Lake formation and catastrophic dam burst during the late pleistocene Laacher See eruption (Germany)

Abstract

Instantaneous overloading of the Rhine River with tephra during the eruption of the Laacher See Volcano c. 12900 aBP led to the formation of a major dam at the bottleneck oulet of the morphological Neuwied Basin. A temporary lake formed upstream between Andernach and Koblenz, extending for some 140 km2 and rising more than 15 m above the pre-eruptive land surface. Collapse of the unstable dam prior to the final phase of the eruption resulted in sudden drainage of the lake. Deposits laid down by the catastrophic floodwaves occur at least as far north as Bonn, more than 50 km downstream from Andernach.