Pathfinder
Editor, Senior Moderator
Japan jolt 8000 times more violent than Christchurch's
By Isaac Davison
5:30 AM Tuesday March, 2011
The Japan earthquake was 8000 times stronger than the Christchurch shake and unzipped a faultline half the size of the North Island, a NZ scientist says.
The magnitude-9 tremor near Japan's east coast on Friday occurred at the same depth as the February 22 quake near Lyttelton, but struck on a far larger fault, believed to be 350km long and 150km wide.
This meant an enormous amount of energy was created as the fault ruptured for 150 seconds.
Associate Professor John Townend, a Victoria University expert in earthquake faults, said early investigations in Japan showed a rupture half the size of the North Island.
"The larger the fault, the larger the earthquake. When you see the fault is around 45,000sq km, moving several metres, you can understand how much grunt there is."
The fault forms the boundary between the Pacific tectonic plate and the North American plate, which sits under northern Japan.
It has been locked up for decades, but slipped up to 10 metres on Friday night.
.../
http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=10712469
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By Isaac Davison
5:30 AM Tuesday March, 2011
The Japan earthquake was 8000 times stronger than the Christchurch shake and unzipped a faultline half the size of the North Island, a NZ scientist says.
The magnitude-9 tremor near Japan's east coast on Friday occurred at the same depth as the February 22 quake near Lyttelton, but struck on a far larger fault, believed to be 350km long and 150km wide.
This meant an enormous amount of energy was created as the fault ruptured for 150 seconds.
Associate Professor John Townend, a Victoria University expert in earthquake faults, said early investigations in Japan showed a rupture half the size of the North Island.
"The larger the fault, the larger the earthquake. When you see the fault is around 45,000sq km, moving several metres, you can understand how much grunt there is."
The fault forms the boundary between the Pacific tectonic plate and the North American plate, which sits under northern Japan.
It has been locked up for decades, but slipped up to 10 metres on Friday night.
.../
http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=10712469
<SCRIPT language=javascript type=text/javascript>aimRenderAd(300, 250, 'RECTANGLE','ContentRect','/SR=1/POS=2');if(!$.browser.msie){ContentRect_frame = $("#ContentRect")[0];ContentRect_frame.src = ContentRect_frame.src;}</SCRIPT>