****************************** 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 ****************************** Observatorio Vulcanológico y Sismológico de Costa Rica OVSICORI-UNA Press Bulletin September 28, 2006 New phreatic eruption from Poas Volcano. On September 25, 2006, at 9:48 pm (03:48 GMT sept 29) Poas Volcano produced one minor phreatic eruption. One specific seismic event was registered at OVSICORI, changing the previous pattern to a stronger, tremor- like signal. Reports from workers near the summit associated such event with a sound rumbling, although nobody witnessed it. A fine spray of sediments was reported several kms W of the summit. No harm to communities, agriculture or animals has been reported. The phreatic event ejected coarser, wet material, from the bottom of the lake, impregnating the W vertical walls of the acidic lake. Finer material was deposited gradually from the summit to the non vegetated area around it. Such eruptions are common to this volcano and they have occurred several times in the last 30 years. E.g. late 70s, 89, 90, 94 and more recently in april 06. Based on a fieldtrip by staff from OVSICORI, seismic information analysis and historical records we can conclude that this event was one of the typical sporadic phreatic events. Hence they can not be discarded to ocurr in the future. Fine details about this eruption and other technical related information (in Spanish) can be found at www.ovsicori.una.ac.cr/informes_prensa/2006 www.ovsicori.una.ac.cr/informes_prensa/2006 ============================================================== 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. ==============================================================
