Strategic Risk Brief
General awareness · Preliminary risk assessment
Source reports and assessments may change as evidence develops. Consult the linked agencies for official information.
2026-11-07 · Revision 1
Evidence cutoff ·
Overall risk assessment · Not assessed.
USGS and JMA reported a magnitude 6.1 earthquake offshore east of Japan’s Kanto region at about 10:39 UTC on 6 November 2026.
Change since previous
This scoped edition concerns a different event from the fire-weather draft and has no comparable previous assessment.
Magnitude 6.1 earthquake off eastern Honshu
Source report
USGS and JMA reported a magnitude 6.1 earthquake offshore east of Japan’s Kanto region at about 10:39 UTC on 6 November 2026.
Preliminary assessment
The two agency products establish a specific event for monitoring any later revisions and documented regional effects.
Confidence · medium. Time horizon · The event and immediate reporting window on 6–7 November 2026..
Uncertainty and contrary evidence
USGS reports 29 km hypocentral depth. The JMA event summary gives about 10 km. Exact depth and station-level independence remain uncertain.
The agency depth estimates differ. The reopened products agree on the occurrence, approximate time and location, and reported magnitude.
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Scope and coverage
One earthquake offshore east of Japan’s Kanto region and the immediate event reporting window.
- Environment and natural hazards · limited assessment
Scope is limited to the occurrence and reported magnitude of this earthquake.
- Governance and geopolitics · not assessed
This topic or regional implication was outside the assessment scope.
- Public health · not assessed
This topic or regional implication was outside the assessment scope.
- Infrastructure and supply chains · not assessed
This topic or regional implication was outside the assessment scope.
- Cybersecurity and AI · not assessed
This topic or regional implication was outside the assessment scope.
- California and Ventura relevance · not assessed
This topic or regional implication was outside the assessment scope.
Watch next
- Check for agency revisions to magnitude, origin or depth if preparing a later edition.
Blind spots
- Shaking impacts, tsunami effects, aftershocks, broader risk and California relevance remain unassessed.