Significant earthquakes of 1861

July 4, 1861 Earthquake: Contra Costa,alameda Counties, California, United States

July 4, 1861

An earthquake struck Contra Costa,alameda Counties, California, United States on July 4, 1861 at 00:11:00 UTC.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date
July 4, 1861
Time
00:11:00 UTC
Place
Contra Costa,alameda Counties, California, United States
Intensity
11 on the Modified Mercalli scale
Tsunami
None recorded
Epicenter
37.500° N, 122.000° W

The toll

Damage
Severe (about $5 to $25 million)

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

Other significant earthquakes nearby

Within 200 km, the deadliest first.

More

Significant earthquakes of 1861The 1800sRecent earthquakes near hereThis day in weather history

Sources

Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI earthquake 2051.