Glaciologists believe that many glaciers in svalbard are polythermal, i. A glacier that fills a valley is called a valley glacier, or alternatively an alpine glacier or mountain glacier. Drainagesystem development in consecutive melt seasons at. Specific storage is determined by dividing the stored volume by the area of the glacier. These notes focus on glacier hydrology with a strong bias toward the basal drainage system and the formulation of basal hydrology models for the purpose of coupling with models of ice ow.
Polythermal glacier hydrology and ice flow dynamics. The drainage pattern of hansbreen and werenskioldbreen, two. Notably absent is any consideration of polythermal bed conditions and content related expressly to the basal hydrology of antarctica. Notes on glacier hydrology mccarthy summer school, 2016. A separate trajectory of model development was motivated by the recognition that the retention, evacuation and distribution of subglacial water is a. However, warm zones in a polythermal glacier and taliks within icerich permafrost can enable the establishment of groundwater flow and the formation of subsurface conduits. The manner by which meltwater drains through a glacier is critical to ice dynamics, runoff characteristics, and water quality. Linksbetween shorttermvelocity variations and the subglacial. Study guide for mass balance, glacial hydrology, glacial flow. The distribution of basal motion beneath a high arctic polythermal glacier volume 49 issue 166 luke copland, martin j. Radioecho sounding determination of polythermal glacier.
Dec 01, 2011 the manner by which meltwater drains through a glacier is critical to ice dynamics, runoff characteristics, and water quality. Earth surface processes and landforms high arctic glacier. The drainage pattern of hansbreen and werenskioldbreen. Here, we show that the lower part of the ablation area of khumbu glacier, a highelevation debriscovered glacier in nepal, may contain 56% temperate. Water flow climate local meteorology surface mass and energy exchange net mass balance dynamic response changes in geometry effect on landscape. Glacial conditions that contribute to the regeneration of fountain glacier proglacial icing, bylot island, canada pablo wainstein,1,2 brian moorman1 and ken whitehead1 1 department of geography, university of calgary, alberta, canada 2 bgc engineering, calgary, alberta, canada abstract.
Temperature measurements show a polythermal structure with subglacial water trapped by the cold lowest part of the glacier 2 c. In this paper we describe three sources of information that radioecho sounding has provided about the subsurface hydrology of a polythermal glacier. A large body of glacial ice astride a mountain, mountain range, or volcano is termed an ice cap or ice field. Hydrobiogeochemical coupling beneath a large polythermal. Notably absent is any consideration of polythermal. Polythermal glacier hydrology and ice flow dynamics request pdf. Pdf the hydrology of glaciers concerns the transfer of meltwater through an ice mass. Recent advances in our understanding of the role of. Apr 27, 2000 in this paper we describe three sources of information that radioecho sounding has provided about the subsurface hydrology of a polythermal glacier. Polythermal glacier studies in svalbard determined by. In the accumulation and upper ablation areas, where ice is predominantly coldbased, summer velocities were slightly higher than overwinter velocities.
However, the interplay of factors governing its spatial and temporal variations such as. Links between shortterm velocity variations and the subglacial hydrology of a predominantly cold polythermal glacier. The lithology is mainly sedimentary, with the upper catchment and headwalls consisting of precambrian carbonates, phyllite and quartzite, permian sandstones, dolomite and limestones and the rest of the catchment comprising triassic to cretaceous siltstones. Linksbetween shorttermvelocity variations and the subglacial hydrology ofa predominantlycold polythermal glacier lukecopland,1martinj. Hydrology of a polythermal glacier, erikbreen, northern. A pdf version of this document can be downloaded from. Polythermal glacier studies in svalbard determined by ground. Next to the glacier is a sediment apron and there is a braid plain around the lake.
Meltwater tends to follow supra and englacial routes and welldeveloped basal hydrological networks are rare. Nov 14, 2018 runoff from highelevation debriscovered glaciers represents a crucial water supply for millions of people in the hindu kushhimalaya region, where peak water has already passed in places. The influence of snow cover thickness on the thermal. A glacier named midre lovenbreen in nw spitsbergen is a typical polythermal glacier, and here norwegian glaciologists have obtained a massbalance record that spans some 35 years. Spatial and temporal variations in glacier hydrology on. Polythermal structure of a himalayan debriscovered. Glacial and glaciohydrologic processes that control the glaciofluvial sediment delivery from erikbreen, a polythermal glacier on the north coast of spitsbergen. The polythermal structure has major implications for glacier hydrology, ice. Apr 27, 2000 radioecho sounding determination of polythermal glacier hydrology radioecho sounding determination of polythermal glacier hydrology copland, luke 20000427 00. Glacier hydrology is the study of the flow of water through glaciers. Proglacial icings are one of the most common forms of extrusive ice found in the canadian arctic. The distribution of basal motion beneath a high arctic. The longitudinal pattern of surface velocity of a large, predominantly cold, polythermal glacier john evans glacier, ellesmere island, canada was measured over summer and winter periods.
Hydrology and dynamics of a polythermal mostly cold high arctic glacier robert g. The influence of snow cover thickness on the thermal regime. Moorman earth science program, university of calgary, calgary. Glacierpermafrost hydrology interactions, bylot island, canada b. Request pdf polythermal glacier hydrology and ice flow dynamics measurements at polythermal john evans glacier, ellesmere island, indicate strong links between spatial and temporal variations. David m hannah and angela m gurnell, a conceptual, linear reservoir runoff model to investigate melt season changes in cirque glacier hydrology, journal of hydrology, 10.
Study site john evans glacier is a polythermal valley glacier on the east coast of ellesmere island, nunavut, canada 7940n, 743ow. Yet there is a need to improve understanding of polythermal glacier hydrology in particular, since nontemperate ice ice below the pressuremelting temperature, lacking interstitial water is commonly encountered in highlatitude ice masses irvinefynn et al. It is a mysterious world, where water running on the surface of the glacier disappears through cracks and holes in the glaciers, and powerful rivers emerge from the glacier snout1. These observations suggest that hydrologically forced variations in glacier flow may be common even in mostly cold glaciers, but the details of the hydrology. Read radioecho sounding determination of polythermal glacier hydrology, proceedings of spie on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Mechanics and thermodynamics of polythermal glaciers. Boon and sharp 2003 observed ponding and drainage events on a polythermal. Dezember 1977 citizen of seelisberg switzerland accepted on the recommendation of prof.
Glacial conditions that contribute to the regeneration of. Radioecho sounding determination of polythermal glacier hydrology. In this paper, the hydrology of glaciers in the higharctic archipelago of svalbard is examined. A cutandclosure origin for englacial conduits in uncrevassed regions of polythermal glaciers volume 55 issue 189 j. However, much of the contemporary knowledge relating to glacier hydrology has been based upon, and conditioned by, understanding gleaned from temperate valley glaciers. Polythermal glaciers, svalbard department of geography. Understanding the expected dynamic range of a glaciers hydrological system is best studied by in situ. Notes on glacier hydrology mccarthy summer school, 2016 contents. Glacierfed rivers provide much of the water supply in some parts of the world. Box 3000, fin90014 university of oulu, finland oulu, finland 2003 abstract the overall aim of this thesis is to emphasise how ground penetrating radar gpr can be used in.
Polythermal structure of a himalayan debriscovered glacier. Agriculture canadian prairies, central asia hydroelectrical power production iceland, france, switzerland, norway. Hydrology of ice sheets most of the interior of large ice sheets frozen to the bed. Prior to the twentyfirst century however, the hydrology of the gris had received little attention, with the excep. Large net losses from storage in the first half of the interval give high and variable discharge, whereas there are moderate net storage gains when discharge is low and invariable in the second half. A glacier forms where the accumulation of snow exceeds its ablation melting and sublimation over many years, often centuries. Hydrology and dynamics of a polythermal mostly cold high arctic. Thus, it is hypothesized that interconnection between glacial and subsurface permafrost hydrological systems does occur in polythermal glacier systems. The northern margin of the glacier has a 510 m high ice cliff, from which large blocks fall dry calving. A glacier that has a mixed basal thermal regime, consisting of both warm ice at 0c and cold ice below 0c. Measurements at polythermal john evans glacier, ellesmere island, indicate strong links between spatial and temporal variations in subglacial hydrology and changes in surface velocity. Glacier hydrology in svalbard, norwegian high arctic.
The recent, growing concern over the future response of polar glaciers and ice sheets to forecasts of a warming climate and lengthening summer. The drainage pattern of hansbreen and werenskioldbreen, two polythermal glaciers in svalbard anja palli, john c. Through the upsurge in interest in polythermal glacier hydrology, coupled with the recent developments in data acquisition and theoretical developments, and similarities alluded to here, sharp et al. Ice caps have an area less than 50,000 km 2 19,000 sq mi by definition. Glacierpermafrost hydrology interactions, bylot island. However, much of the contemporary knowledge relating to glacier hydrology has been based upon, and conditioned by, understanding gleaned. The focus of the aberystwyth team, in association with the universities of leeds, bristol, and swansea has been to record icestructures with a view to establishing. Mapping thermal and hydrological conditions beneath a polythermal glacier with radioecho sounding. Nienow2 1department ofearthandatmosphericsciences,university albertaedmonton,albertat6g2e3canada email. Polythermal glacier regimes are a common, characteristic response in regions with protracted subfreezing winter air temperatures where. Glacierpermafrost hydrology interactions, bylot island, canada. Identify the ways ice mass accumulates and ablates.
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