Reviewed by USGSChile21y ago
M4.2 earthquake 121 km E of Iquique, Chile
Friday, August 19, 2005, 13:18:04 UTC · 20.173°S, 68.986°W
A magnitude 4.2 earthquake struck 121 km E of Iquique, Chile on Friday, August 19, 2005, 13:18:04 UTC, at a depth of 92.9 km (intermediate).
- Magnitude
- 4.2
- Light · mb
- Depth
- 93 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
147 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
93 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 7 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.4 on September 14, 2005. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.7128 km E of Iquique, Chile21y ago · 10 km NE of this epicenter
- 4.4113 km E of Iquique, Chile21y ago · 9 km W of this epicenter
- 3.6141 km ENE of Iquique, Chile21y ago · 49 km N of this epicenter
- 3.8139 km E of Iquique, Chile21y ago · 21 km SE of this epicenter
- 4.3127 km ENE of Iquique, Chile21y ago · 27 km N of this epicenter
- 4.0Tarapaca, Chile21y ago · 43 km N of this epicenter
- 4.0119 km ENE of Iquique, Chile21y ago · 32 km N of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 484 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 · 30 km NW of this epicenter
- 7.751 km W of Atocha, BoliviaNovember 29, 1957 · 252 km E of this epicenter
- 7.3136 km WSW of Challapata, BoliviaJune 6, 1915 · 145 km NE of this epicenter
- 7.334 km NE of Tocopilla, ChileDecember 21, 1967 · 215 km SW of this epicenter
- 7.334 km S of Iquique, ChileFebruary 23, 1933 · 132 km W of this epicenter
- 7.2Near the coast of Tarapaca, ChileOctober 4, 1940 · 152 km W of this epicenter
- 7.278 km SW of Colchani, BoliviaOctober 4, 1910 · 164 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 27,407 recorded deaths. The most severe:
- 1868M8.5
Arica
13 Aug 1868 · 274 km away · intensity XI
25,000 deaths$300 million damagetsunami
- 1877M8.3
Off North Coast
10 May 1877 · 216 km away · intensity XI
2,385 deaths$2 million damagetsunami
- 2005M7.7
Tarapaca
13 Jun 2005 · 30 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 · 216 km away
3 deaths$7 million damage
- 1967M7.5
Northern
21 Dec 1967 · 178 km away
1 deathModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.