Magnitude4.5

Reviewed by USGSGuam11y ago

M4.5 earthquake 33 km N of Yigo Village, Guam

Tuesday, December 30, 2014, 12:14:53 UTC · 13.843°N, 144.893°E

A magnitude 4.5 earthquake struck 33 km N of Yigo Village, Guam on Tuesday, December 30, 2014, 12:14:53 UTC, at a depth of 116.6 km (intermediate). USGS received 2 “Did You Feel It?” reports, with a maximum reported intensity of III (weak). It is the strongest earthquake within 300 km since an M4.6 on December 28, 2014.

Magnitude
4.5
Light · mb
Depth
117 km
Intermediate
Felt reports
2
Max intensity III
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

85 tons of TNT

That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.

Tectonic setting

101 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

117 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

Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.

PlaceIntensityReportsDistance
96910<br>0.330III · Weak1124 km
96922<br>0.330III · Weak1125 km
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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.6 on January 29, 2015. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M4.5
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.627 km NNE of Yigo Village, Guam11y ago · 17 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 642 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:

  1. 1993M7.8

    Tuman Bay, Apra Harbor

    8 Aug 1993 · 96 km away · intensity IX

    $250 million damagetsunami

  2. 1849M7.5

    Guam

    25 Jan 1849 · 173 km away · intensity IX

    Severe damage ($5–24M)tsunami

  3. 1909M8.0

    Guam

    9 Dec 1909 · 150 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  4. 1892M7.5

    Guam

    16 May 1892 · 173 km away · intensity VIII

    Moderate damage ($1–5M)tsunami

  5. 2001M7.0

    Guam

    12 Oct 2001 · 129 km away · intensity VIII

    Moderate damage ($1–5M)

  6. 1825

    Ladrones Island

    Apr 1825 · 173 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