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 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.

A national glacier inventory and variations in glacier extent in Iceland from the Little Ice Age maximum to 2019

JOKULL ◽  
2020 ◽  
Vol 70 ◽  
pp. 1-34
Author(s):  
Hrafnhildur Hannesdóttir ◽  
Oddur Sigurðsson ◽  
Ragnar Þrastarson ◽  
Snævarr Guðmundsson ◽  
Joaquín Belart ◽  
...  
Keyword(s):  
19Th Century ◽  
Little Ice Age ◽  
Volcanic Eruptions ◽  
Ice Age ◽  
Glacier Inventory ◽  
Ice Caps ◽  
Climatic Variations ◽  
Intermediate Size ◽  
Glacier Surges ◽  
The 19Th Century

Abstract — A national glacier outline inventory for several different times since the end of the Little Ice Age (LIA) in Iceland has been created with input from several research groups and institutions, and submitted to the GLIMS (Global Land Ice Measurements from Space, nsidc.org/glims) database, where it is openly available. The glacier outlines have been revised and updated for consistency and the most representative outline chosen. The maximum glacier extent during the LIA was not reached simultaneously in Iceland, but many glaciers started retreating from their outermost LIA moraines around 1890. The total area of glaciers in Iceland in 2019 was approximately 10,400 km2, and has decreased by more than 2200 km2 since the end of the 19th century (corresponding to an 18% loss in area) and by approximately 750 km2 since ~2000. The larger ice caps have lost 10–30% of their maximum LIA area, whereas intermediate-size glaciers have been reduced by up to 80%. During the first two decades of the 21st century, the decrease rate has on average been approximately 40 km2 a-1. During this period, some tens of small glaciers have disappeared entirely. Temporal glacier inventories are important for climate change studies, for calibration of glacier models, for studies of glacier surges and glacier dynamics, and they are essential for better understanding of the state of glaciers. Although surges, volcanic eruptions and jökulhlaups influence the position of some glacier termini, glacier variations have been rather synchronous in Iceland, largely following climatic variations since the end of the 19th century.

scholarly journals Dendrogeomorphological study of glacier fluctuations in the Italian Alps during the Little Ice Age

1999 ◽  
Vol 28 ◽  
pp. 123-128 ◽  
Author(s):  
Manuela Pelfini
Keyword(s):  
Response Time ◽  
19Th Century ◽  
Tree Ring ◽  
Little Ice Age ◽  
Climate Changes ◽  
Rapid Decrease ◽  
Ice Age ◽  
Wood Production ◽  
Italian Alps ◽  
The 19Th Century

AbstractIn the Italian Alps, the maximum advance of the Holocene usually coincided with the Little Ice Age (LIA), which reached a climax for most glaciers during the first two decades of the 19th century. Moraines deposited during the peak of the LIA usually obliterated glacial deposits from previous advances. Using dendrogeomorphology, it is possible to date glacier advances before the LIA peak. In the central Italian Alps, it was possible to pinpoint an advance of Ghiacciaio del Madaccio, which took place in the first two decades of the 17th century. With dendrogeomorphology, it is also possible to reconstruct in detail the behaviour of glaciers during the Little Ice Age climax. Trees growing on the margin of glacier tongues may have suffered damage, recognizable by the presence of wood scars and the formation of particularly thin rings; their dating allows both ice advances and retreats to be dated. This is the case for Ghiacciaio Grande di Verra in the western Italian Alps; owing to the rapid decrease of the tree ring widths, it is possible to recognize climate changes responsible for both lower wood production and, sometimes, subsequent glacier advances, although the latter take place with a certain delay. For Ghiacciaio del Lys in the western Italian Alps, a response time of five years was determined.

scholarly journals Little Ice Age glacial activity in Peter Lougheed and Elk Lakes provincial parks, Canadian Rocky Mountains

1995 ◽  
Vol 32 (5) ◽  
pp. 579-589 ◽  
Author(s):  
Daniel J. Smith ◽  
Daniel P. Mccarthy ◽  
Margaret E. Colenutt
Keyword(s):  
19Th Century ◽  
Little Ice Age ◽  
18Th Century ◽  
Ice Age ◽  
Canadian Rocky Mountains ◽  
Glacial Chronology ◽  
Provincial Parks ◽  
Glacial Expansion ◽  
The 19Th Century ◽  
Glacial Advance

Dendrochronological, lichenometric, and 14C studies at 14 glacier sites in Peter Lougheed and Elk Lakes provincial parks were used to develop a chronology of Little Ice Age glacial events. The earliest indications of glacial activity are represented by moraines deposited prior to the 16th century. A major glacial expansion in the 17th century is recorded at three sites, where I4C dates show glaciers reached their maximum down-valley positions. Lichenometric dates and tree growth suppression records show a phase of glacial activity early in the 18th century, for which there is only sparse morainic evidence. Most moraines in the area date from a glacial advance culminating in the mid-19th century, and moraine formation was complete everywhere by the late 1800's. Recessional moraines are rare in the study area and indicate that ice-front retreat has been relatively continuous since the 19th century. The glacial chronology developed in this work is comparable to that reconstructed for both the Main Ranges of the Canadian Rockies and the Coast Ranges of the southern Cordillera.

scholarly journals Flood events in Transylvania during the Medieval Warm Period and the Little Ice Age

The Holocene ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Ioana Perșoiu ◽  
Aurel Perșoiu
Keyword(s):  
19Th Century ◽  
North Atlantic ◽  
Little Ice Age ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Ice Age ◽  
The North ◽  
High Incidence ◽  
The North Atlantic ◽  
The 19Th Century

We present here the first record of past flooding activity from the Carpathian Mountains, Eastern Europe, based on documentary evidence and sedimentary records along one of the main rivers draining this region (Someșul Mic River). Three periods of increased flood activity have occurred in Transylvania during the last millennium: the first at the beginning of the 10th century (the end of the Dark Ages Cold Period and beginning of the Medieval Warm Period (MWP)); the second at the end of the 16th and beginning of 17th century, during the cold Little Ice Age (LIA) and the third at the end of the 19th century. During the early MWP, generally wet summers resulted in a high incidence of floods and/or high discharges, while the cluster of floods at the end of 16th and beginning of the 17th centuries occurred mostly at flash floods generated during heavy summer thunderstorms. Increasing winter temperatures and spring precipitations probably caused the high incidence of floods at the end of the 19th century. The predominantly wet conditions during the MWP are likely to have resulted from northward penetration of Mediterranean cyclones during a (mostly) positive phase of the North Atlantic Oscillation (NAO), while wet conditions during the LIA arose as a combination of increases in local storminess and moisture transport from the North Atlantic along more southerly positioned westerlies associated with a negative phase of the NAO.

Debris-Covered Glaciers in the Sierra Nevada, California, and Their Implications for Snowline Reconstructions

1994 ◽  
Vol 41 (2) ◽  
pp. 139-153 ◽  
Author(s):  
Douglas H. Clark ◽  
Malcolm M. Clark ◽  
Alan R. Gillespie
Keyword(s):  
Sierra Nevada ◽  
Little Ice Age ◽  
Ice Age ◽  
Climatic Warming ◽  
Floor Rock ◽  
Orographic Effects ◽  
Climatic Trends ◽  
Melt Ponds ◽  
Glacier Ice ◽  
Rock Glaciers

AbstractIce-walled melt ponds on the surfaces of active valley-floor rock glaciers and Matthes (Little Ice Age) moraines in the southern Sierra Nevada indicate that most of these landforms consist of glacier ice under thin (ca. 1 - 10 m) but continuous covers of rock-fall-generated debris. These debris blankets effectively insulate the underlying ice and greatly reduce rates of ablation relative to that of uncovered ice. Such insulation explains the observations that ice-cored rock glaciers in the Sierra, actually debris-covered glaciers, are apparently less sensitive to climatic warming and commonly advance to lower altitudes than do adjacent bare-ice glaciers. Accumulation-area ratios and toe-to-headwall-altitude ratios used to estimate equilibrium-line altitudes (ELAs) of former glaciers may therefore yield incorrect results for cirque glaciers subject to abundant rockfall. Inadvertent lumping of deposits from former debris-covered and bare-ice glaciers partially explains an apparently anomalous regional ELA gradient reported for the pre-Matthes Recess Peak Neoglacial advance. Distinguishing such deposits may be important to studies that rely on paleo-ELA estimates. Moreover, Matthes and Recess Peak ELA gradients along the crest evidently depend strongly on local orographic effects rather than latitudinal climatic trends, indicating that simple linear projections and regional climatic interpretations of ELA gradients of small glaciers may be unreliable.

Post-glacial dynamics of alpine Little Ice Age glacitectonized frozen landforms (Swiss Alps)

2020 ◽  
Author(s):  
Julie Wee ◽  
Reynald Delaloye ◽  
Chloé Barboux
Keyword(s):  
Little Ice Age ◽  
Spatial Configuration ◽  
Sar Interferometry ◽  
Swiss Alps ◽  
Ice Age ◽  
Permafrost Degradation ◽  
Mass Wasting ◽  
Ground Ice ◽  
Slope Movements ◽  
Glacier Ice

<p>Glaciers and frozen debris landforms have coexisted and episodically interacted throughout the Holocene, the former having altered the development, spatial distribution and thermal regime of the latter. In the Alps, the apogee of last interaction phase occurred during the Little Ice Age (LIA). Since then, due to glacier shrinkage, interactions between glaciers and LIA pre-existing frozen debris have gradually diminished and are leaning towards being non-existent. Post-LIA glacier forefields in permafrost environments, including associated glacitectonized frozen landforms (GFL) have shifted from a thermal and mechanical glacier dominant regime towards a periglacial or even post-periglacial regime. GFL are undergoing thermal and mechanical readjustments in response to both the longer-term glacier recession and the more recent drastic climatic warming. They can be expressed by a combination of mass-wasting processes and thaw-induced subsidence.</p><p> </p><p>In various regions of the Swiss Alps, slope movements occurring in a periglacial context have been inventoried in previous works using differential SAR interferometry (DInSAR) (Barboux et al., 2014). In the scope of this study, and focusing solely on mass-wasting GFL, the former inventory allowed the identification of the latter under various spatial configurations within LIA glacier forefields. While most observed GFL are disconnected from the associated glacier, some are still connected. Additionally, ground ice occurs as interstitial or massive (buried) glacier ice. This potentially infers the ongoing of non-uniform morphodynamical readjustments.</p><p> </p><p>To understand the site-specific behaviour of GFL, the analysis of long-term time-series of permafrost monitoring and multi-temporal high-resolution Digital Elevation Models will allow the assessment of the recent evolution of the Aget and Ritord/Challand LIA glacier forefields (46°00’32’’ N, 7°14’20’’ E and 45°57’10’’ N, 7°14’52’’ E, respectively) and their associated GFL (i.e. push-moraines). Both glacier forefields present a contrasting spatial configuration, making their morphodynamical evolution to differ partly from one another. The Aget push-moraine is a back-creeping GFL, which has been disconnected from the Aget glacier since the 1940s at latest. For the last two decades, surface displacement velocities have decelerated in comparison to the accelerating regional trend (PERMOS, 2019). Additionally, a 30% decrease of the electrical resistivity of the frozen ground, combined with locally observed thaw-induced subsidence of up to 10 cm/year suggest an advanced permafrost degradation. The Ritord/Challand system presents a push-moraine disconnected from its glacier as well as several push-moraines connected to a still existing debris-covered glacier. Between 2016 and 2019, surface lowering up to 10 m attesting massive ice melt has been locally detected in the former where buried glacier ice was visually observed. Whereas in the latter, subtle surface displacements ranging from 10 to 30 cm/year occur. This confirms the heterogeneity of the morphodynamical processes occurring in GFL, expressed as a function of both their spatial configuration and ground ice properties.</p><p> </p><p>Barboux, C., Delaloye R. and Lambiel, C. (2014). Inventorying slope movements in an Alpine environment using DInSAR. Earth Surface Processes and Landforms, 39/15, 2087-2099.</p><p>PERMOS 2019. Permafrost in Switzerland 2014/2015 to 2017/2018. Noetzli, J., Pellet, C., and Staub, B. (eds.), Glaciological Report (Permafrost) No. 16-19 of the Cryospheric Commission of the Swiss Academy of Sciences, 104.</p>

scholarly journals Ice-volume changes of selected glaciers in the Swiss Alps since the end of the 19th century

2007 ◽  
Vol 46 ◽  
pp. 145-149 ◽  
Author(s):  
Andreas Bauder ◽  
Martin Funk ◽  
Matthias Huss
Keyword(s):  
19Th Century ◽  
Temporal Variations ◽  
Swiss Alps ◽  
Ice Age ◽  
Aerial Photographs ◽  
Volume Changes ◽  
Thickness Change ◽  
Ice Volume ◽  
The 1960S ◽  
The 19Th Century

AbstractThe evolution of surface topography of glaciers in the Swiss Alps is well documented with high-resolution aerial photographs repeatedly recorded since the 1960s and further back in time with topographic maps including elevation contour lines first surveyed in the mid-19th century. In order to quantify and interpret glacier changes in the Swiss Alps, time series of volume changes over the last 100–150 years have been collected. The available datasets provide a detailed spatial resolution for the retreat period since the end of the Little Ice Age. The spatial distribution as well as temporal variations of the thickness change were analyzed. A significant ice loss since the end of the 19th century was observed in the ablation area, while the changes in the accumulation area were small. We found moderate negative secular rates until the 1960s, followed by steady to positive rates for about two decades and strong ice loss starting in the 1980s which has lasted until the present. An evaluation of 19 glaciers revealed a total ice volume loss of about 13km3 since the 1870s, of which 8.7 km3 occurred since the 1920s and 3.5 km3 since 1980. Decadal mean net balance rates for the periods 1920–60, 1960–80 and 1980–present are –0.29, –0.03 and –0.53ma–1w.e., respectively.

scholarly journals KRYASHENS OF UDMURT PRIKAMYE REGION IN THE LAST THIRD OF THE XVIII - MIDDLE XIX CENTURY

2019 ◽  
Vol 13 (3) ◽  
pp. 485-494
Author(s):  
Nikolai Viktorovich Pislegin ◽  
Vladimir Sergeevich Churakov
Keyword(s):  
Ethnic Group ◽  
19Th Century ◽  
18Th Century ◽  
Territorial Unit ◽  
Late 18Th Century ◽  
Udmurt Republic ◽  
Class Status ◽  
Xix Century ◽  
The 19Th Century ◽  
Over Time

The article comes to view the development of Kryashens, which are connected with Udmurts or with the territory of the modern Udmurt Republic, in the last third of the 18th - middle 19th century. The area in question is the Malmyzh and Elabuga counties of Vyaka province and Mamadysh county of Kazan province. The “Udmurt old-christened” ethno-class status of the inhabitants of the settlements of the Srednekushket volost’ of the Malmyzh county, noted by the sources, was to some extent a “tribute to tradition”. In Mamadysh county in 1834 historically associated with the Udmurts Kryashen settlements were located in 3 volosts; the tendency for their assimilation, which was reflected in the middle of the 18th century, was completed here even earlier, in the first third of the 19th century. In Yelabuga county since its formation there was a old-christened small administrative-territorial unit. In the historical settlements of Kryashens, located in our days in the territory of the Udmurt Republic (Grakhov and Kizner districts), their Udmurt origin, with few exceptions, is not traced. The appearance of this sub-ethnic group of Tatars here was mainly due to migration processes from the nearest southern territory. In this period the norm for the Kryashens was shared with other peoples - Tatars, Mari, Udmurts, and later - Russians. The presence of Russians in historical Kryashen villages steadily increased over time. From the late 18th century the Kryashen volosts often included villages with different ethnic-caste identity. From the second quarter of the 19th century the disappearance of the Kryashen small administrative-territorial units began. It was caused, first of all, by transformations of the state in this sphere.

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.

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