Report on Apoyeque (Nicaragua) — January 1988
Scientific Event Alert Network Bulletin, vol. 13, no. 1 (January 1988)
Managing Editor: Lindsay McClelland.
Apoyeque (Nicaragua) Sulfur smell from active fumaroles
Please cite this report as:
Global Volcanism Program, 1988. Report on Apoyeque (Nicaragua). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 13:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198801-344091.
12.242°N, 86.342°W; summit elev. 518 m
All times are local (unless otherwise noted)
The surface temperature of the crater lake was 28.1-28.8°C on 16 January at 0900. A slight smell of sulfur was evident at the N caldera rim, probably originating from fumaroles 100-200 m below. Fumaroles also remained active in Laguna Jiloa.
Geologic Background. The Apoyeque volcanic complex occupies the broad Chiltepe Peninsula, which extends into south-central Lake Managua. The peninsula is part of the Chiltepe pyroclastic shield volcano, one of three large ignimbrite shields on the Nicaraguan volcanic front. A 2.8-km wide, 400-m-deep, lake-filled caldera whose floor lies near sea level truncates the low Apoyeque volcano, which rises only about 500 m above the lake shore. The caldera was the source of a thick mantle of dacitic pumice that blankets the surrounding area. The 2.5 x 3 km wide lake-filled Xiloá (Jiloá) maar, is located immediately SE of Apoyeque. The Talpetatl lava dome was constructed between Laguna Xiloá and Lake Managua. Pumiceous pyroclastic flows from Laguna Xiloá were erupted about 6100 years ago and overlie deposits of comparable age from the Masaya plinian eruption.
Information Contacts: B. van Wyk de Vries, H. Rymer, and G. Brown, Open Univ; P. Hradecky and H. Taleno, INETER.