M5.1 earthquake 84 km WSW of Tobelo, Indonesia

Thursday, March 20, 2008, 12:15:42 UTC · 1.575°N, 127.261°E

A magnitude 5.1 earthquake struck 84 km WSW of Tobelo, Indonesia on Thursday, March 20, 2008, 12:15:42 UTC, at a depth of 104.6 km (intermediate). It is the strongest earthquake within 300 km since an M5.3 on March 13, 2008.

Magnitude: 5.1; Moderate · mwc
Depth: 105 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

83 km

from the nearest mapped plate boundary, between the Sunda and Birds Head plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: intermediate

105 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 5 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.7 on March 24, 2008. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,799 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 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 173 recorded deaths. The most severe:

1845M7.0
N Sulawesi: Menado, Tikala, Tomohon
8 Feb 1845 · 268 km away · intensity IX
118 deathsModerate damage ($1–5M)tsunami
1855
Maluku: Ternate Island
14 Jul 1855 · 86 km away · intensity IX
34 deathsModerate damage ($1–5M)
1994M7.0
Kau
21 Jan 1994 · 81 km away
9 deathsModerate damage ($1–5M)tsunami
1932M7.7
Sulawesi: Kakas,Langowan,Poso,Tondano
14 May 1932 · 202 km away · intensity VII
7 deathsSevere damage ($5–24M)tsunami
2007M7.5
Molucca Islands: N
21 Jan 2007 · 123 km away
4 deathsLimited damage (under $1M)
2003M7.0
Morotai, Berebere, Daruba
26 May 2003 · 197 km away
1 deathLimited damage (under $1M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers