An 8.8-magnitude earthquake — one of the strongest ever recorded — struck off the coast of Russia’s Kamchatka Peninsula late Tuesday, shaking the region for minutes, damaging infrastructure, and triggering a Pacific-wide tsunami alert.
The quake, occurring at a shallow depth of about 12.5 miles where the Pacific Plate subducts beneath the North American Plate, caused part of the seafloor to thrust upward — the mechanism that generates tsunamis. Waves locally exceeded 15 feet, and experts believe some remote stretches of Kamchatka’s southern coast may have seen waves as high as 50 feet, according to Alexander Rabinovich of the International Tsunami Commission.
But across the broader Pacific, the tsunami impact was milder than feared. Japan recorded 1–3-foot waves, Hawaii saw 5–6 feet, and most of California experienced about a foot of increased wave height, though Crescent City, notorious for amplifying incoming waves due to its shelf shape, saw nearly 4 feet.
Why weren’t the waves larger? That’s the puzzle seismologists are now working to solve. Viacheslav Gusiakov of the Russian Academy of Sciences suggested one key factor: the absence of a major submarine landslide, which can supercharge tsunami energy by up to 90%.
U.S. Geological Survey modeling also shows the earthquake caused 20–30 feet of slip along a roughly 300-mile stretch of fault — far less than the 150 feet of slip seen in the 2011 Tohoku quake that devastated Japan and sent 100-foot waves crashing ashore.
“Earthquakes have a personality,” said Diego Melgar, director of the Cascadia Region Earthquake Science Center. “Those kinds of details really affect the tsunami.”
This event also marks a success for modern warning systems. Tsunami alerts from Russia’s Kamchatka and Sakhalin centers were issued promptly, giving Hawaii, Japan, and the U.S. West Coast hours to prepare. Evacuations were ordered, boats were moved from harbors, and no tsunami-related deaths have been reported so far.
Still, the earthquake’s full toll remains unclear. Damage surveys are just beginning in Kamchatka’s sparsely populated coastal areas, where access is difficult. “It’s too early to say there wasn’t major damage locally,” Melgar cautioned.
The quake’s size and the successful warning response will likely be studied for years. As Tina Dura, a Virginia Tech tsunami researcher, noted: “It definitely created a Pacific-wide tsunami… but it’s a little bit smaller than could be possible in that magnitude of earthquake.”
