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
Authors: Abbott Peter M. , Plunkett Gill , Corona Christophe , Chellman Nathan J. , McConnell Joseph R. , Pilcher John R. , Stoffel Markus , Sigl Michael 
Published: March 2021

Abstract. Volcanic eruptions are a key source of climatic variability, and
reconstructing their past impact can improve our understanding of the
operation of the climate system and increase the accuracy of future climate
projections. Two annually resolved and independently dated palaeoarchives –
tree rings and polar ice cores – can be used in tandem to assess the
timing, strength and climatic impact of volcanic eruptions over the past
∼ 2500 years. The quantification of post-volcanic climate
responses, however, has at times been hampered by differences between
simulated and observed temperature responses that raised questions regarding
the robustness of the chronologies of both archives. While many
chronological mismatches have been resolved, the precise timing and climatic
impact of two major sulfate-emitting volcanic eruptions during the 1450s CE, including the largest atmospheric sulfate-loading event in the last 700 years, have not been constrained. Here we explore this issue through a
combination of tephrochronological evidence and high-resolution ice-core
chemistry measurements from a Greenland ice core, the TUNU2013 record. We identify tephra from the historically dated 1477 CE eruption of the
Icelandic Veiðivötn–Bárðarbunga volcanic system in direct
association with a notable sulfate peak in TUNU2013 attributed to this
event, confirming that this peak can be used as a reliable and precise
time marker. Using seasonal cycles in several chemical elements and 1477 CE
as a fixed chronological point shows that ages of 1453 CE and 1458 CE can be
attributed, with high precision, to the start of two other notable
sulfate peaks. This confirms the accuracy of a recent Greenland ice-core
chronology over the middle to late 15th century and corroborates the
findings of recent volcanic reconstructions from Greenland and Antarctica.
Overall, this implies that large-scale Northern Hemisphere climatic cooling
affecting tree-ring growth in 1453 CE was caused by a Northern Hemisphere
volcanic eruption in 1452 or early 1453 CE, and then a Southern Hemisphere
eruption, previously assumed to have triggered the cooling, occurred later
in 1457 or 1458 CE. The direct attribution of the 1477 CE sulfate peak to the eruption of
Veiðivötn, one of the most explosive from Iceland in the last 1200 years, also provides the opportunity to assess the eruption's climatic
impact. A tree-ring-based reconstruction of Northern Hemisphere summer
temperatures shows a cooling in the aftermath of the eruption of −0.35 ∘C relative to a 1961–1990 CE reference period and
−0.1 ∘C relative to the 30-year period around the event, as well as a
relatively weak and spatially incoherent climatic response in comparison to
the less explosive but longer-lasting Icelandic Eldgjá 939 CE and Laki
1783 CE eruptions. In addition, the Veiðivötn 1477 CE eruption
occurred around the inception of the Little Ice Age and could be used as a
chronostratigraphic marker to constrain the phasing and spatial variability
of climate changes over this transition if it can be traced in more
regional palaeoclimatic archives.