************************************************************************************************ Widespread degassing around the summit and landslide blocking active crater. Turrialba volcano, Costa Rica. From: Eliecer Duarte <eduarte@xxxxxxxxx> ************************************************************************************************ Augmented fumarolic activity has been observed 360 degrees around the external upper summit walls of the active west crater: Such degassing has been acompanied, over these recent 2 months, by widening of radial cracks (1.5 cms average), tall vertical gas and vapor plumes (1-2 kms tall), and one sustained discrete seismic swarm (amounting hundreds of quakes a day). Cracks on the summit showed 94ºC while fumarolic vents, in the lower parts of the crater, show points with temperatures between 120 and 160ºC. During April-May deep burning of dairy pastures and forests reached as far as 3.5km (towards NW and W). Widespread corrosion increases as the rainy season progresses. We may infer from these changes of factors (temperature, pressure, rain showers, unstability, seismic activity and landsliding rate) that blockage of crater bottom will increase degassing through upper walls; thus contributing to rapid weathering process. For detailed (download) Spanish reports, click on http://www.ovsicori.una.ac.cr/biblioteca/index.php?dir=Vulcanologia/Eliecer%20Duarte/ To follow seismic activity click on http://www.ovsicori.una.ac.cr/sismologia/sismogramas_linea.htm ============================================================== 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. ==============================================================
