Reviewed by USGSChile11y ago
M8.3 earthquake 48 km W of Illapel, Chile
Wednesday, September 16, 2015, 22:54:32 UTC · 31.573°S, 71.674°W
A magnitude 8.3 earthquake struck 48 km W of Illapel, Chile on Wednesday, September 16, 2015, 22:54:32 UTC, at a depth of 22.4 km (shallow). USGS received 1,216 “Did You Feel It?” reports, with a maximum reported intensity of IX (violent). The USGS PAGER alert is orange: significant casualties and damage are likely. No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
Tsunami flagUSGS sets this flag for large events in oceanic regions so tsunami warning centers review them. It does not by itself mean a tsunami occurred. Check tsunami.gov and local authorities for official messages.
- Magnitude
- 8.3
- Great · mww
- Depth
- 22 km
- Shallow
- Felt reports
- 1,216
- Max intensity IX
- Est. shaking
- VIII
- Severe (ShakeMap)
- PAGER alert
- Orange
- Impact estimate
- Tsunami
- Flag
- Check tsunami.gov
Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
43 megatons of TNT
That is about 2,823 times the Hiroshima bomb. It released about 89,125 times the energy of a magnitude 5.0.
Tectonic setting
95 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
22 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Santiago, Metropolitana, Chile | V · Moderate | 506 | 231 km |
| Viña del Mar, Valparaíso, Chile | VI · Strong | 46 | 161 km |
| Mendoza, Mendoza, Argentina | V · Moderate | 43 | 306 km |
| Córdoba, Córdoba, Argentina | IV · Light | 43 | 711 km |
| Buenos Aires, Buenos Aires, Argentina | III · Weak | 42 | 1287 km |
| San Bernardo, Metropolitana, Chile | VI · Strong | 30 | 243 km |
| Puente Alto, Metropolitana, Chile | IV · Light | 25 | 249 km |
| Concepción, Bío Bío, Chile | III · Weak | 25 | 597 km |
| La Serena, Coquimbo, Chile | VII · Very strong | 24 | 191 km |
| Ovalle, Coquimbo, Chile | VIII · Severe | 21 | 120 km |
| Valparaíso, Valparaíso, Chile | V · Moderate | 16 | 164 km |
| San Juan, San Juan, Argentina | V · Moderate | 14 | 299 km |
USGS PAGER estimate
Who was exposed to shaking
Modelled from the ShakeMap and population data. Alert level orange: significant casualties and damage are likely.
- VIII · Severe shaking
- 158,000 people
- VII · Very strong shaking
- 698,000 people
- VI · Strong shaking
- 1.8 million people
- V · Moderate shaking
- 7.2 million people
- IV · Light shaking
- 1.1 million people
After the main event
Aftershocks within 400 km
USGS lists 724 M2.5+ earthquakes within 400 km in the following 30 days; the largest was M6.6 on September 21, 2015. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.153 km W of Ovalle, Chile11y ago · 117 km N of this epicenter
- 4.276 km WNW of Illapel, Chile11y ago · 29 km NW of this epicenter
- 4.123 km W of Ovalle, Chile11y ago · 114 km N of this epicenter
- 4.060 km W of Ovalle, Chile11y ago · 107 km N of this epicenter
- 4.243 km W of Ovalle, Chile11y ago · 111 km N of this epicenter
- 4.940 km W of Ovalle, Chile11y ago · 112 km N of this epicenter
- 4.764 km WSW of Ovalle, Chile11y ago · 85 km N of this epicenter
- 4.4102 km WNW of Cartagena, Chile11y ago · 220 km SW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 772 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 · 96 km S of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 45 km NE of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 175 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 126 km S of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 114 km SE of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 182 km S of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 262 km S of this epicenter
- 7.259 km S of San Antonio, ChileApril 9, 1985 · 284 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 51 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4,795 recorded deaths. The most severe:
- 1906M8.2
South Central
17 Aug 1906 · 162 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 102 km away
400 deaths$125 million damage
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 173 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
- 1971M7.8
Central
9 Jul 1971 · 112 km away · intensity IX
83 deaths$236 million damagetsunami
- 1822M8.5
Valparaiso, Quillota, Concon, Aconcagua
20 Nov 1822 · 162 km away · intensity XI
72 deathsExtreme damage ($25M+)tsunami
- 2015M8.3
Central
16 Sep 2015 · 0 km away · intensity IX
15 deaths$600 million damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.