Posted by feww on March 10, 2010
Concepcion: The Roving City Moved by 305cm
The M8.8 megaquake that struck the coast of Chile on February 27, moved the city of Concepcion at least 3 meters (10 feet) to the west, shifting other parts of South America, and places as far apart as the Falkland Islands and Fortaleza, Brazil, researchers say.
Initial measurements, produced from data collected by researchers from four universities and earthquake monitoring centers, as well as geophysicists on the ground in Chile, who depicted the power behind the Chilean megaquake, listed as the fifth-most-powerful instrumentally-recorded earthquake ever.
Buenos Aires, the capital of Argentina moved west by about 2.5cm (1 inch). And Santiago, the Chilean capital, moved about 28cm (11 inches) to the west-southwest. The cities of Mendoza and Valparaiso, located northeast of Concepcion, also moved by more than 13cm, and 27cm respectively.
This partial map of South America shows how far principal cities in Chile moved as a result of the February megaquake. Credit: University of Hawaii. Click Image to enlarge.
This map of South America shows movement of points on the continent as a result of the February megaquake. Credit: University of Hawaii. Click Image to enlarge
The megaquake occurred in a region of the Pacific Ocean which is known as the “Pacific Ring of Fire,” an area of major seismic activity. Major seismic stresses are caused because tectonic plates move press against each other at various fault zones, resulting in earthquakes which release built-up geologic stresses along these convergence zones.
The Chilean megaquake occurred where the Nazca tectonic plate subducted [plunged beneath] the neighboring South American plate.
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Posted in Buenos Aires, Chile Quake, earthquake, Santiago moved | Tagged: argentina, Argentina quake impact, Brazil, chile movement, Concepción, Concepcion movement, Falkland Islands, Fortaleza, Nazca tectonic plate, Pacific Ocean, South America, tectonic plates | 4 Comments »
Posted by feww on October 24, 2009
How El Niño and La Niña affect Rainfall
El Niño 1997
La Niña, 1988
El Niño and its counterpart La Niña alter weather patterns across the world. These images show the strongest El Niño and La Niña events of the past twenty years and their impact on rainfall over North and South America.
The top image pair shows the El Niño event of 1997, and the direct correlation between warm surface waters and rainfall. The 1997 El Niño was unusually strong and brought heavy rain to northwest South America and the southern United States. Cooler ocean temperatures caused drought in Australia and Indonesia, as shown in the 1997 rainfall anomaly image.
The lower image pair shows La Niña in 1988 . La Niña occurs when the eastern Pacific off the coast of South America cools. The unusually cold ocean cools the atmosphere above it. The cool, dense air means less rain falls over the cold waters in the eastern equatorial Pacific. Image reveals that the drought reached Peru and Ecuador in northwest South America. Globally, La Niña causes unusually heavy rain in India, Southeast Asia, Australia, and southeastern Africa.
NASA Earth Observatory images by Rob Simmon and Jesse Allen, based on data from the National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer and the Global Precipitation Climatology Project at NASA Goddard Space Flight Center. Caption by Holli Riebeek. [Edited for brevity by FEWW]
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Posted in Australian drought, rain in India, South America weather, Southeast Asia rain, southeastern Africa | Tagged: El Niño, El Niño and the US, La Niña, La Niña and weather patterns, rainfall, South America, Trade winds | Leave a Comment »
Posted by feww on May 12, 2008
A Shrinking World Series:
Update #1 – Millions of tons of volcanic ash continue to rain down on Patagonia
Ten days after the Chilean volcano erupted for the first time in thousands of years, volcanic ash continues to rain down in Patagonia.
An eruption on the morning of May 2, 2008 forced the evacuation of more than 4,000 people from the town of Chaitén nearby (10 kilometers distant from the volcano) and caused the death of an elderly woman. The eruption continued through to May 4. Towns such as Futaleufú were affected and water supplies were contaminated. The town of Chaitén and Futaleufú were completely evacuated on the morning of May 6, 2008, due to a massive new eruption, with pyroclastic flows and possible emerging of lava. (Source)
The scientists have expressed grave concerns about the potential long-term environmental damage and the harm to the health of people and animals in the area.
“It has spoiled lakes, rivers and lagoons, coated plants in a dense layer of gray, and altered the sensitive habitat of animals now struggling to survive. Satellite images show a white stripe smeared across the southern part of South America.” Reuters said.
A bicycle covered in volcanic ash in Futaleufu town, about 1450 km south of Santiago May 11, 2008. Chaiten volcano began erupting May 2, 2008. (Photo: REUTERS/Ivan Alvarado) Image may be subject to copyright. See FEWW Fair Use Notice.
“I am tremendously worried because this is an environmental, social and ecological disaster,” said Alejandro Beletzky, an environmental scientist in Argentina.
“The presence of volcanic ash in the region, which falls constantly, is very risky for humans, plants and animals,” he said near Esquel, about 2,000km southwest of Buenos Aires. (Source)
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Posted in Climate Change, energy, environment, food, health, new zealand, Tourism, Travel | Tagged: active volcano, Add new tag, animal habitat, animals, argentina, Chaiten, chile, Chile volcano, environmental damage, environmental scientist, Esquel, Futaleufú, health risk, lagoons, lava, Patagonia, plants, pyroclastic flows, Reuters, Shrinking World, South America, volcanic ash | 1 Comment »
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