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4.0 Magnitude Quake Hits Gilroy Amid Ongoing Swarm

11/28/2025

26 3 Full Breakdown

Summary

Story summary

A 4.0 magnitude earthquake struck near Gilroy at 6:00 a.m. on November 26.
The event was preceded by 2.5 magnitude quake near Pinnacles on November 24 and 2.4 near Johannesburg on November 25.
Since November 9, San Ramon has recorded more than 90 small earthquakes, the largest reaching magnitude 3.8.
Experts say these swarms may result from fluid interactions with fault lines.
No significant damage or injuries have been reported.

History

Historical Context

The 1906 San Francisco earthquake struck on April 18, measuring 7.9 in magnitude and resulting in over 3,000 fatalities. The disaster destroyed more than 80% of the city, primarily due to subsequent fires, and left 227,000 to 300,000 people homeless. This event reshaped California's urban landscape, diverting growth from San Francisco to Los Angeles and highlighting the region's seismic vulnerabilities.

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Story summary

A 4.0 magnitude earthquake struck near Gilroy at 6:00 a.m. on November 26.
The event was preceded by 2.5 magnitude quake near Pinnacles on November 24 and 2.4 near Johannesburg on November 25.
Since November 9, San Ramon has recorded more than 90 small earthquakes, the largest reaching magnitude 3.8.
Experts say these swarms may result from fluid interactions with fault lines.
No significant damage or injuries have been reported.

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