Posts Tagged Austria glacier melt

Hallstatter Glacier, Austria retreat

The Hallstatter Glacier (also sometimes called Dachstein Glacier along with the Gosau Glacier) is on the north slope of Dachstein an area of heavy recreational use. The result is good photographic records of glaciers change. This record combined with a recent cooperative project between University of Innsbruck, Blue Sky Weather Analysis and Energie AG Upper Austria provides a good snapshot of glacier change in northern Austria. The glacier begins at 2800 meters and descends to 2200 meters, image below from University of Innsbruck. This project has compiled the annual terminus change of the glacier from 1950-2007, in the image below. The retreat from 1950-1975 averaged 8 meters per year. A period of minor readvance from 1977-1991 occurred, followed by increasingly rapid retreat from 1992-2007 averaging over 10 meters per year in the last decade. Total retreat has been 350 meters from 1950-2007. Over the last century the change is chronicled in the two images, 1900 and 2007, from the Dachstein Project and the 2009 margin is traced in a Google Earth Image, blue line. This project was undertaken because of the importance of the glacier runoff to hydropower production along the Traun and Gosau Watersheds in particular. The change in terminus via mapping from 1969-2002 is evident in the Innsbruck image (2002), the Google Earth image is from 2009. There is thinning particularly of the width of the two main terminus tongues.The mass balance of the glacier has been measured since 2007, every year has had negative balances. In 2011 the snowline was again high, snowpack very limited at the end of the melt season which persisted into October. An Ikonos image from October 2, 2011 indicates that 30-35 percent of the glacier is snowcovered, this is the AAR and it needs to be at 60 for equilibrium.

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Ochsentaler, Austria Rapid Glacier Retreat

Ochsentaler is a glacier in the Silvretta group of southwest Austria. From 1990 to 1995 the glacier retreated 75 meters, from 1995-2000 85 meters, and from 2000-2005 180 m. The accelerating retreat has been driven by substantial negative mass balances. Dyugerov and others (2009) assessed the mass balance of the glacier as averaging -0.5 meters per year lost, from the percentage of snowcovered area remaining at the end of the summer. Measurements on the neighboring Jamtalferner in Austria indicate 15 m of loss from 1990-2009, about 0.75 meters per year. Mass balance losses on Silvretta Glacier, Switzerland indicate a 13 m loss during that same period. Examination of the glacier today indicates an uncrevassed, thin stagnant glacier tongue that is 600 meters long, that is and should continue to rapidly melt. At the head of this section of the glacier is an icefall. The newly exposed bedrock areas at the crest of the icefall indicate reduced iceflow and thinning at this point. The contrast in this icefall region is apparent in the image pair from Christian D. from 1995 and 2011 and the latter image 2009 in Google Earth.
. Ochsnetaler is a popular climb and the upper section of the glacier above the icefall still has a considerable snow covered extent. This glacier is certainly healthier than Stubai Glacieror Presena Glacier and similar to Rotmoosferner.

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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.

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