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Last Update: 2025-07-30T01:11:52.304Z
1. M8.7 Earthquake in Western Pacific, Tsunami Warning Issued
jandrewrogers | 46 points | 2 comments | read
Article Summary
  • A magnitude 8.7 earthquake struck east-southeast of Petropavlovsk-Kamchatsky, Russia, on July 29, 2025, at 23:24:50 UTC.
  • The earthquake occurred at a depth of 18.2 km and was the result of shallow reverse faulting on the subduction zone plate interface of the Kuril-Kamchatka Arc.
  • The Pacific plate is moving west-northwest relative to the North America plate at about 77 mm/year in this region.
  • Earthquakes of this size typically involve slip over a fault area approximately 130 km by 65 km.
  • The Kuril-Kamchatka arc is seismically active, with 31 other M6.5+ events within 250 km of this location in the past century.
  • A M7.4 earthquake on July 20, 2025, is now considered a foreshock to this event.
  • The epicenter is 45 km southeast of the 1952 M9.0 Kamchatka earthquake, which caused a destructive Pacific-wide tsunami.
  • Tsunami warnings were issued, with advisories available at https://www.tsunami.gov/.
  • Impact summaries, technical details, and ground failure estimates (landslide, liquefaction) are available on the USGS event page.
  • The event has been reviewed and confirmed by the USGS National Earthquake Information Center.
Common Themes
Significance and Rarity of the Earthquake

That is _really_ big. It will likely crack the top 8 ever recorded. https://en.wikipedia.org/wiki/Lists_of_earthquakes

yinser | source

That area of Russia has seen quite a bit of massive seismic activity over the last couple of weeks. I keep getting earthquake alerts about each one.

bicx | source
Tsunami Warning and Regional Impact

Quick link to the tsunami view: https://www.tsunami.gov/ Just 'watch' level for US west coast, but warning level for Hawaii

andsoitis | source

Prompt to Gemini 2.5 pro: A new 8.7 earthquake off russia was just announced 30 minutes ago. How does this compare to fukushima in terms of expected impact by the time it hits japan? > A powerful 8.7 magnitude earthquake struck off the coast of Russia's Kamchatka Peninsula on Wednesday morning, prompting tsunami warnings and evacuations in Japan.[1][2] While the seismic event is significant, initial forecasts suggest its impact on Japan will be considerably less severe than the devastating 2011 Tōhoku earthquake and tsunami that led to the Fukushima nuclear disaster. > The 2011 Tōhoku earthquake, which registered a magnitude of 9.0 to 9.1, was one of the most powerful seismic events ever recorded. I'm continued to be impressed.

irjustin | source