4.9

M4.9 Earthquake 149 km SSE of Cordova, AlaskaMarch 17, 2023

2023-03-17 15:04:25 UTC (2023-03-17) · approx. 5:04 AM UTC-10 local

MagnitudeM4.9(mb)
Time15:04 UTC5:04 AM UTC-10
Depth8.6 kmshallow crustal
Coordinates59.267°, -144.938°
Felt byNo felt reports
Status✓ Reviewed by USGS· Tsunami evaluation
Tsunami Warning Issued

On March 17, 2023 at 15:04 UTC, a magnitude 4.9 shallow crustal earthquake struck 149 km SSE of Cordova, Alaska, at a depth of 8.6 km and coordinates 59.2674°, -144.9377°.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — 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 59.27°, -144.94°

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 M4.9 earthquake near 149 km SSE of Cordova, Alaska

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

Earthquake Details

Magnitude
4.9 mb
Depth
8.6 km
shallow crustal
Location
59.2674°N
-144.9377°E
Intensity (MMI)
2.6
weak

Technical Information

Event ID
ak0233hxssds
Event Type
earthquake
Status
✓ Reviewed
Significance
369
RMS Residual
0.71 sec
Last Updated
2023-05-20 23:20:33 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Cordova, Alaska?

The magnitude 4.9 earthquake that struck 149 km SSE of Cordova, Alaska on March 17, 2023 at 15:04 UTC had a depth of 8.6 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 59.2674°, -144.9377°, which is 149 km SSE of Cordova, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: ak0233hxssds). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, March 17, 2023). M4.9 Earthquake 149 km SSE of Cordova, AlaskaMarch 17, 2023. Retrieved May 20, 2023 from https://www.earthquaketracker.org/earthquakes/event/ak0233hxssds/