5.7

M5.7 Earthquake in the Maug Islands region, Northern Mariana Islands — March 6, 2021

2021-03-06 18:51:12 UTC (2021-03-06) · approx. 4:51 AM UTC+10 local

MagnitudeM5.7(mww)
Time18:51 UTC≈ 4:51 AM UTC+10
Depth10.0 kmshallow crustal
Coordinates20.892°, 144.365°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On March 6, 2021 at 18:51 UTC, a magnitude 5.7 shallow crustal earthquake struck in the Maug Islands region, Northern Mariana Islands, at a depth of 10.0 km and coordinates 20.8917°, 144.3647°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.

Physical scale: An earthquake of magnitude 5.7 releases seismic energy equivalent to roughly 5 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 5.2 km — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 20.89°, 144.36°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M5.7 earthquake near Maug Islands region, Northern Mariana Islands

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
5.7 mww
Depth
10.0 km
shallow crustal
Location
20.8917°N
144.3647°E
Intensity (MMI)
3.6
light

Technical Information

Event ID
us7000dgkw
Event Type
earthquake
Status
✓ Reviewed
Significance
500
Azimuthal Gap
21.0°
Min Station Distance
5.788°
RMS Residual
0.82 sec
Last Updated
2025-12-22 18:52:41 UTC

Common Questions

How strong was the magnitude 5.7 earthquake in the Maug Islands region, Northern Mariana Islands?

The magnitude 5.7 earthquake that struck in the Maug Islands region, Northern Mariana Islands on March 6, 2021 at 18:51 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 20.8917°, 144.3647°, which is in the Maug Islands region, Northern Mariana Islands.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.7 earthquakes can continue for days to weeks and gradually diminish over time.

Authoritative source: USGS event page (event ID: us7000dgkw). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, March 6, 2021). M5.7 Earthquake in the Maug Islands region, Northern Mariana Islands — March 6, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000dgkw/