Eleven km of CTD casts, 11 m of mud and a few milligrams of suspended sediment. That’s what the five of us (Seb, Ben, Loic, Lucho and captain Rodrigo) aboard the R/V Sur-Austral have achieved during the last nine days of our field expedition.
Getting to Eyre Fjord took us three days of navigation. To add a sip of scientific excitement to that charming boat trip, we collected CTD profiles along the way to improve our understanding on how Pacific waters enter the fjords and how they may affect recent glacier variability (Pic. 1). After the cruise, the data will be used by our collaborator Dr. Carlos Moffat from the University of Delaware for his project on glacier-ocean interactions in Patagonia.
Our first destination on the way down was Puerto Edén, one of the most remote places in Patagonia. Puerto Edén is a small village of about 70 inhabitants (Pic. 2). A few decades ago, up to 700 people were living there but the arrival of red tides in the region had a devastating effect on the local economy, which is mostly based on fishing. Nowadays, Puerto Edén is surviving on crab fishing and on welcoming few tourists and scientific passersby.
Our journey south brought us through the c. 240-km long Canal Messier, which becomes quite narrow and shallow in some sections. This requires extra maneuvering care from our experienced captain Ródrigo. Otherwhise, we could end up like the so-called ghost ship “El Capitán Leonidas”. This cargo ship ended up grounded on the shallowest part of the canal in 1968 (Pic. 3). No one knows what really happened to the tons of sugar this ship transported, but the strong cases of diabetes reported among dolphins in the area could give a hint!
Our diet on the R/V Sur-Austral consisted mainly in potato, pasta, and rice (sometimes all three together) accompanied by pork ribs, sausages or marinated bacon. However, one afternoon, as we anchored in a Bay protecting us from the wind for the night, our menu got upgraded for a few days by successful net fishing. This resulted in 17 beautiful “robalos” and a 2kg salmon (Pic. 4) prepared by Lucho, Captain Rodrigo’s right hand, who has been of great support and a great cook all along this boat expedition.
On Monday 11th of February 2019 we finally reached Eyre Fjord and had our first view on the impressive advancing glacier. Pio XI Glacier is a 65.7 km long, 1263 km2 large ice mass that continues thickening at a rate of 2.52 m/yr. What a lifetime experience it was for each of us (Pic. 5)!
Picture 5: We were all mesmerized and speechless when we arrived at Pio XI glacier.
As this was not enough, a blue and sunny sky accompanied by a few dolphins around the Sur-Austral finished framing this unreal moment (Pic. 6).
Picture 6: The dolphins loved to play and show off their jumps for us.
Our original plan was to collect around ten sediment cores along a proximal-to-distal profile in Eyre Fjord to examine how the glacier advance and volume growth has influenced the fjord sedimentation. Coring in Eyre Fjord, however, was made rather challenging by the fluffy nature of the proglacial sediment, the great depth of the fjord (up to 580m), and a quasi-systematic wind and water current that slightly drifted our scientific vessel from the targeted coring location. Nevertheless, we managed to recover ten sediment cores for Loic’s PhD project. These cores will help us understand how a glacier advance is recorded in fjord sediments, and the results will ultimately contribute to a better interpretation of fjord sediment records of glacier variability (GLADYS project). Getting mud from such a deep basin is always a rewarding and fun moment that leaves a mark on us for life, or at least on our outfit (Pic. 7)!
Just south of Eyre Fjord lies Falcon Fjord, a fjord fed by multiple retreating glaciers. We didn’t need satellite imagery to figure out if any of the glaciers were calving since as soon as we entered the fjord, we noticed the many icebergs slowly floating away from the calving fronts. This creates a beautiful scenery but also slowed us down significantly as our Captain had to cautiously maneuver between them to reach our pre-selected coring locations (Pic. 8). In total, we collected four sediment cores in Falcon Fjord, which will be made available for a new MSc thesis!
This cruise to Eyre and Falcon fjords marks the end of this year’s expedition in Patagonia. The samples will now be shipped to our lab at Ghent University, where they will be meticulously processed, scanned, and analyzed for a series of physical and geochemical parameters. As such, data obtained on these samples will contribute to the HYDROPROX, Paleo-GLOFs, and GLADYS projects … and to the many related PhD and MSc theses!
Thank you to everyone who contributed to this succesful expedition, which would not have been possible without the support of the COPAS Sur-Austral team in Caleta Tortel!