Reviewed by USGSChile28y ago
M4.1 earthquake 16 km NNW of Lampa, Chile
Tuesday, August 18, 1998, 00:40:26 UTC · 33.139°S, 70.921°W
A magnitude 4.1 earthquake struck 16 km NNW of Lampa, Chile on Tuesday, August 18, 1998, 00:40:26 UTC, at a depth of 76.1 km (intermediate).
- Magnitude
- 4.1
- Light · md
- Depth
- 76 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
182 km
from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
76 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 M2.6 on August 18, 1998. 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 423 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 94 km NW of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 213 km N of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 88 km W of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 62 km N of this epicenter
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 249 km SW of this epicenter
- 7.7103 km NW of Constitución, ChileJanuary 30, 1914 · 285 km SW of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 74 km N of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 69 km W 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 29,465 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 201 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 292 km away · intensity IX
10,000 deaths$100 million damage
- 1906M8.2
South Central
17 Aug 1906 · 102 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 86 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 272 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 230 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.