From Scientific American: Indonesian Tsunami Was Powered by a Deadly Combo of Tectonics and Geography. The magnitude 7.5 earthquake that touched off the tsunami occurred amid a complex puzzle of tectonic plates.
Thanks to Ian McLean of New Zealand for this citation. He says that NZ also has similar tectonic conditions. Here are some of his observations about the seismic conditions and risk in New Zealand.
What I found particularly interesting was the fact that the earthquake occurred in a transition zone. To the west of this zone one plate subducts, and to the east of the zone the plates abut pushing up mountain ranges.
The configuration is similar to the zone in New Zealand where the Kaikoura sequence of earthquakes occurred.. To the north the Pacific plate subducts the Indo-Australian plate; and to the south the plates abut, pushing up the Southern Alps.
In the transition zone is a complex jumble of faults. Several of these ruptured sequentially during the Kaikoura sequence. The damage was unexpectedly severe, especially in Wellington.
But NZ still awaits with apprehension earthquakes along the plate boundaries to the south and north of the transition zone. To the south , the Alpine fault has reached its mean return period. In the north, knowledge about the HIkurangi subduction zone was sparse, but substantial research is now being done.
Ian McLean is a former Chair of NZ Earthquake Commission, and has advised on catastrophe insurance schemes around the world, including helping to form the schemes in Turkey and Romania through the World Bank.
Some spectacular photos of Japan immediately after the tsunami and recently.
Thanks to Bill Cumming for providing the link.
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This NY Times article lays out the conflicts in recovery plans for Japan. November3, 2011. The title, Japan Revives a Sea Barrier That Failed to Hold, is rather understated in that the lengthy article covers a wide range of reconstructions plans and aspects. Yet another example of the failure to adhere to scientific and objective risk assessments, I am sad to say.
Some quotes from the article:
After the tsunami and the nuclear meltdowns at Fukushima, some Japanese leaders vowed that the disasters would give birth to a new Japan, the way the end of World War II had done. A creative reconstruction of the northeast, where Japan would showcase its leadership in dealing with a rapidly aging and shrinking society, was supposed to lead the way.
But as details of the government’s reconstruction spending emerge, signs are growing that Japan has yet to move beyond a postwar model that enriched the country but ultimately left it stagnant for the past two decades. As the story of Kamaishi’s breakwater suggests, the kind of cozy ties between government and industry that contributed to the Fukushima nuclear disaster are driving much of the reconstruction and the fight for a share of the $120 billion budget expected to be approved in a few weeks.
Image via Wikipedia
The insistence on rebuilding breakwaters and sea walls reflects a recovery plan out of step with the times, critics say, a waste of money that aims to protect an area of rapidly declining population with technology that is a proven failure.
Image by autowitch via Flickr
As a result of the tsunami in Japan, a huge floating debris field is due to wash up in Hawaii and the west coast states. Scientists are already are studying the problem and working to head off a marine crisis when the debris makes landfall in 2011. Some modest federal funding has been secured, but I am sure we will be hearing more about this threat in the coming months. See Inouye Steps Up With Money for Tsunami Debris Cleanup