GPS networks are already an important part of everyday life around the world, but an international team of scientists has found a new, potentially life-saving use for them: tsunami warnings.
Researchers from University College London and universities across Japan have studied the tsunami detection capabilities of GPS networks, concluding that the devices can indeed detect destructive waves from space. They also determined that GPS could provide more detailed information than current detection systems – at an extremely low cost – allowing authorities to issue more accurate warnings against tsunami impacts. into the coast.
Tsunamis are created when ocean water is suddenly displaced by earthquakes, landslides, or volcanic eruptions. In the deep ocean, waves are often less than a foot high, but as they approach land at speeds up to 500 miles per hour, they grow rapidly in height before flooding the shore. GPS networks can detect these waves long before they reach land.
Although the disturbance on the ocean’s surface is slight, it is enough to create a ripple effect in the atmosphere. As the air is pushed upward, a sound wave travels to the ionosphere, about 186 miles from Earth, amplifying the scale as it travels. There, the density of electrons in the ionosphere is reduced by the waves, which directly affects the radio signal sent from the GPS satellite to the ground receiver. Researchers have developed an interpretation of changes in radio signals to gather important information about tsunamis.
Image credits: University of London
Currently, tsunami warnings are issued based on seismic activity. The warnings are not necessarily very precise, only suggesting a possible tsunami at some point in the near future, but providing very little other details.
“In 2011, Japan’s warning system underestimated [Tōhoku] wave height. A better warning could have saved many lives and reduced widespread destruction, allowing people to reach higher ground and further from the sea,” said Professor Serge Guillas of UCL Statistical Science and The Alan Turing Institute and senior author of the paper said in a press release. “Our study, a joint effort of statisticians and space scientists, demonstrates a new low-cost method of tsunami detection, as it is based on existing GPS networks and can be implemented worldwide, complementing other ways of detecting tsunamis and improving the accuracy of warning systems. ”
The researchers suspect that if GPS data had been used during the Tōhoku disaster, an accurate tsunami warning could have been issued at least 10 minutes before the wave made landfall, potentially for more people to prepare for the impact.
The team believes that with further studies, they will be able to more accurately determine the size and shape of the tsunami based on GPS radio signals.
“From my experience working for the Japanese government before and witnessing the damage caused by the tsunami, I believe that if this research comes to fruition, it will definitely contribute to saving lives,” said Dr. live many people”. Researcher Ryuichi Kanai of UCL Statistical Science and the Alan Turing Institute, who co-authored the paper.
Researchers’ Research has been published in the magazine Natural Hazards and Earth System Science last month.
