Evidence of the Eldgjá (Iceland) eruption in the GISP2 Greenland ice core: relationship to eruption processes and climatic conditions in the tenth century

Abstract

Glaciochemical studies and the evaluation of tephra in the GISP2 ice core provide information on the characteristics and potential environmental and climatic effects of the mid- to late AD 930s voluminous fissure eruption of Eldgjá, Iceland. The similarity in the chemical composition of basaltic glass shards found in a section of core dated at AD 938 ± 4 compared to proximal glass from the Eldgjá eruption verifies the presence of Eldgjá debris. A dacitic glass present in the same layer probably originated from Eldgjá as well, in which case Eldgjá was the primary contributor of sulphur-rich aerosols to the atmosphere in the late AD 930s. We cannot completely exclude the possibility that another explosive eruption in the AD 930s produced this dacitic glass. Estimated maximum stratospheric loading is 100 X 1012 g H 2SO4 over a 3-6 year period following the eruption, but loading could be as low as half of that value. A search of historical and proxy records for the late AD 930s to early 940s fail to show a consistent period of climatic cooling, especially considering the lack of an absolute date for the Eldgjá eruption. This inconsistent response is similar to that observed after the equally voluminous AD 1783 fissure eruption of Laki, Iceland, using the same proxy data sets. However, a marked drop in surface temperatures in the Northern Hemisphere follows the Laki eruption.

Rhyolitic tephra horizons in northwestern Europe and Iceland from the AD 700s–800s: a potential alternative for dating first human impact

“…n = analyses. Á sólf-1 is correlated with the Eldgjá tephra, which is dated to the ad mid-930s (Zielinski et al, 1995) Á sólf-1 Á sólf-2 Á sólf-3 Á sólf-4a Á sólf-4b Á sólf-5 Á sólf-6a Á sólf-6b n = 9 n = 12 n = 8 n = 6 n = 6 n = 8 n = 11 n = 6 Table 2 Mean geochemical analyses and standard deviations (1 s) of the ad 860 tephra, groups A and B and the rhyolitic component of the Landnám tephra. n = number of analyses.…”

Conceptual Models of 1200 Years of Icelandic Soil Erosion Reconstructed Using Tephrochronology

“…AD 920 (K 920) (Hafl idason et al 1992), and the Eldgjá tephra of ca. AD 935 (E 935) (Zielinski et al 1995). In addition, other tephra horizons used in this study have been historically dated to AD 1300, AD 1341, AD 1357, AD 1500, AD 1510, AD 1721, AD 1755, AD 1821, AD 1823, AD 1918, and AD 1947(Einarsson et al 1980Larsen et al 1999;Thorarinsson 1967Thorarinsson , 1975.…”

Tephra isochrons and chronologies of colonisation

“…Sigl et al (2015) claim to have resolved the discrepancies between ice cores chronologies, by high resolution measuring of 10 Be concentrations in four ice cores (NEEM-2011-S1, TUNU2013 and NGRIP from Greenland and the West Antarctic Ice Cheet Divide Core), improved annual-layer counting, reinterpretation of tephra and sulphate spikes and using tree ring and historical records and other independent age information. All tephra dates that are based on ice core chronologies using, or referencing, GICC05 (Vinther et al, 2006) Zielinski et al, 1995) and to A.D. 933 ± 1 (GICC05 chronology: Vinther et al, 2006). An adjustment of 6 years is suggested by Baillie and McAneney (2015) and the date of A.D. 939 is used by Sigl et al (2015).…”

“…Grönvold et al, 1995;Zielinski et al, 1997;Larsen et al, 1999; et al, 1980;Larsen, 1984;Hafliðason et al, 1992;Zielinski et al, 1995;Sigl et al, 2015; Þórarinsson, 1967;Larsen and Þórarinsson, 1977;Larsen et al, 1999;Sigurðsson, 1982;Hafliðason et al, 2000Hafliðason et al, H-1158 Hekla 1158 Þórarinsson, 1967;Einarsson et al, 1988;Larsen et al, 1999 V- Þórarinsson, 1958;1976;Larsen, 1982;1984;Hafliðason et al, …”