What caused the M 8.3 earthquake in Chile on September 16, 2015?

[davenn]

just offshore of Chile M 8.3

Time 2015-09-16 22:54:32 UTC
Location 31.563°S 71.737°W
Depth 25.0 km
Tsunami alert issued

http://www.sydneystormcity.com/seismograms.htm

Dave

 

[davenn]

my seismogram ... the surface waves are max'ing out the sensor

 

[StevieTNZ]

http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=11514540

A powerful magnitude-8.3 earthquake shook Chile's capital Santiago, causing buildings to sway and people to take refuge in the streets. Several strong aftershocks hit within minutes as tsunami alarms sounded in the nearby port of Valparaiso.

Chilean authorities issued a tsunami alert for the country's entire coast, and U.S. officials posted an alert for Hawaii. Chile's emergency office warned that big waves caused by the quake could hit the coast by 11 p.m (local time).

Here in NZ:

The Ministry of Civil Defence has issued a tsunami warning for East Cape, Chatham Islands, Coromandel and Banks Peninsula.

 

[Astronuc]

http://earthquake.usgs.gov/earthquakes/eventpage/us20003k7a#general_summary
http://earthquake.usgs.gov/earthquakes/eventpage/us20003k7a#scientific_finitefault:us_us20003k7a

http://ptwc.weather.gov/text.php?id=pacific.TSUPAC.2015.09.17.0225

TSUNAMI THREAT FORECAST
-----------------------

  * TSUNAMI WAVES REACHING MORE THAN 3 METERS ABOVE THE TIDE
    LEVEL ARE POSSIBLE ALONG SOME COASTS OF:

        CHILE.

  * TSUNAMI WAVES REACHING 1 TO 3 METERS ABOVE THE TIDE LEVEL ARE POSSIBLE ALONG SOME COASTS OF: 

       FRENCH POLYNESIA.

  * TSUNAMI WAVES REACHING 0.3 TO 1 METERS ABOVE THE TIDE LEVEL ARE POSSIBLE FOR SOME COASTS OF:

      MEXICO... ECUADOR... PERU... ANTARCTICA... JAPAN... NEW
      CALEDONIA... NEW ZEALAND... MARSHALL ISLANDS... FIJI... SAMOA...
      AMERICAN SAMOA... COOK ISLANDS... TOKELAU... VANUATU...
      KIRIBATI... JOHNSTON ISLAND... PALMYRA ISLAND... HOWLAND AND
      BAKER... TONGA... WALLIS AND FUTUNA... PITCAIRN ISLANDS...
      NIUE... SOLOMON ISLANDS... RUSSIA... HAWAII... AND NW HAWAIIAN ISLANDS.

  * TSUNAMI WAVES ARE FORECAST TO BE LESS THAN 0.3 METERS ABOVE
    THE TIDE LEVEL FOR THE COASTS OF
 
      EL SALVADOR... GUATEMALA... HONDURAS... COSTA RICA...
      NICARAGUA... PANAMA... COLOMBIA... AUSTRALIA... PHILIPPINES...
      TAIWAN... CHINA... NORTHERN MARIANAS... GUAM... PALAU... YAP...
      POHNPEI... CHUUK... KOSRAE... NAURU... WAKE ISLAND... MIDWAY
      ISLAND... JARVIS ISLAND... TUVALU... PAPUA NEW GUINEA...
      INDONESIA... VIETNAM... MALAYSIA... AND BRUNEI.

 

[StevieTNZ]

The country's navy said waves up to 4.5 metres had hit city of Coquimbo. Chile state TV showed water flowing in streets of Concon, a coastal town known for its beautiful beaches. Higher water was also seen in other cities.

http://www.stuff.co.nz/world/americas/72142860/earthquake-measuring-83-hits-chile

 

[davenn]

here's the processed seismogram from my sensor ...