M4.7 Earthquake 15 km S of Fern Forest, Hawaii — August 22, 2024
2024-08-22 10:52:44 UTC (2024-08-22) · approx. 12:52 AM UTC-10 local
Felt by 293 people across surrounding communities. Maximum shaking intensity MMI 4.3 (moderate).
On August 22, 2024 at 10:52 UTC, a magnitude 4.7 shallow crustal earthquake struck 15 km S of Fern Forest, Hawaii, at a depth of 6.6 km and coordinates 19.3270°, -155.1227°. The earthquake was reported felt by 293 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.3 (moderate). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 57 seismic stations with good location accuracy and was assigned a USGS significance rating of 469, placing it among routine seismic activity. The nearest populated place is Fern Acres (population 1,504).
Physical scale: An earthquake of magnitude 4.7 releases seismic energy equivalent to roughly 194 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.1 km — 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
Nearest Populated Places
What the Shaking Felt Like
At MMI 4.3 (moderate), people in the most strongly affected areas would have experienced: Mild shaking, similar to a passing truck. Hanging objects swing. Glasses and dishes may rattle. Not commonly felt outdoors.
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 293 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
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 126,037 |
| MMI 4 | light | 26,049 |
Earthquake Details
-155.1227°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.7 earthquake near Fern Forest, Hawaii?
The magnitude 4.7 earthquake that struck 15 km S of Fern Forest, Hawaii on August 22, 2024 at 10:52 UTC had a depth of 6.6 km. It was felt by 293 people with maximum shaking intensity of MMI 4.3 (moderate). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 19.3270°, -155.1227°, which is 15 km S of Fern Forest, Hawaii. The nearest populated place is Fern Acres (population 1,504). View all earthquakes in Hawaii.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 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 4.7 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: hv74419396). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2024, August 22, 2024). M4.7 Earthquake 15 km S of Fern Forest, Hawaii — August 22, 2024. Retrieved November 2, 2024 from https://www.earthquaketracker.org/earthquakes/event/hv74419396/