In Nicaragua active volcanism is concentrated inside the Nicaragua Depression (ND).The red box labeled "B" refers to the 50 x 50 km area that includes Apoyeque on the Chiltepe Peninsula.The earthquake was felt by the population in Sandino City, ~5 km W of the earthquakes.The seismic swarm lasted until 2 October 2009; the total number of detected earthquakes was not disclosed.
The authors concluded that there is a high probability of future, similar eruptions, particularly phreatomagmatic ones, within this area of Nicaragua. At the time of the report, almost four hours after the start of the event, 17 earthquakes had been detected; three events were M 2.3-3.7, at depths ranging from 2.8 to 6 km. The surface temperature of the crater lake was 28.1-28.8°C on 16 January at 0900.With respect to hazards implications, clear vent migration patterns were seemingly absent for this volcanic field. L., Pardo, N., Scolamacchia, T., and Rodriguez, D., 2012, Stratigraphy, geomorphology, geochemistry and hazard implications of the Nejapa Volcanic Field, western Managua, Nicaragua, Journal of Volcanology and Geothermal Research, 213-214: 51-71. This compilation of synonyms and subsidiary features may not be comprehensive.The authors concluded that there is a high probability of future, similar eruptions, particularly phreatomagmatic ones, within this area of Nicaragua. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features.More than 20 earthquakes were detected and the two largest had magnitudes of 2.3 and 3.8, with depths of 2.8 and 6 km respectively; the largest event occurred at 1937 (figure 2).None of these earthquakes were reportedly felt by local populations and the event was assigned an Intensity II. Avellán and others (2012) described the polygenetic Apoyeque volcano as belonging to the Nejapa volcanic field (figure 1), which is bound by the Nejapa fault system.