Key Facts
• At 8:25 AM JST on July 30, 2025, an M8.7 earthquake struck near Kamchatka Peninsula.
• Initial magnitude was M8.0 but later revised to M8.7 by Japan and M8.8 by USGS.
• The earthquake occurred at a depth of approximately 21 km, triggering a tsunami.
• Tsunami warnings issued for Japan’s Pacific coast, from Hokkaido to Kii Peninsula.
• First tsunami wave reached Nemuro, Hokkaido, at 10:17 AM JST.
• Tsunami observed in Kushiro, Miyako, and Choshi, with ongoing monitoring.
• This is the first earthquake above M8.5 since 2012, marking a 13-year gap.
• The earthquake was a reverse fault type caused by the Pacific Plate subducting under the North American Plate.
• Historical context: A similar M9.0 earthquake in 1952 caused widespread tsunamis in Japan.
• Tsunami warnings extend globally, with Hawaii expecting waves of 1–3 meters.
• Residents are advised to avoid coasts and river mouths until warnings are lifted.
Summary
A massive M8.7 earthquake struck near the Kamchatka Peninsula on July 30, 2025, at 8:25 AM JST. Initially reported as M8.0, it was later revised to M8.7 by Japan and M8.8 by USGS. The shallow depth of 21 km triggered a tsunami, prompting warnings across Japan’s Pacific coast, from Hokkaido to Kii Peninsula. The first wave reached Nemuro, Hokkaido, at 10:17 AM JST, with subsequent waves observed in other regions. This marks the first earthquake above M8.5 since 2012. The earthquake, caused by the Pacific Plate subducting under the North American Plate, is a plate-boundary type. Historical parallels include a 1952 M9.0 earthquake in the same region, which caused significant tsunamis. Global tsunami warnings have been issued, with Hawaii expecting waves of 1–3 meters. Residents are urged to stay away from coasts and river mouths until warnings are lifted.
