Reviewed by USGSArgentina28y ago
M4.0 earthquake 15 km NNE of San Martín, Argentina
Friday, July 24, 1998, 20:58:22 UTC · 32.958°S, 68.382°W
A magnitude 4.0 earthquake struck 15 km NNE of San Martín, Argentina on Friday, July 24, 1998, 20:58:22 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.0
- Light · md
- Depth
- 10 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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
415 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
10 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M3.6 on July 25, 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 235 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 · 289 km W of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 263 km W of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 269 km W of this epicenter
- 7.4San Juan, ArgentinaNovember 23, 1977 · 222 km N of this epicenter
- 6.94 km ESE of Chimbas, ArgentinaJanuary 15, 1944 · 163 km N of this epicenter
- 6.972 km WNW of Calingasta, ArgentinaJuly 27, 1917 · 271 km NW of this epicenter
- 6.88 km W of Nueve de Julio, ArgentinaJune 11, 1952 · 143 km N of this epicenter
- 6.862 km ESE of Puente Alto, ChileSeptember 4, 1958 · 176 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 25,006 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 43 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 163 km away · intensity IX
10,000 deaths$100 million damage
- 1965M7.3
Central
28 Mar 1965 · 271 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 117 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1971M7.8
Central
9 Jul 1971 · 268 km away · intensity IX
83 deaths$236 million damagetsunami
- 1977M7.5
San Juan Province: Mendoza
23 Nov 1977 · 211 km away · intensity IX
65 deaths$80 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.