Sólheimajökull Glacier
Sólheimajökull is an 11 km long outlet glacier that originates from the southwestern part of Mýrdalsjökull Glacier. Sólheimajökull has undergone large-scale changes over the last century, mainly due to climate change, with measurements of its glacier snout having been recorded annually since the year 1930.
Between 1930 and 1969, the glacier retreated 977 m but after 1969, the climate cooled, causing the glacier to advance by 495 m until 1995. Ever since, the glacier has been receding continuously or by 1312 m as measured in 2019. The first recorded measurement in 1930 indicates that the snout of the glacier was located 1794 m further from its point today.
In 2011, a glacier lagoon started to form in front of the glacier and has been growing steadily as the glacier continues to melt and retreat. The elementary school Hvolsskóli in Hvolsvöllur, Geoschool of Katla Geopark, visits the site every year to measure both the depth of the lagoon (-60 m) as well as the retreating śnout.
Outlet glaciers
Glaciers in Iceland are normally temperate glaciers meaning that the temperature of the ice is at freezing point and liquid water is found both under and within the ice. Glaciers move forward due to their own weight and gravity. The rate of movement depends on how much water is underneath the glacier, the temperature of the ice and the incline of the landscape.
Glacier crevasses are common and form when glaciers move over uneven grounds or along a mountain side. High quantity of rock fragments and debris in glaciers is known as glacial till. The till collects on the glaciers because of erosion into adjacent surroundings, rock fall from higher landscapes and plucking of the bedrock below the glaciers. In volcanic eruptions ashfall can occur on glaciers as well. The glaciers carry the material before depositing it near the glacial margins. These sediments and landforms are of high importance in understanding the glacial and environmental history of the area. It is therefore very important that visitors behave responsibly to help preserve these formations.
Mýrdalsjökull Glacier and Katla Volcano
Mýrdalsjökull Glacier is the fourth largest glacier in Iceland. It covers an area of 535 km² and has an estimated volume of 140 km³. The glacier has an uneven thickness which measures most in the northern part of the Katla Caldera, about 740 m. The highest points of Mýrdalsjökull Glacier are Hábunga (1497m), Goðabunga (1510 m), Austmannsbunga (1377 m) and Kötlukollar (1320 m), which form the outer line of the caldera of Katla Volcano. Many cauldrons, up to 50 m deep and a few hundred meters in diameter, are visible on the glacier. They are formed due to melting from geothermal areas underneath the glacier.
Katla Volcano is one of the largest and most active volcanic systems in Iceland and its central. Sólheimajökull Glacier 2015 volcano, the 100 km² Katla Caldera, lies below Mýrdalsjökull Glacier. The volcanic system of Katla is much larger, it reaches NE about 70 km towards Síðujökull Glacier. The last volcanic eruption in Katla to break through the ice was in 1918, but there are at least 21 known eruptions since settlement (c. 874 AD) and many of them have caused large glacial outburst floods (jökulhlaup) and heavy ash fall.
Source: Local signage