M3.9 earthquake 103 km NNE of Calama, Chile

Friday, January 18, 2008, 05:02:21 UTC · 21.661°S, 68.392°W

A magnitude 3.9 earthquake struck 103 km NNE of Calama, Chile on Friday, January 18, 2008, 05:02:21 UTC, at a depth of 134.1 km (intermediate).

Magnitude: 3.9; Minor · m
Depth: 134 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: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

11 tons of TNT

That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.

Tectonic setting

18 km

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

Depth: intermediate

134 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 50 km

USGS lists 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M6.1 on February 16, 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 674 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 39 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,408 recorded deaths. The most severe:

1877M8.3
Off North Coast
10 May 1877 · 219 km away · intensity XI
2,385 deaths$2 million damagetsunami
2005M7.7
Tarapaca
13 Jun 2005 · 204 km away
11 deaths$5 million damage
1953M7.4
Northern
7 Dec 1953 · 58 km away
3 deaths$7 million damage
1995M8.0
Antofagasta, Calama, Mejillones
30 Jul 1995 · 270 km away · intensity VII
3 deaths$2 million damagetsunami
2007M7.7
Tocopilla, Maria Elena
14 Nov 2007 · 168 km away · intensity VIII
2 deathsSevere damage ($5–24M)tsunami
1967M7.5
Northern
21 Dec 1967 · 115 km away
1 deathModerate damage ($1–5M)tsunami

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

Nearby trackers