Reviewed by USGSGuam24y ago
M4.2 earthquake 133 km SSW of Merizo Village, Guam
Monday, May 20, 2002, 01:50:02 UTC · 12.182°N, 144.133°E
A magnitude 4.2 earthquake struck 133 km SSW of Merizo Village, Guam on Monday, May 20, 2002, 01:50:02 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.2
- Light · mb
- Depth
- 33 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
40 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
33 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 481 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 · 115 km NE of this epicenter
- 7.2265 km S of Merizo Village, GuamJanuary 28, 1931 · 150 km S of this epicenter
- 7.1261 km S of Merizo Village, GuamMay 9, 1917 · 144 km S of this epicenter
- 7.120 km SSW of Merizo Village, GuamApril 26, 2002 · 114 km NE of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 92 km E of this epicenter
- 7.032 km NNE of Yigo Village, GuamOctober 26, 1912 · 203 km NE of this epicenter
- 7.069 km SSE of Inarajan Village, GuamOctober 12, 2001 · 108 km NE of this epicenter
- 6.7Mariana Islands regionOctober 18, 1935 · 296 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 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 · 115 km away · intensity IX
$250 million damagetsunami
- 1849M7.5
Guam
25 Jan 1849 · 221 km away · intensity IX
Severe damage ($5–24M)tsunami
- 1909M8.0
Guam
9 Dec 1909 · 101 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1892M7.5
Guam
16 May 1892 · 221 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 2001M7.0
Guam
12 Oct 2001 · 108 km away · intensity VIII
Moderate damage ($1–5M)
- 1825
Ladrones Island
Apr 1825 · 221 km away · intensity VIII
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.