I first came across the term "Supervalcanoes" in Bill Bryson's 'A short history of nearly everything'. It was a really fascinating book, which lists out the possible scenarios which could bring about the end of Homo sapiens, one of which happens to be a "Super volcano". Yesterday, I came across an article in the 'Hindu' about a 13th century eruption in Indonesia, which by all accounts could be called the mother of all volcanoes in the last 3700 years. I followed up on that story and came across some very interesting and scary facts.
Scientists had always suspected that a massive catastrophic event had triggered of what is known as the Little Ice Age, sometime after 1250. The Little Ice Age has been abundantly depicted in contemporary accounts of advancing mountain glaciers that destroyed villages and paintings of ice-skating on frozen Dutch canals or on London’s River Thames. Chilling of the Northern Hemisphere was pronounced: cold summers, incessant rains, floods, and resulting poor harvests, according to medieval records. A volcano in Indonesia may be the location of a massive “mystery eruption” that has perplexed volcanologists for decades, according to a new study. The Indonesia’s Samalas volcano, is part of the Rinjani Volcanic Complex on Lombok Island.
Segara Anak Crater Lake formed after the eruption
The eruption occurred in 1257, and it could have been one of the events that started a 600-year cold period called the Little Ice Age. The previously unattributed eruption was an estimated eight times as large as the famed Krakatau explosion (1883) and twice as large as Tambora in 1815,
Volcanic eruptions release sulfur into the atmosphere. After cooling the Earth by reflecting sunlight, this material eventually falls back on Earth and gets deposited on ice sheets. These sulfur samples can be identified in ice cores obtained from polar regions. From the records, Clive Oppenheimer, a volcanologist at the University of Cambridge, found that an eruption in 1257 could have been responsible for the largest release of sulfur in the past 7,000 years.
But locating the volcanic source can be tricky. For the 1257 eruption, there were many candidates: Okataina in New Zealand, El Chichón in Mexico, Quilotoa in Ecuador, and Samalas in Indonesia.
To narrow down their choice, Franck Lavigne at the Pantheon-Sorbonne University and his colleagues had to consider many types of data, as they describe in a paper just published in the PNAS. They combined historical data, geochemistry evidence, carbon dating, and physical data to arrive at the conclusion.
The cataclysm blasted 10 cubic miles (40 cubic kilometers) of debris up to 27 miles (43 kilometers) high into the sky, producing fallout that settled around the world. Near the volcano itself, it settled into thick deposits that the team sampled in over 130 places to produce a stratigraphic and sedimentologic picture of the way the eruption unfolded. Further afield, the volcanic sulfate and tephra became locked in ice core samples taken from both Greenland and Antarctica.
Volcanic eruptions can have a large impact on the climate, which will then have social, economic, and environmental knock-on effects. Though the eruption was equatorial, its impact was felt and noted around the world. "The climate was disturbed for at least two years after the eruption, Medieval chronicles, for example, describe the summer of 1258 as unseasonably cold, with poor harvests and incessant rains that triggered destructive floods—a "year without a summer." The winter immediately following the eruption was warmer in western Europe, however, as would be expected from high-sulfur eruptions in the tropics. The team cites historical records from Arras (northern France) that speak of a winter so mild "that frost barely lasted for more than two days," and even in January 1258 "violets could be observed, and strawberries and apple trees were in blossom. In Indonesia records describe a catastrophe of a far more destructive and immediate sort. Found written on palm leaves, the Old Javanese texts of theBabad Lombok describe a massive volcanic blast that formed a caldera at Mount Samalas, on Lombok Island. The writing describes the deaths of thousands of people due to deadly ashfall and pyroclastic flows that destroyed Pamatan, capital of the kingdom, and surrounding lands. Archaeologists recently put a date of 1258 on the skeletons of thousands of people who were buried in mass graves in London. "We cannot say for sure these two events are linked but the populations would definitely have been stressed," Prof Lavigne told BBC News.
Source:
BBC news
National Geographic News
IBT Times
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