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1.
Anne F. Gellatly Jean M. Grove Alain Bücher Richard Latham Brian W. Whalley 《自然地理学》2013,34(5):399-413
The Taillon Glacier in the French Pyrénées offers one of the most detailed records of recent glacier fluctuations in the region. A comprehensive collection of early maps, paintings, and photographs, together with short-term measurements relating to the ice margins and glacier behavior, have made possible a full reconstruction of the glacier's history since the end of the 19th century. The general pattern of ice-front retreat has been punctuated by a series of significant local readvances, dated 1886–1890, 1906–1911, 1926–1928, 1945, and 1964. The record is compared with the more detailed histories of glaciers from the Alps, and signals a surprising degree of sensitivity for the Taillon Glacier, given its overall size and state of survival. [Key words: Taillon Glacier, Pyrénées, Little Ice Age, glaciology.] 相似文献
2.
John F. Shroder Michael P. Bishop Luke Copland & Valerie F. Sloan 《Geografiska Annaler: Series A, Physical Geography》2000,82(1):17-31
The origin and mobilization of the extensive debris cover associated with the glaciers of the Nanga Parbat Himalaya is complex. In this paper we propose a mechanism by which glaciers can form rock glaciers through inefficiency of sediment transfer from glacier ice to meltwater. Inefficient transfer is caused by various processes that promote plentiful sediment supply and decrease sediment transfer potential. Most debris‐covered glaciers on Nanga Parbat with higher velocities of movement and/ or efficient debris transfer mechanisms do not form rock glaciers, perhaps because debris is mobilized quickly and removed from such glacier systems. Those whose ice movement activity is lower and those where inefficient sediment transfer mechanisms allow plentiful debris to accumulate, can form classic rock glaciers. We document here with maps, satellite images, and field observations the probable evolution of part of a slow and inefficient ice glacier into a rock glacier at the margins of Sachen Glacier in c. 50 years, as well as several other examples that formed in a longer period of time. Sachen Glacier receives all of its nourishment from ice and snow avalanches from surrounding areas of high relief, but has low ice velocities and no efficient system of debris removal. Consequently it has a pronounced digitate terminus with four lobes that have moved outward from the lateral moraines as rock glaciers with prounced transverse ridges and furrows and steep fronts at the angle of repose. Raikot Glacier has a velocity five times higher than Sachen Glacier and a thick cover of rock debris at its terminus that is efficienctly removed. During the advance stage of the glacier since 1994, ice cliffs were exposed at the terminus, and an outbreak flood swept away much debris from its margins and terminus. Like the Sachen Glacier that it resembles, Shaigiri Glacier receives all its nourishment from ice and snow avalanches and has an extensive debris cover with steep margins close to the angle of repose. It has a high velocity similar to Raikot Glacier and catastrophic breakout floods have removed debris from its terminus twice in the recent past. In addition, the Shaigiri terminus blocked the Rupal River during the Little Ice Age and is presently being undercut and steepened by the river. With higher velocities and more efficient sediment transfer systems, neither the Raikot nor the Shaigiri form classic rock‐glacier morphologies. 相似文献
3.
THE 'LITTLE ICE AGE': RE-EVALUATION OF AN EVOLVING CONCEPT 总被引：4，自引：0，他引：4
JOHN A. MATTHEWS KEITH R. BRIFFA 《Geografiska Annaler: Series A, Physical Geography》2005,87(1):17-36
ABSTRACT. This review focuses on the development of the ‘Little Ice Age’ as a glaciological and climatic concept, and evaluates its current usefulness in the light of new data on the glacier and climatic variations of the last millennium and of the Holocene. ‘Little Ice Age’ glacierization occurred over about 650 years and can be defined most precisely in the European Alps (c. AD 1300–1950) when extended glaciers were larger than before or since. ‘Little Ice Age’ climate is defined as a shorter time interval of about 330 years (c. AD 1570–1900) when Northern Hemisphere summer temperatures (land areas north of 20°N) fell significantly below the AD 1961–1990 mean. This climatic definition overlaps the times when the Alpine glaciers attained their latest two highstands (AD 1650 and 1850). It is emphasized, however, that ‘Little Ice Age’ glacierization was highly dependent on winter precipitation and that ‘Little Ice Age’ climate was not simply a matter of summer temperatures. Both the glacier‐centred and the climate‐centred concepts necessarily encompass considerable spatial and temporal variability, which are investigated using maps of mean summer temperature variations over the Northern Hemisphere at 30‐year intervals from AD 1571 to 1900. ‘Little Ice Age’‐type events occurred earlier in the Holocene as exemplified by at least seven glacier expansion episodes that have been identified in southern Norway. Such events provide a broader context and renewed relevance for the ‘Little Ice Age’, which may be viewed as a ‘modern analogue’ for the earlier events; and the likelihood that similar events will occur in the future has implications for climatic change in the twenty‐first century. It is concluded that the concept of a ‘Little Ice Age’ will remain useful only by (1) continuing to incorporate the temporal and spatial complexities of glacier and climatic variations as they become better known, and (2) by reflecting improved understanding of the Earth‐atmosphere‐ocean system and its forcing factors through the interaction of palaeoclimatic reconstruction with climate modelling. 相似文献
4.
Terrace remnants close to the marine limit as well as two separate moraine ridges are observed in front of the glacier Albrechtbreen. The stacking of marine sediments from an original elevation of ca. 60–80 m a.s.l. into the Little Ice Age Moraine gives evidence for a considerably smaller glacier following the early Holocene deglaciation compared to that of the present. The outer moraine is composed of glacial diamicton. Radiocarbon datings of whale ribs, shell fragments and a log taken from sediment in front of Albrechtbreen indicate that the initial deglaciation occurred before 9, 400 B.P. and that the outer moraine was formed during a younger Holocene glacial advance. Lithological differences between the two moraine ridges suggest that the first ice advance occurred during a period with limited permafrost, whereas permafrost was more extensive during the Little Ice Age. 相似文献
5.
The Retreat of Tien Shan Glaciers (Kyrgyzstan) Since the Little Ice Age Estimated from Aerial Photographs, Lichenometric and Historical Data 总被引：2，自引：0，他引：2
Olga Solomina Roger Barry Maria Bodnya 《Geografiska Annaler: Series A, Physical Geography》2004,86(2):205-215
The retreat of 293 glaciers in the Tien Shan Mountains (Kyrgyz Republic) from their maximum extent during the Little Ice Age (LIA) is estimated using aerial photographs from 1980 to 1985 and maps at a scale of 1:25000, constructed during period 1956–1990. Two indices of changes are used: the linear distance from the glacier terminus to its Little Ice Age moraine and the difference in absolute elevation of the terminus and the moraine. Historical information about the front positions of glaciers in the 1880s to the 1930s was used as an indirect control of remote sensing data. The age of moraines in key regions was estimated by lichenometry. On average, Tien Shan glaciers have retreated by 989 ± 540 m since the LIA maximum. Their front elevations (dh) rose by 151 ± 105 m. These changes are similar to changes observed in the Alps and western Norway, Pamir‐Alay and Koryak plateau, but greater than in east Siberia over the same interval. Differences between four regions in Tien Shan (northern, western, inner, central) are generally small, though in the northern Tien Shan the glacier retreat and frontal rise are more prominent (1065 ± 479 m and 215 ± 140 m, respectively). 相似文献
6.
北极斯瓦尔巴群岛冰川大多数属于亚极地型(sub-polar)或多热型(polythermal)。Austre Br(?)ggerbreen和Midre Lovénbreen冰川(＜10km~2)长时间系列物质平衡研究显示,自小冰期结束以来几乎所有的观测年中夏季消融比冬季积累更大,导致冰体稳定地减小;而面积更大、海拔高度更高的冰川如Kongsvegen冰川(105km~2)则更加接近稳定态的平衡。斯瓦尔巴群岛冰川流动速率一般较低,但跃动相当频繁,控制跃动型冰川空间分布的因素包括冰川长度、基底岩性和多热场。可通过冰川水文特征、钻孔温度测量和无线电回波探测获取斯瓦尔巴群岛冰川热场的信息。斯瓦尔巴群岛冰川的低流速和多热性结构对冰川上的排水系统相当重要,整个群岛淡水径流的四个主要来源分别是冰川消融、雪融化、夏季降雨和冰崩解,经验回归方法和模式方法用于计算淡水径流量。因夏季融水渗浸作用、采样分辨率低和化学成分分析有限,早期斯瓦尔巴群岛冰芯的准确定年受到严重影响,但最近的研究显示,来自斯瓦尔巴群岛冰帽的冰芯数据仍然能够提供重要的气候和环境信息。通过我国北极黄河站2005年度科学考察,我们已初步建立了Austre Lovénbreen冰川和Pedersenbreen冰川监测系统,并计划在Austre Lovénbreen冰川进行钻孔温度测量、冰川气象要素观测、冰川前缘水文观测以及冰川厚度和内部结构测量,重点开展斯瓦尔巴群岛冰川基本特征和发育条件、冰川表面能量和物质平衡、冰川波动与气候变化关系、淡水径流年际和季节性变化和气/雪/冰界面过程等方面的研究。 相似文献
7.
8.
PHILIP DELINE MARIE GARDENT FLORENCE MAGNIN LUDOVIC RAVANEL 《Geografiska Annaler: Series A, Physical Geography》2012,94(2):265-283
One of the most glacierized areas in the European Alps, the Mont Blanc massif, illustrates how fast changes affect the cryosphere and the related morphodynamics in high mountain environments, especially since the termination of the Little Ice Age. Contrasts between the north‐west side, gentle and heavily glaciated, and the south‐east side, steep and rocky, and between local faces with varying slope angle and aspect highlight the suitability of the study site for scientific investigations. Glacier shrinkage is pronounced at low elevation but weaker than in other Alpine massifs, and supraglacial debris covers have developed over most of the glaciers, often starting in the nineteenth century. Lowering of glacier surface also affects areas of the accumulation zone. While modern glaciology has been carried out in the massif for several decades, study of the permafrost has been under development for only a few years, especially in the rock walls. Many hazards are related to glacier dynamics. Outburst flood from englacial pockets, ice avalanche from warm‐based and cold‐based glaciers, and rock slope failure due to debuttressing are generally increasing with the current decrease or even the vanishing of glaciers. Permafrost degradation is likely involved in rockfall and rock avalanche, contributing to the chains of processes resulting from the high relief of the massif. The resulting hazards could increasingly endanger population and activities of the valleys surrounding the Mont Blanc massif. 相似文献
9.
Glacier activity at Russkaya Gavan', north-west Novaya Zemlya (Arctic Russia), is reconstructed by particle size analysis of three fjord sediment cores in combination with 14 C and 210 Pb dating. Down-core logging of particle size variation reveals at least two intervals with sediment coarsening during the past eight centuries. By comparing them with reconstructions of summer temperature and atmospheric circulation, these intervals are interpreted to represent two cycles of glacier advance and retreat sometime during ca. AD 1400–1700 and AD 1700–present. Sediment accumulation thus appears to be sensitive to century-scale fluctuations of the Barents Sea climate. The identification of two glacier cycles in the glaciomarine record from Russkaya Gavan' demonstrates that during the "Little Ice Age" major glacier fluctuations on Novaya Zemlya occurred in broad synchrony with those in other areas around the Barents Sea. 相似文献
10.
Chronosequences of 250 to 130 years were established on two late Holocene glacier forelands in the Jotunheimen region of southern Norway. Patterned features occurring within chronologically established time units were studied. Young patterned features, forming 10–20 years after deglaciation, are frost active. Vegetation cover is minimal within the young patterned features, consisting of bryophytes/organic crusts. Soil development within patterned ground is also minimal/absent because frost action retards horizonization. With time and distance from the glaciated ice margin, frost activity declines within the patterned features, suggesting that a thin, active “periglacial zone” exists near the ice margin. Initially, frost activity decreases at the borders of the features with the centers stabilizing later in time. This results in fine-scale soil heterogeneity and variations of soil development. Fine-scale pedogenic development is first encountered at the borders of patterned ground that has developed on terrain exposed since the 1930s, yet soil development is predominantly absent at the centers of patterned ground. With time and distance from the ice margin, frost activity declines and allows patterned features to homogenize from border to center positions in regard to soil characteristics. Across the chronosequences, soils within patterned features pedogenically follow previous soil chronosequence studies, evolving from USDA classifications of Entisols into Inceptisols. Frost disturbance within patterned ground, however, produces a lag effect, that results in longer periods of time for pedogenesis to occur and thinner soils than that of the surrounding terrain. 相似文献
11.
Responses to climatic changes since the Little Ice Age on Maladeta Glacier (Central Pyrenees) 总被引：2，自引：0，他引：2
J. Chueca Cía A. Julin Andrs M.A. Saz Snchez J. Creus Novau J.I. Lpez Moreno 《Geomorphology》2005,68(3-4):167-182
The evolution of Maladeta Glacier (Maladeta massif, central Spanish Pyrenees) since the Little Ice Age maximum is analyzed in this work. The extent of the glacier was mapped into 10 stages using morainic deposits and graphic documents. Climatic data (temperature and precipitation) were reconstructed by using dendroclimatic techniques complemented by recent instrumental records. The results thus obtained confirm the control of the above mentioned climatic factors, particularly annual temperature and winter precipitation, in the evolution of Maladeta Glacier, which has receded from an extent of 152.3 ha in 1820–1830 to 54.5 ha in 2000, a 35.7% reduction in size. The rate of ice wastage has varied during that period, defining several phases of glacial stabilization (1820–1830 to 1857; 1914–1920 to 1934–1935; 1957 to 1981), moderated glacial depletion (1901–1904 to 1914–1920; 1934–1935 to 1957) and marked glacial depletion (1857 to 1901–1904; 1981 to 2000). The evolution of Maladeta Glacier is also in keeping with trends observed from other alpine Mediterranean glaciers, which have experienced a consistent rise in their equilibrium line altitudes during the 19th and 20th centuries as well as associated and prolonged periods of negative mass balance. 相似文献
12.
Owing to increased winter balances especially since AD 1988/89, almost all valley outlet glaciers of Jostedalsbreen in western Norway are experiencing the largest advance since that of the early 18th century, the regional "Little Ice Age" maximum. Brigsdalsbreen advanced 441 m between 1987 and 1997. By the end of this period, the glacier had reached the outlet of the proglacial lake Brigsdalsvatnet, ploughing into unfrozen, fine-grained, water-soaked glaciolimnic sediments from the lake bottom and forming frontal moraines. These moraines are characterised by a lack of internal structures and preferred fabric. Owing to the strong advance, the moraine morphology is constantly changing, leaving only temporary moraine ridges.
Observations made along the glacier front suggest that the formation of these moraines can best be described as "bulldozed moraines", since the term push moraine, commonly associated with advancing glaciers, should be restricted to permafront environments. Different processes involved in moraine formation at frontal and lateral glacier margins result from variations in proglacial sediment properties, microrelief and glacier dynamics. Among these processes, large boulders left in the proglacial areas are pushed forward, forming pressure ridges on the distal side. Some of the largest boulders ( c . 80–120 m3 ) are overturned or rotated by the glacier. 相似文献
Observations made along the glacier front suggest that the formation of these moraines can best be described as "bulldozed moraines", since the term push moraine, commonly associated with advancing glaciers, should be restricted to permafront environments. Different processes involved in moraine formation at frontal and lateral glacier margins result from variations in proglacial sediment properties, microrelief and glacier dynamics. Among these processes, large boulders left in the proglacial areas are pushed forward, forming pressure ridges on the distal side. Some of the largest boulders ( c . 80–120 m
13.
山地冰川与湖泊萎缩所指示的亚洲中部气候干暖化趋势与未来展望 总被引：67，自引：1，他引：67
天山北坡乌鲁木齐河1号冰川与土尤克苏冰川物质平衡观察表示80年代比以前出现大的亏损。青海湖与伊赛克湖在近百年一直处于萎缩状态。从小冰期最盛时以来,乌鲁木齐河谷中冰川面积已缩去44％。上述及其他冰川与湖泊变化证据清楚地指示本世纪气候干暖化趋势增强了,并可能延续到下世纪初。但如由于CO_2及其他痕量气体增加所致的温室效应使下世纪重现全新世早、中期那样的高温,则亚洲中部有可能转为潮湿。 相似文献
14.
Glacier inventory compilation during the past 20 years and modifications of that for the Eastern Pamir and Banggong Lake indicate that there are 46,342 modern glaciers with a total area and volume of 59415 km^2 and 5601 km^3 respectively in China. These glaciers can be classified into maritime and continental (including sub-continental and extremely continental) types. Researches show that glaciers in China have been retreating since the Little Ice Age and the mass wastage was accelerated during the past 30 to 40 years. Being an important part of glaciological studies in China,ice core climatic and environmental studies on Tibetan Plateau and in the Antarctica have provided abundant, high resolution information about past climatic and environmental evolution over the Tibetan Plateau and Antarctica. Except for different parameters recorded in ice cores relating to climate and environment changes on Tibetan Plateau, records from ice cores extracted from different glaciers show that the discrepancies in climatic and environmental changes on the north and south parts of the plateau may be the consequence of different influencing effects from terrestrial and solar sources.Glaciological and meteorological phenomena imply that Lambert Glacier valley is an important boundary of climate in the east Antarctica, which is thought to be connected with cyclonic activities and Circum-polar Waves over the Antarctica. 相似文献
15.
LIU Shiyin WANG Ninglian DUAN Keqin XIAO Cunde DING Yongjian HAN Haidong 《地理学报(英文版)》2004,14(4):401-410
1IntroductionIn the early 1960s, glaciers in western China were classified into maritime- and continental-types by different glacial environment and physical characteristics (Shi and Xie, 1964). With extensive glaciological investigations in the western regions (Lanzhou Institute of Glaciology and Geocryology of CAS, 1988), Lai and Huang (1990) suggested a new classification of temperate, subpolar and quasipolar glaciers, corresponding to the maritime-, subcontinental- and extremely contin… 相似文献
16.
Glacier inventory compilation during the past 20 years and modifications of that for the Eastern Pamir and Banggong Lake indicate that there are 46,342 modern glaciers with a total area and volume of 59415 km2 and 5601 km3 respectively in China. These glaciers can be classified into maritime and continental (including sub-continental and extremely continental) types. Researches show that glaciers in China have been retreating since the Little Ice Age and the mass wastage was accelerated during the past 30 to 40 years. Being an important part of glaciological studies in China, ice core climatic and environmental studies on Tibetan Plateau and in the Antarctica have provided abundant, high resolution information about past climatic and environmental evolution over the Tibetan Plateau and Antarctica. Except for different parameters recorded in ice cores relating to climate and environment changes on Tibetan Plateau, records from ice cores extracted from different glaciers show that the discrepancies in climatic and environmental changes on the north and south parts of the plateau may be the consequence of different influencing effects from terrestrial and solar sources. Glaciological and meteorological phenomena imply that Lambert Glacier valley is an important boundary of climate in the east Antarctica, which is thought to be connected with cyclonic activities and Circum-polar Waves over the Antarctica. 相似文献
17.
Luca Carturan Giovanni A. Baldassi Aldino Bondesan Simone Calligaro Alberto Carton Federico Cazorzi Giancarlo Dalla Fontana Roberto Francese Alberto Guarnieri Nicola Milan Daniele Moro Paolo Tarolli 《Geografiska Annaler: Series A, Physical Geography》2013,95(1):79-96
Smaller glaciers (<0.5 km2) react quickly to environmental changes and typically show a large scatter in their individual response. Accounting for these ice bodies is essential for assessing regional glacier change, given their high number and contribution to the total loss of glacier area in mountain regions. However, studying small glaciers using traditional techniques may be difficult or not feasible, and assessing their current activity and dynamics may be problematic. In this paper, we present an integrated approach for characterizing the current behaviour of a small, avalanche‐fed glacier at low altitude in the Italian Alps, combining geomorphological, geophysical and high‐resolution geodetic surveying with a terrestrial laser scanner. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. The glacier owes its existence to the local topo‐climatic conditions, ensured by high rock walls which enhance accumulation by delivering avalanche snow and reduce ablation by providing topographic shading and regulating the debris budget of the glacier catchment. In the last several years the glacier has displayed peculiar behaviour compared with most glaciers of the European Alps, being close to equilibrium conditions in spite of warm ablation seasons. Proportionally small relative changes have also occurred since the Little Ice Age maximum. Compared with the majority of other Alpine glaciers, we infer for this glacier a lower sensitivity to air temperature and a higher sensitivity to precipitation, associated with important feedback from increasing debris cover during unfavourable periods. 相似文献
18.
GERAINT OWEN JOHN F. HIEMSTRA JOHN A. MATTHEWS LINDSEY J. MCEWEN 《Geografiska Annaler: Series A, Physical Geography》2010,92(4):421-436
A tongue‐like, boulder‐dominated deposit in Tverrbytnede, upper Visdalen, Jotunheimen, southern Norway, is interpreted as the product of a rock avalanche (landslide) due to its angular to subangular boulders, surface morphology with longitudinal ridges, down‐feature coarsening, and cross‐cutting relationship to ‘Little Ice Age’ moraines. The rock avalanche fell onto glacier ice, probably channelled along a furrow between two glaciers, and stopped on the glacier foreland, resulting in its elongated shape and long runout distance. Its distal margin may have become remobilized as a rock glacier, but a rock glacier origin for the entire landform is discounted due to lack of source debris, presence of matrix, lack of transverse ridges, and sparcity of melt‐out collapse pits. Lichenometric dating of the deposit indicates an approximate emplacement age of ad 1900. Analysis highlights the interaction of rock‐slope failures and glaciers during deglacierization in a neoparaglacial setting, with reduced slope stability due to debuttressing and permafrost degradation, and enhanced landslide mobility due to flow over a glacier and topographic channelling. Implications for the differentiation of relict landslides, moraines and rock glaciers are discussed and interrelationships between these landforms are considered in terms of an ice‐debris process continuum. 相似文献
19.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):219-223
A regional model was used to draw the permafrost distribution in the 200 km 2 of the Bagnes-Hérémence area (Western Swiss Alps). The model is based on the fact that permafrost distribution depends mainly on altitude and orientation and that the minimal altitude of active/inactive rock glaciers can be used as an indicator of the lower limit of discontinuous permafrost. The lower limit of relict rock glaciers is also used as an indicator of past distribution of permafrost. An inventory of rock glaciers was therefore made in the study area. The lower limit of permafrost during the Younger Dryas was determined by comparing the position of relict rock glaciers and glacier extension during the Older Dryas. The model was then applied to four periods (Younger Dryas, Little Ice Age, current period and future) in order to show the temporal evolution of permafrost distribution and glacier extension. 相似文献