Magnitude5.1

Reviewed by USGSGuam25y ago

M5.1 earthquake 86 km NNE of Yigo Village, Guam

Tuesday, October 23, 2001, 12:04:52 UTC · 14.250°N, 145.215°E

A magnitude 5.1 earthquake struck 86 km NNE of Yigo Village, Guam on Tuesday, October 23, 2001, 12:04:52 UTC, at a depth of 88.8 km (intermediate). It is the strongest earthquake within 300 km since an M5.2 on October 14, 2001.

Magnitude
5.1
Moderate · mb
Depth
89 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

674 tons of TNT

That is about 1/22 of the Hiroshima bomb. It released about 1 times the energy of a magnitude 5.0.

Tectonic setting

105 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

89 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 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M4.1 on October 30, 2001. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M5.1
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.1Rota region, Northern Mariana Islands25y ago · 42 km SW of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 503 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 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1993M7.8

    Tuman Bay, Apra Harbor

    8 Aug 1993 · 148 km away · intensity IX

    $250 million damagetsunami

  2. 1849M7.5

    Guam

    25 Jan 1849 · 208 km away · intensity IX

    Severe damage ($5–24M)tsunami

  3. 1909M8.0

    Guam

    9 Dec 1909 · 196 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  4. 1892M7.5

    Guam

    16 May 1892 · 208 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  5. 2001M7.0

    Guam

    12 Oct 2001 · 176 km away · intensity VIII

    Moderate damage ($1–5M)

  6. 1825

    Ladrones Island

    Apr 1825 · 208 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

Closest city pages