Surface hydrothermal alteration mapping at Vulcano Island using MIVIS data

Remotely sensed data (airborne hyperspectral Multispectral Infrared and Vis ible Imaging Spectroradiometer (MIVIS) data) were used to map active hydrot hermal areas at Vulcano island (Sicily), related to a shallow magmatic cham ber inducing hot fluid movements in the overlying rocks. A multispectral an alysis was carried out using selected MIVIS band combinations and field spe ctra of selected altered surfaces. Results were checked by field survey, es pecially in the most active La Fossa crater area, where the zonation of a s uperficial high sulphidation hydrothermal system was reconstructed. The ban d selection used was able to clearly discriminate between fresh and hydroth ermally altered rocks, especially at La Fossa crater; but differences betwe en advanced argillic and the silicic alteration facies, as identified by he ld spectra. were not recognized, probably due to the occurrence of fumarole s. Despite the bias introduced by vegetation cover, illumination conditions and buildings, previously unrecognized sites of potential hydrothermal alt eration and fumaroles were mapped in the northern sector of Vulcano island.