Today the weather finally settled down so we were able to deploy the MaxRover ROV. We selected three dive sites inside the crater of Kolombo volcano just to the northwest of Thera. Our first dive descended to the rim of the crater at depth of 163 m. At this site we sampled large dense pumice blocks that were likely produced by the 1650 AD eruption.

The next dive started from the base of the crater floor at about 500 m depth and made two traverses up the crater walls to the rim. In this dive we saw beautiful sections of the different layers that have built up Kolombo from the seafloor to close to the surface. The section showed that the earliest activity was likely dominated by submarine lava flows whereas the later stages changed to more explosive activity.