M4.3 earthquake 3 km NE of Northglenn, Colorado
A magnitude 4.3 earthquake struck 3 km NE of Northglenn, Colorado on Thu, Apr 2, 1981, 9:10 AM MST (16:10 UTC), 8 km (5 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.3 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1981-04-02 16:10:06 UTC
- Depth
- 8.0 km (5.0 mi), shallow
- Epicenter
- 39.910° N, 104.964° W
- Region
- Colorado
- Strongest shaking
- V, moderate shaking
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 4.3 | mb, body-wave | USGS National Earthquake Information Center | Preferred · Reviewed · 1 stations |
| 4.3 | mb, body-wave | USGS historic United States catalog | Final |
What happened
The USGS’s account of the effects of this earthquake.
SLIGHT DAMAGE (VI) AT COMMERCE CITY AND THORNTON. FELT IN ADAMS, ARAPAHOE, BOULDER, CLEAR CREEK, DENVER, DOUGLAS, JEFFERSON, GILPIN, AND WELD COUNTIES.
Maximum observed Modified Mercalli Intensity (MMI) VI
From the USGS event page for usp0001d00. U.S. Geological Survey text and figures are in the public domain.
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- V, moderate shaking
- Peak ground acceleration
- 21.5% of gravity
- Peak ground velocity
- 1.3 cm/s
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 0 in the 60 days after this one and 1 in the 30 days before it.
Before
Earthquakes todayColorado earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0001d00 (also filed as ushis3711). Read Thu, Oct 1, 2026, 11:44 AM UTC.