Seismicity as of mid-May remained at a high level, similar to recent months. There have been ~160 daily volcano-seismic events detected, with little variation. During March there were ~150 seismic signals/day recorded; in December 1996 there were <100 signals/day (BGVN 22:03).

An eruption on 31 July 1994 produced a gas-and-ash column and detectable ash fell as far as 17 km from the summit (BGVN 19:07). Phreatic explosions continued until 12 August 1994 when seismicity began decreasing (BGVN 19:09).

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: Wilfried Strauch, Department of Geophysics, Instituto Nicaraguense de Estudios Territoriales (INETER), P.O. Box 1761, Managua, Nicaragua.