MARN reported that a total of 194 explosions were recorded at San Miguel during 15-29 November, with a daily average of 12 events. Gas, steam, and ash plumes generally rose 500 m above the crater rim, though plumes occasionally rose higher, particularly during 26-27 November as activity intensified. No explosions were detected during 30 November-6 December and seismicity decreased. MARN noted that those living within a 5 km radius should identify evacuation routes and to take preparation measures identified by the Sistema Nacional de Protección Civil.

Geological Summary. The symmetrical cone of San Miguel, one of the most active volcanoes in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. A broad, deep, crater complex that has been frequently modified by eruptions recorded since the early 16th century caps the truncated unvegetated summit, also known locally as Chaparrastique. Flanks eruptions of the basaltic-andesitic volcano have produced many lava flows, including several during the 17th-19th centuries that extended to the N, NE, and SE. The SE-flank flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. Flank vent locations have migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.

Sources: Ministerio de Medio Ambiente y Recursos Naturales (MARN), Protección Civil de El Salvador