3.5

M3.5 Earthquake 2km ENE of Lopez Point, CA — October 14, 2020

2020-10-14 21:42:41 UTC (2020-10-14) · approx. 1:42 PM UTC-8 local

Felt by 10 people across nearby locations. Maximum shaking intensity MMI 4.7 (moderate).

MagnitudeM3.5(ml)
Time21:42 UTC≈ 1:42 PM UTC-8
Depth8.7 kmshallow crustal
Coordinates36.026°, -121.544°
Felt by10DYFI responses· max MMI 4.7
Status✓ Reviewed by USGS

On October 14, 2020 at 21:42 UTC, a magnitude 3.5 shallow crustal earthquake struck 2km ENE of Lopez Point, CA, at a depth of 8.7 km and coordinates 36.0263°, -121.5443°. The earthquake was reported felt by 10 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.7 (moderate). This earthquake was detected by 108 seismic stations with good location accuracy and was assigned a USGS significance rating of 189, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 149 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in California, a region characterized by the San Andreas transform fault system, where the Pacific and North American plates slide past each other at roughly 46 mm per year. The nearest mapped fault system is the San Andreas Fault. View all earthquakes in California.

Learn more: San Andreas Fault · Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 36.03°, -121.54°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.5 earthquake near 2km ENE of Lopez Point, CA

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 10 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M3.5 earthquake near 2km ENE of Lopez Point, CA

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
3.5 ml
Depth
8.7 km
shallow crustal
Location
36.0263°N
-121.5443°E
Felt Reports
10
DYFI responses
Intensity (MMI)
4.7
moderate
Community Intensity
3.8
CDI from reports

Technical Information

Event ID
nc73470856
Event Type
earthquake
Status
✓ Reviewed
Significance
189
Stations Used
108
Azimuthal Gap
177.0°
Min Station Distance
0.174°
RMS Residual
0.13 sec
Last Updated
2020-12-29 23:07:21 UTC

Common Questions

How strong was the magnitude 3.5 earthquake near Lopez Point, CA?

The magnitude 3.5 earthquake that struck 2km ENE of Lopez Point, CA on October 14, 2020 at 21:42 UTC had a depth of 8.7 km. It was felt by 10 people with maximum shaking intensity of MMI 4.7 (moderate). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 36.0263°, -121.5443°, which is 2km ENE of Lopez Point, CA. View all earthquakes in California.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.5 earthquakes can continue for several days and gradually diminish over time.

Has California had earthquakes this big before?

The largest recorded earthquake in California was the M7.9 Fort Tejon earthquake of January 9, 1857. Today's magnitude 3.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: nc73470856). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, October 14, 2020). M3.5 Earthquake 2km ENE of Lopez Point, CA — October 14, 2020. Retrieved December 29, 2020 from https://www.earthquaketracker.org/earthquakes/event/nc73470856/