QuakeScout
Magnitude7.0

Reviewed by USGSChile11y ago

M7.0 earthquake 25 km WNW of Illapel, Chile

Wednesday, September 16, 2015, 23:18:41 UTC · 31.562°S, 71.426°W

A magnitude 7.0 earthquake struck 25 km WNW of Illapel, Chile on Wednesday, September 16, 2015, 23:18:41 UTC, at a depth of 28.4 km (shallow). USGS received 57 “Did You Feel It?” reports, with a maximum reported intensity of VIII (severe). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M8.3 on September 16, 2015.

Magnitude
7.0
Major · mww
Depth
28 km
Shallow
Felt reports
57
Max intensity VIII
Est. shaking
VII
Very strong (ShakeMap)
PAGER alert
Green
Impact estimate
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

477 kilotons of TNT

That is about 32 times the Hiroshima bomb. It released about 1,000 times the energy of a magnitude 5.0.

Tectonic setting

119 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

28 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.

PlaceIntensityReportsDistance
Santiago, Metropolitana, ChileV · Moderate17224 km
Ovalle, Coquimbo, ChileVIII · Severe5113 km
San Juan, San Juan, ArgentinaV · Moderate4276 km
Mendoza, Mendoza, ArgentinaIV · Light3287 km
Illapel, Coquimbo, ChileVIII · Severe238 km
Viña del Mar, Valparaíso, ChileV · Moderate2163 km
La Rioja, La Rioja, ArgentinaIV · Light2500 km
Buenos Aires, Buenos Aires, ArgentinaIII · Weak21265 km
Luján, Buenos Aires, ArgentinaII · Weak21198 km
La Serena, Coquimbo, ChileVII · Very strong1187 km
Salamanca, Coquimbo, ChileVII · Very strong156 km
Valparaíso, Valparaíso, ChileVI · Strong1167 km
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 populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 200 km

USGS lists 696 M2.5+ earthquakes within 200 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.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.0
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.153 km W of Ovalle, Chile11y ago · 119 km N of this epicenter
  2. 4.276 km WNW of Illapel, Chile11y ago · 50 km W of this epicenter
  3. 4.123 km W of Ovalle, Chile11y ago · 110 km N of this epicenter
  4. 4.060 km W of Ovalle, Chile11y ago · 111 km N of this epicenter
  5. 4.243 km W of Ovalle, Chile11y ago · 112 km N of this epicenter
  6. 4.940 km W of Ovalle, Chile11y ago · 113 km N of this epicenter
  7. 4.764 km WSW of Ovalle, Chile11y ago · 90 km NW of this epicenter
  8. 4.249 km NW of Illapel, Chile11y ago · 33 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 780 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.348 km W of Illapel, ChileSeptember 16, 2015 · 24 km W of this epicenter
  2. 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 93 km S of this epicenter
  3. 8.145 km NNW of Illapel, ChileApril 6, 1943 · 34 km N of this epicenter
  4. 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 180 km S of this epicenter
  5. 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 120 km S of this epicenter
  6. 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 108 km S of this epicenter
  7. 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 184 km S of this epicenter
  8. 7.237 km S of San Antonio, ChileMarch 18, 1931 · 263 km S of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 56 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 29,200 recorded deaths. The most severe:

  1. 1861

    Mendoza, San Luiz

    20 Mar 1861 · 283 km away · intensity IX

    14,000 deathsExtreme damage ($25M+)tsunami

  2. 1944M6.9

    San Juan Province

    15 Jan 1944 · 278 km away · intensity IX

    10,000 deaths$100 million damage

  3. 1906M8.2

    South Central

    17 Aug 1906 · 169 km away · intensity XI

    4,000 deaths$100 million damagetsunami

  4. 1965M7.3

    Central

    28 Mar 1965 · 96 km away

    400 deaths$125 million damage

  5. 1920M6.7

    Mendoza

    17 Dec 1920 · 288 km away · intensity VIII

    400 deathsSevere damage ($5–24M)

  6. 1985M8.0

    Central Coast, San Antonio, Valparaiso

    3 Mar 1985 · 177 km away · intensity VIII

    180 deaths$1.5 billion damagetsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

Closest city pages