The largest volcanic eruption in history
The greatest disasters ever - the worst volcanic eruption in 3,700 years - may have occurred about 800 years ago and may have produced a "Pompeii of the Far East", which would be buried on an island in Indonesia, waiting to be discovered.
The largest ever volcanic eruption in history which spread its ash from one pole of the planet to the other would have originated from the Samalas volcano, located on the Indonesian island of Lombok and dated between May and October 1257.
It was believed that the most devastating eruption of the last 3,700 years was that of the Tambora volcano, but according to a 2013 scientific publication the Samalas volcano eruption was eight times larger in magnitude than the infamous Krakatau explosion of 1883 and twice that of Tambora in 1815.
To solve the mystery it was combined existing results with new data obtained through radiocarbon dating and chemical analyzes of volcanic debris, stratigraphic studies and historical documents.
The cataclysm hurled 40 cubic kilometers of debris into the sky, reaching a height of 43,000 meters. When they fell back, they were deposited all over the planet. Samples of these volcanic deposits taken from over 130 different points were analyzed to obtain a stratigraphic and sedimentological picture that would help understand how the eruption took place.
To make the dating of the eruption more precise, the researchers analyzed samples of charred tree trunks and some branches found on the side of the Samalas and Rinjani volcanoes. The data obtained from radiocarbon placed the eruption around the middle of the 13th century and excluded that the samples analyzed were prior to 1257. In this way, it was possible to exclude other volcanoes, such as El Chichón and Okataina: the eruptions produced by them date back to a period incompatible with this time interval.
Volcanic sulfate and tephra trapped inside ice cores taken from both Greenland and Antarctica were also analyzed. From the analysis of ice cores near both poles it was discovered that the eruption was tropical. The data obtained from the analysis of ice cores narrowed the field further, excluding from the shortlist the Quilitoa volcano in Ecuador, which had produced a massive eruption around the same time.
The results of the study of the geochemical composition of glassy fragments found in the ice layers of both Greenland and Antarctica, however, excluded the Quilitoa volcano, since the glass of its tephras was found to be incompatible with that of the fragments. In contrast, glass from the Samalas volcano was found to be compatible.
Although the eruption was equatorial, it had repercussions on the entire world and the climate was affected for at least two years. This was deduced by analyzing the growth rings of some tree trunks that had unusual growth rates, from climate models and from historical documents found in Europe.
Some medieval chronicles, for example, describe the summer of 1258 as an incredibly cold summer, in which harvests were poor and incessant rains fueled destructive flows: it was “a year without a summer.” The winter immediately following the eruption, however, was warmer in Western Europe: an effect that could be traced back to a highly sulfurous eruption that occurred in the tropics.
Historical documents from Arras, in northern France describe a winter so mild that "the ice barely lasted two days", so much so that in January 1258 "there were even violets, strawberries and apple trees in bloom."
Indonesian historical documents instead speak of a more destructive and immediate catastrophe. Written on palm leaves, the Old Javanese texts of Babad Lombok describe a massive volcanic explosion that formed a caldera on Mount Samalas on the island of Lombok. Thousands of people are reported to have died as ashfall and lethal pyroclastic flows destroyed Pamatan, the kingdom's capital, and surrounding lands. Although the documents do not specify an exact date, combining historical data with scientific evidence of the eruption is possible to prove that the catastrophe occurred by the end of the 13th century.
The records describing eruptions of this magnitude are extremely rare because similar explosions only happen once every 600 years. Furthermore whoever wanted to write a chronicle of such an event would have had to be close to the eruption, but at the same time far enough away so as not to be overwhelmed by it.
In the case of the eruption of the Samalas volcano, a historical testimony much more precious than a written text may remain to be discovered: the remains of the capital Pamatan of the ancient kingdom of Lombok, which was probably buried during the devastating explosion.
Pamatan could represent a 'Pompeii of the Far East', but no one currently know its location.
Link to the publication: https://www.pnas.org/doi/abs/10.1073/pnas.1307520110
