M6.4 Earthquake near Gulf of California — June 18, 2023
2023-06-18 20:30:21 UTC (2023-06-18) · approx. 1:30 PM UTC-7 local
Felt by 27 people across nearby locations. Maximum shaking intensity MMI 4.7 (moderate).
On June 18, 2023 at 20:30 UTC, a magnitude 6.4 shallow crustal earthquake struck near Gulf of California, at a depth of 4.0 km and coordinates 23.1671°, -108.6922°. The earthquake was reported felt by 27 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.7 (moderate). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 101 seismic stations with good location accuracy and was assigned a USGS significance rating of 639, making it a moderate-impact event. The nearest populated place is San Jose del Cabo (population 48,518).
Physical scale: An earthquake of magnitude 6.4 releases seismic energy equivalent to roughly 60 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 16 km — 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
Nearest Populated Places
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 27 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 117,028 |
| MMI 4 | light | 1,764,946 |
| MMI 5 | moderate | 44 |
Earthquake Details
-108.6922°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 6.4 earthquake near Gulf of California?
The magnitude 6.4 earthquake that struck near Gulf of California on June 18, 2023 at 20:30 UTC had a depth of 4.0 km. It was felt by 27 people with maximum shaking intensity of MMI 4.7 (moderate). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at 23.1671°, -108.6922°, which is near Gulf of California. The nearest populated place is San Jose del Cabo (population 48,518). View all earthquakes in California.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.4 earthquakes can continue for weeks to months 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 6.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000k9f0). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, June 18, 2023). M6.4 Earthquake near Gulf of California — June 18, 2023. Retrieved August 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000k9f0/