Monday, March 14, 2011

Earthquake and Tsunami in Japan - Early Thoughts

The Japan earthquake and tsunami is hard to take in. As a geologist who works on geologic hazards I want to learn what I can, but the issues raised by this quake extend well beyond a simple understanding of geology.  Large earthquakes are terrible events, but there is a lot to be learned. Geologists, geotechnical engineers, civil engineers, structural engineers and emergency responders all will study these events to try to learn lessons. I hope planners and those that make infrastructure funding decisions will learn as some lessons as well. Lots of lessons for Washington State as we live in a similar geologic setting.

As I digest things, I will write more later. This is an event that overwhelms a geo blogger. I noted a tremendous number of page views from last Friday's post indicating people want to know more, but I do have to work! Silver Fox provides a long list of sites to check HERE. Reuters, BBC, CNN and NY Times have done a commendable job.

A few early thoughts:

1) The areal footage of the tsunami waves was unprecedented as well as some on the ground footage. The images present a hard lesson but one that will be hard to ignore.

2) Large areas that were hit by the tsunami were far from high ground, required reaching high ground via driving and road routes to high ground were not direct. With less than half and hour to reach safety there was little time to escape and for some an impossible task. This takes us back to thought number 1 above. There is a lesson here that very much needs to be considered in Washington State in regards to planning.

3) The tsunami damage combined with the nuclear plant issues dwarf the more typical issues regarding earthquakes as far as building and infrastructure holding up to shaking. In looking at the tsunami wave footage, it appeared buildings were in good condition in general and bridges with wide spans built on alluvial material had withstood the shaking. I am sure there were failures, and where those failures took place and why will add to our ability to properly construct buildings and infrastructure to minimize death and injury.

4) The nuclear power plant issue is stunning. georneys.blogspot has an interview with her father, a nuclear engineer, that is nice cool headed alternative to the news and I must say very well done. But I suspect that this issue will have broad global impacts and have significant imapcts here in Washington State.

So a few early thoughts that I will write about at some future date - likely months from now!


Kat said...

This video of a park in Chiba City during an aftershock made me wonder about the reclaimed portions of Seattle. Are they vulnerable to this same phenomenon?

Lyle said...

I looked up Sanriku earthquakes on Wikipedia and found that there have been 3 major earthquakes in that area 1 in 869, 1 between 1000 and 500 bc and one between 500 bc and 1 bc. Adding these together suggests a recurrence interval of about 1100 years. The article suggested that seismologists had put a 99% probability of an 8.3 in the 30 years following 2007. So although the quake was bigger, it was essentially forecasted. The fact that tsunamis hit Sendai in 869 and earlier (the earlier ones detected the way the cascadia ones are by tsunami deposits) suggests that since the plants were built a lot of new knowledge has been generated, and that plants built today would be built differently.