Natural disasters

The bursting of glacial lakes…

Today, the advance of glaciers poses no real risk for humans; however, a potentially dangerous situation arises when a glacier blocks an adjacent valley or causes a lake to overflow. At present there is no threat from bursting glacial lakes, becauseglaciers, with very few exceptions, have been retreating over the past 150 years.

During the period between 1550 and 1850, when glacial coverage was at its peak, bursting glacial lakes caused a great deal of destruction and numerous casualties. The Ötz valley was home to several such disasters. The biggest disasters have been documented in the Municipality of Längenfeld’s chronicals. Among those, the disaster of 1600, ranks among the worst. It was caused when the Vernagt glacier blocked the upper Rofen valley and formed a glacial dam. When the dam broke, it caused massive devastation in the valley. In 1681, the Vernagt glacier again obstructed the Rofner Ache. The subsequent flooding caused large crop failure and hence numerous victims due to starvation.

In 1770, the Gurgler and Ötz valley were devastated by a bursting glacial lake when the Gurgler glacier acted as dam for a lake that reached an expanse of about 40 ha (ca. 100 acres). When it released, a flash flood rushed down the valley within a few hours.

 

The Gurgl glacial lake in 1770


In 1772 the Vernagt glacier blocked the Rofen valley again, but this time it miraculously released without causing any damage.

The last disasters happened between 1844 and 1848. Again, the whole Ötz valley down to the Inn valley was devastated. In 1848, the dam reached a height of 150 m. The disastrous burst happened on June 13th, 1848 within an hour.