M4.5 Earthquake 9 km ENE of P?hala, Hawaii — September 27, 2022
2022-09-27 22:43:58 UTC (2022-09-27) · approx. 12:43 PM UTC-10 local
Felt by 354 people across surrounding communities. Maximum shaking intensity MMI 5.3 (strong). Aftershock of the M5.2 mainshock.
On September 27, 2022 at 22:43 UTC, a magnitude 4.5 shallow crustal earthquake struck 9 km ENE of P?hala, Hawaii, at a depth of 32.2 km and coordinates 19.2428°, -155.3965°. The earthquake was reported felt by 354 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 5.3 (strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 48 seismic stations with good location accuracy and was assigned a USGS significance rating of 467, placing it among routine seismic activity. The nearest populated place is Pahala (population 1,356).
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 71 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 709 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.2 mainshock that occurred 27 days ago 42 km ESE of Naalehu, Hawaii. Since the mainshock, the USGS has recorded 22 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
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 5.3 (strong), people in the most strongly affected areas would have experienced: Moderate shaking that everyone in the area would feel. Sleeping people are awakened. Dishes and windows may break. Unstable objects may be knocked over.
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 354 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 | 161,388 |
| MMI 4 | light | 1,180 |
Earthquake Details
-155.3965°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near P?hala, Hawaii?
The magnitude 4.5 earthquake that struck 9 km ENE of P?hala, Hawaii on September 27, 2022 at 22:43 UTC had a depth of 32.2 km. It was felt by 354 people with maximum shaking intensity of MMI 5.3 (strong). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 19.2428°, -155.3965°, which is 9 km ENE of P?hala, Hawaii. The nearest populated place is Pahala (population 1,356). View all earthquakes in Hawaii.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.2 one earlier?
No. This magnitude 4.5 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier 42 km ESE of Naalehu, Hawaii. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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 4.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: hv73156112). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, September 27, 2022). M4.5 Earthquake 9 km ENE of P?hala, Hawaii — September 27, 2022. Retrieved December 3, 2022 from https://www.earthquaketracker.org/earthquakes/event/hv73156112/