The coastline of Shiogama, Japan as a tsunami warning had been issued after a huge earthquake
Asahi Shimbun via Getty Images
Millions of people were safely evacuated due to tsunami warnings rapidly issued after a powerful earthquake rumbled off the coast of Russia’s Kamchatka peninsula on 29 July. Though the quake didn’t end up generating waves as large as expected, the speed and scale of the warnings shows the progress tsunami science has made since major tsunamis in 2004 and 2011 killed tens of thousands of people.
“I think it’s a great achievement based on the lessons learned from the past,” says Ravindra Jayaratne at the University of East London, UK.
The improved warnings are largely thanks to an expanded network of sensors monitoring for tsunami hazards. These include seismometers that measure shaking generated by earthquakes, as well as a network of buoys operated by the US National Oceanic and Atmospheric Administration that measure wave height and quickly relay information to satellites. Advances in modelling now enable researchers in tsunami warning offices to use this information to rapidly project where and when the waves will reach shore, and issue alerts.
On 29 July, this system allowed tsunami offices around the Pacific to issue warnings almost immediately after the magnitude-8.8 quake was detected in Russia, one of the strongest on record. In nearby Japan, almost two million people were evacuated from coastal areas. Others were evacuated in Hawai’i, states on the US West Coast and as far south as Chile.
“The reaction was immediate and it was good,” says David Tappin at the British Geological Survey. However, he points out despite the magnitude of the earthquake, it didn’t ultimately generate very large waves or flooding. This suggests there is still room for improvement to more precisely forecast flooding based on early detections of shaking and wave height, he says.
Jayaratne adds some parts of the world vulnerable to tsunamis, such as Bangladesh and Sri Lanka, still lack both adequate warning systems and sufficient public awareness of the dangers. “The past shows that high-tech detection tools are effective only when paired with strong public communication and evacuation planning,” he says. “Coastal areas must run mock drills, maintain public awareness, and ensure alerts reach the most vulnerable via multiple channels.”
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