Showing posts with label Earthquake. Show all posts
Showing posts with label Earthquake. Show all posts
Thursday, May 20, 2010
No tsunami threat to India due to Indonesia earthquake
Friday, March 19, 2010
Earthquake in Chile: A complicated fracture
After closer analysis of the seismic waves radiated by this earthquake during the first 134 seconds after start of the rupture, the researchers came to the conclusion that only the region around the actual epicentre was active during the first minutes. In the second minute the active zone moved north towards Santiago. After that the region south of Concepción became active for a short time. This rupturing trend agrees well with the distribution of the aftershocks during the following three days, as observed by the GEOFON-measuring network of the GFZ up to 03.03.2010.
In the year 1960, the strongest earthquake measured at all to date, with a magnitude of M=9.5, had its origin at Valdivia, south of the region affected now. "The quake of 27 February connects directly to the rupture process of Valdivia," explains Professor Jochen Zschau, Director of the Earthquake Risk and Early Warning Section at the GFZ. "With this, one of the last two seismic gaps along the west coast of South America might now be closed. With the exception of one last section, found in North Chile, the entire earth crust before the west coast of South America has been ruptured within the last 150 years."
The underlying plate tectonic procedure is such that the Nazca-Plate as part of the Pacific Ocean Floor moves eastwards with approximately seventy millimetres per year, collides with South America and thereby pushes under the continent. The hereby developing earthquakes belong to the strongest world-wide. In the course of about one century, the Earth's ruptures completely in a number of strong quakes from Patagonia in the South to Panama in the North. Even Darwin reported, in his diary, of the strong earthquake in Concepción on 20 February 1835 and the resulting Tsunami.
In order to examine the aftershock activity in the now fractured seismic gap, scientists from the GFZ are travelling to Chile on March 13, 2010 where, together with the Chilean Seismological Service, they will set-up a seismological-geodetic network in the area of Concepción-Santiago. Partners from Germany (IFM Geomar, Kiel; Free University of Berlin) and from abroad (Institut de Physique du Globe, Paris; University of Liverpool; United States Geological Survey; IRIS) are also taking part in this measuring campaign. The mission will last about three months. The results, one expects, will be able to provide an insight into the mechanisms of the fracture in the Earth’s crust. This activity is financed on the German side by the GFZ.
Scientists from the GFZ have been examining the collision of the Nazca plate and the South American continent since 1994. As a result of numerous expeditions and measuring campaigns in this area this Potsdam Helmholtz Centre avails of the probably the most dense data record on such a subduction zone. “Within the framework of the DFG Priority Programme “Deformation processes in the Andes”, and with the Geotechnology Project TIPTEQ we have just been able to collect a unique data record for the southern part of the Andes” says Professor Onno Oncken, Director of the Department Geodynamics and Geomaterials at the GFZ, and leader of these studies. "The current quake puts us in the position to precisely compare the tectonics before and afterwards, a unique situation both internationally and in Earth science."
Earthquake in Chile: A complicated fracture
In the year 1960, the strongest earthquake measured at all to date, with a magnitude of M=9.5, had its origin at Valdivia, south of the region affected now. "The quake of 27 February connects directly to the rupture process of Valdivia," explains Professor Jochen Zschau, Director of the Earthquake Risk and Early Warning Section at the GFZ. "With this, one of the last two seismic gaps along the west coast of South America might now be closed. With the exception of one last section, found in North Chile, the entire earth crust before the west coast of South America has been ruptured within the last 150 years."
The underlying plate tectonic procedure is such that the Nazca-Plate as part of the Pacific Ocean Floor moves eastwards with approximately seventy millimetres per year, collides with South America and thereby pushes under the continent. The hereby developing earthquakes belong to the strongest world-wide. In the course of about one century, the Earth's ruptures completely in a number of strong quakes from Patagonia in the South to Panama in the North. Even Darwin reported, in his diary, of the strong earthquake in Concepción on 20 February 1835 and the resulting Tsunami.
In order to examine the aftershock activity in the now fractured seismic gap, scientists from the GFZ are travelling to Chile on March 13, 2010 where, together with the Chilean Seismological Service, they will set-up a seismological-geodetic network in the area of Concepción-Santiago. Partners from Germany (IFM Geomar, Kiel; Free University of Berlin) and from abroad (Institut de Physique du Globe, Paris; University of Liverpool; United States Geological Survey; IRIS) are also taking part in this measuring campaign. The mission will last about three months. The results, one expects, will be able to provide an insight into the mechanisms of the fracture in the Earth’s crust. This activity is financed on the German side by the GFZ.
Scientists from the GFZ have been examining the collision of the Nazca plate and the South American continent since 1994. As a result of numerous expeditions and measuring campaigns in this area this Potsdam Helmholtz Centre avails of the probably the most dense data record on such a subduction zone. “Within the framework of the DFG Priority Programme “Deformation processes in the Andes”, and with the Geotechnology Project TIPTEQ we have just been able to collect a unique data record for the southern part of the Andes” says Professor Onno Oncken, Director of the Department Geodynamics and Geomaterials at the GFZ, and leader of these studies. "The current quake puts us in the position to precisely compare the tectonics before and afterwards, a unique situation both internationally and in Earth science."
Earthquake in Chile: A complicated fracture
Large Earthquake Hits Chile, Generates Tsunami Across Pacific
Tsunami warnings were issued for Hawaii, as well as Australia, New Zealand, Indonesia, Japan, and other countries along the Pacific coastline, as the giant waves triggered by the earthquake reverberated through the entire ocean.
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.
Large Earthquake Hits Chile, Generates Tsunami Across Pacific
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.
Large Earthquake Hits Chile, Generates Tsunami Across Pacific
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