On Friday Evening a Shallow M4.0 Earthquake struck near San Ramon in The United States.

Written by Earthquakelist.org on December 20th, 2025. Last updated January 7th, 2026.

In the evening of Friday December 19th, 2025, a shallow MAG-4.0 earthquake hit under land 3 miles from San Ramon in The United States. The earthquake struck near a very densely populated region.

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Earthquake Summary

The earthquake struck on land in The United States, 3 miles (5 km) south-southeast of San Ramon in California. The center of this earthquake had a very shallow depth of 6 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Dec 19, 2025 07:56PM (Los Angeles Time) - Dec 20, 2025 03:56 Universal Time.
Location:	3 mi SSE of San Ramon, California, The United States. Coordinates 37°44'37"N 121°57'11"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 4.0 Detected by 67 stations. Maximum Error Range ±0.038 .
Depth:	6 mi (10 km) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Tsunami very unlikely While this was a shallow earthquake in a coastal area, it appears to have occurred under land (12 mi from the sea) with a magnitude that is usually not strong enough to cause tsunami's. Always stay cautious - More info here.

Nearby towns and cities

This earthquake may have been felt in The United States . San Ramon in California, The United States is the nearest significant place from the epicenter. The earthquake occurred 3 miles (5 km) south-southeast of San Ramon. The intensity of shaking and damage in San Ramon is estimated to be around level IV on the Modified Mercalli Intensity scale (light shaking, likely no damage).

Multiple major population centers exist within 300km of the earthquake that struck today. San Jose is located 28 mi to the south and experienced an intensity of II (very weak shaking, no damage). San Francisco is located 25 mi to the west and experienced an intensity of II (very weak shaking, no damage). Oakland is located 18 mi to the west-northwest and experienced an intensity of II (very weak shaking, no damage).

An overview of nearby towns and cities is available in the overview below. If places don't have intensity data available, it likely means the experienced impact in those places was fairly small.

Overview of nearby places

Earthquake Intensity Map

The intensity in shaking and damage by this earthquake is illustrated through the map below. The highest intensity measured for this earthquake is IV.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

6 Aftershocks detected

Since this main shock, 6 smaller aftershocks were detected. A 3.9 magnitude earthquake hit 23 hrs later 0.5 mi (0.8 km) east-northeast of this earthquake.

Before this earthquake struck, 2 smaller foreshocks occurred. A 3.8 magnitude earthquake hit 7 mins earlier nearby.

Overview of foreshocks and aftershocks

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

It's always adviced to be cautious of the risk of a larger shock following any significant earthquake, however this risk is fairly small. There is a roughly 94 percent change that no larger main shock will follow in the days following this earthquake.

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since December 14th, 2025, when a 4 magnitude earthquake hit 56 mi (90 km) further northwest. An even stronger magnitude 6 earthquake struck on July 8th, 2021.

In total, 115 earthquakes with a magnitude of 4 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every month.

Tsunami very unlikely

While MAG-6.5+ earthquakes may cause tsunami's, it appears that the epicenter of this earthquake hit under land. In addition, the reported depth is deeper than 100km, making the risk of a tsunami even less likely. However always stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Sources

Last updated 07/01/26 02:08 (). This article is automatically generated based on available data. We keep checking multiple sources for additional information. This article gets updated as new details on this earthquake become available.

1. US Geographic Society (USGS): Earthquake nc75283031
2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20251220_0000040
3. Geonames.org: World Cities Database
4. Google Maps: Static API
5. Earthquakelist.org: Historic Earthquakes Database

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