The observatory gets its feet wet!


Victor recovering a temperature probe on the White Castle hydrothermal vent. Photo Victor

The first part of the dive being dedicated to reconnaissance around the Eiffel Tower hydrothermal vent, Victor then headed to the western side of the lava lake. Objective: find a spot for the other SEAMON monitoring station and its geophysical sensors. The site, as identified from high-resolution maps, is covered with relatively smooth, flat lava flow.

Victor then headed back toward the Eiffel Tower edifice to sample hot fluids using specially designed pressure-resistant bottles that can preserve the gases. The following six hours were dedicated to recovering the temperature probes deployed in 2009 on several active sites around the lava lake. Some of these probes became makeshift substrates for several organisms while others that had been placed in hot fluids were embedded in new, small hydrothermal chimneys. Victor and the elevator resurfaced at 10 in the morning.

Today was a crucial day for the cruise because the first parts of the observatory were deployed from the vessel for mooring. The operation was complex: the 250 kg SEAMON monitoring platform was lowered with a cable. Using an acoustic positioning system (similar to GPS), the descent was monitored and the station could be positioned in the desired location with a precision of 20 m. Don’t forget that we are on a 104 m vessel and over a water depth of 1762 m. Good work Captain!

Tonight, the western side of the observatory will be set up and connected.


A whirl of lava on the western side of the lava lake. Photo Victor

Recovering the elevator starboard. Photo Michael Aron

A device for studying microbial colonisation was also recovered. Photo Victor


Javier, Alexis and Jozée examine the temperature probes that were recovered from the seafloor. Photo Michael Aron
The SEAMON West monitoring platform ready to be deployed from the surface. Photo Jérôme Blandin.