← Evidence Library

Government or official record

USGS Response to an Urban Earthquake—Northridge '94

U.S. Geological Survey

Cross-File evidence ledger

Where this source supports the record

Each entry separates the File’s editorial relevance note from its exact, section-level claims. A bibliography link without a direct claim is labeled plainly.

  1. Natural disasters · 17 January 1994

    The 1994 Northridge Earthquake

    USGS epicenter beneath the San Fernando Valley · United States

    Open File evidence →
    Why editors use it here

    Technical synthesis of the blind-fault rupture, strong shaking, structural surprises, and implications for codes and preparedness.

    1. Quick read

      At 4:30 a.m.

      Reviewed 24 July 2026
    2. Trigger and conditions

      Reverse slip occurred about eighteen kilometers below the valley and lifted a broad area above the buried fault.

      Reviewed 24 July 2026
    3. Uncertainty

      Official death totals vary because sources apply different medical and temporal attribution rules: USGS pages give figures including 33 direct deaths, 57 broadly attributed deaths, and 60 deaths in the event catalog; FEMA has used still higher counts.

      Reviewed 24 July 2026
    4. Why it matters

      Northridge showed that modern codes reduce risk without eliminating it and that concealed faults can sit beneath a metropolis.

      Reviewed 24 July 2026