2.9

M2.9 Earthquake 1 km WSW of Onalaska, Washington — November 19, 2020

2020-11-19 21:01:48 UTC (2020-11-19) · approx. 1:01 PM UTC-8 local

MagnitudeM2.9(ml)
Time21:01 UTC≈ 1:01 PM UTC-8
Depth22.4 kmshallow crustal
Coordinates46.571°, -122.738°
Felt by7DYFI responses· max MMI 2.5
Status✓ Reviewed by USGS

On November 19, 2020 at 21:01 UTC, a magnitude 2.9 shallow crustal earthquake struck 1 km WSW of Onalaska, Washington, at a depth of 22.4 km and coordinates 46.5708°, -122.7377°. The earthquake was reported felt by 7 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.5 (weak).

Physical scale: An earthquake of magnitude 2.9 releases seismic energy equivalent to roughly 304 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 58 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 46.57°, -122.74°

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 M2.9 earthquake near 1 km WSW of Onalaska, Washington

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 7 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 M2.9 earthquake near 1 km WSW of Onalaska, Washington

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

Earthquake Details

Magnitude
2.9 ml
Depth
22.4 km
shallow crustal
Location
46.5708°N
-122.7377°E
Felt Reports
7
DYFI responses
Intensity (MMI)
2.5
weak
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
uw61691897
Event Type
earthquake
Status
✓ Reviewed
Significance
129
Stations Used
63
Azimuthal Gap
40.0°
Min Station Distance
0.096°
RMS Residual
0.17 sec
Last Updated
2021-02-03 17:51:05 UTC

Common Questions

How strong was the magnitude 2.9 earthquake near Onalaska, Washington?

The magnitude 2.9 earthquake that struck 1 km WSW of Onalaska, Washington on November 19, 2020 at 21:01 UTC had a depth of 22.4 km. It was felt by 7 people with maximum shaking intensity of MMI 2.5 (weak). For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.9 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.9 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: uw61691897). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, November 19, 2020). M2.9 Earthquake 1 km WSW of Onalaska, Washington — November 19, 2020. Retrieved February 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/uw61691897/