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California Quake Swarm Triggers ShakeAlert, 4.9 Near Crescent City

5/10/2026

50 3 Full Breakdown

Summary

Story summary

The U.S. Geological Survey issued a ShakeAlert warning Saturday as a swarm of quakes ended with a magnitude 4.5 tremor near Brawley, California.
On May 9, 2026 a magnitude 4.9 quake near Crescent City, California caused no injuries, had 30 felt reports, and followed a 3.5 quake at 4:15 p.m.
On May 8 a magnitude 4.8 quake near Crescent City was upgraded from 4.4, earned a Green Alert, and logged 35 felt reports.

History

Historical Context

On Jan 17 1994 a magnitude 6.7 quake struck the San Fernando Valley, the largest in Los Angeles since the 1971 San Fernando event, killing about 60 people and causing billions in damage. The United States Geological Survey studied the blind-thrust fault and later developed early-warning tools. Today, a swarm near Brawley and May 8-9 tremors near Crescent City echo Northridge’s clustered pattern, underscoring California’s reliance on USGS alerts.

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Story summary

The U.S. Geological Survey issued a ShakeAlert warning Saturday as a swarm of quakes ended with a magnitude 4.5 tremor near Brawley, California.
On May 9, 2026 a magnitude 4.9 quake near Crescent City, California caused no injuries, had 30 felt reports, and followed a 3.5 quake at 4:15 p.m.
On May 8 a magnitude 4.8 quake near Crescent City was upgraded from 4.4, earned a Green Alert, and logged 35 felt reports.

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