Eruption of Hudson Volcano

Date: August 8, 1991 • Location: Aysén, Chile

Hudson Volcano in Chile began to erupt, depositing volcanic ash over 150,000 square kilometres (58,000 sq mi).

Hudson Volcano is the most active volcano in the southern part of the Southern Volcanic Zone of the Andes Mountains in Chile, having erupted most recently in 2011. It was formed by the subduction of the oceanic Nazca Plate under the continental South American Plate. South of Hudson is a smaller volcano, followed by a long gap without active volcanoes, then the Austral Volcanic Zone. Hudson has the form of a 10-kilometre-wide (6-mile) caldera filled with ice; the Huemules Glacier emerges from the northwestern side of the caldera. The volcano has erupted rocks ranging from basalt to rhyolite, but large parts of the caldera are formed by non-volcanic rocks.