***************************************** Monday, May 6, 2007 TURRIALBA VOLCANO, COSTA RICA: UPDATE From: <eduarte@xxxxxxxxx> ***************************************** Due to internal procedures OVSICORI´s Volcano Monitoring team has declared Low Alert Level based on rapid changes documented over the last 3 months. Such level intensifies field work and data collection. Recent observations: Several earthquakes were located in the vicinity of Turrialba volcano in early December 2006, after that all visual changes, reported since June 2005, multiplied. At the end of February a flight over Turrialba´s summit reflected a significative growth in area with burned vegetation (reported previously in September 2006). Dwarf and tall trees looked yellowish due to continuous and sustained gases emitted from crater W. A large number of phone calls from Turrialba City (located some 15km S of the volcano) reported ash columns, something that was eventually discarded. On April 21st a hot spot (mainly H2O, 40ºC) was documented as far as 1.5km SW of the summit, at the base of the volcanic edifice. Concern grows within the settlers, media and OVSICORI´s personnel due to the fact that such finding coincides with the well known Ariete fault (trending WSW-ENE). Such hot spot lies only some 100m from a settlers house and his dairy premises. Yet on may 2nd two larger hot fuming spots were reported by neighbors and documented along the same fault (some 200m SW from the first one). This site releases plenty of vapor (90ºC) overtopping the thick forest. Vapor plumes can be spotted several kms around it. Heat is killing vegetation in some 300 square meters along the S Fault?s plane. Moreover, during this last visit summit area was revisited. Growth of the area impacted by gases on vegetation surrounding the outer flanks (towards the W and SW) was confirmed by settlers and researchers. OVSICORI?s volcano surveillance team continues to monitor the situation closely and will issue additional updates and changes in alert level if needed. For additional information, background, images, and other graphics (Spanish): http://www.ovsicori.una.ac.cr/vulcanologia/Volcan_Turrialba.htm# ************************************************* M.Sc. Eliecer Duarte G. Observatorio Vulcanologico y Sismologico de Costa Rica. OVSICORI-UNA. fax (506) 2610303 tel (506) 2610781 email:eduarte@xxxxxxxxx or eliduarte@xxxxxxxxxxxxxxxx http://www.ovsicori.una.ac.cr ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
