{"id":748194,"date":"2026-06-20T05:23:24","date_gmt":"2026-06-20T05:23:24","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/748194\/"},"modified":"2026-06-20T05:23:24","modified_gmt":"2026-06-20T05:23:24","slug":"powerful-2011-japan-earthquake-may-have-moved-whole-country-further-east","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/748194\/","title":{"rendered":"Powerful 2011 Japan earthquake may have moved whole country further east"},"content":{"rendered":"

Minutes after the massive 2011 Japan earthquake and tsunami that killed nearly 20,000 people<\/a>, \u201ca previously unrecognised\u201d phenomenon may have caused the whole country to shift further eastwards, a new study reveals.<\/p>\n

Such megaquakes<\/a> are often followed by events that cause additional ground motion, which are related to aftershocks.<\/p>\n

But exactly all the different ways in which aftershocks<\/a> arise aren\u2019t very clear, scientists say.<\/p>\n

In a new study, researchers assessed satellite data to study the magnitude 9-Tohoku-Oki earthquake and its seismic aftereffects.<\/p>\n

Researchers found that the devastating quake led to a sudden sliding of blocks of rock past each other along the fault line.<\/p>\n

It also led to seismic waves travelling through the Earth, bouncing off the planet\u2019s core, and traveling back to the surface to reactivate the region\u2019s tectonic plate boundaries.<\/p>\n

These were \u201cshear waves\u201d that travelled through the Earth’s interior and caused rock particles to vibrate in a “shear” or side-to-side motion.<\/p>\n

\"A<\/p>\n

A pedestrian road has collapsed in the massive 8.9-magnitude earthquake (AFP via Getty Images)<\/p>\n

The latest findings reveal a previously unknown hazard that could potentially activate or reactivate the main area of a quake, according to the study published in the journal Science.<\/p>\n

\u201cWe report an extraordinary observation of ground motion in Japan after the moment magnitude 9 2011 Tohoku-Oki earthquake attributed to a multiplate-interface slip event triggered by a shear wave that travelled to the Earth\u2019s core and back,\u201d researchers wrote in the study.<\/p>\n

In the study, scientists re-examined satellite data to look for subtle movements in the minutes surrounding the 2011 quake.<\/p>\n

They found that seismic waves travelling through the Earth and bouncing off the core shifted the whole of Japan by as much as 5-6mm.<\/p>\n

While this may not be a lot and is a common amount of ground movement following large earthquakes, what surprised scientists was the area of land that had actually shifted.<\/p>\n

The triggered slip \u201chas the broadest rupture area of any single event yet documented\u201d, researchers wrote.<\/p>\n

\u201cIts overall length is similar to that of mainland Japan (~3,000 km), exceeding the mainshock rupture length by 6\u20127 times and more than doubling that of the 2004 great Sumatra Earthquake,\u201d they wrote in the study.<\/p>\n

As this ground movement was spread out over several minutes, people may not have felt it happen under their feet, researchers say.<\/p>\n

Yet, this new type of seismic hazard needs to be further studied, researchers say.<\/p>\n

\u201cI think we should be aware of the fact that there could be this potential triggering of an event many minutes after [an earthquake\u2019s] main shaking has passed,\u201d study author Sunyoung Park told Scientific American.<\/p>\n","protected":false},"excerpt":{"rendered":"Minutes after the massive 2011 Japan earthquake and tsunami that killed nearly 20,000 people, \u201ca previously unrecognised\u201d phenomenon…\n","protected":false},"author":2,"featured_media":748195,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,359559,359560,941,10445,128,316372],"class_list":["post-748194","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-au","tag-australia","tag-ground-motion","tag-ground-movement","tag-japan","tag-researchers","tag-science","tag-seismic-waves"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/748194","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=748194"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/748194\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/748195"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=748194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=748194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=748194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}