Climatic and societal impacts of a “forgotten” cluster of volcanic eruptions in 1108-1110 CE

Abstract

Recently revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE. Long considered the product of the 1104 CE Hekla (Iceland) eruption, this event can now be associated with substantial deposition seen in Antarctica under a similarly revised chronology. This newly recognized bipolar deposition episode has consequently been deemed to reveal a previously unknown major tropical eruption in 1108 CE. Here we show that a unique medieval observation of a "dark" total lunar eclipse attests to a dust veil over Europe in May 1110 CE, corroborating the revised ice-core chronologies. furthermore, careful evaluation of ice core records points to the occurrence of several closely spaced volcanic eruptions between 1108 and 1110 CE. The sources of these eruptions remain unknown, but we propose that Mt. Asama, whose largest Holocene eruption occurred in August 1108 CE and is credibly documented by a contemporary Japanese observer, is a plausible contributor to the elevated sulfate in Greenland. Dendroclimatology and historical documentation both attest, moreover, to severe climatic anomalies following the proposed eruptions, likely providing the environmental preconditions for subsistence crises experienced in Western Europe between 1109 and 1111 CE.

Cryptotephra from the Icelandic Veiðivötn 1477 CE eruption in a Greenland ice core: confirming the dating of volcanic events in the 1450s CE and assessing the eruption's climatic impact

“…Zanolini et al, 1985;Legrand and Kirchner, 1990;Moore et al, 1991). Delmas et al (1992) suggested that this so-called "1450 event" was derived from a Southern Hemisphere eruption based on a limited coeval signal in Greenland (Hammer et al, 1980) and associated it with the climate cooling in the tree-ring records to attribute it an age of 1452 CE. Langway et al (1995) subsequently identified a bipolar volcanic event to which they attributed an age of 1459 CE, and Zielinski (1995) attributed this to the large mid-15th century volcanic event.…”

“…acidity and electrical conductivity) using tephra is necessary, when possible, as associations with specific events can become em-bedded in the literature with limited supporting evidence, even if only originally proposed as a possibility. For example, associations between chemical indicators and the Hekla 1104 CE and Vesuvius 79 CE eruptions, which were previously used as historical tie points with no uncertainty while building chronologies (Hammer et al, 1980;Zielinski et al, 1994;Vinther et al, 2006), have been found to be inaccurate following re-evaluation of the Greenland ice-core chronologies (Sigl et al, 2015). The volcanic signal previously associated with the Hekla 1104 CE eruption has been re-dated to 1108 CE, and Guillet et al (2020) have recently proposed that it can be linked to an eruption of Mount Asama, Japan; however, at present this is not supported by tephra evidence.…”

Cryptotephra from the Icelandic Veiðivötn 1477 CE eruption in a Greenland ice core: confirming the dating of 1450s CE volcanic events and assessing the eruption's climatic impact

“…In addition to the ice-core and tephra analysis, we quantified the cooling induced by the V1477 eruption, using the NVOLC v2 dataset of Guillet et al (2020), and compared it to other major Icelandic eruptions of the Common Era. The NVOLC v2 dataset includes 13 tree-ring width (TRW) and 12 maximum latewood density (MXD) chronologies spread across the Northern Hemisphere (NH; for further details see Stoffel et al (2015) and Guillet et al (2017)).…”

“…For example, associations between chemical indicators and the Hekla 1104 CE and Vesuvius 79 CE eruptions, that previously have been used as historical tie points with no uncertainty while building chronologies (Hammer et al, 1980;Zielinski et al, 1994;, have been found to be inaccurate following re-evaluation of the Greenland ice-core chronologies (Sigl et al, 2015). The volcanic signal previously associated with Hekla 1104 CE has been re-dated to 1108 CE and Guillet et al (2020) have recently proposed it can be linked to an eruption of Mount Asama, Japan; however, at present this is not supported by tephra evidence. The volcanic signal previously associated with Vesuvius 79 CE has been redated to 87/88 CE by Sigl et al (2015).…”

The sun of Rome is set! Volcanic dust veils and their political fallout

“…Over the past decade, these diverse techniques have been applied in concert, increasingly in collaboration with historians, to investigate the entangled biographies of volcanoes and humankind (13)(14)(15). Climate proxies and chronological accuracy have improved (16,17), and isotopic analysis of the volcanic sulfur fallout in ice cores (18) has been shown to discriminate between tropospheric and stratospheric transport of the volcanic aerosol.…”