Mount Hudson

Mount Hudson (Spanish: Volcán Hudson, Monte Hudson) is a volcano in the rugged mountains of southern Chile. Lying in the Southern Volcanic Zone of the Andes, it was formed by the subduction of the oceanic Nazca Plate under the continental South American Plate. The Nazca Plate ends there at the Chile Triple Junction; south of Hudson is a smaller volcano then a long gap without active volcanoes. Hudson is a large volcanic caldera, formed partly by non-volcanic rocks and largely filled with ice. The Huemules Glacier emerges from the northwestern side of the caldera. The volcano has erupted rocks ranging from basalt to rhyolite.

In the late Pleistocene and Holocene, Hudson has erupted numerous times. Four large eruptions took place 17,300-17,440 (H0), 7,750 BP (H1), 4,200 BP (H2) and in 1991 AD (H3); they are among the most intense volcanic eruptions in South America. A smaller eruption took place in 1971. The 7,750 BP and 1991 eruptions had a substantial impact on human populations of Patagonia and (for the 7,750 BP eruption) Tierra del Fuego: The 7,750 BP eruption devastated its ecosystem and may have caused substantial shifts in human settlement and lifestyle. During the 1991 eruption, volcanic ash covered a large area in Chile and neighbouring Argentina, causing high mortality in farm animals, aggravating an existing economic crisis, and depositing ash as far as Antarctica. The last eruption was in 2011.