Effects on the Czech Lands of the 1815 eruption of Mount Tambora: responses, impacts and comparison with the Lakagígar eruption of 1783

Abstract

The eruption of Mount Tambora in Indonesia in 1815 was one of the most powerful of its kind in recorded history. This contribution addresses climatic responses to it, the post-eruption weather, and its impacts on human life in the Czech Lands. The climatic effects are evaluated in terms of air temperature and precipitation on the basis of long-term homogenised series from the Prague-Klementinum and Brno meteorological stations, and mean Czech series in the short term (1810–1820) and long-term (1800–2010). This analysis is complemented by other climatic and environmental data derived from rich documentary evidence. Czech documentary sources make no direct mention of the Tambora eruption, neither do they relate any particular weather phenomena to it, but they record extremely cold and wet summers for 1815 and 1816 (the "Year Without a Summer") that contributed to bad grain harvests and widespread grain price increases in 1817. Possible reasons for the cold summers in the first decade of the 19th century cited in the contemporary press included comets, sunspot activity, long-term cooling and finally – as late as 1817 – earthquakes with volcanic eruptions. Here, the Tambora event is compared with the 1783 eruption of Lakagígar in Iceland, with its clearly-pronounced post-volcanic effects on the weather in central Europe (dry fog, heavy thunderstorms, optical phenomena) and the occurrence of significant cold temperature anomalies in winter 1783/84, spring 1784 and the summer and autumn of 1785. These appeared clearly in central European series, Prague-Klementinum included. Comparison of the two eruptions shows that the effects of the Lakagígar eruption in the Czech Lands were climatologically stronger those of the Tambora eruption, while the opposite held for societal responses.