CO2 DISTRIBUTION IN VOLCANIC AREA IN RELATION TO FAULT AND RADON EMISION: A CASE STUDY AT DIENG VOLCANO

PROCEEDINGS JOINT CONVENTION BALI 2007
The 32^nd HAGI, The 36^th IAGI, and The 29^th IATMI Annual Conference and Exhibition

CO2 DISTRIBUTION IN VOLCANIC AREA IN RELATION TO FAULT AND RADON EMISION: A CASE STUDY AT DIENG VOLCANO

Supriyati Andreastuti, Sri Subandini, Suryono, E. Sartini, Sukarnen,

Geological Agency, Center for Volcanology and Geological Hazard Mitigation,
Volcano Technology Research Center
Jl Cendana 15 Yogyakarta

ABSTRACT

Surface manifestation of CO2 in volcanic area forms solfatara, fumarole and moffete fields. CO2 is a common gas found in fault area. Although CO2 gas emission is not always high along the fault zone. Measurement of CO2 gas flux was carried out using Multiwarn Gas Detector. In the location with high CO2 emission (> 25% volume.), the result did not always show high value. Therefore, CO2 can not be use as the main factor for fault tracing. In Dieng, CO2 emission ranges from 0.05 - > 25 % volume. As a whole, CO2 content in this area is up to 96,5 % volume (Sinila). The origin of CO2 is a mixture of biogenic and volcanic.

Radon is another alternative for fault tracing beside mercury (Hg). The measurements of radon using Scintilometer in Ratamba Fault showed negative correlation with distance to the fault. Radon measurements were carried out parallel and perpendicular to the fault zone and decreasing away from the zone. However, this is not applicable to CO2 which showed inconsistencies compare to radon value.