Special Report No 96.
Seismic vibrations recorded under Chaparrastique volcano remain at low values.
In the period from 13 to 20 November 2015, the seismic vibration of San Miguel volcano fluctuated between 87 and 188 RSAM average units per hour, with an average of 128 units.
Until the publication of this report, it was not reported by local observers abnormal activity of the volcano.
Sulfur dioxide emissions show slight fluctuations, but with a tendency to remain stable.
Sulfur dioxide emissions remained below 500 tonnes / day since November 10, 2015. The average of the last seven days is 387 tons / day.
Monitoring records indicates that there is still a possibility that the volcano continues to present trends in its activity that can take the form of small exhalations with gas and ash emissions, so that MARN continues the reinforced monitoring of the volcano.
To this end, the Marn invites journalists and individuals do not approach the top of the volcano, because of the degree of danger it presents.
The symmetrical cone of San Miguel volcano, one of the most active in El Salvador, rises from near sea level to form one of the country’s most prominent landmarks. The unvegetated summit of the 2130-m-high volcano rises above slopes draped with coffee plantations. A broad, deep crater complex that has been frequently modified by historical eruptions (recorded since the early 16th century) caps the truncated summit, also known locally as Chaparrastique. Radial fissures on the flanks of the basaltic-andesitic volcano have fed a series of historical lava flows, including several erupted during the 17th-19th centuries that reached beyond the base of the volcano on the north, NE, and SE sides. The SE-flank lava flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. The location of flank vents has migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater.
November 23, 2015. Chaparrastique ( San Miguel), El Salvador :
Source : Marn, GVP