the region that suggest the fault is active .
“ [ The find ] evoke this part of Alaska is peculiarly prone to tsunami generation , ” lead generator Dr Anne Bécel , from Columbia University ’s Lamont - Doherty Earth Observatory , said in astatement . “ The possibility that such features are far-flung is of globose import . ”
Before the 2011 Japan tsunami , it was thought that regular subduction geographical zone were the most severe ones . In those areas , one plate is sinking under another one , building up tension until it ’s released as a powerful quake . pussyfoot subduction zones , on the other hand , incline to relinquish tensions in frequent pocket-size quakes , so this should keep the establishment of bigger tidal undulation .
But researcher now mean that grovel subduction zone might be part detached from the main scale . Even a modest seism could make the sea floor jump up and down , creating a powerful tsunami on the control surface .
“ With that prominent fault there , that outer part of the plate could move severally and make a tsunami a great deal more effective , ” said co - author Professor Donna Shillington . “ You get a lot more perpendicular motion if the part that relocation is cheeseparing to the seafloor airfoil . ”
The sneak subduction zona is much smaller and lighter than the rest of the home plate , so once movement happens below it , it raise higher and faster than the rest .
While the peril is higher than previously believe , it is difficult to quantify exactly how high-risk it is to survive near such areas . We still do n’t fully see these regions and researchers think this shape might not be an exclusive of the Pacific .
“ We do n’t have icon from many place , " Shillington added . " If we were to look around the earth , we would in all probability see a mickle more . "
Every scrap of selective information provides a more complete pic , and hopefully we ’ll shortly know enough to improve the refuge of the inhabitants before another crushing tsunami happens .
