M5.4 Earthquake 52 km SE of Neijiang, China — September 15, 2021
2021-09-15 20:33:31 UTC (2021-09-15) · approx. 3:33 AM UTC+7 local
Felt by 25 people across nearby locations. Maximum shaking intensity MMI 7.4 (severe).
On September 15, 2021 at 20:33 UTC, a magnitude 5.4 shallow crustal earthquake struck 52 km SE of Neijiang, China, at a depth of 7.1 km and coordinates 29.1944°, 105.3650°. The earthquake was reported felt by 25 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 7.4 (severe). The USGS PAGER system issued a red alert level for this event, indicating widespread severe impact likely. The nearest populated place is Fuji (population 0).
Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 km — a useful intuition for the size of the slip patch on the fault.
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 25 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 | 13,459,846 |
| MMI 4 | light | 82,972,200 |
| MMI 5 | moderate | 4,341,035 |
| MMI 6 | strong | 709,464 |
| MMI 7 | very strong | 210,672 |
Earthquake Details
105.3650°E
Technical Information
Common Questions
How strong was the magnitude 5.4 earthquake near Neijiang, China?
The magnitude 5.4 earthquake that struck 52 km SE of Neijiang, China on September 15, 2021 at 20:33 UTC had a depth of 7.1 km. It was felt by 25 people with maximum shaking intensity of MMI 7.4 (severe). For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 29.1944°, 105.3650°, which is 52 km SE of Neijiang, China. The nearest populated place is Fuji (population 0).
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.4 earthquakes can continue for days to weeks and gradually diminish over time.
Actions
Location
Authoritative source: USGS event page (event ID: us7000fbky). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 15, 2021). M5.4 Earthquake 52 km SE of Neijiang, China — September 15, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000fbky/