4.0

M4.0 Earthquake 270 km N of Saipan, Northern Mariana Islands — January 29, 2021

2021-01-29 23:53:22 UTC (2021-01-29) · approx. 9:53 AM UTC+10 local

MagnitudeM4.0(mb)
Time23:53 UTC≈ 9:53 AM UTC+10
Depth211.2 kmintermediate depth
Coordinates17.649°, 145.606°
Felt byNo felt reports
Status✓ Reviewed by USGS

On January 29, 2021 at 23:53 UTC, a magnitude 4.0 intermediate depth earthquake struck 270 km N of Saipan, Northern Mariana Islands, at a depth of 211.2 km and coordinates 17.6486°, 145.6057°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.65°, 145.61°

Earthquake Details

Magnitude
4.0 mb
Depth
211.2 km
intermediate depth
Location
17.6486°N
145.6057°E

Technical Information

Event ID
us6000deqr
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Azimuthal Gap
130.0°
Min Station Distance
2.407°
RMS Residual
0.49 sec
Last Updated
2021-04-16 19:03:36 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Saipan, Northern Mariana Islands?

The magnitude 4.0 earthquake that struck 270 km N of Saipan, Northern Mariana Islands on January 29, 2021 at 23:53 UTC had a depth of 211.2 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 4.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000deqr). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, January 29, 2021). M4.0 Earthquake 270 km N of Saipan, Northern Mariana Islands — January 29, 2021. Retrieved April 16, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000deqr/