The main feature of the Thera eruption was the generation of huge volumes of pyroclastic flows, which advanced into and over the sea surrounding the volcanic island. Pyroclastic flows are fast-moving, hot and avalanche-like density currents of pumice, gas and ash particles. We now think that we have located the submarine deposits from these pyroclastic
flows. Seismic air-gun surveys today to the south-west and west of Thera (in the Christiana Basin) have revealed a layer 20 to 30 m thick on the sea floor, that is derived from Thera. The layer shows that the pyroclastic flow moved as a single layer, but on steep slopes it has “ wrinkled” up to form a system of terraces or steps on the submarine slopes of the volcano. This discovery of “wrinkling” or deformation is
the first of its kind in the study of submarine pyroclastic flow deposits.

Figure caption: SEABEAM map showing the steps on the seafloor that my
have been produced by pyroclastic flow discharge into the sea.