For our last two days on the field, we went back to lakes. On our to-do list was Lago Plomo and, because we had a reliable boat, a nice running engine, and a few hours to spare, we decided to add an extra glacier-influenced lake: Lago Bayo. During these two days we stayed at Puerto Bertrand next to the Baker river, the largest river in Chile.
Our first lake, Lago Bayo, is fed by Rio Norte on its eastern side but we are more interested in the intermittent proglacial inflow on its western side, Rio Exploradores, which originates from glacier Exploradores. Rio Exploradores only flows into Lago Bayo during periods of high glacier melt (or sub/englacial GLOFs), otherwise, it by-passes the lake and goes straight to the Pacific Ocean. Due to its location in a narrow valley just north of the Northern Patagonian Icefield, the lake is also prone to high levels of precipitation and wind, which we had the “chance” to experience! The wind gusts and heavy rain, combined with a slowly deflating zodiac, prevented us from working continuously on Lago Bayo. Each time the waves started crashing too hard onto our little research vessel we headed back to shore to take shelter in our camioneta. It took us four mini trips to complete our work on the lake. During our third break to wait for the worst of the rain and wind to pass, Seb noticed the sky getting slightly clearer and wanted to head straight back out to the lake. I, however, suggested waiting for the rain and wind to stop, to which El Jefe replied “Hey, this is Patagonia”! Without hesitation, we reinflated the dinghy and within minutes we were crashing into waves again to finish mapping the bathymetry of the lake. Our efforts and soaking wet clothes were well worth it though, as we did retrieve a very promising short core from the lake. Through the liner we can already perceive fine laminated sediment.
Working on Lago Plomo revealed even more adventurous. Although weather was great at our zodiac launch site in sunny and windstill Puerto Bertrand, we did pack ourselves up in several layers of clothing because we knew that Lago Plomo was famous for its high wind-blown waves. It took us a bit less than an hour to reach the entrance of the lake, an 80m-wide gap in the 20m-high late glacial moraine. As soon as we crossed the moraine, we were crashing into waves going upwind towards the Northern Patagonian Icefield. We were soaked within minutes. The lake did live up to its reputation! Due to the deteriorating weather conditions we could only map the bathymetry of the distal half of the lake. This, however, significantly extends the existing data set, which was limited to a few hundreds of meters off the moraine. Lago Plomo will see us again … we will certainly be back in the future to finish mapping the bathymetry of the lake and obtain one or several sediment core(s), which will hopefully hold a high-resolution record of glacier Soler’s retreat.
Our windy day on Lago Plomo concludes our very successful 2018 austral summer fieldtrip. In total, we mapped the bathymetry of five lakes (Lago Confluencia, Lago Juncal, Lago Bayo, Lago Plomo and Lago Calluqueo), obtained 11 lake sediment cores, gathered 2 river sediment samples and retrieved sediment samples and turbidity data from the moorings that we had deployed one year earlier in Steffen and Baker fjords. We would like to thank the staff at CIEP for their logistical support, our collaborators at EULA and COPAS (University of Concepción), and of course all of the friendly Patagonian people, who never hesitated to help these two geolocos!
PS: Sorry for the lack of illustration of our work on the lakes but we were too busy trying to keep afloat!