Special Report No. 2 – Downward trend of volcanic tremor on the volcano Chaparrastique.
Friday, 11 March 2016 11:41
Date and time of publication: 03/11/2016 10:00:00
From 8:40 p.m. Thursday, March 10, until the date of issuance of this report, the seismic vibrations of the Chaparrastique volcano showed a downward trend. In the last 24 hours, the tremor has fluctuated between 90 and 231 RSAM units on average per hour, with an average of 176 units, the maximum threshold of normal behavior RSAM value is 150 units .
Surveillance cameras show the upper zone of the volcano very darkened . Local observers have not reported observing surface anomalies over the volcano.
MARN continues to monitor with improved monitoring devices, maintains close communication with the General Directorate of Civil Protection and local observers.
MARN invites journalists and people not to approach the summit of the volcano, because of the degree of danger it poses.
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.
March 13 , 2016. San Miguel, El Salvador :
Source : Marn, GVP.
Photo : M Faucher