(CNN) Medieval observations of the Moon are helping modern-day researchers study a mysterious cluster of volcanic eruptions on Earth.
Monks and other writers of the era described lunar eclipses in detail, when the Moon is completely in the Earth’s shadow. The incident at this time was thought to foretell disaster.
Their writing often mentions a reddish orb around the eclipsed moon, as well as more unusual instances where the eclipsed moon appears to disappear from the sky entirely.
The Japanese poet Fujiwara no Teika wrote, “The ancients had never seen it as at this time, the position of the moon’s disk was not visible, just as if it had disappeared during an eclipse … It was truly something to fear,” wrote the Japanese poet Fujiwara no Teika, 2 An unprecedented dark eclipse seen on December 12, 1229.
What historians didn’t know: An exceptionally dark eclipse is associated with the presence of large amounts of volcanic dust in the atmosphere, according to Sebastien Gillet, a senior research associate at the Institute of Environmental Sciences at the University of Geneva. .
Gillette Believes that medieval manuscripts contain an important source of information about a large but little-understood volcanic eruption In the world.
“Improving our knowledge of these otherwise enigmatic eruptions is critical to understanding whether and how past volcanism may have influenced not only climate but also society in the Middle Ages,” Gillett said in a news release.
Over a five-year period, Gillett and his colleagues searched 12th- and 13th-century European, Middle Eastern, and East Asian sources for descriptions of the moon, which — when combined with ice core and tree ring data — allowed more accurate dating of what scientists thought was the moon. Could be the biggest volcanic eruption the world has ever seen.
Of a total of 64 lunar eclipses that occurred in Europe between 1100 and 1300, the study found, Published April 5 in the journal NatureFound 51 documentations. In six of these cases, these documents also state that the moon was exceptionally dark — in May 1110, January 1172, December 1229, May 1258, November 1258, and November 1276.
These dates correspond to five major volcanic eruptions identified from traces of volcanic ash found in polar ice cores – in 1108, 1171, 1230, 1257 and 1276. Lombok Island in Indonesia.)
“These eruptions were significantly more powerful than most well-known volcanic eruptions in recent history,” Gillett said. “One of these powerful eruptions, the 1257 eruption of Samlas, stands as one of the largest volcanic eruptions of the past millennium.”
“The resulting volcanic aerosols blocked sunlight and caused major climate disruptions. Historical records show that the following summer in Europe … was one of the coldest summers recorded in the last millennium.”
Researchers believe the volcanic eruption occurred three to 20 months before the eclipse, based on observations of recent eruptions and their effects on lunar eclipses.
“We only knew about these eruptions because they left traces on the ice in Antarctica and Greenland,” the study said. co-author Clive Oppenheimer, a professor at the University of Cambridge, said in a news release.
“By combining data from ice cores and descriptions from medieval texts, we can now better estimate when and where some of the largest eruptions of this period occurred.”
The Little Ice Age
Climate scientists typically trace past volcanic eruptions by measuring the amount — and acidity — of volcanic ash in cores drilled from polar ice or by inferring sudden temperature changes in tree ring records.
However, these sources sometimes conflict, because volcanic eruptions disrupt weather patterns in different ways depending on their location, intensity and timing, said Andrea Sim and Eduardo Zorita, chair of forest growth and dendroecology at the Institute of Forest Sciences in Freiburg, Germany. , Helmholtz-Zentrum Heron, a senior scientist at a German research center, commented on the study.
“The strength of Gillett and colleagues’ study lies in the precision with which the authors estimated the timing of volcanic eruptions — pinpointing the year and, in some cases, even the month of the event,” the pair noted. Seim and Zorita were not involved in the study.
The study says the new research will help shed light on the onset of the Little Ice Age, a period of cold weather between 1280 and 1340 that disrupted harvests, saw the advance of European glaciers and, according to some historians, leading to changes in social and economic systems.