M5.8 Earthquake 7 km NNE of Tonalá, Mexico — August 9, 2023
2023-08-09 09:33:26 UTC (2023-08-09) · approx. 3:33 AM UTC-6 local
Felt by 31 people across nearby locations. Maximum shaking intensity MMI 4.4 (moderate).
On August 9, 2023 at 09:33 UTC, a magnitude 5.8 intermediate depth earthquake struck 7 km NNE of Tonalá, Mexico, at a depth of 103.0 km and coordinates 16.1516°, -93.7276°. The earthquake was reported felt by 31 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.4 (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 226 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 533, placing it among routine seismic activity. The nearest populated place is Julian Grajales (population 1,293).
Physical scale: An earthquake of magnitude 5.8 releases seismic energy equivalent to roughly 8 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 6.1 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Mexico, a region characterized by the Middle America Trench, where the Cocos Plate subducts beneath the North American Plate. The nearest mapped fault system is the Middle America Trench. View all earthquakes in Mexico.
Learn more: 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 31 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 | 2,675,509 |
| MMI 4 | light | 6,047,968 |
Earthquake Details
-93.7276°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.8 earthquake near Tonalá, Mexico?
The magnitude 5.8 earthquake that struck 7 km NNE of Tonalá, Mexico on August 9, 2023 at 09:33 UTC had a depth of 103.0 km. It was felt by 31 people with maximum shaking intensity of MMI 4.4 (moderate). For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 16.1516°, -93.7276°, which is 7 km NNE of Tonalá, Mexico. The nearest populated place is Julian Grajales (population 1,293). View all earthquakes in Mexico.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.8 earthquakes can continue for days to weeks and gradually diminish over time.
Has Mexico had earthquakes this big before?
The largest recorded earthquake in Mexico was the M8.1 Chiapas earthquake of September 8, 2017. Today's magnitude 5.8 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000kyty). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, August 9, 2023). M5.8 Earthquake 7 km NNE of Tonalá, Mexico — August 9, 2023. Retrieved October 17, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000kyty/