Laguna Potrok Aike is located in the Argentinian part of Patagonia, just north of the Strait of Magellan. It is situated inside of a maar crater that was likely formed some 700.000 years ago through an erupting volcano. The maar lake has a diameter of approximately 3.5 km and a maximum water depth of 100 m. Vegetation around the lake is sparse and known as Patagonian steppe. The area is one of the major source areas for dust that is blown to Antarctica and found in the ice cores.
From 2002 to 2006, several pre-site surveys took place at the lake, mainly led by the Geopolar working group of the University of Bremen, Germany. During these expeditions, several seismic reflection surveys were carried out (by the ETH Zurich, Switzerland; the University of Geneva, Switzerland; by the University of Gent, Belgium, and by us), and sediment cores were taken by the geologists of the University of Bremen, Germany. Using the seismic profiles we could identify a sedimentary infill of several hundred meters in the maar crater (article). These data also showed the turbulent paleoclimate history that was reflected in the lake's sediments: The lake level of this lake has changed significantly through time (article 1, article 2). It is even possible that the lake fell dry at a certain point in its history. At the present-day shore of the lake, old lake-level terraces are well recognizable at up to 20 m above the current lake level (see photos in the gallery below this text).
After 6 years of intense pre-site studies at Laguna Potrok Aike we were finally able to carry out the deep drilling project PASADO within the framework of the International Continental Deep Drilling Program (ICDP). The deep drilling was done in fall 2008 and penetrated some 100 m into the sediment. With the long cores retrieved we could show that the lake level was some 20 m higher during the last Glacial. We could also reconstruct the paleoclimate history of the past ca. 50.000 years in this area.