Scientists discovered a new method for detecting tsunamis that could improve response times and alerts before the deadly natural walls of water hit the shore, a press statement reveals.
The new method detects tsunamis by the magnetic fields they generate when moving through the ocean's conductive water. These magnetic fields can be detected a few minutes before rising sea levels, giving a few potentially life-saving extra moments of response time.
The first real-world evidence of tsunami magnetic field detection
Researchers had previously predicted that tsunamis could be detected via magnetic fields, but they lacked the data to prove the hypothesis. Now, a team of researchers from the American Geophysical Union (AGU), outlined their new method using real-world data for the first time. They published their findings in a new paper in the Journal of Geophysical Research: Solid Earth.
The researchers used data from a 2009 tsunami in Samoa and a 2010 tsunami in Chile to show they could predict the height of tsunami waves using magnetic field detection. Their study proves that magnetic fields arrive ahead of the sea level change prior to a tsunami. Though results vary depending on water depth, they showed that with a depth of roughly 4,800 meters, a magnetic field could be detected approximately a minute before a change in sea levels.
"It is very exciting because in previous studies we didn’t have the observation [of] sea level change," said Zhiheng Lin, one of the study authors, from Kyoto University. "[Now] we have observations [of] sea-level change, and we find that the observation agrees with our magnetic data as well as theoretical simulation."
New methods could save many lives
To reach their results, the team looked at simultaneous measurements of sea-level change based on seafloor pressure data and magnetic field measurements during the tsunamis in Samoa and Chile. They found that the magnetic field during these tsunamis was so sensitive they allowed a wave height of even a few centimeters to be detected accurately.
The AGU team isn't the only one working to improve predictions of these catastrophic events. In February, Riken and Fujitsu announced that they were developing an AI tool for predicting tsunamis, using the world's fastest supercomputer, Fugaku. Such work can help to improve models for predicting tsunamis in the future that could potentially help to save thousands of lives. The 2011 Tohoku tsunami in Japan, for example, led to the death of 18,000 people, while the Boxing Day tsunami of 2004 had a death toll of approximately 230,000. More would likely have died if it were not for existing alert systems, but improvements to those systems could still save many more.