4.6

M4.6 Earthquake 35 km ESE of Adak, AlaskaJune 20, 2024

2024-06-20 17:24:01 UTC (2024-06-20) · approx. 5:24 AM UTC-12 local

Felt by 1 person across nearby locations.

MagnitudeM4.6(mwr)
Time17:24 UTC5:24 AM UTC-12
Depth58.8 kmshallow crustal
Coordinates51.722°, -176.175°
Felt by1DYFI response· max MMI 3.3
Status✓ Reviewed by USGS

On June 20, 2024 at 17:24 UTC, a magnitude 4.6 shallow crustal earthquake struck 35 km ESE of Adak, Alaska, at a depth of 58.8 km and coordinates 51.7218°, -176.1748°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.3 (light). This earthquake was detected by 106 seismic stations with good location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 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 51.72°, -176.17°

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 M4.6 earthquake near 35 km ESE of Adak, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response 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 M4.6 earthquake near 35 km ESE of Adak, Alaska

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

Earthquake Details

Magnitude
4.6 mwr
Depth
58.8 km
shallow crustal
Location
51.7218°N
-176.1748°E
Felt Reports
1
DYFI responses
Intensity (MMI)
3.3
light
Community Intensity
5.3
CDI from reports

Technical Information

Event ID
us7000mtm3
Event Type
earthquake
Status
✓ Reviewed
Significance
326
Stations Used
106
Azimuthal Gap
129.0°
Min Station Distance
0.201°
RMS Residual
0.70 sec
Last Updated
2024-08-30 18:17:07 UTC

Common Questions

How strong was the magnitude 4.6 earthquake near Adak, Alaska?

The magnitude 4.6 earthquake that struck 35 km ESE of Adak, Alaska on June 20, 2024 at 17:24 UTC had a depth of 58.8 km. It was felt by 1 person with maximum shaking intensity of MMI 3.3 (light). For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 51.7218°, -176.1748°, which is 35 km ESE of Adak, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000mtm3). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, June 20, 2024). M4.6 Earthquake 35 km ESE of Adak, AlaskaJune 20, 2024. Retrieved August 30, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000mtm3/