Advanced GPS System Will Improve Natural Disaster Warnings

By enhancing the capabilities of current GPS technologies, scientists have developed an early warning system that should be able to provide real-time, accurate information about hazards from extreme weather events, earthquakes and tsunamis.

The system is being tested in Southern California, where it has already been used to help alert people about the risk of flash floods associated with a summer monsoon rain event.

The system makes use of existing GPS stations that have been upgraded with inexpensive seismic monitors and meteorological sensors.

"These advancements in monitoring are being applied to public safety threats, from tall buildings and bridges to hospitals in regions of risk for natural hazards," said Yehuda Bock of Scripps Institution of Oceanography. "Meaningful warnings can save lives when issued within one to two minutes of a destructive earthquake, several tens of minutes for tsunamis, possibly an hour or more for flash floods, and several days or more for extreme winter storms."

In the case of the summer monsoon flash flood warning, water vapor and atmospheric moisture data collected by a NOAA research laboratory in Colorado was relayed to the system in California.

"These water vapor measurements are currently being used to help forecasters better monitor developing weather during periods between satellite overpasses and weather balloon launches," said research scientist Angelyn Moore of NASA's Jet Propulsion Laboratory. "Our project is upgrading GPS ground stations to get these data to forecasters in minutes to seconds to help them better understand whether summer monsoonal moisture is likely to cause harmful flash flooding."

Meteorologist Mark Jackson, who is in charge of NOAA's National Weather Service office in Oxnard, Calif., said that the GPS networks provide forecasters with timely and critical information they use to make more accurate weather forecasts and warn the public of any potential dangers.

"Having such detailed and timely information on how much moisture is available helps us better understand and forecast our extreme winter storms fueled by what are known as atmospheric rivers. It can also help us better pinpoint and anticipate thunderstorms capable of producing flash flooding," he said.

Regarding other natural disasters, such as earthquakes and subsequent tsunamis, the warning system can be used to issue alerts moments after a seismic event. The system improves earthquake warning by analyzing the primary shock waves of an earthquake, which can be used to predict the power of the more intense secondary waves that come later.

"The warning time can range between several seconds to as long as two minutes, depending on distance from the earthquake's epicenter. The earthquake magnitude and other critical fault parameters can be rapidly and accurately determined to generate ground intensity maps throughout the affected region, and form the basis of tsunami warnings," the Scripps Institution of Oceanography wrote in a statement.