Cerro Negro

Boca, or lava vent of August 1999 eruption, Photo from La Prensa's web site

This beautiful view of Cerro Negro was taken in 198? after microearthquake activity near the cone and the appearence of a line of low-temperature fumaroles (while splotches) on the ridge in rhs foreground (Cerro la Mula).  Cerro Negro looked like this for the two decades between the 1971 eruption and the next eruption which occurred just prior to the great tsunami earthquake of 1992.

1968 eruption. Photo by ??.  Note the boca of the 1968 flow in foreground, with sub-plinian activity at the main vent.

Photo by Dennis Neilson as we flew over Cerro Negro in 1972.  Note the pyroclastic apron downwind (toward lower left) of the cone and several generations of lava flows in shades of  black to green.  The vegetated volcano on the lower rhs is part of the Las Pilas-El Hoyo complex..