Volcanic Gas Sampling
Christoph Kern acquires ultraviolet images of volcanic gas over the dome and crater of Mount St. Helens. Although practically invisible to the human eye, sulfur dioxide absorbs ultraviolet light and appears dark in images captured by the equipment. Sulfur dioxide is typically emitted from magma as it approaches the surface, so surveys are conducted on a regular basis at Mount St. Helens and other Cascades volcanoes to determine if magma is on the move. Sulfur dioxide was not detectable during this particular measurement.