Bastien Confino (RTS) spoke with Guillaume Massé, a geochemist at the French National Center for Scientific Research (CNRS) and Université Laval in Quebec. Photos by Noé Sardet (Parafilms, EPFL).

French below…

The members of the ACE expedition enjoyed a spectacular view of the Mertz Glacier Tongue. /La langue du glacier Mertz offre un spectacle grandiose aux participants de l’expédition ACE.

– Now that we are nearing this Glacier, a place you know well. How do you feel?

Even when you’ve been here many times before, those ice cliffs still take your breath away. And the vast Antarctic ice cap is just mind-boggling.

 – The ACE expedition’s initial aim was to visit the subantarctic islands. A stop on the Mertz Glacier was not high on the list of priorities. What changed?

We decided to take advantage of this circum-Antarctic expedition to fit in a detour to the continent itself. The area around the Mertz Glacier is extremely interesting from a scientific perspective because the glacier plays a key role in controlling a variety of ocean parameters here. In 2010, this tongue of ice stretched around 150 kilometers over the ocean. Then an 85-kilometer long iceberg – more than half the length of the tongue – broke off. This event triggered far-reaching changes to surface water conditions, especially west of the glacier.

 – But you have a ROPOS submersible onboard – isn’t that for seeing what’s going on below the surface?

One of the project’s goals is to study how these surface changes affect deep-water creatures. It’s pretty straightforward. When a stretch of ocean is covered with ice, less sunlight reaches the sea depths. We assume that both photosynthesis and primary production slow too. Since the ecosystem and the trophic chain depend on primary production, we want to see how various deep-sea communities have changed in the years since the iceberg broke off. Recently, we noticed that some of the canyons close to the Mertz Glacier hosted extremely dense coral communities, which have been declared an endangered ecosystem. We have data on how this ecosystem grew before the glacier broke off, and we’d like to understand how it survived or adapted in response to the changes.