4.0

M4.0 Earthquake near Rat Islands, Aleutian Islands, Alaska — June 27, 2020

2020-06-27 21:35:55 UTC (2020-06-27) · approx. 9:35 AM UTC+12 local

MagnitudeM4.0(mb)
Time21:35 UTC≈ 9:35 AM UTC+12
Depth54.4 kmshallow crustal
Coordinates51.605°, 177.999°
Felt byNo felt reports
Status✓ Reviewed by USGS

On June 27, 2020 at 21:35 UTC, a magnitude 4.0 shallow crustal earthquake struck near Rat Islands, Aleutian Islands, Alaska, at a depth of 54.4 km and coordinates 51.6048°, 177.9989°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 51.60°, 178.00°

Earthquake Details

Magnitude
4.0 mb
Depth
54.4 km
shallow crustal
Location
51.6048°N
177.9989°E

Technical Information

Event ID
us7000ad82
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Azimuthal Gap
161.0°
Min Station Distance
0.481°
RMS Residual
0.80 sec
Last Updated
2020-09-05 17:35:27 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Rat Islands, Aleutian Islands, Alaska?

The magnitude 4.0 earthquake that struck near Rat Islands, Aleutian Islands, Alaska on June 27, 2020 at 21:35 UTC had a depth of 54.4 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000ad82). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2020, June 27, 2020). M4.0 Earthquake near Rat Islands, Aleutian Islands, Alaska — June 27, 2020. Retrieved September 5, 2020 from https://www.earthquaketracker.org/earthquakes/event/us7000ad82/