Satellite observation of active carbonatite volcanism at Ol Doinyo Lengai, Tanzania

Natrocarbonatite lavas extruded by Ol Doinyo Lengai volcano, Tanzania, exhibit the lowest known magmatic eruption temperatures, ranging between 500 and 600 C. Nevertheless, as shown here, the near-infrared bands 5 and 7 of the Landsat Thematic Mapper (TM), and the mid-infrared channel 3 of the spaceborne Advanced Very High Resolution Radiometer (AVHRR) are able to detect thermal emission from active carbonatites. Laboratory-measured visible-to-near-infrared reflectance spectra of both silicate and carbonatite rocks from Ol Doinyo Lengai are used to infer spectral emissivities, enabling interpretation of satellite measurements. Given the remote location of this unique volcano, satellite remote sensing could play a valuable role in its future surveillance, and offers a potential means for distinguishing between silicate and carbonatite eruptions.