M4.9 Earthquake 9 km WNW of Kawerau, New Zealand — March 17, 2023
2023-03-17 19:58:06 UTC (2023-03-17) · approx. 7:58 AM UTC+12 local
Felt by 9 people across nearby locations. Maximum shaking intensity MMI 6.3 (very strong).
On March 17, 2023 at 19:58 UTC, a magnitude 4.9 shallow crustal earthquake struck 9 km WNW of Kawerau, New Zealand, at a depth of 6.6 km and coordinates -38.0565°, 176.6083°. The earthquake was reported felt by 9 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 6.3 (very 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 74 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 375, placing it among routine seismic activity. The nearest populated place is Kawerau (population 6,702).
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in New Zealand, a region characterized by the Hikurangi subduction zone in the North Island and the Alpine Fault in the South Island. The nearest mapped fault system is the Alpine Fault. View all earthquakes in New Zealand.
Learn more: Magnitude scale · Aftershock sequences
Nearest Populated Places
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 9 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 | 555,285 |
| MMI 4 | light | 47,900 |
| MMI 5 | moderate | 2,349 |
| MMI 6 | strong | 7,593 |
Earthquake Details
176.6083°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.9 earthquake near Kawerau, New Zealand?
The magnitude 4.9 earthquake that struck 9 km WNW of Kawerau, New Zealand on March 17, 2023 at 19:58 UTC had a depth of 6.6 km. It was felt by 9 people with maximum shaking intensity of MMI 6.3 (very strong). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -38.0565°, 176.6083°, which is 9 km WNW of Kawerau, New Zealand. The nearest populated place is Kawerau (population 6,702). View all earthquakes in New Zealand.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
Has New Zealand had earthquakes this big before?
The largest recorded earthquake in New Zealand was the M8.2 Wairarapa earthquake of January 23, 1855. Today's magnitude 4.9 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000jkyc). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, March 17, 2023). M4.9 Earthquake 9 km WNW of Kawerau, New Zealand — March 17, 2023. Retrieved May 20, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000jkyc/