Lys Glacier Rapid Retreat, Italy

Lys Glacier drains south from Lyskamm in the Monta Rosa Group of Italy.  This glacier has a long history of observations that have indicated two short term advances in the 20th century 1912-21 and 1973-85 amidst a broader retreat.  The net change for the 1915-2004 interval was a 600 meter retreat (Smiraglia et al, 2006). They also noted a 10% area extent loss from 1975-2003, and since the glacier was advancing up to 1985 this change occurred more rapidly.  The Italian Glacier Commission report on terminus change of this glacier annually in the two latest reports Lys Glacier retreated 10 m in 2012 and 20 m in 2011. The total reported retreat from 2005-2012 was 186 m, more than 20 m per year. Here we examine Landsat images from 1990 to 2014.

lys ge

Google Earth Image

In 1990 two branches of the glacier merged in the valley bottom and extended to the red arrow marking the terminus of the glacier at that time.  The yellow arrow indicates the 2014 terminus position, and the yellow A indicates a prominent bedrock knob that a branch of the glacier encircles, pink arrows.  By 2013 the glacier in the main valley have separated, there are a few small lakes forming amidst the decaying stagnant ice tongue between the yellow and red arrow.  The bedrock knob at Point A has greatly expanded. In 2014 none of the termini reach the floor of the main valley.  As the stagnant ice melts, the lake area is expanding indicating that a new alpine lake will likely form.  The retreat from 1990-2014 is 1300 meters.  A closeup in 2009 from Google Earth indicates the two tongues with bedrock below separating them from the main valley floor, red arrows. There is still some relict ice below on the valley floor detached from the active glacier, blue arrows, that has small lake developing amid the stagnant ice. There is substantial crevassing above both actual termini, but not immediately. The retreat should slow now that the glacier has retreated onto steeper slopes, having lost the low elevation low slope valley tongue.
The retreat of this glacier is similar to that of nearby Verra Grande Glacier. lys glacier 1990
1990 landsat image
lys glacier 2013
2013 Landsat image
lys glacier 2014
2014 Landsat Image
lys glacier terminus
Google Earth Image

Lobbia Glacier Retreat, Italy and World War I relic exposure

The summer of 2012 was a warm one in the Italian Alps. This has led to large losses in glacier volume and exceptional surface melting. One example of this has been the exposure via melting of a considerable amount of World War I relics. One location noted has been the Ago Di Nardis Glacier in the Trentino Mountains, where artillery ammunition is observed Image from Maffei Glauco / Trentino Italian / EPA. In this post we use Landsat imagery from 1999, 2011 and 2012 to examine the retreat of Lobbia Glacier with a small note on the retraction of Ago Di Nardis Glacier. The Lobbia Glacier is adjacent to the Mandrone Glacier that has been examined in detail by the Università di Brescia, Italy (Ranzi et al, 2010), which lost over a meter of ice thickness on average from 1999-2006. The Lobbia Glacier retreat from 1999-2010 has been observed by the Italian Glaciological Survey and found to have retreated 140 meters from 1999-2005, and 45 m from 2006-2009. In the Landsat images the red arrow indicates the retraction in glacier width of Ago Di Nardis Glacier at the 3000 meter level. The Orange dot indicates the 1999 terminus location of Lobbia Glacier. The yellow arrow indicates the expansion of a bare rock area that had been surrounded by ice in 1999 on Lobbia Glacier. The purple arrow indicates the separation of horseshoe shape glacier adjacent to Lobbia Glacier.. The glacier has a low slope and few crevasses. The combination indicates low velocity and even stagnant conditions. The slopes on the west side of the glacier, yellow arrow are not retaining snowcover and no longer feed the glacier tongue. The lack of a consistent and persistent snowcover indicates a glacier that cannot survive (Pelto, 2010), image from TecTask. The current glacier health parallels that of Dosde Glacierand Presena Glacier

Careser Glacier Breaking Up, Italy

The last year with a significant positive balance on the glacier was 1977, in the majority of years since 1980 the glacier has had no accumulation zone, which equates to an accumulation area ratio of zero (Carturan and Seppi, 2007). This translates to a glacier with no income of snow, but still plenty of losses via melting, which means the glacier cannot survive, and of course will drive the retreat (Pelto, 2010). Luca Carturan, University of Padova, provides both a chart of mass balance and a comparison of the glacier from 1967 to 2009, red bars indicate negative mass balance. The glacier has the longest mass balance record of any Italian glacier and the data is submitted annually to the World Glacier Monitoring Service. Carturan et al (2012) examine the mass balance distribution in more detail, in their Figure 2 the glacier is separated from its most western appendage (W), but the center part (C) is still connected to the main section (M) of the glacier, red dots are the around glacier watershed. . The images below are a series of Landsat images from 1999, 2003, 2009 and 2011. The red arrows indicate two narrow ice connections that were intact between the west-center-main part of glacier in 1999 and 2003. By 2009 the west section is not connected, and by 2011 the center connection is also gone. The deeper blue color of the glacier indicates a lack of snowcover, snowcover can be seen on the glaciers north of the ridge above the Careser Glacier. Careser Glacier fits the pattern of thinning, lack of accumulation zone and separation as seen at Presena Glacier, Dosde Glacier and Cavagnoli Glacier

Dosde Glacier, Italy retreat and separation

Dosdè Glacier in the Dosdè-Piazzi Group of the Italian Alps has been the focus of research by the University of Milan Department of Geography in the last decade to both chronicle its retreat, examine the causes, and evaluate the impacts and potential mitigation steps. In 1954 there was a Dosdè Est, Dosdè Centrale and Dosdè Ovest glaciers with respective areas of 1.2 and 0.8 and 0.9 square kilometers. By 2003 the areas had been reduced to 0.8, 0.5 and 0.3 square kilometers. This is evident in the picture from 1932 and 2007 of the Dosdè Glacier group from Guglielmina Diolaiuti, University of Milan. I have added arrows annotating key changes Est is on the left, Centale in the middle and Ovest (labelled Ost) on the right. The purple arrow indicates the separation of two glaciers. The blue arrow indicates the change in glacier size near the top of the peak. The orange arrow notes the thinning of the glacier near the current glacier tongue. The green arrow indicates the retreat at the head of the glacier indicating thinning even in the accumulation zone. This glacier lost all of its snowcover in several recent summers including 2010, in this Google Earth view the summer of 2010 is ongoing and their are a few white patches of snowpack from the previous winter, that were then lost. This inconsistency of the accumulation zone is a sign of a glacier that cannot survive In this region at least 6 glaciers have been observed to disappear in the last 50 years. The continued decline in area and lack of accumulation zone persistence does not suggest that glaciers in this mountain massif will survive. Dosdè Est has retreated over 400 meters in the last 50 year, but of more importance to its survival is the degree of thinning apprarent from the terminus to its head. Dosdè Est has been the focus of study utilizing a covering blanket to examine its efficacy in reducing ablation as was done on Stubai Glacier in Austria. The University of Milan group reported a 43% decline in snow ablation and a 100% decline in ice ablation. The retreat of this glacier follows the trend of increasingly rapid and widespread retreat seen throughout the Italian Alps, as chronicled by the Italian Glacier Commission, which reported more than 95% of the over 100 glaciers examined retreating from 2000-2005. The smaller size and elevation range of the Dosdè Glacier group makes them more vulnerable to complete loss than Forni Glacier.

Forni Glacier, Italy Retreat

Forni Glacier is the largest valley glacier in Italy. It is currently 5 km long and has retreated 2.5 kilometers since its Little Ice Age Maximum. It is in the Cevedale Group, Alps and part of the Parco Nazionale dello Stelvio. In this image the Little Ice Age terminal moraine is the prominent sharp debris ridge in the foreground, twenty years ago the glacier descended beyond the bottom of the image. The Italian Glaciologic Commission has observed and reported its annual terminus change over the last 30 years to the World Glacier Monitoring Service. The glacier began a sustained retreat in 1988, after advancing a small distance in the 1970-1987 period. As reported by the IGC to the WGMS from 1990-1995 Forni Glacier retreated 290 m, between 1995 and 2000 130 m, and from 2000-2005 115 m. Using IKONOS (Bellingeri and Zini, 2006 stereoscopic high resolution imagery linear retreat of the glaciers tongue was established as 520 meters for Forni Glacier in the 1981-2003 period. The glacier was found to have lost an average of 15 m in thickness in this period, 60 m near the terminus. The glacier as seen below above the key icefalls has a substantial consistent accumulation zone. It is the terminus tongue below the icefall that is at risk with current climate. A close up view of the terminus illustrates the region that has been deglaciated in the last 20 years, there is virtually no green vegetation evident in this region. The lower section of the glacier is rapidly downwasting still.