Getting started at Cluster 3

Work at Cluster 4 ended with the dive at Snake Pit, we are now heading to Cluster 3.

In order to supplement existing data, bathymetric and reflectivity profiles were made along the Kane Fracture Zone during transit from Cluster 4 to Cluster 3.

The study at Cluster 3 began with two CTD deployments and a rock dredging operation. During the HERMINE campaign in 2017, a CTD carried out in Cluster 3 indicated strong anomalies especially in methane. One of the CTDs on Monday was made in the same area to confirm the anomaly observed 2017 and the other more towards the south to better delineate the expansion of the hydrothermal plume. Both CTDs showed turbidity, methane and manganese anomalies with values similar to those of 2017 in the same area.

Depsite the fact that Ewan (co-head scientist) had put an order in for sulphides, the dredge on the axial ridge recovered fragments of pillow lava.

Finally, on Tuesday, Florian went for a "ride" in the Nautile on the axial ridge. The seabed was composed of pillow lava and blocks with very little sediment cover, some draped lava forms were seen but only at the end of the dive. During the last 20 minutes of the dive, a brownish-ochre patch was observed on the sediments and sampled by the Nautile team. These are sulphide deposits attesting to past hydrothermal activity, meaning that Ewan will finally get his samples!