4.3

M4.3 Earthquake 41 km WNW of Saipan, Northern Mariana IslandsSeptember 5, 2021

2021-09-05 22:37:08 UTC (2021-09-05) · approx. 8:37 AM UTC+10 local

MagnitudeM4.3(mb)
Time22:37 UTC8:37 AM UTC+10
Depth232.9 kmintermediate depth
Coordinates15.415°, 145.430°
Felt byNo felt reports
Status✓ Reviewed by USGS

On September 5, 2021 at 22:37 UTC, a magnitude 4.3 intermediate depth earthquake struck 41 km WNW of Saipan, Northern Mariana Islands, at a depth of 232.9 km and coordinates 15.4148°, 145.4301°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 15.41°, 145.43°

Earthquake Details

Magnitude
4.3 mb
Depth
232.9 km
intermediate depth
Location
15.4148°N
145.4301°E

Technical Information

Event ID
us7000fatm
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Azimuthal Gap
151.0°
Min Station Distance
18.418°
RMS Residual
0.25 sec
Last Updated
2021-11-17 17:23:50 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Saipan, Northern Mariana Islands?

The magnitude 4.3 earthquake that struck 41 km WNW of Saipan, Northern Mariana Islands on September 5, 2021 at 22:37 UTC had a depth of 232.9 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000fatm). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, September 5, 2021). M4.3 Earthquake 41 km WNW of Saipan, Northern Mariana IslandsSeptember 5, 2021. Retrieved November 17, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000fatm/