DOCSLIB.ORG

KAME and KETTLE TOPOGRAPHY Definition Origin Bibliography Cross

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
KAME and KETTLE TOPOGRAPHY Definition Origin Bibliography Cross K KAME AND KETTLE TOPOGRAPHY the form of low alluvial fans (if deposited on land) or deltas (if deposited in standing water).The glaciofluvial landform include kame, kame terrace, kettle, kettle holes, Amit Kumar outwash plains, etc. Department of Geology, Centre of Advanced Study in Geology, Panjab University, Chandigarh, India Bibliography Benn, D. I., and Evans, D. J. A., 1998. Glaciers and Glaciation. Definition London: Arnold. A kame is a stratified geomorphologic feature which is Hambrey, M., and Alean, J., 2004. Glaciers, 2nd edn. Cambridge: created by deposition action of glacier meltwater, an irreg- Cambridge University Press. ularly shaped hill or mound composed of sand, gravel, and till, commonly associated with end moraine. A kame may Cross-references occur as an isolated hill but in general each kame is one Glaciofluvial mound in a low-lying terrain of many hummocks, terraces, Glaciogenic Deposits ridges, and hollows. Kames are often associated with ket- tle holes. Kettles are depressions in the outwash plains, which formed due to the melting of large ice blocks and this is referred to as kame and kettle topography. Kame KATABATIC WIND: IN RELATION WITH SNOW and kettle topography is an indicator of a high-discharge AND GLACIERS supraglacial and englacial drainage system of a glacier in the final stages of melt, and large quantities of glacially Amit Kumar derived debris associated with meltwater. Centre of Advanced Study in Geology, Department of Geology, Panjab University, Chandigarh, India Origin Glacier meltwater that exists in the ablation area of gla- Synonyms ciers during the melting season flows down on the glacier Drainage wind; Fall winds; Piteraq and williwaw surface, in the ice, or on the bedrock, making complex sys- tems of drainage channels. Deformation of ice, movement Definition of glacier, freezing, and melting processes influence on the Katabatic wind (Greek: katabaino – to go down) is the position and form of channels. Meltwater escapes through common name for downslope winds flowing from high numerous small and temporary streams. These streams elevations of mountains, plateaus, and glacier down their carry sediments for longer distances and deposit them in slopes to the valleys or planes underneath. Such winds various forms. Sometimes, these streams also carry some are sometimes also called fall winds. Particularly, it is ice. Thus, the deposition of sediments after the ablation a wind that carries high density air from a higher elevation (melting of glacier) is called glaciofluvial deposits and down a slope under the force of gravity. This occurs on the the landforms resulting from such deposits are called largest scale as the outflowing winds from Greenland and glaciofluvial landforms. The sediments are deposited in Antarctica. In Greenland these winds are called Piteraq Vijay P. Singh, Pratap Singh & Umesh K. Haritashya (eds.), Encyclopedia of Snow, Ice and Glaciers, DOI 10.1007/978-90-481-2642-2, # Springer Science+Business Media B.V. 2011 672 KILIMANJARO and in South America as well as in Alaska, it is wind Geographic setting known as a Williwaw. Kilimanjaro is a massive, dormant volcano in Tanzania, Alpine valleys produce their own local wind systems as built up of both lava flows and pyroclastic material, situ- a result of thermal differences. The cold air slides down the ated roughly equidistant (300 km) south of the Equator slope under gravity during night. The radiative cooling of and west of the Indian Ocean. Three primary volcanic the ground surface under clear and calm conditions during centers are thought to have been active sequentially since night provides colder air near the surface. The nighttime the Pleistocene, which together form the Kilimanjaro downslope movement of the colder air is referred to as massif: Shira (4,005 m), Mawenzi (5,140 m), and Kibo katabatic winds. The anabatic wind is developed prior to (5,895 m). At the apex of Kibo is a relatively flat caldera the daytime, whereas katabatic drainage is developed in measuring 1.9 by 2.7 km (Figure 1); Uhuru Peak is the the night. The katabatic winds usually flow gently down- highest point along the southern scarp, 180 m above slope with low speed, but greater speeds are also experi- the caldera floor. enced when the depth of cold air is large and the slope is higher. History of cryospheric research on Kilimanjaro Bibliography The earliest scientific discussion of snow and ice on Kili- “ ” Benn, D. I., and Evans, D. J. A., 1998. Glaciers and Glaciation. manjaro began with the initial European discovery of London: Arnold. the snowcap by Johannes Rebmann in 1848. English Bennett, M. R., and Glasser, N. F., 1996. Glacial Geology: Ice Geographers were incredulous, and dismissed Rebmann’s Sheets and Landforms. Chichester: Wiley. report for more than a decade (Meyer, 1891). Hans Meyer Colbeck, S., 1980. Dynamics of Snow and Ice Masses. London: climbed nearly to the crater rim in 1887, reaching the sum- Academic. mit 2 years later on 6 October 1889 (Meyer, 1891). Addi- Defant, F., 1949. Zur Theorie der Hangwinde, nebst Bemerkungen zur Theorie der Berg- und Talwinde. (On the theory of slope tional European scientists soon reached the summit area winds, along with remarks on the theory of mountain and valley and published their qualitative findings. Logistical con- winds.). Archiv für Meteorologie Geophysik und straints rendered ascents and fieldwork considerably more Bioklimatologie, A1, 421–450. difficult than at present, yet virtually every account Singh, P., and Singh, V. P., 2001. Snow and Glacier Hydrology. describes features and processes not unlike those of today. Dordrecht: Kluwer. Most also discuss the decreasing extent of ice, and many predict disappearance – within decades – of either indi- vidual glaciers or all of the mountain’s ice. KILIMANJARO Mid-twentieth-century perspectives on Kibo’s summit and slope glaciers were provided by Humphries (1959), Douglas R. Hardy Downie and Wilkinson (1972), and Hastenrath (1984). Climate System Research Center and Department Henry Osmaston (1989) then published an analysis of gla- of Geosciences, University of Massachusetts, Morrill cier Moraine (qv) as mapped from aerial photographs, Science Center, Amherst, MA, USA which for the first time quantified the nineteenth century extent of glaciers on the mountain. Hastenrath and Greischar (1997) built upon Osmaston’s work and pro- Definition vided the first cartographic documentation of ice reces- Kilimanjaro is Africa’s highest mountain (5,895 m), sion. Thereafter, a resurgence of research on Kibo began located in northern Tanzania just south of the Kenya bor- 0 0 in February 2000 with Ice Core (qv) drilling, aerial pho- der (3 4 S; 37 21 E). At the seasonally snow-covered tography, and installation of an automated weather station 2 summit, the extent of glacier ice is now less than 2 km , (AWS) on the Northern Icefield (Hardy, 2002; Thompson roughly half of that remaining on the continent. et al., 2002). A Network of Stakes (qv) has expanded steadily since 2000 to represent most of the glacierized Overview area at the summit, and two additional AWS are now oper- The cryosphere is sparsely represented in Africa, primar- ating on summit glaciers (Mölg et al., 2008). ily on a small handful of the continent’s highest moun- Today, as during the nineteenth century, snow and ice tains. Among these is Kilimanjaro, the “white roof of on Kilimanjaro are again controversial. A new ice-extent Africa,” whose glaciers have achieved notoriety far out map released in 2001 was accompanied by a prediction of proportion to their size (miniscule), importance as that the glaciers could disappear within 20 years (Irion, a water resource (negligible), or potential contribution to 2001). Kilimanjaro was quickly employed to symbolize sea-level rise (zero). Yet, Kilimanjaro’s summit mantle the impacts of global warming (e.g., Greenpeace, 2001). of Snow (qv) and Ice (qv) is starkly beautiful, and thus However, cautious statements by scientists such as Kaser among the mountain’s most fascinating, distinctive, and et al. (2004, p. 337) that “...mass loss on the summit ... best-known attributes. Thousands of international visitors is little affected by air temperature,” or Mote and Kaser are attracted annually, bringing valuable tourism revenue (2007,p.325)that“... loss of ice on Mount Kilimanjaro to Tanzania. cannot be used as proof of global warming,” were eagerly KILIMANJARO 673 Kilimanjaro, Figure 1 Kibo peak of Kilimanjaro, with remnants of the ice cap (qv) that once encircled the summit. The crater is the area surrounded by ice and labeled “KIBO.” Contours are in meters. Solid circle symbols indicate location of 2000 ice-core drilling sites (Thompson et al., 2002), and the ice extent is shown for five epochs (1912–1989 after Hastenrath and Greischar (1997), 2000 after Thompsen et al. (2002)). NIF, EIF, and SIF are the former Northern, Eastern, and Southern Ice Fields (respectively), FWG Furtwa¨ngler Glacier, UP Uhuru Peak (5,895 m), and LPG Little Penck Glacier. Automated weather stations currently operate near the NIF and SIF drill sites. embraced by those seeking to cast doubts about global (Coutts, 1969; Hemp, 2006). This precipitation pattern warming (e.g., GES, 2004). Resolution of the modern-time accounts in part for the asymmetrical distribution of gla- controversy awaits a comprehensive understanding of how ciers on Kilimanjaro. Kilimanjaro’s summit climate has been impacted by large- Precipitation at the summit annually totals only 10% scale atmospheric circulation changes; this effort is well of that received by the forest below, and snow is the pre- underway (Mölg et al., 2009;Thompsonetal.,2009; dominant form of precipitation at elevations above the Winkler et al., 2010). mean annual freezing-level altitude, roughly 4,700 m (Hastenrath, 1984). Snowfall can occur at any time of year, but is primarily associated with northern Tanzania’s Climate two seasonally-wet periods, the November–December Kilimanjaro rises 5,000 m above the surrounding plains, “short rains,” and the “long rains” of March to May.
Load more

Recommended publications
  • Basal Control of Supraglacial Meltwater Catchments on the Greenland Ice Sheet
    The Cryosphere, 12, 3383–3407, 2018 https://doi.org/10.5194/tc-12-3383-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Basal control of supraglacial meltwater catchments on the Greenland Ice Sheet Josh Crozier1, Leif Karlstrom1, and Kang Yang2,3 1University of Oregon Department of Earth Sciences, Eugene, Oregon, USA 2School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China 3Joint Center for Global Change Studies, Beijing 100875, China Correspondence: Josh Crozier ([email protected]) Received: 5 April 2018 – Discussion started: 17 May 2018 Revised: 13 October 2018 – Accepted: 15 October 2018 – Published: 29 October 2018 Abstract. Ice surface topography controls the routing of sur- sliding regimes. Predicted changes to subglacial hydraulic face meltwater generated in the ablation zones of glaciers and flow pathways directly caused by changing ice surface to- ice sheets. Meltwater routing is a direct source of ice mass pography are subtle, but temporal changes in basal sliding or loss as well as a primary influence on subglacial hydrology ice thickness have potentially significant influences on IDC and basal sliding of the ice sheet. Although the processes spatial distribution. We suggest that changes to IDC size and that determine ice sheet topography at the largest scales are number density could affect subglacial hydrology primarily known, controls on the topographic features that influence by dispersing the englacial–subglacial input of surface melt- meltwater routing at supraglacial internally drained catch- water. ment (IDC) scales ( < 10s of km) are less well constrained. Here we examine the effects of two processes on ice sheet surface topography: transfer of bed topography to the surface of flowing ice and thermal–fluvial erosion by supraglacial 1 Introduction meltwater streams.
    [Show full text]
  • 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.
    [Show full text]
  • An Esker Group South of Dayton, Ohio 231 JACKSON—Notes on the Aphididae 243 New Books 250 Natural History Survey 250
    The Ohio Naturalist, PUBLISHED BY The Biological Club of the Ohio State University. Volume VIII. JANUARY. 1908. No. 3 TABLE OF CONTENTS. SCHEPFEL—An Esker Group South of Dayton, Ohio 231 JACKSON—Notes on the Aphididae 243 New Books 250 Natural History Survey 250 AN ESKER GROUP SOUTH OF DAYTON, OHIO.1 EARL R. SCHEFFEL Contents. Introduction. General Discussion of Eskers. Preliminary Description of Region. Bearing on Archaeology. Topographic Relations. Theories of Origin. Detailed Description of Eskers. Kame Area to the West of Eskers. Studies. Proximity of Eskers. Altitude of These Deposits. Height of Eskers. Composition of Eskers. Reticulation. Rock Weathering. Knolls. Crest-Lines. Economic Importance. Area to the East. Conclusion and Summary. Introduction. This paper has for its object the discussion of an esker group2 south of Dayton, Ohio;3 which group constitutes a part of the first or outer moraine of the Miami Lobe of the Late Wisconsin ice where it forms the east bluff of the Great Miami River south of Dayton.4 1. Given before the Ohio Academy of Science, Nov. 30, 1907, at Oxford, O., repre- senting work performed under the direction of Professor Frank Carney as partial requirement for the Master's Degree. 2. F: G. Clapp, Jour, of Geol., Vol. XII, (1904), pp. 203-210. 3. The writer's attention was first called to the group the past year under the name "Morainic Ridges," by Professor W. B. Werthner, of Steele High School, located in the city mentioned. Professor Werthner stated that Professor August P. Foerste of the same school and himself had spent some time together in the study of this region, but that the field was still clear for inves- tigation and publication.
    [Show full text]
  • Multiple Glaciation and Gold-Placer
    MULTIPLE GLACIATION AND GOLD-PLACER STATE OF ALASKA DEPARTMENT OF NATURAL RESOURCES DIVISION OF GEOLOGICAL & GEOPHYSICAL SURVEYS 1990 MULTIPLE GLACIATION AND GOLD-PLACER FORMATION, VALDEZ CREEK VALLEY, WESTERN CLEARWATER MOUNTAINS, ALASKA By Richard D. Reger and Thomas K. Bundtzen Division of Geological & Geophysical Surveys Professional Report 107 Prepared in cooperation with U.S.Bureau of Mines Fairbanks, Alaska 1990 STATE OF ALASKA Steve Cowper, Governor DEPARTMENT OF NATURAL RESOURCES Lennie Gorsuch, Commissioner DIVISION OF GEOLOGICAL AND GEOPHYSICAL SURVEYS Robert B. Forbes, Director and State Geologist Cover: Oblique aerial view northeast of Valdez Creek Mine and glaciated lower Valdez Creek valley. Photograph courtesy of Valdez Creek Mining Company. Available from Alaska Division of Geological and Geophysical Surveys, 3700 Airport Way, Fairbanks, AK 997094699 and from U.S. Geological Sulvey Earth Science Information Centers, 4230 University Drive, Room 101, Anchorage, AK 99508 and 605 West 4th Avenue, Room G84, Anchorage, AK 99501. Mail orders should be addressed to the DGGS office in Fairbanks. Cost $4.50. CONTENTS I'age Abstract ............................................................................................................................................................................ Introduction and mining history ................................................................................................................................ Acknowledgments ..........................................................................................................................................................
    [Show full text]
  • Glacier (And Ice Sheet) Mass Balance
    Glacier (and ice sheet) Mass Balance The long-term average position of the highest (late summer) firn line ! is termed the Equilibrium Line Altitude (ELA) Firn is old snow How an ice sheet works (roughly): Accumulation zone ablation zone ice land ocean • Net accumulation creates surface slope Why is the NH insolation important for global ice• sheetSurface advance slope causes (Milankovitch ice to flow towards theory)? edges • Accumulation (and mass flow) is balanced by ablation and/or calving Why focus on summertime? Ice sheets are very sensitive to Normal summertime temperatures! • Ice sheet has parabolic shape. • line represents melt zone • small warming increases melt zone (horizontal area) a lot because of shape! Slightly warmer Influence of shape Warmer climate freezing line Normal freezing line ground Furthermore temperature has a powerful influence on melting rate Temperature and Ice Mass Balance Summer Temperature main factor determining ice growth e.g., a warming will Expand ablation area, lengthen melt season, increase the melt rate, and increase proportion of precip falling as rain It may also bring more precip to the region Since ablation rate increases rapidly with increasing temperature – Summer melting controls ice sheet fate* – Orbital timescales - Summer insolation must control ice sheet growth *Not true for Antarctica in near term though, where it ʼs too cold to melt much at surface Temperature and Ice Mass Balance Rule of thumb is that 1C warming causes an additional 1m of melt (see slope of ablation curve at right)
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Surficial Geology and Soils of the Elmira -Williamsport Region, New York and Pennsylvania
    Surficial Geology and Soils of the Elmira -Williamsport Region, New York and Pennsylvania GEOLOGICAL SURVEY PROFESSIONAL PAPER 379 Prepared cooperatively by the U.S. Department of the Interior^ Geological Survey and the U.S. De­ partment of Agriculture^ Soil Conservation Service Surficial Geology and Soils of the Elmira-Williamsport Region, New York and Pennsylvania By CHARLES S. DENNY, Geological Survey, and WALTER H. LYFORD, Soil Conservation Service With a section on FOREST REGIONS AND GREAT SOIL GROUPS By JOHN C. GOODLETT and WALTER H. LYFORD GEOLOGICAL SURVEY PROFESSIONAL PAPER 379 Prepared cooperatively by the Geological Survey and the Soil Conservation Service UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C., 20402 CONTENTS Page Soils Continued Page Abstract--- ________________________________________ 1 Sols Bruns Acides, Gray-Brown Podzolic, and Red- Introduction_______________________________________ 2 Yellow Podzolic soils.._--_-_-__-__-___-_-__-__ 34 Acknowledgments-- _ ________________________________ 3 Weikert soil near Hughesville, Lycoming County, Topography. _______________________________________ 3 Pa______________________________________ 34 Bedrock geology.___________________________________ 4 Podzols and Sols Bruns Acides ____________________ 36 Surficial deposits of pre-Wisconsin age_________________ 4 Sols Bruns Acides and LowHumic-Gley soils._______ 37 Drift...__.____________________________________ 5 Chenango-Tunkhannock association. __________ 37 Colluvium and residuum_--_______-_--_-___-_____ 6 Chenango soil near Owego, Tioga County, Drift of Wisconsin age_-_-___________________________ 6 N.Y_________________________________ 37 Till. ________________________________________ 6 Lordstown-Bath-Mardin-Volusia association.... 39 Glaciofluvial deposits.___________________________ 7 Bath soil near Owego, Tioga County, N.Y.
    [Show full text]
  • Trip F the PINNACLE HILLS and the MENDON KAME AREA: CONTRASTING MORAINAL DEPOSITS by Robert A
    F-1 Trip F THE PINNACLE HILLS AND THE MENDON KAME AREA: CONTRASTING MORAINAL DEPOSITS by Robert A. Sanders Department of Geosciences Monroe Community College INTRODUCTION The Pinnacle Hills, fortunately, were voluminously described with many excellent photographs by Fairchild, (1923). In 1973 the Range still stands as a conspicuous east-west ridge extending from the town of Brighton, at about Hillside Avenue, four miles to the Genesee River at the University of Rochester campus, referred to as Oak Hill. But, for over thirty years the Range was butchered for sand and gravel, which was both a crime and blessing from the geological point of view (plates I-VI). First, it destroyed the original land form shapes which were subsequently covered with man-made structures drawing the shade on its original beauty. Secondly, it allowed study of its structure by a man with a brilliantly analytical mind, Herman L. Fair­ child. It is an excellent example of morainal deposition at an ice front in a state of dynamic equilibrium, except for minor fluctuations. The Mendon Kame area on the other hand, represents the result of a block of stagnant ice, probably detached and draped over drumlins and drumloidal hills, melting away with tunnels, crevasses, and per­ foration deposits spilling or squirting their included debris over a more or less square area leaving topographically high kames and esker F-2 segments with many kettles and a large central area of impounded drainage. There appears to be several wave-cut levels at around the + 700 1 Lake Dana level, (Fairchild, 1923). The author in no way pretends to be a Pleistocene expert, but an attempt is made to give a few possible interpretations of the many diverse forms found in the Mendon Kames area.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Forecasting Temperate Alpine Glacier Survival from Accumulation Zone Observations
    The Cryosphere, 4, 67–75, 2010 www.the-cryosphere.net/4/67/2010/ The Cryosphere © Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License. Forecasting temperate alpine glacier survival from accumulation zone observations M. S. Pelto Environmental Sciences, Nichols College, Dudley, MA 01571, USA Received: 16 April 2009 – Published in The Cryosphere Discuss.: 19 May 2009 Revised: 18 December 2009 – Accepted: 19 January 2010 – Published: 29 January 2010 Abstract. Temperate alpine glacier survival is dependent on change (WGMS, 2008). The worldwide retreat of moun- the consistent presence of an accumulation zone. Frequent tain glaciers is one of the clearest signals of ongoing climate low accumulation area ratio values, below 30%, indicate the change (Haeberli and Hoelzel, 1995; Oerlemans, 1994). The lack of a consistent accumulation zone, which leads to sub- retreat is a reflection of strongly negative mass balances over stantial thinning of the glacier in the accumulation zone. This the last 30 years (WGMS, 2007). In some cases the negative thinning is often evident from substantial marginal recession, balances have led to the loss of a glacier (Pelto, 2006; Knoll emergence of new rock outcrops and surface elevation de- and Kerschner, 2009). cline in the accumulation zone. In the North Cascades 9 of Terminus change observations identify the response of the the 12 examined glaciers exhibit characteristics of substantial glacier to recent climate changes; however, terminus change accumulation zone thinning; marginal recession or emergent does not identify the ability of a glacier to survive. A glacier bedrock areas in the accumulation zone. The longitudinal can retreat rapidly and still reestablish equilibrium.
    [Show full text]