NOAA Scientists Find Tsunami “Shadow” Visible from Space

[SoCalDem]

http://www.noaanews.noaa.gov/stories2009/20090715_tsunami.html


NOAA Scientists Find Tsunami “Shadow” Visible from Space

July 15, 2009

The ground track of the Jason-1 satellite is shown here as it crossed the Sumatra-Andaman tsunami at hourly intervals after the earthquake occurred. White stars show the location of the tsunami wave sources. The ground track of the Jason-1 satellite is shown here as it crossed the Sumatra-Andaman tsunami at hourly intervals after the earthquake occurred. White stars show the location of the tsunami wave sources.

For the first time, NOAA scientists have demonstrated that tsunamis in the open ocean can change sea surface texture in a way that can be measured by satellite-borne radars. The finding could one day help save lives through improved detection and forecasting of tsunami intensity and direction at the ocean surface. “We’ve found that roughness of the surface water provides a good measure of the true strength of the tsunami along its entire leading edge. This is the first time that we can see tsunami propagation in this way across the open ocean,” said lead author Oleg Godin of NOAA’s Earth System Research Laboratory and the Cooperative Institute for Research in Environmental Sciences, in Boulder, Colo.

Large tsunamis crossing the open ocean stir up and darken the surface waters along the leading edge of the wave, according to the study. The rougher water forms a long, shadow-like strip parallel to the wave and proportional to the strength of the tsunami. That shadow can be measured by orbiting radars and may one day help scientists improve early warning systems. The research is published online this week in the journal, Natural Hazards and Earth System Sciences.

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In 1994, a tsunami shadow was captured by video from shore moments before the wave struck Hawaii. That observation and earlier written documentation of a shadow that accompanied a deadly tsunami on April 1, 1946, inspired Godin to develop his theory. He tested the theory during the deadly December 26, 2004, Indian Ocean tsunami, the result of the Sumatra-Andaman earthquake.

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[Rhiannon12866]

1. Yikes! Fascinating article... K&R.

And that's an adorable pic... :hi: