Scientists Try to Learn from Japanese Earthquake

22 April 2011

Japan launched its earthquake early warning system, seen here, in 2006. It provides crucial time for power plants to go offline and trains to brake before shaking starts.

California children practice self-protection in an earthquake drill. Annual preparedness exercises are held in California, and more states will join this year.

The Earth “rang like a bell” when one of the greatest earthquakes ever recorded struck the eastern coast of Japan and sent shock waves to monitoring stations around the globe. What science learns from the March 11 data will help all nations better understand, prepare for and protect themselves from the damage such violent natural phenomena can do.

David Applegate, a scientist at the U.S. Geological Survey, said analysis of the waves of motion and their timing at various points around the globe can help communities develop greater awareness of their vulnerability to earthquakes and adopt stronger standards for construction that will withstand shaking.

“There is quite a bit that can be done in terms of making our communities more resilient,” Applegate said at an April 21 press briefing, “whether it is in terms of building codes, preparedness or the rapidity and richness of information we have for response.”

Applegate said the Japanese operate the world’s most sophisticated earthquake warning system. With constant surveillance of seismic activity, the system sets off alarms when shaking is detected. Those alarms give warning, perhaps only seconds, but enough time for actions to lessen damage or protect life in the moments between the Earth’s sudden rumble at one point and the arrival of the shaking at points distant from the quake site.

“You’re trying to outrun the seismic waves with your system,” Applegate said. For instance, in the recent Great Eastern Japan quake, the movement of tectonic plates occurred beneath the ocean floor off the coast of Japan. The alarm sent out by the early warning system allowed enough time for the country’s magnetic trains to be halted, providing greater protection from derailment of trains filled with passengers.

The U.S. Geological Survey (USGS) has developed several tools that Applegate says should help emergency responders better prepare for earthquakes and recognize the points where their communities have the greatest vulnerabilities. For instance, USGS produces a “ShakeMap” after an event that measures and displays seismic activity and its severity. The ShakeMap is combined with a geographic map of a community to create a ShakeCast, which will allow identification of the bridges, highway overpasses and other structures that could be the most vulnerable to shaking and have the greatest potential for casualties.

In a moment of crisis, invariably accompanied by a breakdown in communications, Applegate says, this tool can help emergency responders decide where to send the ambulances first or understand where roads have been made impassable. He says the tool is being used in earthquake-prone California and by other state departments of transportation.

“It’s being used by the [U.S.] Veterans Administration for hospitals, and it is being used internationally as well by a number of different entities to be able to make information actionable and to improve the rapidity of their response,” Applegate said.

The tremendous economic losses and a death toll in excess of 300,000 caused by the 2010 earthquake in Haiti demonstrate the importance of preparedness. Haiti had not experienced a serious quake for more than 200 years. Efforts of recent decades to map earthquake likelihood around the globe did not account for great quakes of the distant past, so awareness that such a thing could happen in Haiti was low.

USGS is collaborating with an international effort being led by Italy to create a Global Earthquake Model, Applegate said. It “is a very important effort going forward,” he said. The project aims to map seismic activity — present and historical — everywhere on the globe so that all countries will better understand the possibility of an event and their vulnerability.