Tectonic Summary
This earthquake occurred at the boundary between the Nazca and South American tectonic plates. The two plates are converging at a rate of 80 mm per year. The earthquake occurred as thrust-faulting on the interface between the two plates, with the Nazca plate moving down and landward below the South American plate.
Coastal Chile has a history of very large earthquakes. Since 1973, there have been 13 events of magnitude 7.0 or greater. The February 27 shock originated about 230 km north of the source region of the magnitude 9.5 earthquake of May, 1960 – the largest earthquake worldwide in the last 200 years or more. This giant earthquake spawned a tsunami that engulfed the Pacific Ocean. An estimated 1600 lives were lost to the 1960 earthquake and tsunami in Chile, and the 1960 tsunami took another 200 lives among Japan, Hawaii, and the Philippines. Approximately 870 km to the north of the February 27 earthquake is the source region of the magnitude 8.5 earthquake of November, 1922. This great quake significantly impacted central Chile, killing several hundred people and causing severe property damage. The 1922 quake generated a 9-meter local tsunami that inundated the Chile coast near the town of Coquimbo; the tsunami also crossed the Pacific, washing away boats in Hilo harbor, Hawaii. The magnitude 8.8 earthquake of February 27, 2010 ruptured the portion of the South American subduction zone separating these two massive historical earthquakes.
A large vigorous aftershock sequence can be expected from this earthquake.
BULLETIN
TSUNAMI MESSAGE NUMBER 11
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
549 AM HST SAT FEB 27 2010
TO - CIVIL DEFENSE IN THE STATE OF HAWAII
SUBJECT - TSUNAMI WARNING SUPPLEMENT
A TSUNAMI WARNING CONTINUES IN EFFECT FOR THE STATE OF HAWAII.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
ORIGIN TIME - 0834 PM HST 26 FEB 2010
COORDINATES - 36.1 SOUTH 72.6 WEST
LOCATION - NEAR COAST OF CENTRAL CHILE
MAGNITUDE - 8.8 MOMENT
MAGNITUDE - 8.4 RICHTER (MS)
LAT - LATITUDE (N-NORTH, S-SOUTH)
LON - LONGITUDE (E-EAST, W-WEST)
TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
PER - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.
EVALUATION
A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG
COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION
SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.
A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE
CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD
COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE
INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST.
TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT
RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI
WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE
CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED
BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH
TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.
THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS
1119 AM HST SAT 27 FEB 2010
MESSAGES WILL BE ISSUED HOURLY OR SOONER AS CONDITIONS WARRANT.
Chile is devastated by the earthquake and tsunami. So far been found about 800 dead. The bridges have collapsed and most of the roads are unusable. The resources are transmitted by air to the affected areas.
I live luckyly far from the zone of disaster.
As I know ocean waves have arrived to Hawaii, Japan and Australia.
Blake Tewa (5 mt)
Joined: Jun 25, 2007
Posts: 680
Location: Florida
Posted:
Wed Mar 03, 2010 4:30 am
Baikal wrote:
Chile is devastated by the earthquake and tsunami. So far been found about 800 dead. The bridges have collapsed and most of the roads are unusable. The resources are transmitted by air to the affected areas.
I live luckyly far from the zone of disaster.
As I know ocean waves have arrived to Hawaii, Japan and Australia.
Thankfully for most other countries hit by the tsunami, the waves turned out to be smaller than they could have been.
View next topic View previous topic
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
