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Kamchatka earthquake and Japan alert error

Updated 14 times since CLSTR started tracking revisions of this situation.

What changed

2026-10-20 23:22 UTC → 2026-10-21 09:48 UTC · added removed

A magnitude 6.9 to 7.0 earthquake struck the Kamchatka Peninsula in eastern Russia on October 16, 2026. The epicenter was located on land, approximately 76 kilometers northeast of Ozernovskiy between the Opala and Ksudach volcanoes, at a depth of 130 to 152 kilometers. In Petropavlovsk-Kamchatsky, residents reported tremors with an intensity of up to five points in some areas, causing objects to fall and light fixtures to swing, leading some to evacuate homes as a precaution. No immediate casualties, significant structural damage, or tsunami threats were reported by agencies such as the US National Tsunami Warning Center or NOAA. The seismic event triggered a major error by the Japan Meteorological Agency (JMA), which issued an unprecedented emergency earthquake warning erroneously predicting a magnitude 9.9 event near the Kuril Islands. A magnitude 9.9 event This figure would have exceeded the 1960 Valdivia earthquake, the strongest earthquake ever recorded in history. recorded. The alert caused widespread alarm across Japan, spanning regions from Hokkaido to the Tokai area, and triggered triggering automatic safety protocols, including the temporary suspension of Shinkansen high-speed rail services and local tram services in Sapporo. The warning also activated emergency notifications on millions of mobile phones and public loudspeaker systems. Approximately eight minutes after Following the initial alert, retraction of the alert, JMA retracted the warning, marking Director Ryuichi Nomura issued a formal apology, attributing the first time an official error to technical failures in earthquake ‘alert’ (keihou) has been formally withdrawn. JMA officials, including Ayataka Ebita and Shinya Tsukada, apologized for the “significant anxiety scale and inconvenience” caused. intensity prediction methods. Investigations revealed confirmed the error resulted from a software processing anomaly where a domestic magnitude formula was applied to a data from distant earthquake. Specifically, a function designed to exclude observation points located more than 700km from the epicenter failed to operate correctly, causing were improperly integrated into the system automated calculation process. The agency is currently investigating why these points were included to assume the quake was roughly 680km further from Japan than it actually was. prevent a recurrence.

Versions

  1. 2026-10-21 09:48 UTC Kamchatka earthquake and Japan alert error
  2. 2026-10-20 23:22 UTC Kamchatka earthquake and Japan alert error
  3. 2026-10-18 09:51 UTC Kamchatka earthquake and Japan alert error
  4. 2026-10-17 18:00 UTC Kamchatka earthquake and Japan alert error
  5. 2026-10-17 06:59 UTC Kamchatka earthquake and Japan alert error
  6. 2026-10-17 05:03 UTC Kamchatka earthquake and Japan alert error
  7. 2026-10-17 04:39 UTC Kamchatka earthquake and Japan alert error
  8. 2026-10-17 00:02 UTC Kamchatka earthquake and Japan alert error
  9. 2026-10-17 00:00 UTC Kamchatka earthquake and Japan alert error
  10. 2026-10-16 17:38 UTC Kamchatka earthquake and Japan alert error
  11. 2026-10-16 16:10 UTC Kamchatka earthquake and Japan alert error
  12. 2026-10-16 13:33 UTC Kamchatka earthquake and Japan alert error
  13. 2026-10-16 13:31 UTC Kamchatka earthquake and Japan alert error
  14. 2026-10-16 13:08 UTC Kamchatka Peninsula earthquake and Japan alert error
  15. 2026-10-16 13:08 UTC Kamchatka Peninsula earthquake and JMA alert error

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