Powerful 8.7 earthquake off Kamchatka triggers tsunami alerts across Pacific coastlines

One of the strongest earthquakes in recent memory hit off Russia's far eastern Kamchatka Peninsula early Wednesday morning. The quake was initially measured at magnitude 8.0 but later upgraded to 8.7 by the US Geological Survey. It struck at a shallow depth of 19.3 km, around 125 km southeast of Petropavlovsk-Kamchatsky, a city with a population of around 165,000 along the Avacha Bay coastline.

"Today's earthquake was serious and the strongest in decades of tremors," said Kamchatka Governor Vladimir Solodov in a statement posted on Telegram. He added, "According to preliminary information there were no injuries, but a kindergarten was damaged."

The Russian Ministry for Emergency Situations confirmed that tsunami waves measuring 3 to 4 metres had been recorded in parts of the Kamchatka region following the quake.

Earthquake today: Tsunami alerts and evacuations follow

Authorities in the Sakhalin region swiftly ordered the evacuation of residents in the small town of Severo-Kurilsk. Governor Valery Limarenko confirmed the decision via Telegram after the tsunami threat became clear. Emergency services in Kamchatka also issued statements warning that waves of up to 32 cm could hit the region’s eastern coast.

In Japan, the Meteorological Agency issued a tsunami advisory after the earthquake struck. It warned of waves reaching up to 1 metre on its Pacific coastline. The agency said the quake had occurred at 8:25 a.m. local time and estimated the magnitude at 8.0.

Despite the size of the tremor, Japan's NHK reported it was only mildly felt in Hokkaido, the country's northernmost major island, about 250 kilometres away from the epicentre. No damage had been reported in Japan at the time of publishing.

Tsunami warnings expand across the Pacific basin

The US Tsunami Warning System issued an alert just hours after the quake, warning of "hazardous tsunami waves" expected along some parts of the Russian and Japanese coastlines. The alerts didn’t stop there. Watches and warnings were issued for Guam, Micronesia, and the US West Coast.

The US National Tsunami Warning Center in Alaska placed parts of the Aleutian Islands under immediate warning. Other alerts covered coastal areas in California, Oregon, Washington, and Hawaii. A tsunami watch extended to the broader Pacific region, including Alaska’s southern panhandle.

According to the US Tsunami Warning System:

• South Korea, North Korea, and Taiwan may see wave heights below 0.3 metres
• The Philippines, Marshall Islands, Palau, Kosrae, and Chuuk may experience waves between 0.3 and 1 metre
• Guam, Hawaii, and parts of Japan may see waves ranging from 1 to 3 metres
• Northwestern Hawaiian Islands and sections of the Russian coastline may face waves exceeding 3 metres

Experts caution on shallow epicentres

Shinichi Sakai, a seismologist at the University of Tokyo, told NHK that such quakes can cause dangerous tsunamis even at long distances if the epicentre is shallow. He noted, "A distant earthquake can still cause a tsunami here if it’s shallow and powerful enough."

Japan, like Kamchatka, lies on the Pacific Ring of Fire, a highly active seismic zone known for producing frequent and powerful earthquakes. The region constantly faces the risk of tsunamis due to its tectonic setting.

A volatile region with history

This isn’t the first time Kamchatka has felt the impact of major seismic activity. Earlier in July, five significant earthquakes struck near the peninsula, the strongest registering at magnitude 7.4. That quake occurred 144 km east of Petropavlovsk-Kamchatsky at a depth of 20 km.

Going further back, on 4 November 1952, a magnitude 9.0 earthquake off Kamchatka caused large-scale tremors and sent 9.1-metre waves crashing into Hawaii. Remarkably, no fatalities were reported despite the scale of destruction.

Wednesday's quake has again brought global attention to the volatility of the Pacific Rim. While no casualties have been confirmed so far, the scale of the tremor and the extent of tsunami alerts reflect the serious potential risks for countries and territories across the region.

Emergency response teams remain on standby, and monitoring continues.