******************************************************* Ruapehu volcanic activity update Science Alert Level 2 From: Art Jolly <A.Jolly@xxxxxxxxxx> ******************************************************* GNS scientists are continuing to monitor the activity at Ruapehu since the eruption last week on 25th September. A surveillance flight at Ruapehu was made today during a break in the weather. Good views of the crater lake were obtained. The surface of the lake was very calm with no evidence of strong degassing. The recent snowfall has covered the deposits from last week's eruption. An airborne survey to analyse gases in the volcanic plume was also completed. Preliminary analysis of the data suggests that the fluxes of sulphur dioxide and carbon dioxide from the volcano are low; this means that there is probably no new magma at shallow depths in the volcano. GNS scientist Karen Britten said that conditions were close to ideal for both observations and gas measurements. Analysis of water samples taken on Friday 28th September shows that there has been no major change in the chemistry of the crater lake. A slight increase in magnesium is consistent with vent fluids being injected into the lake after the eruption. Seismicity has remained low since the eruption on 25th September; the only significant event over the last week has been a smaller volcanic earthquake on Saturday 29th October. We advise people to follow Department of Conservation guidelines for access to the mountain. The Alert Level remains at 2 (minor eruptive activity) and will continue to be re-assessed regularly. Please visit the Geonet website for this and previous bulletins and associated images. http://www.geonet.org.nz/news/index.html http://www.geonet.org.nz/volcano/alert-bulletins/index.html Arthur Jolly Senior Volcano Geophysicist GNS Science Wairakei Research Centre Private Bag 2000 Taupo 3352 New Zealand Ph: +64-7-376-0133 Fax: +64-7-374-8199 ============================================================== 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. ==============================================================
