What Is Glaciology?

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What is glaciology? ● any of the branches of science dealing with snow or ice ● Land ice vs floating ice (ocean, lakes, rivers) ● Land ice: Glaciers and ice sheets, ice-rich permafrost Water on Earth Freshwater 3% Other 1.2% Glaciers: 1% Greenland Groundwater 11% ~30 % Saline (oceans) Glaciers and Antarctica 97% Icesheets 88% 69-75 % Sealevel equivalent: Antarctica ~57 m; Greenland ~ 7 m; others ~0.5 m National Snow and Ice Data Center Glaciers: Rivers of ice This is boring, show a movie Valley Glacier Ice field (e.g. Bagley) Hanging Glaciers Tidewater Glacier Icefield (Seward) Surge-type Glacier Piedmont Glacier (Malaspina) Space Shuttle Picture Icefall Topography of the Earth at high latitudes, the climate system is at least as effective as plate tectonics in producing high elevation topography, and it does it quicker (both on the way up and the way down) If you take fresh water out of the ocean, you have to pile it up somewhere. That growing or shrinking pile is part of the climate system. What are the feedbacks here? What can make the pile shrink the fastest? Is that going on now? Topography of the Earth at high latitudes, the climate system is at least as effective as plate tectonics in producing high elevation topography, and it does it quicker (both on the way up and the way down) If you take fresh water out of the ocean, you have to pile it up somewhere. That growing or shrinking pile is part of the climate system. What are the feedbacks here? What can make the pile shrink the fastest? Is that going on now? <–1.5 –0.5 –0.2 0 0.2 0.5 m/yr Pritchard et al., 2009, Nature Glaciers 101 Accumulation (more snow than melt) Climate ELA (Equilibrium Line Altitude) Ablation (more melt than snow) Ice flow: interesting physics Cross section of a glacier Medial moraines Lateral Moraines Lateral moraine Medial moraines Barnard Glacier Surface moraine Terminal moraines .

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Calving Processes and the Dynamics of Calving Glaciers ⁎ Douglas I
Earth-Science Reviews 82 (2007) 143–179 www.elsevier.com/locate/earscirev Calving processes and the dynamics of calving glaciers ⁎ Douglas I. Benn a,b, , Charles R. Warren a, Ruth H. Mottram a a School of Geography and Geosciences, University of St Andrews, KY16 9AL, UK b The University Centre in Svalbard, PO Box 156, N-9171 Longyearbyen, Norway Received 26 October 2006; accepted 13 February 2007 Available online 27 February 2007 Abstract Calving of icebergs is an important component of mass loss from the polar ice sheets and glaciers in many parts of the world. Calving rates can increase dramatically in response to increases in velocity and/or retreat of the glacier margin, with important implications for sea level change. Despite their importance, calving and related dynamic processes are poorly represented in the current generation of ice sheet models. This is largely because understanding the ‘calving problem’ involves several other long-standing problems in glaciology, combined with the difficulties and dangers of field data collection. In this paper, we systematically review different aspects of the calving problem, and outline a new framework for representing calving processes in ice sheet models. We define a hierarchy of calving processes, to distinguish those that exert a fundamental control on the position of the ice margin from more localised processes responsible for individual calving events. The first-order control on calving is the strain rate arising from spatial variations in velocity (particularly sliding speed), which determines the location and depth of surface crevasses. Superimposed on this first-order process are second-order processes that can further erode the ice margin.
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A Globally Complete Inventory of Glaciers
Journal of Glaciology, Vol. 60, No. 221, 2014 doi: 10.3189/2014JoG13J176 537 The Randolph Glacier Inventory: a globally complete inventory of glaciers W. Tad PFEFFER,1 Anthony A. ARENDT,2 Andrew BLISS,2 Tobias BOLCH,3,4 J. Graham COGLEY,5 Alex S. GARDNER,6 Jon-Ove HAGEN,7 Regine HOCK,2,8 Georg KASER,9 Christian KIENHOLZ,2 Evan S. MILES,10 Geir MOHOLDT,11 Nico MOÈ LG,3 Frank PAUL,3 Valentina RADICÂ ,12 Philipp RASTNER,3 Bruce H. RAUP,13 Justin RICH,2 Martin J. SHARP,14 THE RANDOLPH CONSORTIUM15 1Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA 2Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA 3Department of Geography, University of ZuÈrich, ZuÈrich, Switzerland 4Institute for Cartography, Technische UniversitaÈt Dresden, Dresden, Germany 5Department of Geography, Trent University, Peterborough, Ontario, Canada E-mail: [email protected] 6Graduate School of Geography, Clark University, Worcester, MA, USA 7Department of Geosciences, University of Oslo, Oslo, Norway 8Department of Earth Sciences, Uppsala University, Uppsala, Sweden 9Institute of Meteorology and Geophysics, University of Innsbruck, Innsbruck, Austria 10Scott Polar Research Institute, University of Cambridge, Cambridge, UK 11Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA 12Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada 13National Snow and Ice Data Center, University of Colorado, Boulder, CO, USA 14Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada 15A complete list of Consortium authors is in the Appendix ABSTRACT. The Randolph Glacier Inventory (RGI) is a globally complete collection of digital outlines of glaciers, excluding the ice sheets, developed to meet the needs of the Fifth Assessment of the Intergovernmental Panel on Climate Change for estimates of past and future mass balance.
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Glaciers and Their Significance for the Earth Nature - Vladimir M
HYDROLOGICAL CYCLE – Vol. IV - Glaciers and Their Significance for the Earth Nature - Vladimir M. Kotlyakov GLACIERS AND THEIR SIGNIFICANCE FOR THE EARTH NATURE Vladimir M. Kotlyakov Institute of Geography, Russian Academy of Sciences, Moscow, Russia Keywords: Chionosphere, cryosphere, glacial epochs, glacier, glacier-derived runoff, glacier oscillations, glacio-climatic indices, glaciology, glaciosphere, ice, ice formation zones, snow line, theory of glaciation Contents 1. Introduction 2. Development of glaciology 3. Ice as a natural substance 4. Snow and ice in the Nature system of the Earth 5. Snow line and glaciers 6. Regime of surface processes 7. Regime of internal processes 8. Runoff from glaciers 9. Potentialities for the glacier resource use 10. Interaction between glaciation and climate 11. Glacier oscillations 12. Past glaciation of the Earth Glossary Bibliography Biographical Sketch Summary Past, present and future of glaciation are a major focus of interest for glaciology, i.e. the science of the natural systems, whose properties and dynamics are determined by glacial ice. Glaciology is the science at the interfaces between geography, hydrology, geology, and geophysics. Not only glaciers and ice sheets are its subjects, but also are atmospheric ice, snow cover, ice of water basins and streams, underground ice and aufeises (naleds). Ice is a mono-mineral rock. Ten crystal ice variants and one amorphous variety of the ice are known.UNESCO Only the ice-1 variant has been – reve EOLSSaled in the Nature. A cryosphere is formed in the region of interaction between the atmosphere, hydrosphere and lithosphere, and it is characterized bySAMPLE negative or zero temperature. CHAPTERS Glaciology itself studies the glaciosphere that is a totality of snow-ice formations on the Earth's surface.
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Landtype Associations (Ltas) of the Northern Highland Scale: 1:650,000 Wisconsin Transverse Mercator NAD83(91) Map NH3 - Ams
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Edges of Ice-Sheet Glaciology
Important Things Ice Sheets Do, but Ice Sheet Models Don’t Dr. Robert Bindschadler Chief Scientist Hydrospheric and Biospheric Sciences Laboratory NASA Goddard Space Flight Center [email protected] I’ll talk about • Why we need models – from a non-modeler • Why we need good models – recent observations have destroyed confidence in present models • Recent ice-sheet surprises • Responsible physical processes “…understanding of (possible future rapid dynamical changes in ice flow) is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.” IPCC Fourth Assessment Report, Summary for Policy Makers (2007) Future Sea Level is likely underestimated A1B IPCC AR4 (2007) Ice Sheets matter Globally Source: CReSIS and NASA Land area lost by 1-meter rise in sea level Impact of 1-meter sea level rise: Source: Anthoff et al., 2006 Maldives 20th Century Greenland Ice Sheet Sea level Change (mm/a) -1 0 +1 accumulation 450 Gt/a melting 225 Gt/a ice flow 225 Gt/a Approximately in “mass balance” 21st Century Greenland Ice Sheet Sea level Change (mm/a) -1 0 +1 accumulation melting ice flow Things could get a little better or a lot worse Increased ice flow will dominate the future rate of change A History Lesson • Less ice in HIGH SEA LEVEL Less warmer ice climates • Ice sheets More shrink faster LOW ice than they TEMPERATURE WARM grow • Sea level change is not COLD THEN NOW smooth Time Decreasing Mass Balance (Source: Luthcke et al., unpub.) Greenland Ice Sheet Mass Balance GREENLAND (Source: IPCC FAR) Antarctic Ice Sheet Mass Balance ANTARCTICA (Source: IPCC FAR) Pace of ice sheet changes have astonished experts is the common agent behind these changes Ice sheets HATE water! Fastest Flow at the Edges Interior: 1000’s meters thick and slow Perimeter: 100’s meters thick and fast Source: Rignot and Thomas Response time and speed of perturbation propagation are tied directly to ice flow speed 1.
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Ilulissat Icefjord
World Heritage Scanned Nomination File Name: 1149.pdf UNESCO Region: EUROPE AND NORTH AMERICA __________________________________________________________________________________________________ SITE NAME: Ilulissat Icefjord DATE OF INSCRIPTION: 7th July 2004 STATE PARTY: DENMARK CRITERIA: N (i) (iii) DECISION OF THE WORLD HERITAGE COMMITTEE: Excerpt from the Report of the 28th Session of the World Heritage Committee Criterion (i): The Ilulissat Icefjord is an outstanding example of a stage in the Earth’s history: the last ice age of the Quaternary Period. The ice-stream is one of the fastest (19m per day) and most active in the world. Its annual calving of over 35 cu. km of ice accounts for 10% of the production of all Greenland calf ice, more than any other glacier outside Antarctica. The glacier has been the object of scientific attention for 250 years and, along with its relative ease of accessibility, has significantly added to the understanding of ice-cap glaciology, climate change and related geomorphic processes. Criterion (iii): The combination of a huge ice sheet and a fast moving glacial ice-stream calving into a fjord covered by icebergs is a phenomenon only seen in Greenland and Antarctica. Ilulissat offers both scientists and visitors easy access for close view of the calving glacier front as it cascades down from the ice sheet and into the ice-choked fjord. The wild and highly scenic combination of rock, ice and sea, along with the dramatic sounds produced by the moving ice, combine to present a memorable natural spectacle. BRIEF DESCRIPTIONS Located on the west coast of Greenland, 250-km north of the Arctic Circle, Greenland’s Ilulissat Icefjord (40,240-ha) is the sea mouth of Sermeq Kujalleq, one of the few glaciers through which the Greenland ice cap reaches the sea.
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Glacier Movement
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Glacial Geomorphology☆ John Menzies, Brock University, St
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66 Journal of Glaciology the Formation of Fjords Many
66 JOURNAL OF GLACIOLOGY THE FORMATION OF FJORDS By RENE KOECHLIN (Blonay, Switzerland) MANY explanations of the origin of fjords are to be found in works on geography and geology as well as in guide books, but none of them seems fully to meet the case. Fjords are the natural result of the laws which govern the movement of glaciers; they are formed by erosion of the beds of glaciers as they flow into the sea and in the course of centuries become displaced inland. For a further account the reader is referred to my two papers on the theory of glacier mechanism. *f The Laws of Glacier Movement. Just as liquid precipitation in temperate countries follows its course to the ocean under the impulse of gravity, so does the solid precipitation transformed by compression into ice in Polar regions make its way seawards, eroding its bed as it flows and excavating a rock channel. The erosion is slight in the accumulation areas, but increases greatly at lower levels where I have calculated that it is of the order of i cm. a year, as opposed to no more than o-2 to i-o mm. a year for the whole glacier system; the latter figures have been established by the measurement of the amount of solid material found in the streams issuing from glaciers. Erosion takes place uniformly throughout the'bed of the ice stream, so that the glacier gradually sinks into the ground parallel to the surface. At the same time it cuts its way headward (see Fig.
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Glacial Processes and Landforms-Transport and Deposition
Glacial Processes and Landforms—Transport and Deposition☆ John Menziesa and Martin Rossb, aDepartment of Earth Sciences, Brock University, St. Catharines, ON, Canada; bDepartment of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, Canada © 2020 Elsevier Inc. All rights reserved. 1 Introduction 2 2 Towards deposition—Sediment transport 4 3 Sediment deposition 5 3.1 Landforms/bedforms directly attributable to active/passive ice activity 6 3.1.1 Drumlins 6 3.1.2 Flutes moraines and mega scale glacial lineations (MSGLs) 8 3.1.3 Ribbed (Rogen) moraines 10 3.1.4 Marginal moraines 11 3.2 Landforms/bedforms indirectly attributable to active/passive ice activity 12 3.2.1 Esker systems and meltwater corridors 12 3.2.2 Kames and kame terraces 15 3.2.3 Outwash fans and deltas 15 3.2.4 Till deltas/tongues and grounding lines 15 Future perspectives 16 References 16 Glossary De Geer moraine Named after Swedish geologist G.J. De Geer (1858–1943), these moraines are low amplitude ridges that developed subaqueously by a combination of sediment deposition and squeezing and pushing of sediment along the grounding-line of a water-terminating ice margin. They typically occur as a series of closely-spaced ridges presumably recording annual retreat-push cycles under limited sediment supply. Equifinality A term used to convey the fact that many landforms or bedforms, although of different origins and with differing sediment contents, may end up looking remarkably similar in the final form. Equilibrium line It is the altitude on an ice mass that marks the point below which all previous year’s snow has melted.
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Glacier Mass Balance This Summary Follows the Terminology Proposed by Cogley Et Al
Summer school in Glaciology, McCarthy 5-15 June 2018 Regine Hock Geophysical Institute, University of Alaska, Fairbanks Glacier Mass Balance This summary follows the terminology proposed by Cogley et al. (2011) 1. Introduction: Definitions and processes Definition: Mass balance is the change in the mass of a glacier, or part of the glacier, over a stated span of time: t . ΔM = ∫ Mdt t1 The term mass budget is a synonym. The span of time is often a year or a season. A seasonal mass balance is nearly always either a winter balance or a summer balance, although other kinds of seasons are appropriate in some climates, such as those of the tropics. The definition of “year” depends on the measurement method€ (see Chap. 4). The mass balance, b, is the sum of accumulation, c, and ablation, a (the ablation is defined here as negative). The symbol, b (for point balances) and B (for glacier-wide balances) has traditionally been used in studies of surface mass balance of valley glaciers. t . b = c + a = ∫ (c+ a)dt t1 Mass balance is often treated as a rate, b dot or B dot. Accumulation Definition: € 1. All processes that add to the mass of the glacier. 2. The mass gained by the operation of any of the processes of sense 1, expressed as a positive number. Components: • Snow fall (usually the most important). • Deposition of hoar (a layer of ice crystals, usually cup-shaped and facetted, formed by vapour transfer (sublimation followed by deposition) within dry snow beneath the snow surface), freezing rain, solid precipitation in forms other than snow (re-sublimation composes 5-10% of the accumulation on Ross Ice Shelf, Antarctica).
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Glacial Terminology
NRE 430 / EEB 489 D.R. Zak 2003 Lab 1 Glacial Terminology The last glacial advance in Michigan is known as the Wisconsin advance. The late Wisconsin period occurred between 25,000 and 10,000 years ago. Virtually all of Michigan's present surface landforms were shaped during this time. A. Glacial Materials Glacial Drift: material transported and deposited by glacial action. Note that most glacial features are recessional, i.e., they are formed by retreating ice. Materials deposited during glacial advance are usually overridden and destroyed or buried before the glacier has reached its maximum. Till: unstratified drift (e.g., material not organized into distinct layers), ice-transported, highly variable, may consist of any range of particles from clay to boulders. Ice-deposited material is indicated by random assemblage of particle sizes, such as clay, sand and cobbles mixed together. Ice-worked material is indicated by sharp-edged or irregular shaped pebbles and cobbles, formed by the coarse grinding action of the ice. Outwash: stratified drift (e.g., material organized into distinct horizontal layers or bands), water-transported, consists mainly of sand (fine to coarse) and gravel rounded in shape. Meltwater streams flowing away from glacier as it recedes carries particles that are sorted by size on deposition dependent upon the water flow velocity – larger particles are deposited in faster moving water. Water-deposited material is indicated by stratified layers of different sized sand particles and smooth rounded pebbles, consistent in size within each band. Water-worked material is indicated by smooth, rounded particles, formed by the fine grinding action of particles moved by water.
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