CHARACTERIZATION OF VOLCANIC ACTIVITY BASED ON SO2 EMISSION RATE AND THERMAL ANOMALY USING REMOTE SENSING METHODS AND SEISMICITY DATA

• Main Author: Alfianti, Hilma
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/56925
• Institution: Institut Teknologi Bandung

Agung volcano, Bromo volcano, and Sinabung volcano have high volcanic activity over the last decade. These three volcanoes are representative of the Sunda Arc segmentation which consists of the Sumatran Arc-Zone and the Java Arc-Zone with different plate movement speeds and different eruption characteristics, hence would be fascinating to study the characteristics of their volcanic activity patterns based on SO2 gas emission rates and thermal anomaly which are correlated with the seismicity data. Measurement of SO2 emission rates in the field was carried out using the Differential Optical Absorption Spectroscopy (DOAS). The SO2 emission rates were calculated based on SO2 column density, measurement distance, wind speed, and wind direction. In addition, SO2 emissions were detected using Ozone Monitoring Instrument (OMI) images with daily global coverage. Thermal anomaly detection was performed using Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of Thermal Infrared (TIR) subsystem with high spatial resolution (90×90 m). ASTER TIR images were corrected for radiometric and thermal atmospheric. The emissivity and brightness temperature separation algorithm were applied to obtain surface temperature of Agung volcano, Bromo volcano, and Sinabung volcano. All the data were correlated with the seismicity of each volcano. The SO2 emission rates were correlated with the magma ascent to the shallow depth in an open-system volcano (Bromo volcano). In closed-system volcanoes (early phase of Agung and Sinabung), SO2 emission was detected after the transition of closed-system to open-system. Magmatic injection from the reservoir to shallow depth was detected as thermal anomalies, such as in Agung Volcano. Whereas in Bromo volcano, the thermal anomaly was insignificant. It was interpreted because Bromo volcano has an explosive eruption at a short period, so the ASTER image cannot capture the thermal anomaly properly. Thermal anomaly in Sinabung volcano was not well observed due to cloud cover around the study site. The increase in SO2 emission rate and thermal anomaly were interpreted by new magmatic injection to the shallow depth and it can be used as indicators for the increasing magmatic activity and can be applied for volcano monitoring.