Spatio-temporal evolution of the Kolumbo Volcanic Chain and its link to
the volcanic plumbing system of Santorini
Abstract
The Christiana-Santorini-Kolumbo volcanic field in the southern Aegean
Sea is one of the most hazardous volcanic regions in the world. Forming
the northeastern part of this volcanic field, the Kolumbo Volcanic Chain
(KVC) comprises more than 20 submarine volcanic cones. However, due to
their inaccessibility, little is known about the spatio-temporal
evolution and tectonic control of these submarine volcanoes and their
link to the volcanic plumbing system of Santorini. In this study, we use
multichannel reflection seismic imaging to study the internal
architecture of the KVC and its link to Santorini. We show that the KVC
evolved during two episodes, which initiated at ~1 Ma
with the formation of mainly effusive volcanic edifices along a NE-SW
trending zone. The cones of the second episode were formed mainly by
submarine explosive eruptions between 0.7 and 0.3 Ma and partly
developed on top of volcanic edifices from the first episode. We
identify two prominent normal faults that underlie and continue the two
main trends of the KVC, indicating a direct link between tectonics and
volcanism. In addition, we reveal several buried volcanic centers and a
distinct volcanic ridge connecting the KVC with Santorini, suggesting a
connection between the two volcanic centers in the past. This connection
was interrupted by a major tectonic event and, as a result, the two
volcanic systems now have separate, largely independent plumbing systems
despite their proximity.