3.3

M3.3 Earthquake 21 km SSE of Naalehu, HawaiiOctober 10, 2021

2021-10-10 22:45:47 UTC (2021-10-10) · approx. 12:45 PM UTC-10 local

MagnitudeM3.3(ml)
Time22:45 UTC12:45 PM UTC-10
Depth35.0 kmshallow crustal
Coordinates18.881°, -155.513°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 10, 2021 at 22:45 UTC, a magnitude 3.3 shallow crustal earthquake struck 21 km SSE of Naalehu, Hawaii, at a depth of 35.0 km and coordinates 18.8807°, -155.5127°.0

Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.1 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 105 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 18.88°, -155.51°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from submitted citizen responses 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 M3.3 earthquake near 21 km SSE of Naalehu, Hawaii

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

Earthquake Details

Magnitude
3.3 ml
Depth
35.0 km
shallow crustal
Location
18.8807°N
-155.5127°E
Community Intensity
1.0
CDI from reports

Technical Information

Event ID
hv72748887
Event Type
earthquake
Status
✓ Reviewed
Significance
162
Stations Used
54
Azimuthal Gap
260.0°
RMS Residual
0.12 sec
Last Updated
2021-12-18 19:58:49 UTC

Common Questions

How strong was the magnitude 3.3 earthquake near Naalehu, Hawaii?

The magnitude 3.3 earthquake that struck 21 km SSE of Naalehu, Hawaii on October 10, 2021 at 22:45 UTC had a depth of 35.0 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: hv72748887). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 10, 2021). M3.3 Earthquake 21 km SSE of Naalehu, HawaiiOctober 10, 2021. Retrieved December 18, 2021 from https://www.earthquaketracker.org/earthquakes/event/hv72748887/