3.6

M3.6 Earthquake 16 km ESE of Naalehu, Hawaii — June 23, 2021

2021-06-23 18:22:16 UTC (2021-06-23) · approx. 8:22 AM UTC-10 local

MagnitudeM3.6(ml)
Time18:22 UTC≈ 8:22 AM UTC-10
Depth36.1 kmshallow crustal
Coordinates18.989°, -155.451°
Felt by2DYFI responses· max MMI 3.2
Status✓ Reviewed by USGS

On June 23, 2021 at 18:22 UTC, a magnitude 3.6 shallow crustal earthquake struck 16 km ESE of Naalehu, Hawaii, at a depth of 36.1 km and coordinates 18.9893°, -155.4510°. The earthquake was reported felt by 2 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.2 (light).

Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.7 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 181 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 18.99°, -155.45°

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 M3.6 earthquake near 16 km ESE of Naalehu, Hawaii

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 2 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 M3.6 earthquake near 16 km ESE of Naalehu, Hawaii

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

Earthquake Details

Magnitude
3.6 ml
Depth
36.1 km
shallow crustal
Location
18.9893°N
-155.4510°E
Felt Reports
2
DYFI responses
Intensity (MMI)
3.2
light
Community Intensity
2.2
CDI from reports

Technical Information

Event ID
hv72542552
Event Type
earthquake
Status
✓ Reviewed
Significance
199
Stations Used
58
Azimuthal Gap
219.0°
RMS Residual
0.11 sec
Last Updated
2021-08-27 18:58:40 UTC

Common Questions

How strong was the magnitude 3.6 earthquake near Naalehu, Hawaii?

The magnitude 3.6 earthquake that struck 16 km ESE of Naalehu, Hawaii on June 23, 2021 at 18:22 UTC had a depth of 36.1 km. It was felt by 2 people with maximum shaking intensity of MMI 3.2 (light). 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 3.6 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.6 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: hv72542552). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, June 23, 2021). M3.6 Earthquake 16 km ESE of Naalehu, Hawaii — June 23, 2021. Retrieved August 27, 2021 from https://www.earthquaketracker.org/earthquakes/event/hv72542552/