Reviewed by USGSChile40y ago
M5.5 earthquake 71 km SSW of Antofagasta, Chile
Sunday, March 15, 1987, 06:03:02 UTC · 24.285°S, 70.557°W
A magnitude 5.5 earthquake struck 71 km SSW of Antofagasta, Chile on Sunday, March 15, 1987, 06:03:02 UTC, at a depth of 23.6 km (shallow). It is the strongest earthquake within 300 km since an M6.2 on March 6, 1987.
- Magnitude
- 5.5
- Moderate · mw
- Depth
- 24 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
3 kilotons of TNT
That is about 1/6 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.
Tectonic setting
92 km
from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
24 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 75 km
USGS lists 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M6.1 on March 22, 1987. 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 238 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2121 km SSE of San Pedro de Atacama, ChileDecember 9, 1950 · 271 km E of this epicenter
- 8.060 km W of Diego de Almagro, ChileDecember 4, 1918 · 242 km S of this epicenter
- 7.79 km SSW of Taltal, ChileDecember 28, 1966 · 134 km S of this epicenter
- 7.684 km SSE of Antofagasta, ChileMarch 5, 1987 · 42 km E of this epicenter
- 7.583 km NNE of Taltal, ChileJuly 13, 1936 · 63 km SE of this epicenter
- 7.550 km WNW of Diego de Almagro, ChileJune 8, 1909 · 208 km S of this epicenter
- 7.454 km WSW of Diego de Almagro, ChileOctober 4, 1983 · 250 km S of this epicenter
- 7.334 km NE of Tocopilla, ChileDecember 21, 1967 · 275 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 13 recorded deaths. The most severe:
- 1983M7.3
Northern: Copoapo-Chanaral
4 Oct 1983 · 250 km away · intensity VII
5 deaths$1 million damagetsunami
- 1966M7.8
Taltal, Catalina
28 Dec 1966 · 136 km away · intensity VIII
3 deathsUnder $1 million damagetsunami
- 1946M7.9
Northern
2 Aug 1946 · 246 km away
2 deathsSevere damage ($5–24M)tsunami
- 1936M7.3
Taltal
13 Jul 1936 · 61 km away
1 deathModerate damage ($1–5M)tsunami
- 1987M7.3
Antofagasta, Arica
5 Mar 1987 · 42 km away · intensity VI
1 deathModerate damage ($1–5M)tsunami
- 1971M6.3
Catalina, Antofagasta
17 Jun 1971 · 192 km away · intensity V
1 deathModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.