Relationships between glacier and rock glacier in the Maritime Alps, Schiantala Valley, Italy

2007 ◽  
Vol 68 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Adriano Ribolini ◽  
Alessandro Chelli ◽  
Mauro Guglielmin ◽  
Marta Pappalardo
Keyword(s):  
Little Ice Age ◽  
Geophysical Methods ◽  
Ice Crystals ◽  
Ice Age ◽  
Ice Formation ◽  
Dc Resistivity ◽  
Rock Glacier ◽  
Maritime Alps ◽  
Rock Glaciers ◽  
The Relationship

AbstractIn the Schiantala Valley of the Maritime Alps, the relationship between a till-like body and a contiguous rock glacier has been analyzed using geomorphologic, geoelectric and ice-petrographic methodologies. DC resistivity tomographies undertaken in the till and in the rock glacier show the presence of buried massive ice and ice-rich sediments, respectively. Ice samples from a massive ice outcrop show spherical gas inclusions and equidimensional ice crystals that are randomly orientated, confirming the typical petrographic characteristics of sedimentary ice. The rock glacier formation began after a phase of glacier expansion about 2550"50 14C yr BP. Further ice advance during the Little Ice Age (LIA) overrode the rock glacier root and caused partial shrinkage of the pre-existing permafrost. Finally, during the 19th and 20th centuries, the glacial surface became totally debris covered. Geomorphological and geophysical methods combined with analyses of ice structure and fabric can effectively interpret the genesis of landforms in an environment where glaciers and permafrost interact. Ice petrography proved especially useful for differentiating ice of past glaciers versus ice formed under permafrost conditions. These two mechanisms of ice formation are common in the Maritime Alps where many sites of modern rock glaciers were formerly occupied by LIA glaciers.

Are There Any Active Rock Glaciers in the Tatra Mountains?

2014 ◽  
Vol 48 (1) ◽  
Author(s):  
Stanisław Kędzia
Keyword(s):  
Little Ice Age ◽  
High Probability ◽  
Ice Age ◽  
Tatra Mountains ◽  
Rock Glacier ◽  
Rock Glaciers ◽  
The Tatra Mountains

AbstractResearch on rock glaciers have been conducted in the Tatra Mountains for about 100 years. About 30 years ago, there were papers suggesting that part of the Tatra rock glaciers was formed during the Little Ice Age. About 20 years ago, permafrost was discovered in the mountains. This discovery marked the beginning of research on the activity of rock glaciers. Ten years ago, a study was carried out on the rock glacier near the Velké Hincovo Pleso lake, which excluded any activity of this glacier in the last few hundred years, despite the high probability of the existence of permafrost in it. The following paper presents the results of lichenometric dating conducted for the activity of rock glaciers in the Świstówka Roztocka and the Buczynowa valleys.

scholarly journals Equilibrium-line altitudes and rock glaciers during the Younger Dryas cooling event, Ferwall group, western Tyrol, Austria

1999 ◽  
Vol 28 ◽  
pp. 141-145 ◽  
Author(s):  
Rudolf Sailer ◽  
Hanns Kerschner
Keyword(s):  
Little Ice Age ◽  
Younger Dryas ◽  
Late Glacial ◽  
Ice Age ◽  
Equilibrium Line ◽  
Rock Glacier ◽  
Equilibrium Line Altitude ◽  
Discontinuous Permafrost ◽  
Rock Glaciers ◽  
Temperature Depression

AbstractThree cirques in the Ferwall group, western Tyrol, Austria, which are characterized by distinct Late-glacial moraines and rock glaciers, are discussed. The morphology of the moraines and the depression of the equilibrium-line altitude suggest they were deposited during the Egesen Stadial (Younger Dryas), which can be subdivided into three substages. Rock-glacier formation was initialized during or after the Egesen II substage. They became inactive at the Pleistocene—Holocene transition. ELA values are 290–320 m lower than the Little Ice Age ELA during the Egesen I substage, 190–230 m lower during the Egesen II substage and 120 —160 m lower during the Egesen III substage. The lowering of the rock-glacier belt (discontinuous permafrost) during and after the Egesen II substage is about 400 m, indicating a mean annual air-temperature depression in the order of 3 K. During the Egesen I (earlyYounger Dryas), the climate seems to have been rather cold and wet with precipitation similar to present-day values. During later phases (Egesen II and III), the climate remained cold and became increasingly drier. The rise of the ELA during the Egesen I—III substages seems to have been mainly caused by a decrease in precipitation.

Distribution and characteristics of rock glaciers in the southern part of Jasper National Park, Alberta

1978 ◽  
Vol 15 (4) ◽  
pp. 540-550 ◽  
Author(s):  
B. H. Luckman ◽  
K. J. Crockett
Keyword(s):  
Little Ice Age ◽  
National Park ◽  
Ice Age ◽  
Rock Glacier ◽  
Genetic Classification ◽  
Climatic Fluctuations ◽  
Glacial Ice ◽  
Jasper National Park ◽  
Rock Glaciers ◽  
Two Phases

One hundred and nineteen rock glaciers were identified in an aerial photograph inventory of 4632 km2 in Jasper National Park, Alberta. Morphological subdivision indicated 33 lobate, 76 tongue-shaped and 10 spatulate rock glaciers, whereas a 'genetic' classification identified 65 'glacial' (ice-cored) and 54 'non-glacial' (ice-cemented) rock glaciers. Head elevations of the glacial group (mean 2318 m) are significantly higher than the non-glacial group (mean 2256 m). The total elevation range of rock glaciers is 1710–2670 m.Optimal rock glacier sites are below north- or northeast-facing quartzite cliffs in cirques or on valley walls. These topographic and geologic controls produce a greater concentration of rock glaciers in the Main Ranges than the Front Ranges. Rock glacier head elevations rise eastwards and, to a lesser extent, southward across the area in response to regional climatic and latitudinal effects. Two phases of pre-'Little Ice Age' rock glacier activity are recognized on morphologic grounds and, since Little Ice Age glaciers overrode most of the evidence of Holocene glacier fluctuation, provide a major source of information on Holocene climatic fluctuations. Preliminary data suggest most rock glacier activity pre-dates the Little Ice Age and the oldest phases probably occurred between 6600 and 9000 BP.

Dynamics of an active rock glacier (Ötztal Alps, Austria)

2004 ◽  
Vol 62 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Jana Berger ◽  
Karl Krainer ◽  
Wolfram Mostler
Keyword(s):  
Little Ice Age ◽  
High Surface ◽  
Weather Conditions ◽  
Surface Flow ◽  
Ice Age ◽  
Rock Glacier ◽  
Glacial Origin ◽  
Seasonal And Diurnal Variations ◽  
Rock Glaciers ◽  
Local Weather

The rock glacier Innere Ölgrube, located in a small side valley of the Kauner Valley (Ötztal Alps, Austria), consists of two separate, tongue-shaped rock glaciers lying next to each other. Investigations indicate that both rock glaciers contain a core of massive ice. During winter, the temperature at the base of the snow cover (BTS) is significantly lower at the active rock glacier than on permafrost-free ground adjacent to the rock glacier. Discharge is characterized by strong seasonal and diurnal variations, and is strongly controlled by the local weather conditions. Water temperature of the rock glacier springs remains constantly low, mostly below 1°C during the whole melt season. The morphology of the rock glaciers and the presence of meltwater lakes in their rooting zones as well as the high surface flow velocities of >1 m/yr point to a glacial origin. The northern rock glacier, which is bounded by lateral moraines, evolved from the debris-covered tongue of a small glacier of the Little Ice Age with its last highstand around A.D. 1850. Due to the global warming in the following decades, the upper parts of the steep and debris-free ice glacier melted, whereas the debris-covered glacier tongue transformed into an active rock glacier. Due to this evolution and due to the downslope movement, the northern rock glacier, although still active, at present is cut off from its ice and debris supply. The southern rock glacier has developed approximately during the same period from a debris-covered cirque glacier at the foot of the Wannetspitze massif.

scholarly journals Supraglacial debris-transport variability over time: examples from Switzerland and Iceland

1996 ◽  
Vol 22 ◽  
pp. 181-186 ◽  
Author(s):  
W.B. Whalley ◽  
C.F. Palmer ◽  
S.J. Hamilton ◽  
D. Kitchen
Keyword(s):  
19Th Century ◽  
Little Ice Age ◽  
Ice Age ◽  
Debris Transport ◽  
Actual Volume ◽  
Glacier Ice ◽  
Rock Glaciers ◽  
Slow Moving ◽  
The 19Th Century ◽  
Over Time

The volume of debris in the left-lateral, Little Ice Age (LIA:AD1550–1850) moraine of the Feegletscher, Valais, Switzerland was compared with the actual volume being transported currently by the glacier. The latter is smaller by a factor of about two. In Tröllaskagi, north Iceland, a surface cover of debris on top of a very slow moving glacier ice mass (glacier noir, rock glacier) has been dated by lichenometry. The age of the oldest part is commensurate with LIA moraines in the area. Knowing the volume of debris of a given age allows an estimate of the debris supply to the glacier in a given time. Again, there appears to have been a significant reduction in debris to the glacier since the turn of the 19th century. Debris input in the early LIA seems to have been particularly copious and this may be important in the formation of some glacier depositional forms such as rock glaciers.

scholarly journals Climate and social change at the start of the Late Antique Little Ice Age

The Holocene ◽  
2020 ◽  
Vol 30 (11) ◽  
pp. 1643-1648 ◽  
Author(s):  
Peter N Peregrine
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Little Ice Age ◽  
Historical Data ◽  
Ice Age ◽  
Late Antique ◽  
Social Disruption ◽  
Epidemic Disease ◽  
Vulnerability To Climate Change ◽  
The Relationship

The Late Antique Little Ice Age, spanning the period from 536 CE to roughly 560 CE, saw temperatures in the Northern Hemisphere drop by a degree C in less than a decade. This rapid cooling is thought to have caused widespread famine, epidemic disease, and social disruption. The relationship between cooling and social disruption is examined here using a set of high-resolution climate and historical data. A significant link between cooling and social disruption is demonstrated, but it is also demonstrated that the link is highly variable, with some societies experiencing dramatic cooling changing very little, and others experiencing only slight cooling changing dramatically. This points to variation in vulnerability, and serves to establish the Late Antique Little Ice Age as a context within which naturalistic quasi-experiments on vulnerability to climate change might be conducted.

scholarly journals A new model for quantifying subsurface ice content based on geophysical data sets

2010 ◽  
Vol 4 (2) ◽  
pp. 787-821 ◽  
Author(s):  
C. Hauck ◽  
M. Böttcher ◽  
H. Maurer
Keyword(s):  
Seismic Velocity ◽  
Geophysical Methods ◽  
Geophysical Data ◽  
Swiss Alps ◽  
Unfrozen Water ◽  
Detailed Knowledge ◽  
Data Sets ◽  
Rock Glacier ◽  
Heterogeneous Distribution ◽  
Rock Glaciers

Abstract. Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings requires a relation between the measured variables (e.g. electrical resistivity, seismic velocity) and the actual subsurface constituents (rock, water, air, ice). In this work we present a model, which provides estimates of the volumetric fractions of these four phases from tomographic electrical and seismic images. The model is tested using geophysical data sets from two rock glaciers in the Swiss Alps, where ground truth information in form of borehole data is available. First results confirm the applicability of the so-called 4-phase model, which allows to quantify the contributions of ice-, water- and air within permafrost areas as well as detecting the firm bedrock. Apart from a similarly thick active layer with enhanced air content for both rock glaciers, the two case studies revealed a heterogeneous distribution of ice and unfrozen water within rock glacier Muragl, where bedrock was detected at depths of 20–25 m, but a comparatively homogeneous ice body with only minor heterogeneities within rock glacier Murtèl.

scholarly journals The origin of glacial alpine landscape in Tröllaskagi Peninsula (North Iceland)

2016 ◽  
Vol 42 (2) ◽  
pp. 341 ◽  
Author(s):  
N. Andrés ◽  
L. M. Tanarro ◽  
J. M. Fernández ◽  
D. Palacios
Keyword(s):  
North Atlantic ◽  
Little Ice Age ◽  
Ice Age ◽  
Important Advance ◽  
North Central ◽  
The North ◽  
Significant Difference ◽  
Rock Glaciers ◽  
Basalt Plateau ◽  
Tertiary Basalt

The Tröllaskagi peninsula is located in north central Iceland, between meridians 19º30’W and 18º10’W , limited by Skagafjödur fiord to the west and the Eyjafjödur fiord to the east, jutting out into the North Atlantic to latitude 66º12’N and linked to the central Icelandic highlands to the south. The peninsula is a Tertiary basalt plateau topped by flat summits with altitudes of 1000-1500 m, intensely dissected by the drainage network. The aim of this present study is to synthesize the recent advances in our understanding of the landscape and its dynamics in the Tröllaskagi peninsula and find the origin of its significant difference from the rest of Iceland. Results of the most recent research suggest the situation of Tröllaskagi as ice-free, delimited by the two great glacial outlets flowing down from the Icelandic Ice Sheet through the Skagafjödur and Eyjafjödur fiords, from at least the Oldest Dryas to the end of the Early Preboreal. Inland in Tröllaskagi, the glaciers formed in the north-facing cirques without losing their alpine characteristics during the Late Pleistocene and Holocene. The advances of these glaciers during the Oldest, Older and Youngest Dryas and the Early Preboreal were only a few hundred metres greater than the most important advance in the second half of the Holocene, during the Little Ice Age. Only a few of these glaciers remained debris-free and are sensitive to the minor climate oscillations. The rest, due to the important geomorphological activity on their walls, developed into debris-covered and rock glaciers and lost this significant dynamism.

scholarly journals GEOMATIC METHODS APPLIED TO THE CHANGE STUDY OF THE LA PAÚL ROCK GLACIER, SPANISH PYRENEES

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1771-1775
Author(s):  
A. Martínez-Fernández ◽  
E. Serrano ◽  
J. J. Sanjosé ◽  
M. Gómez-Lende ◽  
A. Pisabarro ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Satellite System ◽  
Ice Age ◽  
Rock Glacier ◽  
Glacier Surface ◽  
The North ◽  
Spanish Pyrenees ◽  
Gnss Receivers ◽  
Rock Glaciers ◽  
Global Navigation Satellite

<p><strong>Abstract.</strong> Rock glaciers are one of the most important features of the mountain permafrost in the Pyrenees. La Paúl is an active rock glacier located in the north face of the Posets massif in the La Paúl glacier cirque (Spanish Pyrenees). This study presents the preliminary results of the La Paúl rock glacier monitoring works carried out through two geomatic technologies since 2013: Global Navigation Satellite System (GNSS) receivers and Terrestrial Laser Scanning (TLS) devices. Displacements measured on the rock glacier surface have demonstrated both the activity of the rock glacier and the utility of this equipment for the rock glaciers dynamic analysis. The glacier has exhibited the fastest displacements on its west side (over 35&amp;thinsp;cm&amp;thinsp;yr<sup>&amp;minus;1</sup>), affected by the Little Ice Age, and frontal area (over 25&amp;thinsp;cm&amp;thinsp;yr<sup>&amp;minus;1</sup>). As an indicator of permafrost in marginal environments and its peculiar morphology, La Paúl rock glacier encourages a more prolonged study and to the application of more geomatic techniques for its detailed analysis.</p>

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