Diffuse emission of carbon dioxide from Cerro Negro volcano, Nicaragua, Central America

We report the first detailed Soil CO2 efflux survey carried out at Cerro Ne gro volcano, Nicaragua, Central America. Soil CO2 efflux values ranged from 0.5 to 35,000 g m(-2) d(-1). Spatial distribution Of CO2 efflux shows that volcanic gas is mainly released from the summit crater and the fissures op ened during the August 1999 eruption. The total CO2 output of Cerro Negro i s conservatively estimated to be 2,800 t d(-1), based on a study area of 0. 58 Km(2). Contour maps of soil CO2 efflux, ground temperature, and delta C- 13(CO2) distributions support an important magmatic contribution for the to tal output of CO2 at Cerro Negro volcano.