Hekla 3 eruption
999 BCE.
Shown on the map at 63.983°, -19.700°.
The Hekla 3 eruption (H-3) c. 1000 BC is considered the most severe eruption of Hekla during the Holocene. It threw about 7.3 cubic kilometres (1.8 cu mi) of volcanic rock into the atmosphere, placing its Volcanic Explosivity Index (VEI) at 5. This would have caused a volcanic winter, cooling temperatures in the Northern Hemisphere for several years afterwards. An eighteen-year span of global cooling that is recorded in Irish bog oaks has been attributed to H-3. The eruption is detectable in Greenland ice cores, the bristlecone pine sequence, and the Irish oak sequence of extremely narrow growth rings. Andy Baker's team of researchers dated it to 1021 BC ±130. A "high chronology" (earlier) interpretation of the above results is preferred by Baker, based also on growth of stalagmites. In Sutherland, northwest Scotland, a spurt of four years of doubled annual luminescent growth banding of calcite in a stalagmite is datable to 1135 BC ±130. A rival, "low-chronology" interpretation of the eruption has been made by Andrew Dugmore: 2879 BP (929 BC ±34). In 1999, Dugmore suggested a non-volcanic explanation for the Scottish results.
Text from the Wikipedia article Hekla 3 eruption, licensed CC BY-SA 4.0.