M5.5 Earthquake near Southern Qinghai, China — May 21, 2021
2021-05-21 18:12:15 UTC (2021-05-21) · approx. 1:12 AM UTC+7 local
Maximum shaking intensity MMI 6.8 (very strong).
On May 21, 2021 at 18:12 UTC, a magnitude 5.5 shallow crustal earthquake struck near Southern Qinghai, China, at a depth of 10.0 km and coordinates 34.6170°, 98.4674°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Huanghe (population 0).
Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 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
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 | 617,852 |
| MMI 4 | light | 38,327 |
| MMI 5 | moderate | 634 |
| MMI 6 | strong | 248 |
Earthquake Details
98.4674°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.5 earthquake near Southern Qinghai, China?
The magnitude 5.5 earthquake that struck near Southern Qinghai, China on May 21, 2021 at 18:12 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 34.6170°, 98.4674°, which is near Southern Qinghai, China. The nearest populated place is Huanghe (population 0).
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.
Actions
Location
Authoritative source: USGS event page (event ID: us6000ef48). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, May 21, 2021). M5.5 Earthquake near Southern Qinghai, China — May 21, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000ef48/