M4.3 earthquake 21 km NNE of Yigo Village, Guam

Monday, May 25, 2015, 04:00:10 UTC · 13.712°N, 144.981°E

A magnitude 4.3 earthquake struck 21 km NNE of Yigo Village, Guam on Monday, May 25, 2015, 04:00:10 UTC, at a depth of 123.6 km (intermediate).

Magnitude: 4.3; Light · mb
Depth: 124 km; Intermediate
Felt reports: 0; Max intensity I
Est. shaking: —; No ShakeMap
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

43 tons of TNT

That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.

Tectonic setting

113 km

from the nearest mapped plate boundary, between the Philippine Sea and Mariana plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: intermediate

124 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.

After the main event

Aftershocks within 50 km

USGS lists 5 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on June 7, 2015. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 658 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1993M7.8
Tuman Bay, Apra Harbor
8 Aug 1993 · 84 km away · intensity IX
$250 million damagetsunami
1849M7.5
Guam
25 Jan 1849 · 184 km away · intensity IX
Severe damage ($5–24M)tsunami
1909M8.0
Guam
9 Dec 1909 · 135 km away · intensity VIII
Moderate damage ($1–5M)tsunami
1892M7.5
Guam
16 May 1892 · 184 km away · intensity VIII
Moderate damage ($1–5M)tsunami
2001M7.0
Guam
12 Oct 2001 · 114 km away · intensity VIII
Moderate damage ($1–5M)
1825
Ladrones Island
Apr 1825 · 184 km away · intensity VIII
Moderate damage ($1–5M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers