Reviewed by USGSArgentina28y ago
M3.6 earthquake 26 km NNW of Albardón, Argentina
Thursday, August 20, 1998, 09:34:36 UTC · 31.213°S, 68.629°W
A magnitude 3.6 earthquake struck 26 km NNW of Albardón, Argentina on Thursday, August 20, 1998, 09:34:36 UTC, at a depth of 100.0 km (intermediate).
- Magnitude
- 3.6
- Minor · md
- Depth
- 100 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
4 tons of TNT
That is about 1/3,975 of the Hiroshima bomb. A magnitude 5.0 releases about 126 times more energy.
Tectonic setting
381 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
100 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.1 on September 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 338 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 · 293 km SW of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 260 km W of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 286 km SW of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 283 km SW of this epicenter
- 7.4San Juan, ArgentinaNovember 23, 1977 · 85 km E of this epicenter
- 7.136 km SW of Monte Patria, ChileOctober 15, 1997 · 249 km W of this epicenter
- 6.94 km ESE of Chimbas, ArgentinaJanuary 15, 1944 · 34 km SE of this epicenter
- 6.972 km WNW of Calingasta, ArgentinaJuly 27, 1917 · 139 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 29 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 24,985 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 177 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 34 km away · intensity IX
10,000 deaths$100 million damage
- 1965M7.3
Central
28 Mar 1965 · 276 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 80 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1971M7.8
Central
9 Jul 1971 · 282 km away · intensity IX
83 deaths$236 million damagetsunami
- 1977M7.5
San Juan Province: Mendoza
23 Nov 1977 · 76 km away · intensity IX
65 deaths$80 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.