A new tracking method has been devised

Jul 28, 2009 07:01 GMT  ·  By
Satellite observations inadvertently caught the path of the deadly tsunami on 26 December 2004
   Satellite observations inadvertently caught the path of the deadly tsunami on 26 December 2004

The trickiest thing about tsunamis, the large waves that cause massive devastation when they reach the beaches, is that they can travel very fast, at 500 kilometers per hour, under the ocean surface, and not be visible on the surface until a certain set of conditions is met. Researchers from the US National Oceanic and Atmospheric Administration (NOAA) figured out that, at one point, by using radars to measure the turbulences that “undercover” tsunamis caused in the lower atmosphere, they could potentially survey hundreds or even thousands of kilometers, and thus set up an efficient warning grid.

Physicist Oleg Godin, from the NOAA Cooperative Institute for Research in Environmental Sciences, in Boulder, Colorado, was the first one to propose in 2004 the method known as “side-looking,” in which radar devices survey the ocean surface from an angle, and are able to cover large distances. At this point, flood prevention is done using buoys laden with sensors, and by employing satellite observations. But these methods fail simply because they cannot cover all the areas that are at risk of being devastated.

Incidentally, at the time of the large Sumatra-Andaman earthquake, which generated the infamous tsunami that killed thousands and devastated coastlines across the Indian Ocean, NOAA had its Jason-1 satellite in orbit, and it was placed exactly in the position that allowed it to survey the tsunami. By sheer accident, the satellite was able to demonstrate that side-looking worked, as, at the time of the observations, it exhibited the exact same type of traits that Godin hypothesized theoretically.

Publishing in the July issue of the Natural Hazards and Earth System Sciences, NOAA experts report the results of their analysis on the images Jason-1 collected some years ago. They conclude without the shadow of a doubt that the abnormalities the satellite saw in the ocean surface were, indeed, caused by rapid water movements, and added that the data was consistent with what a tsunami in its underwater stage might look like, ScienceNow reports.