Increased activity began 11 November, when sizeable explosions began to occur at a rate of about 1/hour, in contrast to about 1/month during the preceding year. Ash from some of the larger explosions reached the Pacific Ocean, about 35 km from the volcano. By early January, explosion frequency had declined to 1-2/day and ashfall was no longer reaching the ocean.

Geological Summary. Telica, one of Nicaragua's most active volcanoes, has erupted frequently since the beginning of the Spanish era. This volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately E, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby.

Information Contacts: A. Aburto Q., Instituto de Investigaciones Sísmicas; D. Harlow, USGS.