Reviewed by USGSGuam29y ago
M5.4 earthquake 78 km NE of Yigo Village, Guam
Tuesday, April 29, 1997, 17:21:57 UTC · 14.081°N, 145.350°E
A magnitude 5.4 earthquake struck 78 km NE of Yigo Village, Guam on Tuesday, April 29, 1997, 17:21:57 UTC, at a depth of 97.5 km (intermediate). It is the strongest earthquake within 300 km since an M6.5 on April 23, 1997.
- Magnitude
- 5.4
- Moderate · mwc
- Depth
- 98 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
2 kilotons of TNT
That is about 1/8 of the Hiroshima bomb. It released about 4 times the energy of a magnitude 5.0.
Tectonic setting
128 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
98 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 75 km
USGS lists 2 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.8 on May 21, 1997. 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 445 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 · 136 km SW of this epicenter
- 7.6198 km E of Saipan, Northern Mariana IslandsApril 5, 1990 · 268 km NE of this epicenter
- 7.0176 km ESE of San Jose Village, Northern Mariana IslandsMay 18, 1913 · 189 km E of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 191 km S of this epicenter
- 7.032 km NNE of Yigo Village, GuamOctober 26, 1912 · 52 km SW of this epicenter
- 7.0233 km ESE of Saipan, Northern Mariana IslandsJune 14, 1942 · 275 km E of this epicenter
- 6.549 km N of Yigo Village, GuamApril 23, 1997 · 50 km W of this epicenter
- 6.5112 km NE of Saipan, Northern Mariana IslandsJune 6, 1993 · 235 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 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 · 136 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 · 180 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
- 1825
Ladrones Island
Apr 1825 · 221 km away · intensity VIII
Moderate damage ($1–5M)tsunami
- 1834
Agana
May 1834 · 221 km away
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.