scholarly journals Coherent-stable scatterers detection in SAR multi-interferograms: Feature fuzzy fusion in Alpine glacier geophysical context

2007 ◽  
Author(s):  
G. Vasile ◽  
E. Trouve ◽  
L. Valet ◽  
J.-M. Nicolas ◽  
L. Bombrun ◽  
...  
Keyword(s):  
Alpine Glacier ◽  
Fuzzy Fusion

Interaction between water pressure in the basal drainage system and discharge from an Alpine glacier before and during a rainfall-induced subglacial hydrological event

1997 ◽  
Vol 24 ◽  
pp. 288-292 ◽  
Author(s):  
Andrew P. Barrett ◽  
David N. Collins
Keyword(s):  
Water Level ◽  
Water Pressure ◽  
Drainage System ◽  
Water Levels ◽  
Drainage Network ◽  
Alpine Glacier ◽  
Hydraulic Conditions ◽  
Borehole Water ◽  
Progressive Growth ◽  
Resultant Increase

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.

ALPINE GLACIER ADVANCE DURING MIS 11 IN THE MCMURDO DRY VALLEYS, ANTARCTICA

2016 ◽  
Author(s):  
Kate M. Swanger ◽  
◽  
Joerg M. Schaefer ◽  
Gisela Winckler
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Alpine Glacier ◽  
Glacier Advance

scholarly journals Short term variations of tracer transit speed on alpine glaciers

2010 ◽  
Vol 4 (3) ◽  
pp. 381-396 ◽  
Author(s):  
M. A. Werder ◽  
T. V. Schuler ◽  
M. Funk
Keyword(s):  
Drainage System ◽  
Relative Importance ◽  
Short Term ◽  
Diurnal Variability ◽  
Alpine Glacier ◽  
Two Component ◽  
Transit Speed ◽  
Underlying Processes ◽  
Diurnal Maximum ◽  
Tracer Experiments

Abstract. We first present the results of a series of tracer experiments conducted on an alpine glacier (Gornergletscher, Switzerland) over a diurnal discharge cycle. For these injections, a moulin was used into which an ice marginal lake was draining, providing a relatively constant discharge. The measured tracer transit speeds show two diurnal maxima and minima. These findings are qualitatively different to existing observations from two series of injections conducted at Unteraargletscher (Switzerland) using a moulin fed by supraglacial meltwater having a high diurnal variability, which displayed one diurnal maximum and minimum. We then develop and use a simple two-component model of the glacier drainage system, comprising a moulin and a channel element, to simulate the measured transit speeds for all three injection series. The model successfully reproduces all the observations and shows that the same underlying processes can produce the qualitatively different behaviour depending on the different moulin input discharge regimes. Using the model, we assess the relative importance of the different measurement quantities, show that frequent measurements of moulin input discharge are indispensable and propose an experiment design to monitor the development of the drainage system over several weeks.

The fluctuations of italian glaciers during the last century: a contribution to knowledge about alpine glacier changes

2007 ◽  
Vol 89 (3) ◽  
pp. 167-184 ◽  
Author(s):  
Michele Citterio ◽  
Guglielmina Diolaiuti ◽  
Claudio Smiraglia ◽  
Carlo D'agata ◽  
Teresa Carnielli ◽  
...  
Keyword(s):  
Alpine Glacier ◽  
Glacier Changes

Assessing the influence of bedrock discontinuities on glacier fractures using ground-penetrating radar and structure from motion

2021 ◽  
Author(s):  
Niccolò Dematteis ◽  
Fabrizio Trolio ◽  
Daniele Giordan
Keyword(s):  
Structure From Motion ◽  
Ground Penetrating Radar ◽  
Digital Terrain Model ◽  
Volume Estimation ◽  
Strong Impact ◽  
Alpine Glacier ◽  
Terrain Model ◽  
Bedrock Topography ◽  
Related Risk ◽  
Ground Penetrating

<p>The Planpincieux Glacier lies in the Italian side of the Grandes Jorasses massif (Mont Blanc area), toward the Ferret Valley, in the Courmayeur municipality. This is a highly touristic area, visited every year by tens of thousands of people.</p><p>In summers 2019 and 2020, large portions of the Montitaz Lobe of the glacier (estimated volumes of 250000 m<sup>3</sup> and 500000 m<sup>3</sup> respectively) became unstable and menaced the Planpincieux village. According to runout simulations, such volumes could have reached and damaged a small bridge, buildings or the main valley road, depending on the volume involved in the collapse. Therefore, robust volume estimation was required for the realisation of effective safety plans.</p><p>To this aim, a helicopter-borne ground-penetrating-radar (GPR) survey was conducted in July 2020 with the novel dual polarization AIRETH system. Such a survey provided the ice thickness (20-60 ±10 m) of the unstable portion  and the bedrock topography along transects.</p><p>Besides, multiple helicopter and drone photogrammetric surveys were acquired since 2017, which provided the digital terrain model (DTM) and the orthophotos of the glacier using structure from motion (SfM) technique.</p><p>Merging GPR and SfM allowed at reconstructing the evolution of the glacier shrinkage in the period where DTMs were available. Moreover, it was possible to assess the correspondence of several bedrock discontinuities with large recurrent fractures.</p><p>Even though it is commonly acknowledged that the bedrock topography influences the glacier morphology, their correspondence has been rarely demonstrated in an Alpine glacier.</p><p>Since the fractures provoked by the bedrock discontinuities might destabilise the underlying glacier portion, the knowledge of the actual position of such fractures can help in the quantitative evaluation of the glacier instability. This can have a strong impact in the potential glacier-related risk assessment and management.</p>

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