HE-3 AND METHANE IN SAKURAJIMA CALDERA, KAGOSHIMA BAY, JAPAN

Volcanic gases from the submerged caldera of Sakurajima Volcano are ch aracterized by He-3/He-4 = 6.1R(A), CH4/He-3 almost-equal-to 10(9), an d a ratio of excess SIGMACO2 to He-3 of 140 x 10(9). Helium in the Kag oshima Bay waters is a mixture of volcanic helium and atmospheric-solu bility helium in surface waters, and provides a strong signature for s eawater injected into the protocaldera by flow through the volcanic ed ifice, the probable source of the warm deep water that replaces the co lder, more saline deep water of the North Basin in November.