Reviewed by USGSChile28y ago
M3.1 earthquake 56 km ENE of Machalí, Chile
Monday, July 13, 1998, 21:04:21 UTC · 34.081°S, 70.052°W
A magnitude 3.1 earthquake struck 56 km ENE of Machalí, Chile on Monday, July 13, 1998, 21:04:21 UTC, at a depth of 11.1 km (shallow).
- Magnitude
- 3.1
- Minor · md
- Depth
- 11 km
- Shallow
- 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
674 kg of TNT
That is about 1/22,353 of the Hiroshima bomb. A magnitude 5.0 releases about 708 times more energy.
Tectonic setting
267 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: shallow
11 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
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 M3.7 on July 17, 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 331 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 · 225 km NW of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 199 km NW of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 193 km NW of this epicenter
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 231 km SW of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 204 km NW of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 178 km NW of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 140 km W of this epicenter
- 7.259 km S of San Antonio, ChileApril 9, 1985 · 144 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 41 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 19,472 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 184 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1906M8.2
South Central
17 Aug 1906 · 217 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 215 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 286 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 206 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 186 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.