M3.6 Earthquake 5 km WSW of Anchorage, Alaska — June 30, 2020
2020-06-30 22:58:22 UTC (2020-06-30) · approx. 12:58 PM UTC-10 local
Felt by 218 people across surrounding communities.
On June 30, 2020 at 22:58 UTC, a magnitude 3.6 shallow crustal earthquake struck 5 km WSW of Anchorage, Alaska, at a depth of 45.1 km and coordinates 61.1922°, -149.9822°. The earthquake was reported felt by 218 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.9 (weak).
Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.8 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 184 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
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.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 218 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-149.9822°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.6 earthquake near Anchorage, Alaska?
The magnitude 3.6 earthquake that struck 5 km WSW of Anchorage, Alaska on June 30, 2020 at 22:58 UTC had a depth of 45.1 km. It was felt by 218 people with maximum shaking intensity of MMI 2.9 (weak). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 61.1922°, -149.9822°, which is 5 km WSW of Anchorage, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.6 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 3.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: ak0208dd96es). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, June 30, 2020). M3.6 Earthquake 5 km WSW of Anchorage, Alaska — June 30, 2020. Retrieved October 7, 2020 from https://www.earthquaketracker.org/earthquakes/event/ak0208dd96es/