By Bill Chadwick
|Axial Seamount 2015 Expedition video highlights from ROV Jason dive J2-820, including collection of samples from the 2015 lava flows on the north rift zone, fluids from hydrothermal vents (including some where vent animals have already colonized), and microbial mats on the new lavas. Video by Jesse Crowell in association with Saskia Madlener at 77th Parallel Productions. Music by James Andrew Menking|
|Map of the 2015 lava flows on Axial’s north rift zone, showing our Jason dive track (in blue).|
|Thick fluffy microbial mat has grown on top of the 2015 lava flows while they are cooling.|
|Thin edge of the 2015 lava flows where they are dark and glassy and not covered with microbial mat.|
We found many new hydrothermal vents on the new flows, areas where warm shimmering water (up to 20°C) was coming out of the seafloor, undoubtedly heated up by the eruption and the slow cooling of the lavas (we know there were few vents on the north rift zone before the eruption). We saw a lot of microbial flocculant floating in the water, suggesting that “snowblower vents” exist on the new flows, but we just did not run across them. One exciting surprise was that we found several vents that had already been colonized by vent animals –tubeworms (Ridgeia piscesae) and Pandorae worms (Paralvinella pandorae) (below-top). The tubeworms are small (less than 5 cm long), having colonized and grown only in the last 4 months, but interestingly the Pandorae worms are unusually large, perhaps because of the lack of competition in these brand-new vents right after an eruption (according to our colleague Verena Tunnicliffe at University of Victoria).
Our first dive with Jason was very successful, but unfortunately it had to be cut short due to rising winds and seas. The forecast is for the weather to get worse before it gets better, so we will likely not be able to dive again for a few days and we’ll be conducting other operations in the meantime.