4.5

M4.5 Earthquake 138 km NE of Opotiki, New ZealandSeptember 2, 2021

2021-09-02 19:24:51 UTC (2021-09-02) · approx. 7:24 AM UTC+12 local

MagnitudeM4.5(mb)
Time19:24 UTC7:24 AM UTC+12
Depth43.2 kmshallow crustal
Coordinates-37.115°, 178.382°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 2, 2021 at 19:24 UTC, a magnitude 4.5 shallow crustal earthquake struck 138 km NE of Opotiki, New Zealand, at a depth of 43.2 km and coordinates -37.1149°, 178.3824°.

Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — 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

Map showing earthquake epicenter at -37.11°, 178.38°

Earthquake Details

Magnitude
4.5 mb
Depth
43.2 km
shallow crustal
Location
-37.1149°N
178.3824°E

Technical Information

Event ID
us7000f9ry
Event Type
earthquake
Status
✓ Reviewed
Significance
312
Azimuthal Gap
135.0°
Min Station Distance
0.450°
RMS Residual
0.99 sec
Last Updated
2021-11-06 20:28:27 UTC

Common Questions

How strong was the magnitude 4.5 earthquake near Opotiki, New Zealand?

The magnitude 4.5 earthquake that struck 138 km NE of Opotiki, New Zealand on September 2, 2021 at 19:24 UTC had a depth of 43.2 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at -37.1149°, 178.3824°, which is 138 km NE of Opotiki, New Zealand. View all earthquakes in New Zealand.

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.

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 4.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000f9ry). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 2, 2021). M4.5 Earthquake 138 km NE of Opotiki, New ZealandSeptember 2, 2021. Retrieved November 6, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f9ry/