Recent Volcanism and the Stratosphere

In the quiet years after the 1956 eruption of the Bezymianny volcano in central Kamchatka, it is doubtful that any volcano vented into the stratosphere until the 1963 eruptions of Agung (Bali), Trident (Alaska), and Surtsey (Iceland). From 1963 to the Hekla (Iceland) event in May 1970, two latitudinal belts of volcanoes have ejected ash and gases into the stratosphere. One belt is equatorial and the other is just below the Arctic Circle. The latter, where the tropopause is considerably lower, may have been the principal source of replenishment of volcanic dust and gases to the stratosphere. Submarine and phreatic volcanic eruptions may have been the sources of reported increase of water vapor in the stratosphere.