⊕earthquakeactive
M4.0 Earthquake — 72 km SSW of Atka, Alaska
M4.0
51.6020° N, 174.6250° W·US-AK
Started 5d agoEvent Details
Typeearthquake
SeverityM4.0
Statusactive
Location51.6020°N, 174.6250°W (US-AK)
Started2026-07-20T14:37:50.629+00:00
Last Updated2026-07-21T14:38:15.602+00:00
Sourceusgs
Source URLearthquake.usgs.gov
Confidence1.00
Impact Zones
Catastrophic Impact Zone
Severe structural damage expected. Immediate danger to life.
Severe Impact Zone
Significant structural damage possible. Exercise extreme caution.
Moderate Impact Zone
Light to moderate damage. Check structures for damage.
Affected Zone
Shaking felt. Minor damage possible in vulnerable structures.
Zone estimates are based on scientific models and may differ from actual local conditions.
Impact Analysis
Population Exposed157
Structures in Zone60
Population from ACS 5-Year 2022 tract sampling; structure counts from Microsoft Building Footprints or Census ACS housing data, capped by USGS NLCD 2021 developed land. Estimates for situational awareness — not for actuarial, regulatory, or underwriting use.
Historical Comparison
No historical analogs available yet.
Related
Zone estimates are based on scientific models and may differ from actual local conditions.