5.4

M5.4 Earthquake 165 km SSW of Merizo Village, Guam — July 14, 2021

2021-07-14 09:24:52 UTC (2021-07-14) · approx. 7:24 PM UTC+10 local

MagnitudeM5.4(mww)
Time09:24 UTC≈ 7:24 PM UTC+10
Depth10.0 kmshallow crustal
Coordinates12.001°, 143.858°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On July 14, 2021 at 09:24 UTC, a magnitude 5.4 shallow crustal earthquake struck 165 km SSW of Merizo Village, Guam, at a depth of 10.0 km and coordinates 12.0005°, 143.8578°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Umatac Village (population 903).

Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 km — a useful intuition for the size of the slip patch on the fault.

Nearest Populated Places

Umatac Villagepop. 903
MMI 2.8 (weak)
Merizo Villagepop. 2,152
MMI 2.8 (weak)
Inarajan Villagepop. 3,052
MMI 2.8 (weak)
Chalan Pago-Ordot Villagepop. 6,822
MMI 2.7 (weak)
Barrigada Villagepop. 8,875
MMI 2.7 (weak)
Mangilao Villagepop. 15,191
MMI 2.7 (weak)
Map showing earthquake epicenter at 12.00°, 143.86°

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 M5.4 earthquake near 165 km SSW of Merizo Village, Guam

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

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak170,233

Earthquake Details

Magnitude
5.4 mww
Depth
10.0 km
shallow crustal
Location
12.0005°N
143.8578°E
Intensity (MMI)
2.9
weak

Technical Information

Event ID
us7000elui
Event Type
earthquake
Status
✓ Reviewed
Significance
449
Azimuthal Gap
31.0°
Min Station Distance
1.861°
RMS Residual
0.46 sec
Last Updated
2025-12-22 19:06:52 UTC

Common Questions

How strong was the magnitude 5.4 earthquake near Merizo Village, Guam?

The magnitude 5.4 earthquake that struck 165 km SSW of Merizo Village, Guam on July 14, 2021 at 09:24 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 12.0005°, 143.8578°, which is 165 km SSW of Merizo Village, Guam. The nearest populated place is Umatac Village (population 903).

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.4 earthquakes can continue for days to weeks and gradually diminish over time.

Authoritative source: USGS event page (event ID: us7000elui). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, July 14, 2021). M5.4 Earthquake 165 km SSW of Merizo Village, Guam — July 14, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000elui/