Tuesday, March 22, 2011

Asia@home hacks earthquakes

The catastrophic Sendai earthquake cast a long shadow over events at the International Symposium on Grid Computing in Taipei this year, and its associated satellite events. Not only in terms of cancellations of most participants from Japan as well as delays and detours for those who were routed through Tokyo. But also in the sessions. And nowhere more so, perhaps, than in the two-day Asia@home hackfest, dedicated as it was to earthquake science. One speaker after another showed data from the magnitude 9 earthquake that had rocked Japan like nothing ever before recorded in that country. (The image here shows aftershocks, all at more than magnitude 4, courtesy of Carl Christensen, Quake-Catcher Network project)

Staring at a map dense with red dots showing hundreds of large aftershocks off the coast of Japan, Stanford University researcher Carl Christensen shook his head saying simply "I've never seen anything like it". He described his relief when the project he works on, Quake-Catcher Network, managed to get back in touch with a laptop that had been contributing seismological data to the project, more than a week after the same device suddenly disappeared off the internet, following the massive quake. At least that particular volunteer was presumably out of harm's way.

Another talk provided a poignant reminders of the even greater toll that earthquakes and their offspring, tsunamis, can take on the populations countries with less resources than Japan. Benny Hendrawanto of the Indonesian Meteorological, Climatological and Geophysical Agency described to participants how the 2004 Aceh earthquake and tsunami took the lives of over 200,000 people, ten times more than estimates for Sendai.

Faced with such enormous consequences, what can ordinary citizens do? One of the more hopeful messages from the hackfest was that cheap sensors, like the one Carl was monitoring near Sendai, can provide the sort of dense monitoring networks that countries like Taiwan or Japan already have, at a fraction of the cost. This could be a great boon for developing regions.

It may take some time before such volunteer-based networks gain official acceptance as part of an early warning system. But even before that happens, the sensors could help to avert some of the worst dangers, by helping local authorities to spot regions where quake-induced motion is amplified or persists much longer due to the local geology, and ban housing developments there.

Elizabeth Cochran demonstrated this with data collected from over a hundred volunteer sensors in and around the city of Christchurch, New Zealand, which had suffered huge damage at the hands of a relatively low magnitude quake, just 6.3 on the Richter scale. What was immediately apparent from the data was that the sensors near the city centre kept shaking far longer than those in the immediate vicinity of the quake epicentre. The unfortunate local geology seemed to be a key factor in the unusually large damage sustained by the city during that quake.

The event was billed a hackfest, and true to form, the afternoon sessions included a chance to install the USB sensors on participants' laptops and test their sensitivity. This was not just for fun. Dr. Wen-Tzong Liang of the Institute of Earth Sciences at Taiwan's Academia Sinica proposed distributing such sensors in schools in Taiwan and throughout the region, as both a way to introduce earthquake science into classrooms and a way to build cheap senor networks. Participants concluded the hackfest with an ambitious action list, which included putting Dr. Liang's vision into practice.

The grimness of the news from Japan surely contributed to a sense of resolve amongst the Asia@home hackfest participants that this event should have some beneficial impact on the security of the region.

1 comment:

PrAM said...

mantap ,,,,,juncons