scholarly journals Extension of Glacier de Saint-Sorlin, French Alps, and equilibrium-line altitude during the Little Ice Age

2002 ◽  
Vol 48 (160) ◽  
pp. 118-124 ◽  
Author(s):  
Louis Lliboutry
Keyword(s):  
Little Ice Age ◽  
Meteorological Data ◽  
Vertical Gradient ◽  
Winter Precipitation ◽  
Ice Age ◽  
Equilibrium Line ◽  
Equilibrium Line Altitude ◽  
French Alps ◽  
The Mean ◽  
Accumulation Area Ratio

AbstractGlacier de Saint-Sorlin, French Alps, left terminal moraines at 1.3, 2.9 and 3.7 km ahead of the present terminus. According to proxy data and to historical maps, these were formed in the 19th, 18th and 17th centuries, respectively. A plateau at 2700–2625 m was then surrounded by ice but never became an accumulation area. This fact shows that the equilibrium-line altitude (ELA) on the glacier never dropped below 2300 m. The following simple models apply sufficiently to yield reliable estimations of past ELA: (1) a uniform and constant vertical gradient of the mass balance, down to the terminus; and (2) a plane bed, with a slope of 8.5° and a uniform width. Then in a steady situation the accumulation–area ratio is 1/2. Compared to the mean for 1956–72, at the onset of the Little Ice Age the balances were higher by 3.75 m ice a−1, and the ELA was 400 m lower. Correlations between 1956–72 balances and meteorological data suggest that during the melting season the 0°C isotherm was about 800 m lower, while the winter precipitation at low altitudes did not change. These correlations may have been different in the past, but an equal lowering of the ELA and of the 0°C isotherm, as assumed by several authors, seems excluded.

scholarly journals Glacier equilibrium line altitude variations during the “Little Ice Age” in the Mediterranean Andes (30◦–37◦ S)

2019 ◽  
Author(s):  
Álvaro González-Reyes ◽  
Claudio Bravo ◽  
Mathias Vuille ◽  
Martin Jacques-Coper ◽  
Maisa Rojas ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Pearson Correlation ◽  
Temporal Changes ◽  
Global Climate Models ◽  
Ice Age ◽  
Equilibrium Line ◽  
Equilibrium Line Altitude ◽  
Mountainous Regions ◽  
The Mean ◽  
The Mediterranean

Abstract. The "Little Ice Age" (LIA; 1500–1850 Common Era (CE)), has long been recognized as the last period when mountain glaciers in many regions of the Northern Hemisphere (NH) recorded extensive growth intervals in terms of their ice mass and frontal position. The knowledge about this relevant paleoclimatic interval is vast in mountainous regions such as the Alps and Rocky Mountains in North America. However, in extra-tropical Andean sub-regions such as the Mediterranean Andes of Chile and Argentina (MA; 30º–37º S), the LIA has been poorly documented. Paradoxically, the few climate reconstructions performed in the MA based on lake sediments and tree rings do not show clear evidence of a LIA climate anomaly as observed in the NH. In addition, recent studies have demonstrated temporal differences between mean air temperature variations across the last millennium between both hemispheres. This motivates our hypothesis that the LIA period was not associated with a significant climate perturbation in the MA region. Considering this background, we performed an experiment using daily climatic variables from three Global Climate Models (GCMs) to force a novel glaciological model. In this way, we simulated temporal variations of the glacier equilibrium-line altitude (ELA) to evaluate the glacier response during the period 1500–1848 CE. Overall, each GCM shows temporal changes in annual ELA, with anomalously low elevations during 1640–1670 and 1800–1848 CE. An interval with high ELA values was identified during 1550–1575 CE. The spectral properties of the mean annual ELA in each GCM present significant periodicities between 2–7 years, and also significant decadal to multi-decadal signals. In addition, significant and coherent cycles at interannual to multi-decadal scales were detected between modeled mean annual ELAs and the first EOF1 extracted from Sea Surface Temperature (SST) within the El Niño 3.4 of each GCM. Finally, significant Pearson correlation coefficients were obtained between the mean annual ELA and Pacific SST on interannual to multi-decadal timescales. According to our findings, we propose that Pacific SST variability was the main modulator of temporal changes of the ELA in the MA region of South America during 1500–1848 CE.

scholarly journals Climate reconstruction since the Little Ice Age by modelling Koryto glacier, Kamchatka Peninsula, Russia

2008 ◽  
Vol 54 (184) ◽  
pp. 125-130 ◽  
Author(s):  
Satoru Yamaguchi ◽  
Renji Naruse ◽  
Takayuki Shiraiwa
Keyword(s):  
20Th Century ◽  
Meteorological Data ◽  
Ice Core ◽  
Kamchatka Peninsula ◽  
Winter Precipitation ◽  
Ice Age ◽  
Equilibrium Line Altitude ◽  
Ice Cap ◽  
Glacier Terminus ◽  
Tree Ring Data

AbstractBased on the field data at Koryto glacier, Kamchatka Peninsula, Russia, we constructed a one-dimensional numerical glacier model which fits the behaviour of the glacier. The analysis of meteorological data from the nearby station suggests that the recent rapid retreat of the glacier since the mid-20th century is likely to be due to a decrease in winter precipitation. Using the geographical data of the glacier terminus variations from 1711 to 1930, we reconstructed the fluctuation in the equilibrium-line altitude by means of the glacier model. With summer temperatures inferred from tree-ring data, the model suggests that the winter precipitation from the mid-19th to the early 20th century was about 10% less than that at present. This trend is close to consistent with ice-core results from the nearby ice cap in the central Kamchatka Peninsula.

Exposure dating of a pronounced glacier advance at the onset of the late-Holocene in the central Tyrolean Alps

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1350-1358 ◽  
Author(s):  
Andrew P Moran ◽  
Susan Ivy Ochs ◽  
Marcus Christl ◽  
Hanns Kerschner
Keyword(s):  
Little Ice Age ◽  
Late Holocene ◽  
Ice Age ◽  
Similar Reaction ◽  
Equilibrium Line Altitude ◽  
Alpine Valley ◽  
Modern Times ◽  
Exposure Dating ◽  
Glacier Advance ◽  
Accumulation Area Ratio

A two-phased moraine system in the high Alpine valley of Lisenser Längental in the Stubai Alps of western Austria is located in an intermediate morphostratigraphic position constrained by ‘Egesen Stadial’ (Younger Dryas) moraines down valley and ‘Little Ice Age’ (‘LIA’) positions (modern times) up valley. The equilibrium line altitude (ELA) was about 50 m lower than during the ‘LIA’ when applying an accumulation area ratio of 0.67. Exposure dating of boulders with 10Be yields a mean age of 3750 ± 330 years for the more extensive outer moraine system and a single age of 3140 ± 280 years for the inner one. The ages correspond well to the ‘Loebben oscillation’, a sequence of multi-decadal to multi-centennial cooling phases at the onset of the late-Holocene, also recognized in other Alpine records. The climatic downturn was severe enough to cause small to medium-sized Alpine glaciers in the central Alps to advance significantly beyond their ‘LIA’ extent, but too short to trigger a similar reaction with large glaciers.

scholarly journals Relation between the Mass Balance of Western Canadian Mountain Glaciers and Meteorological Data

1988 ◽  
Vol 34 (116) ◽  
pp. 11-18 ◽  
Author(s):  
Anne Letréguilly
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Winter Precipitation ◽  
Summer Temperature ◽  
Equilibrium Line ◽  
Regression Equations ◽  
Equilibrium Line Altitude ◽  
Mountain Glaciers

AbstractThe mass balance, summer balance, winter balance, and equilibrium-line altitude of three Canadian glaciers (Peyto, Place, and Sentinel Glaciers) are compared with the meteorological records of neighbouring stations for the period 1966—84. While Peyto Glacier’s mass balance is almost entirely related to summer temperature, Sentinel Glacier’s mass balance is mostly controlled by winter precipitation. Place Glacier is influenced by both elements. Statistical reconstructions are presented for the three glaciers, using the best regression equations with the meteorological records since 1938.

scholarly journals Changes of the equilibrium-line altitude since the Little Ice Age in the Nepalese Himalaya

2008 ◽  
Vol 48 ◽  
pp. 93-99 ◽  
Author(s):  
Rijan Bhakta Kayastha ◽  
Sandy P. Harrison
Keyword(s):  
Little Ice Age ◽  
Climate Model ◽  
Ice Age ◽  
Equilibrium Line ◽  
Inventory Data ◽  
Equilibrium Line Altitude ◽  
Glacier Inventory ◽  
Climate Gradients ◽  
Climate Records

AbstractChanges of the equilibrium-line altitude (ELA) since the end of the Little Ice Age (LIA) in eastern Nepal have been studied using glacier inventory data. The toe-to-headwall altitude ratios (THARs) for individual glaciers were calculated for 1992, and used to estimate the ELA in 1959 and at the end of the LIA. THAR for debris-free glaciers is found to be smaller than for debris-covered glaciers. The ELAs for debris-covered glaciers are higher than those for debris-free glaciers in eastern Nepal. There is considerable variation in the reconstructed change in ELA (ΔELA) between glaciers within specific regions and between regions. This is not related to climate gradients, but results from differences in glacier aspect: southeast- and south-facing glaciers show larger ΔELAs in eastern Nepal than north- or west-facing glaciers. The data suggest that the rate of ELA rise may have accelerated in the last few decades. The limited number of climate records from Nepal, and analyses using a simple ELA–climate model, suggest that the higher rate of the ΔELA between 1959 and 1992 is a result of increased warming that occurred after the 1970s at higher altitudes in Nepal.

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.

scholarly journals Relation between the Mass Balance of Western Canadian Mountain Glaciers and Meteorological Data

1988 ◽  
Vol 34 (116) ◽  
pp. 11-18 ◽  
Author(s):  
Anne Letréguilly
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Winter Precipitation ◽  
Summer Temperature ◽  
Equilibrium Line ◽  
Regression Equations ◽  
Equilibrium Line Altitude ◽  
Mountain Glaciers

AbstractThe mass balance, summer balance, winter balance, and equilibrium-line altitude of three Canadian glaciers (Peyto, Place, and Sentinel Glaciers) are compared with the meteorological records of neighbouring stations for the period 1966—84. While Peyto Glacier’s mass balance is almost entirely related to summer temperature, Sentinel Glacier’s mass balance is mostly controlled by winter precipitation. Place Glacier is influenced by both elements. Statistical reconstructions are presented for the three glaciers, using the best regression equations with the meteorological records since 1938.

High sensitivity of North Iceland (Tröllaskagi) debris-free glaciers to climatic change from the ‘Little Ice Age’ to the present

The Holocene ◽  
2017 ◽  
Vol 27 (8) ◽  
pp. 1187-1200 ◽  
Author(s):  
José María Fernández-Fernández ◽  
Nuria Andrés ◽  
Þorsteinn Sæmundsson ◽  
Skafti Brynjólfsson ◽  
David Palacios
Keyword(s):  
20Th Century ◽  
Air Temperature ◽  
Little Ice Age ◽  
Satellite Image ◽  
High Sensitivity ◽  
Ice Age ◽  
Aerial Photographs ◽  
Early 20Th Century ◽  
Equilibrium Line Altitude ◽  
The Mean

The Tröllaskagi peninsula is located in northern Iceland, between meridian 19°30′W and 18°10′W, jutting out into the North Atlantic to latitude 66°12′N. The aim of this research is to study recent glacier changes in relation to climatic evolution of the Gljúfurárjökull and Tungnahryggsjökull debris-free valley glaciers in Tröllaskagi. Glacier extent mapping and spatial analysis operations were performed with ArcGIS (ESRI), using analysis of aerial photographs from 1946, 1985, 1994 and 2000, and a 2005 SPOT satellite image. The results show that these glaciers lost a quarter of their surface area between the ‘Little Ice Age’ and 2005. In this paper, the term ‘Little Ice Age’ follows Grove (2001) as the most recent period when glaciers extended globally between the medieval period and the early 20th century. The abrupt climatic transition of the early 20th century and the 25-year warm period 1925–1950 triggered the main retreat and volume loss of these glaciers since the end of the ‘Little Ice Age’. Meanwhile, cooling during the 1960s, 1970s and 1980s altered the trend, with advances of the glacier snouts. Between the ‘Little Ice Age’ and the present day, the mean annual air temperature and mean ablation season air temperature increased by 1.9°C and 1.5°C, respectively, leading to a 40–50 m rise in the equilibrium line altitude (ELA) of the glaciers during this period. The response of these glaciers depends not only on the mean ablation season air temperature evolution but also on other factors such as winter precipitation. The models applied show a precipitation increase of up to more than 700 mm since the ‘Little Ice Age’.

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