3.0

M3.0 Earthquake 7 km SSE of Houston, Alaska — November 27, 2020

2020-11-27 17:54:27 UTC (2020-11-27) · approx. 7:54 AM UTC-10 local

Felt by 14 people across nearby locations.

MagnitudeM3.0(ml)
Time17:54 UTC≈ 7:54 AM UTC-10
Depth39.9 kmshallow crustal
Coordinates61.565°, -149.785°
Felt by14DYFI responses· max MMI 2.3
Status✓ Reviewed by USGS

On November 27, 2020 at 17:54 UTC, a magnitude 3.0 shallow crustal earthquake struck 7 km SSE of Houston, Alaska, at a depth of 39.9 km and coordinates 61.5649°, -149.7845°. The earthquake was reported felt by 14 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.3 (weak).

Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.

Learn more: Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 61.56°, -149.78°

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.

USGS ShakeMap intensity contours for the M3.0 earthquake near 7 km SSE of Houston, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 14 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M3.0 earthquake near 7 km SSE of Houston, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
3.0 ml
Depth
39.9 km
shallow crustal
Location
61.5649°N
-149.7845°E
Felt Reports
14
DYFI responses
Intensity (MMI)
2.3
weak
Community Intensity
2.9
CDI from reports

Technical Information

Event ID
ak020f9cv7yh
Event Type
earthquake
Status
✓ Reviewed
Significance
143
RMS Residual
0.70 sec
Last Updated
2021-02-06 18:28:39 UTC

Common Questions

How strong was the magnitude 3.0 earthquake near Houston, Alaska?

The magnitude 3.0 earthquake that struck 7 km SSE of Houston, Alaska on November 27, 2020 at 17:54 UTC had a depth of 39.9 km. It was felt by 14 people with maximum shaking intensity of MMI 2.3 (weak). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 61.5649°, -149.7845°, which is 7 km SSE of Houston, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.0 earthquakes can continue for several days and gradually diminish over time.

Has Alaska had earthquakes this big before?

The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 3.0 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: ak020f9cv7yh). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, November 27, 2020). M3.0 Earthquake 7 km SSE of Houston, Alaska — November 27, 2020. Retrieved February 6, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak020f9cv7yh/