'Merging Tsunami' Amplified Destruction In Japan 50
Hugh Pickens writes "The magnitude-9.0 Tohoku-Oki temblor, the fifth-most powerful quake ever recorded, triggered a tsunami that doubled in intensity over rugged ocean ridges, amplifying its destructive power at landfall, as seen in data from NASA and European radar satellites that captured at least two wave fronts that day, which merged to form a single, double-high wave far out at sea. This wave was capable of traveling long distances without losing power. Ocean ridges and undersea mountain chains pushed the waves together along certain directions from the tsunami's origin. 'It was a one-in-10-million chance that we were able to observe this double wave with satellites,' says study team member Y. Tony Song. 'Researchers have suspected for decades that such 'merging tsunamis' might have been responsible for the 1960 Chilean tsunami that killed about 200 people in Japan and Hawaii, but nobody had definitively observed a merging tsunami until now.' The study suggests scientists may be able to create maps that take into account all undersea topography, even sub-sea ridges and mountains far from shore to help scientists improve tsunami forecasts."
Thinking through the uses... (Score:5, Interesting)
Better understanding and forecasting would be a fantastic thing. It would certainly save lives. However, after watching the footage of the tsunami in question, there's a little part of my brain that wonders whether it would do much more than tweak the odds for people in a few marginal cases.
I suppose where there's a much clearer use for this is in making infrastructure and resilience planning decisions. It will never be practical to say "people shouldn't live in areas that might be hit by tsunamis". As the "Boxing Day" tsunami demonstrated, the areas in question are absolutely vast - and as the Japanese tsunami demonstrated, they can stretch miles inland. I just don't see how countries could afford to give up such huge tracts of habitable land to mitigate against the risk of "once every couple of centuries" events. What might be practical, however, is to think about how to site critical pieces of infrastructure (such as... say... nuclear power plants, as well as hospitals, emergency response centres, transportation hubs) so as to minimise their exposure to these events - and understanding the paths that future tsunamis are likely to follow is going to be key to that.
And protecting your key infrastructure is vital to saving lives in the days and weeks after a catastrophe - particularly in nations less wealthy and less resilient than Japan (which understandably struggled even despite those advantages).
Re:Thinking through the uses... (Score:5, Interesting)
What might be practical, however, is to think about how to site critical pieces of infrastructure (such as... say... nuclear power plants...
Honest question - does anyone know why the Fukushima plant was built on the east coast of Japan, facing the bomb-waiting-to-go-off [google.co.uk] that is the massive subduction zone a few miles off shore?
Why wasn't it built on the west coast, so it was sheltered by the island itself? I know hindsight is a wonderful thing, but looking at the map this seems like a schoolboy error to me.
Re:Thinking through the uses... (Score:5, Interesting)
Of course, it's worth remembering that while a lot of people had their lives disrupted, the casualties directly caused by Fukushima were limited. If you're looking for examples of disastrous infrastructure planning decisions with fatal consequences, I'd suggest reading up on the Vajont Dam [wikipedia.org]. I've seen this used in public sector training courses as a cautionary example of what the consequences of rushed, sloppy or biased planning decisions can be. It also, largely through coincidence, involves a tsunami (and one with a much, much greater wave height than that which hit Japan this year) - and a freshwater one to boot.