The caldera was formed after the colossal Laacher See eruption datedto 12,900 years ago. The remaining crust collapsed into the emptymagma chamber below, probably two or three days after the eruption.An estimated 6 km³ of magma was erupted, producing around 16 km³of tephra. This massive eruption thus had a Volcanic Explosivity Index(VEI) of 6, and was larger than the colossal 1991 eruption of MountPinatubo (Philippines) which also had a VEI of 6 (10 km³ of tephraerupted). Tephra deposits from the eruption dammed the Rhine,creating a 140 km2 (50 sq mi) lake. When the dam broke, an outburstflood swept downstream, leaving deposits as far away as Bonn. TheLaacher See is a potentially active volcano, proven by seismic activitiesand heavy thermal anomalies under the lake. carbon dioxide gas frommagma still bubbles up at the southeastern shore.EifelLaacher SeeLocation: 50.24 ° N, 7.16° EElevation: 274 m 6. Nov. 2003HOME