Ground-based remote sensing of gas emissions from Teide volcano (Tenerife, Canary Islands, Spain): first results

Teide volcano, the Spanish highest peak (3716 m), is located in the central part of Tenerife, Canary Islands. An anomalous seismic activity was detected in and around Tenerife Island since middle of 2001 reaching a peak of seismicity in may 2004 by the National Seismic Network (IGN). Volcanic gases can provide a valuable information about this volcanic unrest at Tenerife; therefore, measurements of major and some minor volcanic gas components emitted by the fumarolic activity at the summit crater of Teide volcano were performed by means of optical remote sensing on September 2005. During this measurement campaign an UV-DOAS system and three op-TDL systems were used to monitor major and minor volcanic gas components in the open atmosphere inside the summit crater. The UV-DOAS system was used for monitoring SO2 and CS2, while three TDL-systems were used for monitoring CO2, H2S and HF. It could be demonstrated successfully, that the optical remote sensing instruments used (UV-DOAS and op-TDLs) were very appropriate to monitor continuously these volcanic gas components. In addition CO2 flux measurements were performed at the summit crater of Teide volcano by means of well established methods. By multiplying CO2 flux data by (gas)i/CO2 ratios provided by optical remote sensing measurements, it is possible to estimate flux values for several detected volcanic gas components during this measurement campaign.