By Ben Newsome from Ithaca College
The geography of Aysén is unique and interesting – and arguably the most beautiful region of Chile. Between the fjords, valleys, glaciers, and stunning mountains, Aysén is a gorgeous and geographically fascinating area to explore. Some of the most important geographical features include the northern and southern Patagonian ice fields, the third largest after Antarctica and Greenland. To the eastern side of the region, you have arid steppe landscapes filled with guanaco and ñandú, and the west is filled with lush forests and mountains.
Our expedition here in the region had a strong start in Valle Chacabuco – a valley formed by glacial recession 20,000 years ago that carved the landscape when it pushed east, and eventually receded west. The Aysén region had lots of glaciation during the last glacial maximum, and most of Chilean Patagonia was under ice during that period. This ice carved and formed several valleys in the area, Chacabuco being one of the most popular places visited in Patagonia. As you move further east into the valley, the climate becomes much more arid because of the rainshadow effect. At this latitude, wind primarily moves eastward – picking up moisture as it moves throughout the landscape, contributing to the aridity. Alongside this, as clouds move over landscapes and high mountains like the Andes, they lose their capacity to hold water – making rainfall significantly less frequent. This is called the orographic effect, and is part of the reason as to why Chacabuco is so dry.
Our trip to Calluqueo glacier was one of my favorite moments from the semester, both because of the below freezing temps and the jaw-dropping glacier itself. Located south of Cochrane (our base-camp town), this glacier used to reach the road (the one we travelled to reach it) only 40 years ago, which is a shockingly short period of time for a glacier to retreat the amount it did – about 4 kilometers. Along the glacial lake at the bottom of the glaicer, we can observe moraines and rotational landslides, geological and glaciological events that occurred when the glacier retreated. Besides the epic views and provocative geological history, the Tehuelche people have gravesites around Calluqueo.
Jeinimeni was a trip full of tiring sweeping transects, cold conditions, and some of the most beautiful sights of the entire trip. The post-glacial lake was formed similarly to Chacaubuco – during the last glacial maximum a glacier covered the entire area, and pushed eastward to carve out the valley. As it receded west, the valley that formed and the water that melted off the glacier created Lago Jeinimeni. Prior to the glacial maximum 150 million years ago, plate tectonics were moving apart creating the rocks that are still there today. 60 million years ago subduction events occurred, pushing plates upwards which formed the surrounding mountains. Combine those with the glacier formation, and you have probably the most beautiful sights to see in Patagonia National Park.
The geography of Aysén is some of the most fascinating in the world – and some I believe everyone should experience first-hand at some point in their lives. My time here in Patagonia has been full of incredible sights, and some of the most beautiful geography I have ever seen.