New tsunami warning system may save lives

In 2004, the Indian Ocean tsunami claimed the lives of tens of thousands of people, who didn’t have time to evacuate to higher ground.

Tony Song and his colleagues at the Jet Propulsion Lab in Pasadena, California are developing a new warning system they say would quickly alert coastal dwellers that a tsunami might be coming. It uses GPS technology to detect the horizontal motion of the sea floor.

These scientists say they can use this technology to predict a tsunami before a tsunami even starts. This is a new way of looking at how an earthquake causes a tsunami, says Tony Song.

Until now, scientists have tried to predict tsunamis by measuring the magnitude of an earthquake. The more powerfully the earthquake pushes the ocean floor up, the larger the potential tsunami – or so researchers thought.

Song and his team have found that what really matters is not the vertical movement of the ocean floor. Instead, the size and power of a tsunami depends on the amount of energy an earthquake transfers to the ocean when it causes the ocean floor to move from side to side.

GPS technology can detect this side to side movement of the ocean floor and almost instantly calculate the type of tsunami it will generate.

Tony Song: We use that technology to detect the ground motion caused by the earthquake. But this technology is based on a new theory called ‘horizontal momentum transfer to the ocean’ that generates a tsunami.

There are already many GPS stations in place in coastal regions — enough to test the new tsunami warning system. When more stations are added in target areas where earthquakes are likely to happen, the system could warn people well in advance of a deadly tsunami, and help save many lives.

Our thanks today to NASA: explore, discover, understand.

Our thanks to:
Tony Song
Oceanographer
Jet Propulsion Laboratory
NASA