Geomorphic influence on small glacier response to post Little Ice Age climate warming: Julian Alps, Europe

The evolution of glaciers and ice patches, as well as the equilibrium-line altitude (ELA) since the Little Ice Age (LIA) were investigated in the Julian Alps (south-eastern European Alps) including ice masses previously unreported. 23 permanent firn and ice bodies have been recognized in the 1853 km2 of this alpine sector, covering a total area in 2012 of 0.385 km2, about one-fifth of the area covered during the LIA (2.350 km2)… … The ice masses in the region are at the lowest elevations of any glaciers in the Alpine Chain, and are characterized by low dynamics. The ELAs of the two major LIA glaciers (Canin and Triglav) have been established at 2275 ± 10 m and 2486 ± 10 m, respectively, by… ... Changes in the ELA and glaciers extension indicate a decoupling from climate. This is most evident in the smallest avalanche-dominated ice bodies, which are currently controlled mainly by precipitation… … resilient to recent climate warming instead of rapidly disappearing as should be expected

Geometry and paleo-ice content of rock glaciers in the southeastern Alps (NE Italy – NW Slovenia)

Rock glaciers in the southeastern Alps of Slovenia and Italy have been mapped in detail using high resolution digital elevation model and orthophotos, supported by field-based observations. A total of 52 rock glaciers with an area of 3.40 km2 have been delineated on a rock glacier map, divided in 18 sections at a scale of 1:15,000. Several geometrical parameters of rock glaciers have been calculated and their activity degree has been inferred. 90% of rock glaciers have been classified as relict, while the rest are assumed to be of uncertain activity and might still contain some ice. The volumetric ice content and water volume equivalent of the studied rock glaciers for the period of their activity has been calculated to 0.055 ± 0.011 km3 and 0.049 ± 0.010 km3, respectively, which is very close to the ice volume of glaciers reconstructed for this area during the little ice age to 0.069 km3.</p

Dimension Estimate for the Global Attractor of an Evolution Equation

We estimate the dimension of the global attractor of an evolution equation by the study of the evolution of the n-dimensional volumes under the flow. We compare these results with the estimate of the dimension of the inertial manifold

4-D quantitative GPR analyses to study the summer mass balance of a glacier: A case history

In order to assess the seasonal changes of the topography, the inner structure and the physical properties of a small glacier in the Eastern Alps, we performed a 4-D multi frequency GPR survey by repeating the same data acquisition in four different periods of the year 2013. The usual glacier mass balance estimation encompasses only topographic variations, but the real evolution is much more complex and includes surface melting and refreezing, snow metamorphism, and basal melting. We analyzed changes in both the imaged geometrical-morphological structures and the densities, estimated from GPR data inversion. The inversion algorithm uses reflection amplitudes and traveltimes to extract the electromagnetic velocity in the interpreted layers and the densities of the frozen materials through empirical relations. The obtained results have been compared and validated with direct measures like snow thickness surveys, density logs within snow pits and ablation stakes. This study demonstrates that GPR techniques are a fast and effective tool not only for glacial qualitative studies, but also for detailed glacier monitoring and accurate quantitative analyses of crucial glaciological parameters like density distribution and water runoff

Spatial and climatic characterization of three glacial stages in the Upper Krnica Valley, SE European Alps

The southeastern European Alps represent the spot where mean annual precipitation is at its highest in the entire Alpine chain. Accordingly, the glacial evolution here might have a different spatial and chronological pattern if compared with other alpine areas. This paper discusses geomorphological evidence of three glacial stages from the Krnica Valley in the Julian Alps of Slovenia, and is the first step towards a comprehensive palaeoglaciological studies in this alpine sector. Very well-preserved glacial landforms in the Upper Krnica Valley allowed the reconstruction of glacier surface topographies and corresponding equilibrium line altitudes (ELAs) by means of field-based geomorphological and sedimentological data and by using geospatial analysis. The uppermost frontal moraines belong to the Little Ice Age (LIA) and the corresponding ELA is estimated at 1973 m a.s.l. Other two stages with the ELA depressed by 50 m and 161 m compared to the LIA ELA, suggest early Holocene and Younger Dryas ages of the palaeoglaciers, respectively. This assumption ensues from absolute age datings and related ELA depressions observed elsewhere in the European Alps. The presence of buried ice under the debris in the Krnica cirque, imaged through geophysical investigations, point to peculiar microclimatic conditions able to preserve relict glacier ice. This is favoured by the recursive presence of snow on the ground caused by the extreme summer shading and the significant winter snow-recharge triggered by snowblow and avalanche feeding. The possible evolution of such relict ice under the ongoing climate warming is also discussed

Dynamics of a Gross-Pitaevskii Equation with Phenomenological Damping

We study the dynamical behavior of solutions of an n-dimensional nonlinear Schrödinger equation with potential and linear derivative terms under the presence of phenomenological damping. This equation is a general version of the dissipative Gross-Pitaevskii equation including terms with first-order derivatives in the spatial coordinates which allow for rotational contributions. We obtain conditions for the existence of a global attractor and find bounds for its dimension

Recent evolution of Marmolada glacier (Dolomites, Italy) by means of ground and airborne GPR surveys

A 10-year-long evolution of ice thickness and volume of the Marmolada glacier is presented. Quantitative measurements have been performed by using two different Ground Penetrating Radar (GPR) datasets. A ground-based survey using two different ground-coupled systems equipped with 100 MHz and 35 MHz antennas was performed in 2004. In 2015 the dataset was collected by using a helicopter-borne step frequency GPR equipped with a 100 MHz antenna. Through a critical discussion of the two different methodologies, we show how both approaches are useful to estimate the ice volume within a glacier, as well as its morphological characteristics and changes with time, even if datasets are acquired in different periods of the year. The observed 2004–2014 ice volume reduction of the Marmolada glacier is equal to about 30%, while the area covered by ice decreased by about 22%. The glacier is now splitted in several separated units. It is very likely that the fragmentation of the Marmolada glacier observed in the period 2004–2014 was accelerated due to irregular karst topography. By applying the observed 2004–2014 ice-melting trend for the future although the Marmolada glacier might behave slightly differently compared to glaciers on non-karstic terrains owing to dominant vertical subglacial drainage, it will likely disappear by the year 2050. Only few isolated very small and thin ice patches will eventually survive due to avalanche feeding and shading at the foot of the north-facing cliffs

Is that a relict rock glacier?

The distribution of rock glaciers is often used to investigate the occurrence of permafrost inmountain areas and to understand their climate and paleoclimate evolution. This requires the creation of regional and global inventories capable of discriminating active and relict landforms in order to forecast the presence or absence of ice in the ground. In this paper, geomorphological, geophysical and microclimatic surveys are performed on a rock glacier of the Carnic Alps (Eastern European Alps). In the classification currently used for implementing regional inventories of permafrost evidence in the Alps, this rock glacier would be defined as relict. However the geophysical, climatological and geomorphological results indicate that internal ice is widespread in large portions of the rock glacier. These are generally interpreted as ice in pore spaces and local ice lenses, probably without layers of massive ice. Moreover the occurrence of ice during the maximum thawing season at depths b15 m, assumed here as the depth of zero annual amplitude, suggests that the ice occurring within the rock glacier is related to current cryotic conditions due to density driven air flow (i.e. the chimney effect). This research demonstrates that the current altitudinal limit of alpine permafrost can be locally several hundreds of meters lower than forecasted byempiricalmodeling based only on the rock glacier distribution and classification. Therefore, rock glacier classifications based only on remote sensing and geomorphological evidence as the main sources for extracting regional climate and paleoclimate signals should be treated with caution

Rock glaciers, protalus ramparts and pronival ramparts in the south-eastern Alps

Rock glaciers and protalus ramparts are characteristic landforms of the periglacial domain often used as markers for the occurrence of permafrost in mountain terrains. As such, relict rock glaciers can be used for paleoclimate reconstructions. We present here the first previously unreported rock glacier inventory of the south-eastern Alps (including the north-eastern-most region of Italy and Slovenia), interpreted from high resolution orthophotos and a high resolution digital terrain model interpolated from airborne laser scanning (LiDAR). We mapped 53 rock glaciers covering a total area of 3.45 km2. … … Using paleoclimate reconstruction based on the 1981–2010 climatological record of the area, we infer that the rock glaciers formed during one of the dry and cold periods of the late Pleistocene and early Holocene. Possible evolution of the active pronival forms observed in the most maritime area of this alpine sector is also discussed