Signal

Seismic: What the ground recorded

Signal of the Twelve-Day War, June 2025

The most differentiating seismic finding is a null result. Neither the US GBU-57 strikes on Fordow (22 June) nor the Israeli strikes were large enough to enter the global seismic catalogs: a live query of both USGS and EMSC returns zero cataloged events at Fordow across the entire war. Conventional bombs, even 30,000-pound ones dropped in sequence, release orders of magnitude less energy than a small nuclear test, so only local Iranian stations saw them. The magnitudes circulating online conflate three different events, and seismology can time and size a blast but cannot see whether centrifuges were destroyed.

Seismologists and other earth scientists who can read catalogs like USGS and EMSC are also paid by AI labs to grade how models reason about the earth, and the AITraining.jobs page for earth and environmental scientists lists those roles, on a pay tracker under common ownership with Blackwing.

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The question
Did the bunker-busters register on seismographs, and can shaking reveal what happened inside the mountain?
Global catalogs are empty at Fordow
A live query of the USGS earthquake catalog for the Fordow box (34.4-35.4N, 50.4-51.5E) across 13-24 June returns zero events. The 22 June GBU-57 strikes did not register teleseismically.
EMSC confirms the same null
The independent European-Mediterranean network returns no cataloged event at Fordow either; its only nearby events in the window were natural M3.2 and M3.3 quakes 130-150 km away.
~1,500 small blast tremors, up to about M2
Mehdi Zare of Iran's Institute of Earthquake Engineering and Seismology said local stations recorded over 1,500 explosion-induced tremors during the 12 days; blasts near Fordow, Natanz and Isfahan reached only about magnitude 2.
The viral 'M4.3 bunker-buster' figure is unsupported
A widely-shared claim that stations recorded magnitude 4.3 from the strikes appears in no primary seismic catalog and is attributed to no named agency. Treat it as an unverified viral number.
The real M2.5 was an Israeli strike, days earlier
The magnitude-2.5 tremor near Qom that many outlets pinned on the US strike was reported by Iran's Seismological Center on 16 June, coinciding with Israeli airstrikes near Fordow, not the 22 June US strike.

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