Reviewed by USGSChile21y ago
M4.2 earthquake 146 km E of Iquique, Chile
Sunday, October 16, 2005, 20:15:31 UTC · 19.979°S, 68.773°W
A magnitude 4.2 earthquake struck 146 km E of Iquique, Chile on Sunday, October 16, 2005, 20:15:31 UTC, at a depth of 107.6 km (intermediate).
- Magnitude
- 4.2
- Light · mb
- Depth
- 108 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
168 km
from the nearest mapped plate boundary, between the Altiplano and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
108 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M3.8 on November 11, 2005. 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 466 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8102 km ENE of Iquique, ChileJune 13, 2005 · 44 km W of this epicenter
- 7.751 km W of Atocha, BoliviaNovember 29, 1957 · 240 km SE of this epicenter
- 7.3136 km WSW of Challapata, BoliviaJune 6, 1915 · 114 km NE of this epicenter
- 7.334 km NE of Tocopilla, ChileDecember 21, 1967 · 244 km SW of this epicenter
- 7.334 km S of Iquique, ChileFebruary 23, 1933 · 160 km W of this epicenter
- 7.2Near the coast of Tarapaca, ChileOctober 4, 1940 · 173 km W of this epicenter
- 7.278 km SW of Colchani, BoliviaOctober 4, 1910 · 154 km SE of this epicenter
- 7.268 km SSE of Arica, ChileAugust 8, 1987 · 166 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 45 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 27,409 recorded deaths. The most severe:
- 1868M8.5
Arica
13 Aug 1868 · 280 km away · intensity XI
25,000 deaths$300 million damagetsunami
- 1877M8.3
Off North Coast
10 May 1877 · 247 km away · intensity XI
2,385 deaths$2 million damagetsunami
- 2005M7.7
Tarapaca
13 Jun 2005 · 44 km away
11 deaths$5 million damage
- 1987M6.9
Arica, Iquique
8 Aug 1987 · 166 km away · intensity VII
5 deaths$1 million damage
- 1953M7.4
Northern
7 Dec 1953 · 236 km away
3 deaths$7 million damage
- 1970M4.6
Potosi
6 Mar 1970 · 293 km away
2 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.