Hochalm Glacier Retreat, Austria

Hochalm Glacier is Austrian Alps. The glacier drains into the Malta River, which hosts a 40 MW run of river hydropower plant. Fischer et al (2014) note that the Ankogel-Hochalmspitzegruppe glacier area has declined from a Little Ice Age extent of 39.7 square kilometers, 19.2 square kilometers in 1969 to 16.0 square kilometers in 1998 and 12.1 square kilometers in 2012. They note the disintegration and separation of many glaciers in the region. The World Glacier Monitoring Service reported the terminus retreat of 80 m for Hochalm Glacier from 2001-2010.

Here we examine the Hochalm Glacier and two neighboring glaciers and their response to climate change from 1990 to 2013 using Landsat imagery. The red line in each Landsat image is in the same location cutting across the Hochalm Glacier. The yellow line is in the same location transecting the Grosselend Glacier. In 1990 Hochalm Glacier has two termini tongues and has a width of 1.1 km extending past the red line. On Grosselend Glacier the terminus area extends beyond the yellow across the entire width of the glacier. The purple arrow indicates a small pocket glacier that has an area of approximately 0.45 square kilometers. In 2000 the Hochalm Glacier has just two narrow termi extending past the red line. The Grosselend Glacier still extends beyond the yellow line. In 2013 the southern terminus of Hochalm Glacier has disintegrated and only the northern terminus reaches the red line. On Grosselend Glacier approximately 40% of the glacier width reaches the yellow line, the main terminus tongue at the yellow arrow has retreated to the yellow line. The area of the glacier at the purple arrow is now 0.23 square kilometers, half of its 1990 extent.

A 2006 Google Earth image of the Hochalm Glacier’s southern terminus indicates how thin it is with no crevassing, red arrow, and several large bedrock areas amidst the glacier, purple arrow. There are numerous annual horizons exposed just below the snowline as well, blue line. The retreat of Hochalm Glacier from 1990-2013 is 200 m for the northern terminus and 450 m for the southern terminus. For Grosselend Glacier the retreat of the main terminus is 450-500 m since 1990. The retreat follows that of Austrian glaciers as a whole as noted by Fisher et al (2014), and Abermann et al (2009). The glacier is thinning even in its upper regions, which indicates it cannot survive (Pelto, 2010). The retreat of Ochsentaler, Sulztalferner and Obersublzbach Glacier indicate a similar story.
hochalm 1990
1990 Landsat image

hochalm 2000
2000 Landsat image

hochalm 2013
2013 Landsat image

Hochalm glacier ge
2006 Google Earth image

Rotmoosferner Retreat and Dynamic Change

There are currently 51 glaciers in the Ötztal Nature Park. Right now, glaciers cover 27% of the total area of the Ötztal Nature Park. All have been retreating, from 1987-2006. Detailed mapping of these glaciers and Rotmoosferner by Abermann and others (2009), University of Innsbruck provide interesting results. Ötztal glaciers lost 8 % of their total area. One of the glaciers that has a long record of observation is Rotmoosferner. This glacier has retreated 2.1 km since the Little Ice Age and 600 meters since 1969, 15 meters per year. A detailed map of Rotmoosferner from Abermann and others (2009) University of Innsbruck indicates that in 1975 it was joined to the Wasserfallferner, but in 2005 it separated. In the image above the Rotmoosferner is to the lower left and the Wasserfallferner above and to the right. Compare this image to one taken four years later at the end of the post. In the last decade new rock outcrops have emerged in the middle of the Rotmoosferner. These outcrops are noted in the google earth image below. The annotated image also indicates the former zone of connection to the Wasserfallferner. A map of the outline of the glaciers clearly identifies the new outcrops and the separation of the glaciers. The map is based on satellite imagery and older aerial photographic based maps by Abermann and others (2009) from 1969, 1997 and 2006. The retreat from 1969-1997 occurred across a relatively flat foreland. The current retreat is up a steeper slope, since 2001 retreat has averaged 18 m per year. The appearance of the rock outcrops in the mid-section of the glacier as the map shows, indicates little contribution to the tongue of the glacier, and that retreat of this lower section will continue to be rapid. The glacier still does appear to have an accumulation zone most years and is thus not forecast to disappear with current climate.
The picture below is from September of 2008 from Jakob Abermann, Institute of Meteorology and Geophysics, University of Innsbruck. Note the change versus the first picture from four years earlier. The exposed rock area has expanded amazingly and is nearly cutting off the lower tongue.