Reviewed by USGSGuam11y ago
M3.9 earthquake 51 km E of Yigo Village, Guam
Monday, May 18, 2015, 03:31:08 UTC · 13.605°N, 145.363°E
A magnitude 3.9 earthquake struck 51 km E of Yigo Village, Guam on Monday, May 18, 2015, 03:31:08 UTC, at a depth of 65.2 km (shallow).
- Magnitude
- 3.9
- Minor · mb
- Depth
- 65 km
- Shallow
- 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
11 tons of TNT
That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.
Tectonic setting
107 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
65 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on June 7, 2015. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 641 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.832 km S of Inarajan Village, GuamAugust 8, 1993 · 92 km SW of this epicenter
- 7.6198 km E of Saipan, Northern Mariana IslandsApril 5, 1990 · 294 km NE of this epicenter
- 7.120 km SSW of Merizo Village, GuamApril 26, 2002 · 99 km SW of this epicenter
- 7.0176 km ESE of San Jose Village, Northern Mariana IslandsMay 18, 1913 · 200 km E of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 140 km S of this epicenter
- 7.032 km NNE of Yigo Village, GuamOctober 26, 1912 · 50 km NW of this epicenter
- 7.0233 km ESE of Saipan, Northern Mariana IslandsJune 14, 1942 · 290 km NE of this epicenter
- 7.069 km SSE of Inarajan Village, GuamOctober 12, 2001 · 110 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 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 · 92 km away · intensity IX
$250 million damagetsunami
- 1849M7.5
Guam
25 Jan 1849 · 227 km away · intensity IX
Severe damage ($5–24M)tsunami
- 1909M8.0
Guam
9 Dec 1909 · 129 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1892M7.5
Guam
16 May 1892 · 227 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 2001M7.0
Guam
12 Oct 2001 · 110 km away · intensity VIII
Moderate damage ($1–5M)
- 1825
Ladrones Island
Apr 1825 · 227 km away · intensity VIII
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.