Base surges were first observed at underwater and underground in nuclear explosions, where ring-like turbulent clouds spread radially at hurricane speeds (up to 30 m/s). Base-surge clouds also spread radially from many volcanic eruption columns, especially where surface or ground water mixes with the rising magma column.
A base surge was photographed at Capelinhos volcano, Azores on 10th October 1957. The eruption cloud rose to a height of 500 m, then collapsed and spread radially in a, dark gray base surge loaded with hyaloclastic debris. The base surge was gray and full of ash, and rolled rapidly out over the top of the tuff ring and across the ocean surface. The sea up to 100 m in front of the advancing surge was hit with blocks dropped from the radial plumes.
During 1965 Taal volcano (Philippines) erupted and base surges traveled 4 km and killed 189 people. Base surges were first identified during ocean nuclear weapons explosions in the Pacific.