Geomorphological analysis on the interaction of Alpine glaciers and rock glaciers since the Little Ice Age

2018 ◽  
Vol 30 (5) ◽  
pp. 580-591 ◽  
Author(s):  
Robert Kenner
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Alpine Glaciers ◽  
Rock Glaciers ◽  
Geomorphological Analysis

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 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 Distribución espacial y temporal de glaciares, glaciares cubiertos y glaciares rocosos durante la última deglaciación en el valle de La Bonaigua (Pirineo Central)

2020 ◽  
Vol 46 (2) ◽  
pp. 413-446
Author(s):  
J. Ventura-Roca
Keyword(s):  
High Resolution ◽  
Little Ice Age ◽  
Ice Age ◽  
Lidar Data ◽  
Forest Environment ◽  
Digital Elevation ◽  
Rock Glaciers ◽  
Elevation Model ◽  
Glacial Landforms ◽  
Central Pyrenees

The application of the paleogeographic method to the study of glacial landforms and rock glaciers allows their morphometric and sedimentological characterization, the establishment of a detailed morphostratigraphic sequence and a chronological proposal for the identified glacial phases. This study analyzes 86 landforms (57 glacial deposits, 21 rock glaciers and 8 protalus ramparts) in the Bonaigua Valley (Noguera Pallaresa Basin, Central Pyrenees), with special attention to the differentiation between debris-covered glaciers and rock glaciers. Other subjects studied concerning rock glaciers are: distinguish its glacial or periglacial origin; the possible current activity of some landforms, and the detection of rock glaciers located at low altitudes (in the current forest environment) through the use of high-resolution digital elevation model (2x2 m) from LIDAR data. The chronological hypothesis elaborated by correlation with other high Pyrenean valleys (with absolute ages available) includes 7 phases (6 glacial phases and 1 periglacial phase) in which co-exist and/or evolve, in a paraglacial dynamic, glaciers, debris-covered glaciers and rock glaciers, and that we temporarily place between the end of the Oldest Dryas and the Little Ice Age.

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.

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.

Advance of alpine glaciers during final retreat of the Cordilleran ice sheet in the Finlay River area, northern British Columbia, Canada

2008 ◽  
Vol 69 (2) ◽  
pp. 188-200 ◽  
Author(s):  
Thomas R. Lakeman ◽  
John J. Clague ◽  
Brian Menounos
Keyword(s):  
British Columbia ◽  
Little Ice Age ◽  
Sediment Cores ◽  
Ice Sheet ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Ice Age ◽  
Last Glaciation ◽  
Alpine Glaciers ◽  
Cordilleran Ice Sheet

Sharp-crested moraines, up to 120 m high and 9 km beyond Little Ice Age glacier limits, record a late Pleistocene advance of alpine glaciers in the Finlay River area in northern British Columbia. The moraines are regional in extent and record climatic deterioration near the end of the last glaciation. Several lateral moraines are crosscut by meltwater channels that record downwasting of trunk valley ice of the northern Cordilleran ice sheet. Other lateral moraines merge with ice-stagnation deposits in trunk valleys. These relationships confirm the interaction of advancing alpine glaciers with the regionally decaying Cordilleran ice sheet and verify a late-glacial age for the moraines. Sediment cores were collected from eight lakes dammed by the moraines. Two tephras occur in basal sediments of five lakes, demonstrating that the moraines are the same age. Plant macrofossils from sediment cores provide a minimum limiting age of 10,550–10,250 cal yr BP (9230±5014C yr BP) for abandonment of the moraines. The advance that left the moraines may date to the Younger Dryas period. The Finlay moraines demonstrate that the timing and style of regional deglaciation was important in determining the magnitude of late-glacial glacier advances.

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: AD 1550–1850) 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.

Climate variability and Alpine glaciers evolution in Northwestern Italy from the Little Ice Age to the 2010s

2014 ◽  
Vol 122 (3-4) ◽  
pp. 595-608 ◽  
Author(s):  
Guido Nigrelli ◽  
Stefania Lucchesi ◽  
Stefania Bertotto ◽  
Gianfranco Fioraso ◽  
Marta Chiarle
Keyword(s):  
Climate Variability ◽  
Little Ice Age ◽  
Ice Age ◽  
Alpine Glaciers

scholarly journals 19th century glacier retreat in the Alps preceded the emergence of industrial black carbon deposition on high-alpine glaciers

2018 ◽  
Vol 12 (10) ◽  
pp. 3311-3331 ◽  
Author(s):  
Michael Sigl ◽  
Nerilie J. Abram ◽  
Jacopo Gabrieli ◽  
Theo M. Jenk ◽  
Dimitri Osmont ◽  
...  
Keyword(s):  
Black Carbon ◽  
19Th Century ◽  
Little Ice Age ◽  
Ice Core ◽  
Ice Cores ◽  
Ambient Air ◽  
Radiative Properties ◽  
Ice Age ◽  
Alpine Glaciers ◽  
The Alps

Abstract. Light absorbing aerosols in the atmosphere and cryosphere play an important role in the climate system. Their presence in ambient air and snow changes the radiative properties of these systems, thus contributing to increased atmospheric warming and snowmelt. High spatio-temporal variability of aerosol concentrations and a shortage of long-term observations contribute to large uncertainties in properly assigning the climate effects of aerosols through time. Starting around AD 1860, many glaciers in the European Alps began to retreat from their maximum mid-19th century terminus positions, thereby visualizing the end of the Little Ice Age in Europe. Radiative forcing by increasing deposition of industrial black carbon to snow has been suggested as the main driver of the abrupt glacier retreats in the Alps. The basis for this hypothesis was model simulations using elemental carbon concentrations at low temporal resolution from two ice cores in the Alps. Here we present sub-annually resolved concentration records of refractory black carbon (rBC; using soot photometry) as well as distinctive tracers for mineral dust, biomass burning and industrial pollution from the Colle Gnifetti ice core in the Alps from AD 1741 to 2015. These records allow precise assessment of a potential relation between the timing of observed acceleration of glacier melt in the mid-19th century with an increase of rBC deposition on the glacier caused by the industrialization of Western Europe. Our study reveals that in AD 1875, the time when rBC ice-core concentrations started to significantly increase, the majority of Alpine glaciers had already experienced more than 80 % of their total 19th century length reduction, casting doubt on a leading role for soot in terminating of the Little Ice Age. Attribution of glacial retreat requires expansion of the spatial network and sampling density of high alpine ice cores to balance potential biasing effects arising from transport, deposition, and snow conservation in individual ice-core records.

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