The Smithsonian Institution's Global Volcanism Program treats it as part of the Santorini volcano,[3] though at least one source maintains that it is a separate magmatic system.

The crater floor, averaging about 505 m below the sea surface, is marked in its northeast area by a field of hydrothermal vents and covered by a thick bacterial community, the 2006 NOAA expedition discovered.

Superheated (measured as hot as 224 °C) metal-enriched water issuing from the vents has built chimneys of polymetallic sulfide/sulfates to a maximum height of 4 m, apparently accumulated since the 1650 event.

The 2006 expedition initiated new seismic air-gun techniques in order to determine the volume and distribution of the submarine volcanic deposit of pumice and ash on the sea floor around Santorini, which has been studied extensively since 1975.

In October 2022 it was announced that a previously undetected magma chamber had been discovered approximately 2 to 4 km below sea level in the Kolumbo underwater volcano.