Multisource and temporal thermal infrared remote sensing of Hasandag Stratovolcano (Central Anatolia, Turkey)
Özet
Hasandag ˘ is a double-peaked long-dormant volcano, where associated volcanic risk is poorly known and needs to
be assessed. Weak fumaroles and water vapor emissions have been observed at several vents, on the western
flank of the Greater Hasandag ˘ summit, between 3000 and 3100 m (a.s.l.). The highest temperature and CO2
values measured in those vents were ~ 70 ◦C and > 100,000 ppm respectively. Multisource and wide-period
thermal remote sensing analyses were performed to investigate the thermal state and to test the possibilities
of remote thermal monitoring of the volcano.
MODIS daily surface temperature data were analyzed for a period of 18 years. We used a statistical approach
using the Seasonal Decomposition of Time-series procedure to decompose the temperature data into the trend,
seasonal, and remainder components. The trend component was used to analyze temporal thermal anomalies in
comparison to the decomposed meteorological temperature data. 56 nighttime ASTER TIR imagery acquired
between 2001 and 2018 had been used to derive and analyze the Surface temperature, Surface temperature
anomaly and Relative radiative heat flux. High-resolution ground-based and aerial thermal mosaic images were
built to investigate the thermal radiation over the summit fumarole zone and its structural dependence.
A baseline reference value for thermal monitoring of the fumarole zone was achieved using remotely sensed
data and time-series decomposition of long-term TIR data. The resolution of the thermal imagery positively
affects the mapping and monitoring capability. A permanent ground-based thermal observation station should be
established for direct and remote thermal monitoring of the fumarole zone.
