M2.2 Earthquake 10 km S of Kapaau, Hawaii — October 21, 2020
2020-10-21 21:59:01 UTC (2020-10-21) · approx. 11:59 AM UTC-10 local
Felt by 10 people across nearby locations.
On October 21, 2020 at 21:59 UTC, a magnitude 2.2 shallow crustal earthquake struck 10 km S of Kapaau, Hawaii, at a depth of 22.5 km and coordinates 20.1398°, -155.8053°. This earthquake was detected by 51 seismic stations with good location accuracy and was assigned a USGS significance rating of 79, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 2.2 releases seismic energy equivalent to roughly 32.2 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 21 m — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Hawaii, a region characterized by intraplate volcanic activity over the Hawaiian mantle plume hotspot, with seismicity driven by magma intrusion and flank instability. View all earthquakes in Hawaii.
Learn more: Magnitude scale · Aftershock sequences
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 10 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
-155.8053°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 2.2 earthquake near Kapaau, Hawaii?
The magnitude 2.2 earthquake that struck 10 km S of Kapaau, Hawaii on October 21, 2020 at 21:59 UTC had a depth of 22.5 km. For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 20.1398°, -155.8053°, which is 10 km S of Kapaau, Hawaii. View all earthquakes in Hawaii.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.2 earthquakes can continue for several days and gradually diminish over time.
Has Hawaii had earthquakes this big before?
The largest recorded earthquake in Hawaii was the M7.9 Ka'u District earthquake of April 2, 1868. Today's magnitude 2.2 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: hv72191381). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, October 21, 2020). M2.2 Earthquake 10 km S of Kapaau, Hawaii — October 21, 2020. Retrieved January 9, 2021 from https://www.earthquaketracker.org/earthquakes/event/hv72191381/