M4.5 Earthquake 53 km ENE of Port-Olry, Vanuatu — March 25, 2021
2021-03-25 21:35:55 UTC (2021-03-25) · approx. 8:35 AM UTC+11 local
Aftershock of the M5.2 mainshock.
On March 25, 2021 at 21:35 UTC, a magnitude 4.5 intermediate depth earthquake struck 53 km ENE of Port-Olry, Vanuatu, at a depth of 127.6 km and coordinates -14.8635°, 167.5306°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.2 mainshock that occurred 16 days ago 35 km NE of Luganville, Vanuatu. Since the mainshock, the USGS has recorded 0 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 Vanuatu, a region characterized by the New Hebrides subduction zone, where the Australian Plate subducts eastward at approximately 90 mm per year. View all earthquakes in Vanuatu.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
167.5306°E
Technical Information
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Common Questions
How strong was the magnitude 4.5 earthquake near Port-Olry, Vanuatu?
The magnitude 4.5 earthquake that struck 53 km ENE of Port-Olry, Vanuatu on March 25, 2021 at 21:35 UTC had a depth of 127.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -14.8635°, 167.5306°, which is 53 km ENE of Port-Olry, Vanuatu. View all earthquakes in Vanuatu.
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 35 km NE of Luganville, Vanuatu. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Vanuatu had earthquakes this big before?
The largest recorded earthquake in Vanuatu was the M7.9 Vanuatu earthquake of October 7, 2009. Today's magnitude 4.5 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000dy78). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, March 25, 2021). M4.5 Earthquake 53 km ENE of Port-Olry, Vanuatu — March 25, 2021. Retrieved June 2, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000dy78/