Naaju Breaking News, Live Updates, Latest Headlines, Viral News, Top Stories, Trending Topics, Videos
[ad_1]
The largest volcanic eruption of the last 5,000 years was in Cerro Blanco, in the central Andes, Argentina, some 4,200 years ago, according to research conducted by a team of Spanish-Argentinian scientists. The studied eruption has revealed a cloud of gas and ash reaching a height of 32 km which spread over an area of 500 000 km2, which corresponds almost to the whole of the Spanish territory .
"With the data known today, it is the largest of the period," says geologist Jose Luis Fernández Turiel, of the Institute of Earth Sciences Jaume Almera of the CSIC and Barcelona. first author of the work published in the magazine Geological studies. The researchers found ash from this eruption 400 kilometers from the volcano, near the city of Santiago del Estero. Cerro Blanco is located 4,400 meters above sea level, at the southern tip of the Andean plateau, which today corresponds to the province of Catamarca, in the north-east of the country.
The research conducted by Fernández Turiel aimed to determine the connection between arsenic in water and volcanic ash. However, by collecting dozens of ash samples in this Andean region, scientists discovered that almost all of them came from a single eruption. "The works are changing the model of active volcanism that we had in the Andean region.Until now, it was thought that in the central volcanic area everything worked in the same way as in the southern zone: many volcanoes with many eruptions over time.We found that there were few eruptions, but with a high volume of magma and a very high explosivity, "says Fernández Turiel.
The authors estimate that the eruption of Cerro Blanco had a volcanic explosive index of 7, similar to that which destroyed 3,000 years ago the Minoan civilization of Thera, the Greek island known today. Under the name of Santorini. According to his estimates, the volume of magma has doubled that of the eruption of the Indonesian volcano Tambora of 1815, responsible for the decrease in global temperature. The eruption of Cerro Blanco caused the collapse of the back of the volcano and formed a boiler six kilometers wide.
Magma and volcanic ash have ended with life in its surroundings. This helps to understand the lack of hunter-gatherer societies in the region, according to Argentina Norma Ratto, archaeologist at the Institute of Cultures of the University of Buenos Aires and Conicet (Council National Council for Scientific and Technical Research). "About 80 kilometers from here, in Antofagasta, there are records of occupation 10,000 years ago, but in the region where we work, the oldest dates back 1,000 years before our era. about 3,000 years ago, "says Ratto. . "Throughout the region, there are high-rise sanctuaries with volcano offerings that reflect the ritual of the people, which combines eruptions with the wrath of the gods," he adds.
The researchers studied 62 outcrops in the region and collected more than 230 ash samples in different campaigns, which were badyzed using different petrological and geochemical techniques to determine their origin. The University of Las Palmas de Gran Canaria and the Institute of Natural Resources and Agrobiology of Salamanca (Spain), as well as the National University of Mar del Plata and the University of Tucumán (Argentina) also participated in these workshops.
.
[ad_2]
Source link
