3.9

M3.9 Earthquake 272 km N of Saipan, Northern Mariana IslandsOctober 15, 2023

2023-10-15 20:56:50 UTC (2023-10-15) · approx. 6:56 AM UTC+10 local

MagnitudeM3.9(mb)
Time20:56 UTC6:56 AM UTC+10
Depth258.3 kmintermediate depth
Coordinates17.666°, 145.537°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 15, 2023 at 20:56 UTC, a magnitude 3.9 intermediate depth earthquake struck 272 km N of Saipan, Northern Mariana Islands, at a depth of 258.3 km and coordinates 17.6662°, 145.5369°.

Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 17.67°, 145.54°

Earthquake Details

Magnitude
3.9 mb
Depth
258.3 km
intermediate depth
Location
17.6662°N
145.5369°E

Technical Information

Event ID
us6000lgv7
Event Type
earthquake
Status
✓ Reviewed
Significance
234
Stations Used
26
Azimuthal Gap
161.0°
Min Station Distance
4.104°
RMS Residual
1.19 sec
Last Updated
2023-12-26 21:24:43 UTC

Common Questions

How strong was the magnitude 3.9 earthquake near Saipan, Northern Mariana Islands?

The magnitude 3.9 earthquake that struck 272 km N of Saipan, Northern Mariana Islands on October 15, 2023 at 20:56 UTC had a depth of 258.3 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.9 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000lgv7). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, October 15, 2023). M3.9 Earthquake 272 km N of Saipan, Northern Mariana IslandsOctober 15, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lgv7/