The 2008 Glaciological Survey - Central Alps - Lombardy

The 2008 Glaciological Survey Central Alps - Lombardy Scientific coordination, tex t and data processing: R iccardo Scotti, Andrea Toffaletti, Luca Bonardi, Paolo Pagliardi Mountain sectors and operators (76) SPLUGA-LEI L. Colzani, E. Congiu, M. D’Amico, M. Felisa, S. Losa, B. Mezzera, F. Rossini, C. Scolari, R. Scotti, F. Villa CODERA-MASINO L. Colzani, G. Di Gallo, M. Marzorati, R. Scotti, A. Barilli DISGRAZIA-MALLERO D. Airoldi, A. Almasio, I. Bollati, F. Cambieri, M. Fransci, G. Di Gallo, L. Muchetti, P. Pagliardi, M. E. Peroschi, G. Rovedatti, R. Scotti, M. Urso BERNINA D. Bellingeri, M. Butti, L Colzani, A. Galluccio, D. Gerussi, M. Gianatti, P. Pagliardi, A. Salvetti, R. Scotti, M. Zambenedetti 2008 glaciological Survey SCALINO-PAINALE M. Butti, E. Benedetti, M .Gianatti DOSDE’-LIVIGNO S. Alberti, A. Bera, G. Cola, D. Colombarolli, L. Colzani, D. De Felice, A. Galluccio, F. Galluccio, M. Gianatti, P. Pagliardi, D. Parrino, S. Ratti, M. Marzorati, R. Scotti, C. Speranza ORTLES-CEVEDALE C. Bessi, L. Bolognini, L. Bonetti, A. Borghi, P. Bottio, R. Bottio, G. Casartelli, G. Catasta, G. Cola, D. Colombarolli, L. Colzani, L. Farinella, M. Fioletti, A. Galluccio, Ac Galluccio, M. Gianatti, E. Meraldi, P. Pagliardi, A. Scaltriti, C. Scolari, R. Scotti; F. Strozzi, M. Zambenedetti ADAMELLO C. Bessi, P. Cinanni, M. Frosio, A. Elli, L. Imberti, G. Lojacono, A. Mussi, V. Paneri, P. Pagliardi, D. Perego, P. Reale, F. Roveda, R. Scotti, A. Toffaletti, M. Zambenedetti OROBIE S. Anghileri, E. Benedetti, R. Bianchi, M. Butti, S. D’Adda, D. Gerussi, M. Gianatti, M .Fransci, F. Locatelli, F. Mocci, D. Perego, L. Pironi, G. Rovedatti, A. Scherini, V. Sciaresa, R. Scotti, A. Sesini, S. Vigani, F. Villa - 22 - The 2008 Glaciological survey1 1 a slight decrease. Despite the very negative scenario, this is a slight improvement over the previous year, when all glaciers had strong to moderate decrements. Curiously, the sectors whose snow cover was better than their historical average value in the early summer days were the ones to suffer the worst decrements. What are the explanations for such a negative season? The answer has implicitly been outlined in the snow-meteorological report already. Despite an amount of precipitation in line with the average value for the season, thanks mainly to the April-May period, the snow did not last until the end of the season; such result is a consequence of the high temperature of the summer months. The thickness reduction of the glacier’s fronts was comparable to that of previous years; the frequent May precipitations probably led to a net differentiation between the upper basins, well fed by snowfalls, and their rain-washed termini. By the end of July, the residual snow had disappeared almost everywhere under 3200 m a.s.l., letting the hot August and early September days to melt down the exposed ice and, where present, most of the residual snow. Locally, the snow cover lasted till the end of the season above 3300 m a.s.l. and on some glaciers with avalanche accumulation. The SGL Glaciological Survey, though delayed by the abundant snowfall of mid-September, has nevertheless produced meaningful data, having investigated 95,4% of the glacialized surface of the Region. The most important results are the largely negative mass balances and the investigation of morphologies peculiar to a phase of glacial dissolution: the deep bédières (Campo Nord), the ever wider For the survey methodology see www.sgl.cluster.it - 23 - 2008 glaciological Survey “How did the glaciers fare during the last summer?” This is the most frequent question that mountain lovers, friends and curious people have been asking us since last September. Such direct and concise question is worth a similarly short and clear answer: “Badly”. Then the astonished speaker: “But why? A bad summer again? With all the snow that fell down ... and the bad weather we have had …” At this point, it is worth to analyse in depth a season that, despite the very negative result, has shown some shy signals of a recovery if compared to the glaciological disasters of the past few years. The differences among the various mountain sectors of Lombardy, almost zeroed during the last years because of very negative dynamic indexes everywhere, this year have become visible again. So, it is clear that the western sectors have fared better than the eastern ones: the Spluga/Lej, Codera/Masino, Disgrazia, Orobic Alps, though undergoing a negative season, have ended with some residual snow coverage over all apparatuses. Photographic observations and ield surveys proved that some small glaciers had an almost positive season: the best examples are: Mortee, Calvo, Rasica Est, Cassandra Centrale, Dente di Coca and Pizzo dell’Omo Ovest. Unfortunately all are very small apparatuses; their combined size being only 2% that of the Adamello Glacier which, on the other side, had a heavily negative season. For the same reason, all glaciers belonging to the SGL sample list showed a negative trend versus the 2007 situation. The 47 glaciers of the sample were chosen for their size and for being representative of their own sectors. 23,4% of them showed a dynamic index pointing to a strong decrease, 59,4% to a moderate decrease and 19,2% to moraine cover, the frequent dismemberments induced by the loss of mass (Passo di Chiareggio, Venerocolo, Porola), the formation and widening of proglacial lakes (particularly important is the widening of the Est Fellaria proglacial lake) and the lessening of break-up morphologies (crevasses, seracs). Hence, briely, the negative trend for our glaciers continued in 2008 as well, though we could say something like “better than worse”. Coming from years that were anticipating the glaciological and climatic scenarios predicted for the end of XXI century, this might be of some satisfaction. The data of the 2008 Survey 2008 glaciological Survey During the 2008 Glaciological Survey, 96 glaciers were subjected to a complete glaciological survey 1(36,5% of existing glaciers); their combined area was 9061,4 ha or 83,6% of Lombardy glacialized surface. Adding the photographic observations2 (103) the number of glacial apparatuses, inclusive of both glaciers and glacierettes, increases to 199 (75,7 % of all glacial bodies or 95,4 % of the entire regional glacial area). Tab. 1: total glacialized regional surface investigated during the 2008 Glaciological Survey and comparisons with the previous biennium (absolute values in ha and %) (* without photographic observations). Year Total regional area covered by glaciers (ha) Total area investigated (ha) Total area surveyed (%) 2006 11.004,7 8.690,0 79* 2007 10.967,7 10.242,8 93,3 2008 10.838,6 10.344,1 95,4 1 Complete glaciological survey means that a detailed on-site investigation was performed by the designated operators; where possible, their evaluation included: snow line altitude, minimum altitude of the front, front measurements. Operators also remarked the morphologies variations versus the previous survey. 2 Photographic observation means that a glacier is investigated through one or more photos taken from selected photographic stations to allow meaningful comparisons over the years. Such observations do not provide dynamic indexes. - 24 - Tab. 2: Summary of 2008 surveys and photographic observations (sectors and total). Spluga Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Glaciers (n°) 8 3 11 13 (% of total number) 61,5 23,1 84,6 Area (ha) (% of total area) 215,5 33,6 249,1 263,6 81,8 12,7 94,5 Codera-Masino Complete surveys Photographic observations Survey + Photo observations Total existing glaciers 4 12 16 26 15,4 46,2 61,5 88,5 86,9 175,4 227,8 38,8 38,1 77,0 11 13 24 28 39,3 46,4 85,7 814,3 122,1 936,4 955,7 85,2 12,8 98,0 8 2 10 13 61,5 15,4 76,9 2151,1 46,1 2197,2 2230,2 96,5 2,1 98,5 2 1 3 8 25,0 12,5 37,5 200,9 3,3 204,2 226,4 88,7 1,5 90,2 7 10 17 20 35,0 50,0 85,0 209,7 193,1 402,8 429,8 48,8 44,9 93,7 6 1 7 11 54,5 9,1 63,6 118,1 11,9 130,0 146,0 80,9 8,2 89,0 24 15 39 55 43,6 27,3 70,9 2788,2 525,3 3313,5 3576 78,0 14,7 92,7 12 17 29 39 30,8 43,6 74,4 2356,8 141,6 2498,4 2527,1 93,3 5,6 98,9 14 29 43 50 28,0 58,0 86,0 118,3 118,8 237,1 256 46,2 46,4 92,6 Area (ha) (% of total area) 9.061,4 1.282,7 10.344,1 10.838,6 83,6 % 11,8 % 95,4 % - Disgrazia-Mallero Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Bernina Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Scalino-Painale Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Dosdè-Piazzi Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Ortles Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Adamello Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Orobie Complete surveys Photographic observations Survey + Photo observations Total existing glaciers Glaciers (n°) Complete surveys Photographic observations Survey + Photo observations Total existing glaciers (2007) 96 103 199 263 (% of total number) 36,5 % 39,2 % 75,7 % - - 25 - 2008 glaciological Survey Livigno ANALYSIS OF VARIATIONS This chapter presents data and information collected during the 2008 surveys. The dynamic phase of each glacier is evaluated on the basis of the last available survey. Variations versus 2007 All 47 glaciers, when compared with their 2007 data, are in a shrinking phase, with a net prevalence (80,8%) of strong and moderate decrements. The tendency of the last years is conirmed and 2008 is the 4th consecutive year in which 100% of sampled glaciers were reported in a decrement phase when compared against their previous survey. The statistical analysis highlights the negative peak of the Ortles–Cevedale Sector, with 4 strong decrements and 7 moderate decrements. Tab. 3: 2008 dynamic phases of Lombardy glaciers. 2008 glaciological Survey Total Uncertain New strong moderate Stable slight moderate strong extinct Mountain sector slight Increment phase Decrement phase Spluga-Lei 0 1 1 2 0 0 0 0 0 1 4 Codera-Masino 0 0 2 1 0 0 0 0 0 0 3 Disgrazia-Mallero 0 0 5 3 0 0 0 0 0 0 8 Bernina 0 1 3 1 0 0 0 0 0 0 5 Scalino-Painale 0 1 0 0 0 0 0 0 0 0 1 Dosdè-Piazzi 0 1 2 0 0 0 0 0 0 0 3 Livigno 0 1 2 0 0 0 0 0 0 0 3 Ortles-Cevedale 0 4 7 0 0 0 0 0 0 0 11 Adamello 0 2 3 0 0 0 0 0 0 0 5 Orobie 0 0 2 2 0 0 0 0 0 0 4 Total % 0 11 27 9 0 0 0 0 0 0 47 0% 23,4% 57,4% 19,2% 0% 0% 0% 0% 0% 0% 100% Totali % 47 0 0 0 0 47 100% 0% 0% 0% 0% 100% Tab. 4: The overall dynamic phase of Lombardy glaciers over the last 7 hydrological years. Hydrological year % Decreasing glaciers % Stable glaciers % Increasing glaciers % Uncertain glaciers 2001-2002 90,4 6,7 1,0 1,9 2002-2003 100,0 0,0 0,0 0,0 2003-2004 73,6 8,0 17,3 1,1 2004-2005 100,0 0,0 0,0 0,0 2005-2006 100,0 0,0 0,0 0,0 2006-2007 100,0 0,0 0,0 0,0 2007-2008 100,0 0,0 0,0 0,0 - 26 - Fig. 1: The dynamic index of glaciers surveyed during the 2008 glaciological survey, as % over the total number (each column shows the total number of glaciers in that class). 2008 glaciological Survey Fig. 2: The Vedretta del Mandrone on September 20, 2008, when the the reading of the ablation stakes at the snout of the glacier took place. The glacier was covered by 10 cm of fresh snow fallen a few days earlier that had ended the 2008 ablation season (photo by A. Toffaletti). - 27 - Snow Line Altitude Minimum altitude (m) Terminus variation Glacier Dynamic Phase Tab. 5: the list of glaciers surveyed in 2008 and the comparison with their previous surveys. Also indicated are: the front variation, the minimum altitude of the front (QMF), the snow line altitude, a brief note and the glaciological operators involved. Note: for the details of dynamic phases, see tab. 10 at the end of the chapter. Notes (Operators) Settore Spluga/Lei Pizzo Ferrè DF -0,5 2698 irr. 20% of total surface covered by residual snow; further thinning. (E. Congiu, S. Losa) Suretta S DL -22,5 2700 n.v. Mass balance measured with differential GPS, scarce residual snow cover (F. Villa, R. Scotti) Ponciagna DM n.v. thickness loss; residual snow cover almost absent (L. Colzani) Cima di Lago W DL N.M. n.v. recent snow cover, snow line not assessable, front shrinkage (L. Colzani) Codera/Masino Sivigia NE DM Passo di Bondo DL Pioda S DM 2530 -16,5 2810 2850 residual snow covering 15% of the surface, lower sector in a dismemberment phase (A. Barilli, L. Colzani) 3070 snow cover only at the base of the rocky cliffs, moderate loss of thickness (M. Marzorati) n.v. the link to the patch below 3064 m a.s.l. (CTR) has dissolved; snow cover hard to evaluate (G. Di Gallo) 2008 glaciological Survey Disgrazia/Mallero Predarossa DM -5 2625 3300 residual snow cover under Sella di Pioda and at the base of the cliffs, the separation of upper and lower sectors is progressing (M. Urso, I. Bollati, D. Airoldi) Cassandra E DL -11,5 2915 3180 good residual snow cover, strong thinning at the front. (R. Scotti, M. Fransci) Ventina DM -6,5 2222 2950 irregular snow cover, though more consistent than in previous years; overall thinning of the tongue (M. E. Peroschi, F. Cambieri) Pizzo Ventina DL 2470 2650 avalanche accumulations over the 40% of the surface (M. E. Peroschi, F. Cambieri, M. Urso, A, Almasio) Disgrazia DM -2 2610 2900 more extensive snow cover in comparison with previous years, though insuficient to achieve an equilibrium balance (P. Pagliardi) Sissone DM -58 2600 2950 strong withdrawal of the front and substantial morphologic variations in the lower part; snow cover over 40% of the surface (A. Almasio) Vazzeda DM N.M. 3000 residual snow cover scarcer than nearby glaciers (A. Almasio, R. Scotti, M. Urso, I. Bollati, D. Airoldi) Pizzo Tremogge DL N.M. 3010 n.v. no substantial changes; slight thinning. (M. Urso, I. Bollati, D. Airoldi) Scerscen Inf. DM -5 2640 n.v. overall thinning of the lower portion (A. Salvetti, D. Bellingeri, L. Colzani) Scerscen Sup. DM 2750 3170 thinning tongue; 155 cm of ice lost at 3100 m (A. Galluccio, M. Zambenedetti, P. Pagliardi, L. Colzani) Bernina Caspoggio DF Fellaria W DM Fellaria E DL N.M. n.v. N.M. dramatic mass loss, negligible snow cover (L. Colzani) 3400 right low detached; scanty snow cover. (M. Butti, P. Pagliardi) 3450 fairly good residual snow cover towards the Fellaria Plateau, evolution of the tongue with a remarkable widening of the proglacial lake (M. Butti, P. Pagliardi, D. Gerussi) Scalino/Painale Pizzo Scalino DF -10 2620 ass. negligible snow cover; dramatic, overall thinning. (M. Butti) Dosde'/Piazzi Cardonnè DF 2530 3100 irregular snow cover, northern wall decaying (A. Galluccio, G. Cola) - 28 - Dynamic Phase Terminus variation Minimum altitude (m) Snow Line Altitude Notes (Operators) Dosdè E DM -20 2560 3000 irregular residual snow cover, strong withdrawal, loss of mass (F. Galluccio, S. Ratti) Val Viola W DM -13 2825 irr small ields of residual snow, substantial decrement (S. Ratti, F. Galluccio) Val Nera W DM Campo N DF Saliente DM Vitelli DM Zebrù DM Zebrù E Glacier Livigno n.v. -18 2840 scarce snow cover since the beginning of August (S. Alberti, R. Scotti) 3100 new weather station installed, 220 cm of ice lost at 2985 m a.s.l.(D. Colombarolli, A. Bera) irr. residual snow cover at the base of the cliffs over the about 30% of the surface; fully covered by debris (S. Ratti) Ortles/Cevedale 3160 residual snow cover on the accumulation basin; front area in a dismemberment phase. (A. Scaltriti, A. Galluccio) 2600 n.v. areal shrinkage (A.C. Galluccio) DM -13,5 2843 n.v. loss of mass in the left frontal area. (A. Galluccio) Forà DF -26 2760 n.v. detachment of an ice lens with morainic cover in the snout area; strong retreat (L. Colzani) Gran Zebrù DF -11 2990 ass. no residual snow, thinning front, dramatic shrinkage. (D. Colombarolli, M. Fioletti) Cedec DM -9 n.v. indented front, very signiicant mass loss at the snout (D. Colombarolli, M. Fioletti) Palon de la Mare DM -13 3012 3400 residual snow cover over the 20% of the surface, clear shrinking of the snout. (L. Farinella, C. Bessi) Forni DF -13 2510 3500 very scarce snow cover, as in 2007; dramatic overall mass loss (G. Cola) Dosegù DM -38,5 2850 3300 strong retreat at the snout, good snow cover over the accumulation basin (A. Borghi, L. Bolognini) Sforzellina DM -3,5 2800 ass. some moderate avalanche accumulations, overall mass loss (R. Bottio) Alpe S DF N.M. ass. no snow cover, evident overall loss of mass (L. Bonetti, P. Pagliardi, G. Cola) Adamello Pisgana W DF -24 2565 ass. overall loss of mass, weak link with the accumulation basin (F. Roveda) Venerocolo DM -12 2570 3150 very scarce snow cover (15% of the surface area); now separated from the Vedretta dei Frati (A. Toffaletti) Avio Centrale DM 2900 snow cover, from avalanches only, over 30% of the surface area; moderate withdrawal (C. Bessi, G. Catania) Aviolo DM irr thinning of the central portion, snow in the upper sectors and right hydrographical side (P. Pagliardi) Adamello DF 3300 scarce snow cover, signiicant mass loss below 3200 m (P. Pagliardi, D. Perego, A. Toffaletti, A. Elli) Marovin DL -6 2060 2200 residual snow cover over the 50% of the surface, slightly negative mass balance (M. Butti) Lupo DL 0 2440 2620 residual snow cover over 40% of the surface, snout unchanged, slightly negative mass balance (R. Scotti, F. Villa, S. D’Adda, F. Mocci, A. Mussi, L. Imberi, P. Cinanni) Porola DM 2540 n.v. the lower sector has split from the accumulation basin in the steepest central portion (M. Merati) Trobio W (Tre Conini) DM irr very scarce snow cover. Ice withdrawal at the front and near the rocky cliff, negative mass balance (S. D’Adda, F. Mocci) 2730 Orobie Abbreviations: N.M.: Not measured; n.v.: Not evaluated; ass: Absent; irr.: Irregular - 29 - 2008 glaciological Survey -17 Variations versus previous surveys (before 2007) Tab. 6: The dynamic index of glaciers surveyed in 2008 which had their previous survey before 2007 (totals: number of glaciers in each class and their % over the total). moderate strong New Uncertain Total Stable 0 0 0 4 slight 0 moderate 0 Mountain sector strong slight Increment phase Decrement phase extinct 2008 glaciological Survey Fig. 3: The small Vedretta di Remulo (Adamello Massif), despite its low altitude, does not show many variations versus the previous survey (2003). The protection offered by the rocky wall and the avalanche accumulations has kept this glacial apparatus substantially stable. (September 18, 2008; photo by V. Paneri). Spluga- Lei 0 2 2 0 Codera-Masino 0 0 0 0 0 0 0 0 0 1 1 Disgrazia-Mallero 0 1 2 0 0 0 0 0 0 0 3 Bernina 0 3 0 0 0 0 0 0 0 0 3 Scalino-Painale 0 1 0 0 0 0 0 0 0 0 1 Dosdè-Piazzi 3 1 0 0 0 0 0 0 0 0 4 Livigno 0 0 0 0 0 0 0 0 0 3 3 Ortles-Cevedale 3 6 3 1 0 0 0 0 0 0 13 Adamello 4 0 0 2 1 0 0 0 0 0 7 Orobie 1 3 4 0 2 0 0 0 0 0 10 Totali % Totali % 0 11 17 11 3 3 0 0 0 0 4 49 22,4% 34,7% 22,4% 6,1% 6,1% 0% 0% 0% 0% 6,2% 100% 42 0 0 0 4 49 63,3% 0% 0% 0% 6,2% 100% - 30 - The 46 glaciers considered in this section were not surveyed in 2007; comparisons are only possible with 2006 data or earlier, up to 1996 (Passo Savoretta Glacier). The predominant dynamic phase is one of “decrement” (63,3%) while 22,4% of all surveyed glaciers were found extinct. The number of extinctions collected in 2008 conirms the trend of the previous glaciological surveys: altogether, 46 glaciers have disappeared between 2005 and 2008. Figg. 4 and 5: (left) the Verva Maggiore Glacier (Dosdè-Piazzi Sector) in 2008 (photo by D. Parrino) and (right, photo by V. Bianchi) in 2003, date of the previous survey. The glacial retreat is quite evident; the terminus has moved upvalley more than 300 m in 5 years. 2008 glaciological Survey Fig. 6: The dynamic index of the glaciers surveyed in 2008 which had their previous survey before 2007. - 31 - Last survey Snow Line Altitude Minimum altitude (m) Terminus variation Glacier Dynamic Phase Tab. 7: List of the glaciers surveyed in 2008 and comparison with their previous surveys (prior to 2007). Also indicated are: the front variation, the minimum altitude of the front (QMF), the snow line altitude, the date of the previous survey, a brief note and the glaciological operators involved. Note: for the details of dynamic phases, see tab. 10 at the end of the chapter. Notes (Operators) Settore Spluga/Lei irr. 2005 some residual snow from avalanches, loss of mass, abundant debris coverage (F. Rossini, C. Scolari, E. Congiu) DM irr. 2002 20% residual snow cover (R. Scotti, E. Congiu) DF irr. 2002 wide, but irregular, seasonal snow cover, dramatic loss of mass (E. Congiu) DF irr. 2001 good residual seasonal snow cover, dramatic overall loss of mass (E. Congiu) Pizzo Quadro N DM Tambò Orsareigls Morteè N.M Codera/Masino n.v. 2005 snow frustrate a precise evaluation, very slight surface variation (A. Barilli, R. Scotti) Pizzo Torrone I Corni Bruciati I DM 2620 n.v. 1998 unchanged area; loss of mass, thickening debris coverage (M. Urso, I. Bollati, D. Airoldi) Corni Bruciati II DM 2660 n.v. 1998 unchanged area, loss of mass (M. Urso, I. Bollati, D. Airoldi) Passo di Chiareggio DF 2750 2850 2005 residual snow cover in the upper portion, the debris covered tongue has detached from the rest of the glacier (A. Almasio) Disgrazia/Mallero -580 2008 glaciological Survey Bernina Fellaria Centrale DF 2950 1999 full morainic cover, drastic loss of mass, avalanches accumulation (M. Butti) Fellaria Sup. I DF 2950 2000 drastic loss of mass, fairly good seasonal snow cover (M. Butti, D. Gerussi) Fellaria Sup. Ii DF n.v. 2000 drastic loss of mass, fairly good seasonal snow cover (M. Butti, D. Gerussi) Scalino/Painale Pizzo Painale SW 2830 DF n.v. 2001 70% snow cover, dramatic overall loss of mass (E. Benedetti) Dosdè/Piazzi Verva Minore Verva Maggiore E DF -331 2775 ass. 2002 reclassiied as “minor glacial formation” (D. De Felice, C. Speranza, D. Parrino) 2003 major terminus retreat, drastic mass and surface loss (D. De Felice, C. Speranza, D. Parrino) Cantone di Dosdè II E 1998 reclassiied as “minor glacial formation” (S. Ratti, F. Galluccio) Dosde' W Inf. E 1999 reclassiied as “minor glacial formation” (S. Ratti, F. Galluccio) Val Nera E I n.v. 2002 full morainic cover, some patches of residual snow (early observation) (R. Scotti) Val Nera Centrale I n.v. 2002 fully covered by debris (S. Alberti, R. Scotti) Monte Val Nera I n.v. 2002 good snow cover (August 3) (S. Alberti, R. Scotti) Livigno Ortles/Cevedale Campo DM n.v. 2002 snow cover on the orographic left side, loss of mass versus the last survey (G. Cola, R. Scotti) Coninale W DF ass. 2000 no snow cover, wide morainic cover, drastic decrement from the last survey (D. Colombarolli) - 32 - Snow Line Altitude Last survey ass. 2003 no residual snow cover, 2 huge landslides cover 30% of its surface (G. Cola) San Giacomo S DF ass. 2000 almost fully covered by debris, no snow cover, loss of mass since the previous survey (G. Cola) Pizzo Tresero N DM ass. 2002 several debris lows over the ice, almost without snow cover since the beginning of August (A.C. Galluccio) 2002 negligible, residual ice mass at the edge of the proglacial lake (P. Pagliardi) Punta Sforzellina W Sobretta NE Sup. Minimum altitude (m) DM Terminus variation Col de la Mare Dynamic Phase Notes (Operators) Glacier E DF irr. 2002 patch of ice with some residual snow (G. Cola, R. Scotti) E ass. 2002 full debris cover, reclassiied as “minor glacial formation” (G. Cola, R. Scotti) Sobretta NW DF 3220 2002 separation of the upper right plate, strong retreat (D. Colombarolli) Profa DF n.v. 1998 separation of the left plate, strong shrinkage (D. Colombarolli) Monte Gavia NW DL 2980 2000 full snow cover, positive annual balance, slight mass loss from the last survey (D. Colombarolli) Passo Savoretta E ass. 1996 small ice patch covered by debris, reclassiied as “minor glacial formation” (D. Colombarolli) DF ass. 2002 no snow cover, strong shrinkage (P. Pagliardi) Sobretta NE Inf. Pietre Rosse N Piano delle Platigliole 2980 small patch of irn and snow of aeolian origin, irstly observed in 2007 (A. Galluccio, P. Pagliardi) NEO Adamello small, debris buried ice patch, reclassiied as “minor glacial formation” (A. Toffaletti) 2730 2002 full snow cover, slight decrement from the last survey (P. Pagliardi) 2800 2002 extended snow cover, slight decrement from the last survey (P. Pagliardi) 2900 2003 minimal size but substantially unchanged from the previous survey, full snow cover (V. Paneri) E 2002 reduced to a small patch, reclassiied as “minor glacial formation” (V.Paneri) E 2000 no residual snow or ice (V. Paneri) E Cima Laste N DL Cima Wanda DL Remulo S Macesso Triangolo 2900 Orobie Monte Torena Sup. S 2740 2740 2000 full snow cover, substantially stable from the previous survey (L. Pironi) Druet DF irr. 2002 withdrawal of the terminus, net decrement (M. Butti,R. Scotti) Fascere DF irr. 2002 some seasonal snow patches, fully covered by debris, strong loss of mass (M. Butti, R. Scotti) Pioda Inf. DM 2500 2500 2002 full snow cover, overall loss of mass (M. Butti, R. Scotti) Pioda Sup. DM 2585 2585 2002 full snow cover, overall loss of mass (M. Butti, R. Scotti) Pizzo Brunone DF 2510 2510 2001 buried ice plate headed to extinction, covered by annual snow (M. Merati) Bocchetta di Podavitt DM 2345 2345 2001 almost stable surface but net mass decrement (R. Bianchi, G.M. Lucini) Podavista S 2130 2120 1999 very extensive snow cover, substantially unchanged (R. Bianchi, G.M. Lucini) M. Costone E irr. 2001 no ice left, reclassiied as “minor glacial formation” (M. Zambenedetti) Recastello DM n.v. 2001 signiicant loss of mass since the last survey (S. D’Adda, F. Mocci) Abbreviations: N.M.: Not measured; n.v.: Not evaluated; ass: Absent; irr.: Irregular - 33 - 2008 glaciological Survey 2002 Lavedole The terminus variations The sample glaciers of Italian Glaciological Committee (CGI) Some glaciers subject to a complete survey have their linear terminus variations measured. The algebraic symbol indicates a downvalley advance (+) or an upvalley withdrawal (-). The variation is not directly linked to the snow-meteorological trend of the season. Many are the additional factors (such as: glacier response time, bedrock morphology, lux velocity, etc…) that make this parameter of little use in evaluating the state of the glacier in the survey year. However these glaciers carry an historical series of linear front measurements, which makes their continuous monitoring extremely interesting. Our glaciers, along with other Italian glaciers, are part of the historical sample of ice bodies surveyed by CGI. The sample is divided into two sets. Groups 1 and 2, selected on the basis of their glaciological importance and representativeness, include the glaciers measured once a year; group 3 include the glaciers measured on a rotational basis, generally once every 5 years. In the present phase of signiicant and prolonged decrements, the front measurements are coherent with the dynamic index: out of the 26 glaciers with annual measurement, only 1 has held its previous position; all the others have shown sometimes consistent shrinkages. The Passo di Chiareggio and Verva Maggiore Glaciers multi-year decrements were paroxysmal and caused by the dismemberments of dead-ice blocks, a typical feature of an intense withdrawal phase. 2008 glaciological Survey Tab. 8: Summary of terminus measurement data, versus 2007 and previous years. Variations versus 2007 decrements increments unchanged 26 25 (96,2 %) 0 1 (3,8 %) Variations versus previous years decrements increments unchanged 3 3 (100 %) 0 0 Fig. 7: The terminus variations of the Lombardy’s sample glaciers over the last 18 years. - 34 - Tab. 9: The front variations of the sample glaciers since 1990: the dynamic phase is expressed by the algebraic sign. Year Number of measured glaciers 1990 1991 Withdrawing glaciers Stable glaciers Advancing glacier % number % number % 40 35 87,5 2 5,0 3 7,5 26 23 88,5 2 7,7 1 3,8 1992 35 33 94,4 1 2,8 1 2,8 1993 36 32 88,8 2 5,6 2 5,6 1994 47 39 83,0 5 10,6 3 6,4 1995 44 38 86,4 4 9,1 2 4,5 1996 52 48 92,3 1 1,9 3 5,8 1997 55 37 67,3 1 1,8 17 30,9 1998 61 53 86,9 2 3,3 6 9,8 1999 57 47 82,5 6 10,5 4 7,0 2000 57 53 93,0 2 3,5 2 3,5 2001 24 14 58,3 2 8,4 8 33,3 2002 53 42 79,2 0 0 11 20,8 2003 62 56 90,4 3 4,8 3 4,8 2004 49 42 85,7 1 2,1 6 12,2 2005 57 53 93,0 3 5,3 1 1,7 2006 33 32 97 1 3 0 0 2007 30 29 96,7 0 0 1 3,3 2008 28 27 96,4 1 3,6 0 0 Tab. 10: The synthetic indexes used in order to deine the annual dynamic phase of Lombardy glaciers. Dynamic index Description S (Stable) meaningful morphologic variation versus the previous survey. Extensive snow cover. IL (Slight increment) snow cover over most of the glacier: slight increment of irn versus the previous year. IM (Moderate increment) snow cover over the whole glacier; terminus shows some advancement. IF (Strong increment) snow cover over the whole glacier and surrounding areas; signiicant snout advancement. DL (Slight decrement) Scarce snow cover, slight terminus retreat; or stable front but slightly reduced thickness. DM (Moderate decrement) Very scarce or absent snow cover, veriied terminus retreat; thickness and area reduction. DF (Strong decrement) No snow cover, strong terminus retreat, or stable front but reduction of both thickness and area. I (Uncertain) the dynamic phase is doubtful (uncertain data, debris cover and so on…) E (Extinct) / EC (Extinct conirmation) Extinct during the current year / already extinct in the previous years - 35 - 2008 glaciological Survey number MOST SIGNIFICANT PICTURES 2008 glaciological Survey The Pizzo Ferrè Glacier in the Spluga Sector (August 24, 2008, E. Congiu). The Nord-East Sivigia Glacier, Codera-Masino Sector, taken on September 20, 2008 by A. Barilli. - 36 - The two Fellaria Glaciers (Bernina) from Cima Fontana (September 9, 2008). Note the size of the proglacial lake of the East Fellaria Glacier (foreground) responsible, through the associated calving processes, for the sustained melting of the tongue (photo by M. Butti). 2008 glaciological Survey This large-scale photo, taken by G. Cola on August 31, 2008, shows the greater part of the Forni Glacier basin in Upper Valtellina. The picture outlines the scarce, annual and multiannual, residual snow accumulations. - 37 - 2008 glaciological Survey The,Sissone Glacier in the Disgrazia Sector (August 30, 2008, photo by A. Almasio). The Pizzo Scalino Glacier, without residual snow cover (September 10, 2008, photo by M. Butti). - 38 - The East Val Viola Glacier, in upper Val Viola Bormina, Dosdè-Piazzi Sector (August 10, 2008, photo by R. Scotti). - 39 - 2008 glaciological Survey The Dosdè Centrale Glacier in Val Viola Bormina (September 1, 2008, photo by F. Galluccio) 2008 glaciological Survey The West Val Viola Glacier in a photo taken on August 31, 2008 (photo by S. Ratti) and in a 20year old picture (photo below). Note the great loss of mass (photo by M. Lojacono, 1985). - 40 - - 41 - 2008 glaciological Survey The East Dosdè Glacier (Dosdè-Piazzi Sector) on September 1, 2008 (above, photo by F. Galluccio) and in 1985 (below, photo by A. Galluccio). The terminus has withdrawn more than 200 m in 20 years. 2008 glaciological Survey A 20-year interval separates these two photos of the Campo Nord Glacier in the Livigno Sector. Both the loss of mass and the strong reduction of the ice-walls are quite evident. The crevasses at the terminus are almost gone, while the debris cover has increased. The grooves cut into the ice by melting processes are visible, with 2 deep bédières on the surface (above, photo by R. Scotti, August 3, 2008; below, by A. Galluccio, 1988). - 42 - In the Livigno Sector many glaciers have suffered signiicant withdrawal over the last decades. The South Vago Glacier in a picture taken by R. Scotti on August 3, 2008 (above) and (below) by A. Galluccio in 1988. Comparing the 2 images, one can notice the substantial dismemberment and the extinction of the apparatus. 2008 glaciological Survey - 43 - 2008 glaciological Survey The Vitelli Glacier (Ortles-Cevedale) from Punta Radisca, on August 29, 2008. The accumulation basin was still covered by the annual snow (photo by P. Pagliardi). The Dosegù Glacier (Ortles-Cevedale) on August 21, 2008 (photo by A. Borghi). - 44 - The terminus of the Forni Glacier (Ortles-Cevedale) on August 8, 2008 (photo by G. Cola). 2008 glaciological Survey The Gran Zebrù Glacier (Ortles-Cevedale) almost devoid of its snow cover. (August 30, 2008, photo by C. Scolari). - 45 - 2008 glaciological Survey The Pian di Neve (Adamello) in a photo taken at the beginning of August, 2008 from Passo di Salarno. The snow cover was so thin that the ice was emerging (photo by P. Cinanni). - 46 - The Vederetta del Venerocolo Glacier (Adamello) on August 30, 2008 (photo by A. Toffaletti); excluding the avalanche accumulations at the foot of the fans of the northern Adamello wall, the snow is very scarce. In the box: the break-up of the ice channel that, until last year, was linking the Vedretta dei Frati and the Vedretta del Venerocolo Glaciers. 2008 glaciological Survey - 47 - 2008 glaciological Survey The Vedretta dell’Avio Centrale Glacier (Adamello Group) was showing some snow cover over about 30% of its surface and a continuously thinning terminus (August 29, 2008, photo by P. Cinanni). The Vedretta di Pisgana Ovest (Adamello) in a detail of its median part. The link between the front portion (foreground) and the accumulation basins is getting narrower (September 9, 2008; photo by F. Roveda). - 48 - The Lupo Glacier (Orobic Alps) in a picture taken on August 30, 2008 by S. D’Adda. 2008 glaciological Survey The Monte Torena Superiore Glacier (Orobic Alps) fully covered by snow on August 24, 2008 (photo by L. Pironi). - 49 -