DOCSLIB.ORG

Characteristics of the Bergschrund of an Avalanche-Cone Glacier in the Canadian Rocky Mountains

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characteristics of the Bergschrund of an Avalanche-Cone Glacier in the Canadian Rocky Mountains JOlIl"lla/ o/G/aci%gl'. VoL 29. No. 10 1. 1983 CHARACTERISTICS OF THE BERGSCHRUND OF AN AVALANCHE-CONE GLACIER IN THE CANADIAN ROCKY MOUNTAINS By G ERALD OSBORN (Department of Geology and Geophysics, Uni versity o f Calgary, Calgary, Alberta T2N I N4, Canada) ABSTRACT. Fi eld study of th e bergschrund of a small avalanche-cone glacier at the base of Mt Chephren, in Banff Nati onal Park , has been ca rried out as part of a general ex pl oratory study of glacier-head crevasses in th e Canadi an Roc ki es. The bergsc hrun d consists of a wide. shall ow. partl y bedrock-fl oored gap, und erneath whi ch ex tends a nearl y vertical Ralldklu!I, and a small , offset, subsidi ary crevasse (or crevasses). The fo ll owin g observations rega rdin g the behavior of th e bergsc hruncl and ice adjacent to it are of parti cul ar interest: ( I) topograph y of the subglaeial bedrock is a control on the location of the main bergschrund and subsidi a ry crevasses. (2) th e main bergschrund and subsid ia ry crevasse(s) are conn ected by subglacial gaps betwee n bedrock and ice; th e gaps are part of th e "bergschrund system" , (3) snow/ ice immedi ately down-glacier of the bergschrund system moves nea rl y verticall y dow nwa rd in response to rotational fl ow of the glacier. a ll owin g the bergschrund components to keep the same location and size fro m year to year, (4) an inde pend ent accumul ati on, fl ow. and ablation system ex ists in th e snow/ice up-glac ier of the bergschrund system. (5) most of th e vo id space in the bergsc hrund sy stem is maintained through the winter, alth ough the wide, shall ow part of th e main bergschrund fill s up with snow. (6) some mass transfer of snow/ ice occurs across the bergschrund system, (7) displ acement across th e bergsc hrund due to fl ow of th e main glac ier body results in signifi cantl y more snow bei ng deposited each wi nter down-glacier of th e bergsc hrund than up-glacier of it. R ESUME. Caracteristiqlles de la rimaye d 'ulI glacier forme par UII cone d'avala l1 che da lls les MOl1t agnes Rocheuses Ca ll adiel1n es. O n a conduit un e etude sur le ter rain de la rim aye c1 'un petit glacier forme par un conc d'avalanche, da ns le cadre d'un e etude generaie exp loratoire des rim ayes cl ans les Rocheuses Ca nad ienn es. Le glacier se situe au pi ed de la paroi nord -est du Mt Chep hren dans le Parc Na ti onal de Ba nff. La prin cipale rilll aye consiste en un espace la rge peu profond a ll ant en part ie jusq u'au bedrock. so us laquell e s'etend 'unc crevasse presq ue verti ca le entre le bedrock et le corps prin cipal du glacier. La ri maye s'ctrangle avant d'attei ndre le cOle sud-esl du cone, mais de pelites crevasse ann exes la po ursuivent dans line zone decli ve. La locali sa tion de la rilll aye prin ci pale et des crevasses ann exes est en parti e liee a la topograph ie dll bedrock so us-jacent. Les observations sui vantes concern ant le co mportemen t de la rilllaye et de la glace avoisin ante offrent un interet parti culier: ( I) la rim aye principale et les crevasses annexes ont to utes re li ees par des cavites so us-glaciaires ent re le bedrock et la glace. ces cavites fo nt partie du systeme de la rim aye, (2) I'ablation se produit pe nd an t r ete it la surface des glaces profondes aussi bien que sur la surface supcrieure du glacier, (3) la neige c1evcnant glacc immediatement en-dessous du systeme de la rim aye se dcp lace presque ve rti calement en raiso n de I'ecoul ement ro tationn el du glacier, ce q ui perm et au systeme de la ri ll1aye de conserver la Il1 cll1 e locali sati on et la 111 cme formc d'ann ee en an nee. (4) un systeme independ ant ecoul emen t-ablatio n existe dans le neve a u-dessus du syste 111 e de la ri111 aye. (5) la plu s gra nde part ie de I'espace vide dans le systeme de la rim aye se maintient pend ant I'hi ve r bi en que la portion large et peu profonde de la rimaye principale se rell1pli sse de neige, (6) un certain transfert de ll1 asse de neve se produit a travers le systeme de la rim aye. (7) le de pl acement it travers la rill1 aye dfJ a I'ecoul ement aboutit it ce qu ' il se depose de mani ere sig nifi cati ve, plu s c1e neige chaqlle ann ee cn-desso us de la rim aye qu'au dessus. Z USAMMENFASSUNG. Charaklerisliken des Bergschrulldes eirles Lawillell kegelgletschers ill dell Kalladischell Rocky Mountain s. Feldunlersuchungen des Bergsc hrun des an ein e l11 kleinen Lawinenk cgelgletscher wurden als Teil ein er all ge l11 einen Studie der zu ngenfernen Glelscherspalten in den Kanadi schen Rocky Mountain s durchgefiihrt. Der Gletscher liegt am Fusse der Nordos tfi an ke des Mt Chephren il11 Banff National Park. Ocr Haupt-Bergschrund besteht aus einer weit en. seicht en Spalte, teilweise iiber Felsgrund, unter der sich ein e fast senk recht e Kluft zwi schen dem Fels und de l11 eige ntlichen Gletscherk ii per erstrec kL Der Bergsc hrund streicht aus, bevor er die Siidostseite des Kegels erreicht, setzt sich aber in kl ein en, geslaffe lten Nebenspalten fo rt. Di e Lage dcs Haupt-Bergsc hrund es un d der Nebenspaiten steht te il weise im Zusa mmenh ang mit der Topographi c des Felsun tergr un des. Di e folgende n Beobachtllngen ii ber den Bergschrund un d das ihm benachba rte Eis diirften vo n 55 Downloaded from https://www.cambridge.org/core. 26 Sep 2021 at 11:14:44, subject to the Cambridge Core terms of use. 56 JOURNAL OF GLACIOLOGY besonderem Interesse sein: (I) Oer Haupt-Bergschrund und seine Nebenspalten sind durchwegs durch subglazial e Liicken zwischen Fels und Eis miteinander verbunden ; die Liicken sind ein Teil des " Bergschrundsystems'·. (2) Ablation tritt im Sommer an den subglazialen EisoberfHichen ebenso auf wie an der Gletscheroberfl ache. (3) Schnee und Eis unmittelbar unter dem Bergschrundsystem bewegt sich nahezu senkrecht nach unten infolge des rotierenden Gletscherflusses, wodurch die Bergschrundkomponenten von Jahr dieselbe Lage und Griisse beibehalten kiinnen. (4) In Schnee und Ei s iiber dem Bergschrundsystem besteht ein ei genes Fluss- und Ablationssystem. (5) Ein Grossteil des Leerraumes im Bergschrundsystem bleibt auch im Winter offen, a bwo hl der weite, seichte Teil des Hauptbergschrundes si ch mit Schnee fiill!. (6) Ein gewisser Transport von Schnee und Eis findet auch iiber das Bergschrundsystem statl. (7) Verlagerungen iiber den Bergschrund infolge von Fliessbewegungen fiihren im Winter zu wesentlich griisseren Schneeablagerungen unter dem Bergschrund als iiber ihm. INTRODUCTION "Bergschrund" has been defined as "the crevasse occurring at the head of a mountain glacier, which separates the moving snow and ice of the glacier from the relatively immobile snow and ice adhering to the headwall of the valley" (American Geological Institute, 1962). Despite the fact that bergschrunds are the most obvious structural features on many cirque and valley glaciers, very little is known about their general characteristics and behavior, and about the nature of ice motion immediately up-glacier and down-glacier of them. The bergschrund, according to Battle and Lewis (1951), "resembles a living organism with a life-cycle concerning which we are extremely ignorant". While aspects of particular bergschrunds or Randkliifte have been described in the literature (e.g. Battle, 1952; Battle and Lewis, 1951; McCall, 1960), most prior field study in and of glacier-head gaps has concentrated on thermal regimes in the gaps and associated problems of cirque headwall erosion. This paper presents some observations of a particular bergschrund, and behavior of the ice adjacent to it. Field study took place during the summers of 1977, 1978, and 1979. Difficult and hazardous working conditions (probably one reason why bergschrunds have received so little attention) limited the amount of data that could be gathered and necessitate considerable speculation; nevertheless some interesting findings have emerged. THE MT CHEPHREN SITE The bergschrund described here occurs in a very small avalanche-cone glacier rather than a typical cirque glacier. The glacier is the north-western most of three small glaciers fed by avalanches from the north-east flank of Mt Chephren, in Banff National Park, Alberta (Fig. I). The elevation of the toe is about 1 960 m. The 150 m-long glacier retains a shape appropriate to its avalanche-cone genesis (Fig. 2) but contains the normal accoutrements of a cirque glacier, including sedimentary layering in the ice which dips up-glacier near the toe, and, of course, the bergschrund. Peripheral to the base of the cone is a moraine undoubtedly built during the Cavell Advance of the last few centuries (Luckman and Osborn, 1979). Observations suggest that direct snow-fall plays an insignificant role in nourishment of the glacier; the snow which persists through the summer season is mostly avalanche snow.
Load more

Recommended publications
  • Local Topography Increasingly Influences the Mass Balance of A
    Local topography increasingly influences the mass balance of a retreating cirque glacier Caitlyn Florentine1, 2, Joel Harper2, Daniel Fagre1, Johnnie Moore2, Erich Peitzsch1 1U.S. Geological Survey, Northern Rocky Mountain Science Center, West Glacier, Montana, 59936, USA 5 2Department of Geosciences, University of Montana, Missoula, Montana, 59801, USA Correspondence to: Caitlyn Florentine ([email protected]) Abstract. Local topographically driven processes, such as wind drifting, avalanching, and shading, are known to alter the relationship between the mass balance of small cirque glaciers and regional climate. Yet partitioning such local effects from regional climate influence has proven difficult, creating uncertainty in the climate representativeness of some glaciers. We 10 address this problem for Sperry Glacier in Glacier National Park, USA using field-measured surface mass balance, geodetic constraints on mass balance, and regional climate data recorded at a network of meteorological and snow stations. Geodetically derived mass changes between 1950-1960, 1960-2005, and 2005-2014 document average mass change rates during each period at -0.22±0.12 m w.e. yr-1, -0.18±0.05 m w.e. yr-1, and -0.10±0.03 m w.e. yr-1. A correlation of field- measured mass balance and regional climate variables closely (i.e. within 0.08 m w.e. yr-1) predicts the geodetically 15 measured mass loss from 2005-2014. However, this correlation overestimates glacier mass balance for 1950-1960 by +1.18±0.92 m w.e. yr-1. Our analysis suggests that local effects, not represented in regional climate variables, have become a more dominant driver of the net mass balance as the glacier lost 0.50 km2 and retreated further into its cirque.
    [Show full text]
  • Geomorphic Character, Age and Distribution of Rock Glaciers in the Olympic Mountains, Washington
    Portland State University PDXScholar Dissertations and Theses Dissertations and Theses 1987 Geomorphic character, age and distribution of rock glaciers in the Olympic Mountains, Washington Steven Paul Welter Portland State University Follow this and additional works at: https://pdxscholar.library.pdx.edu/open_access_etds Part of the Geology Commons, and the Geomorphology Commons Let us know how access to this document benefits ou.y Recommended Citation Welter, Steven Paul, "Geomorphic character, age and distribution of rock glaciers in the Olympic Mountains, Washington" (1987). Dissertations and Theses. Paper 3558. https://doi.org/10.15760/etd.5440 This Thesis is brought to you for free and open access. It has been accepted for inclusion in Dissertations and Theses by an authorized administrator of PDXScholar. For more information, please contact [email protected]. AN ABSTRACT OF THE THESIS OF Steven Paul Welter for the Master of Science in Geography presented August 7, 1987. Title: The Geomorphic Character, Age, and Distribution of Rock Glaciers in the Olympic Mountains, Washington APPROVED BY MEMBERS OF THE THESIS COMMITTEE: Rock glaciers are tongue-shaped or lobate masses of rock debris which occur below cliffs and talus in many alpine regions. They are best developed in continental alpine climates where it is cold enough to preserve a core or matrix of ice within the rock mass but insufficiently snowy to produce true glaciers. Previous reports have identified and briefly described several rock glaciers in the Olympic Mountains, Washington {Long 1975a, pp. 39-41; Nebert 1984), but no detailed integrative study has been made regarding the geomorphic character, age, 2 and distribution of these features.
    [Show full text]
  • Geology of Hyder and Vicinity Southeastern Alaska
    DEPARTMENT OF THE INTERIOR Roy O. West, Secretary U. S. GEOLOGICAL SURVEY George Otis Smith, Director Bulletin 807 GEOLOGY OF HYDER AND VICINITY SOUTHEASTERN ALASKA WITH A RECONNAISSANCE OF CHICKAMIN RIVER BY A. F. RUDDINGTON UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1&29 ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS TJ.S.OOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 35 CENTS PER COPY CONTENTS Page Foreword, by Philip S. Smith._________________________ vn Introduction...____________________________________________________ 1 Field work_.._.___._.______..____...____. -_-__-. .. 1 Acknowledgments. _-_-________-_-___-___-__--_____-__-- -____-_ 2 History._________________________________________________________ 2 Bibliography ________-______ _____________._-__.-___-__--__--_--_-_ 3 Alaska.__-___-__---______-_-____-_-___--____-___-_-___-__-___ & British Columbia____-_____-___-___________-_-___--___.._____- 4 Geography_______________________________________-____--___-__--_ 4 Location and transportation facilities.___________________________ 4 Climate. __--______-______.____--__---____-_______--._--.--__- 5 Vegetation ___________________________________________________ 6 Water power._--___._____.________.______-_.._____-___.-_____ 7 Topography-___________--____-_-___--____.___-___-----__--_-- 7 General features of the relief----______-_---___-__------_-_-_ 7 Streams.._ _______________________________________________ 9 Glaciation.. _ __-_____-__--__--_____-__---_____-__--_----__ 10 Geology.... __----_-._ -._---_--__-.- _-_____-_____-___-_ 13 General features___-_-____-__-__-___-..____--___-_-____--__-._ 13 Hazelton group._....._.._>___-_-.__-______----_-----'_-__-..-- 17 General character.-----.-------.-------------------------- 17 Greenstone and associated rocks.._______.__.-.--__--_--_--_ 18 Graywacke-slate division.._________-_-__--_-_-----_--_----_ 19 Coast.Range intrusives__________-__-__--___-----------_-----_- 22 Texas Creek batholith and associated dikes..__--__.__-__-__-.
    [Show full text]
  • Antarctic Primer
    Antarctic Primer By Nigel Sitwell, Tom Ritchie & Gary Miller By Nigel Sitwell, Tom Ritchie & Gary Miller Designed by: Olivia Young, Aurora Expeditions October 2018 Cover image © I.Tortosa Morgan Suite 12, Level 2 35 Buckingham Street Surry Hills, Sydney NSW 2010, Australia To anyone who goes to the Antarctic, there is a tremendous appeal, an unparalleled combination of grandeur, beauty, vastness, loneliness, and malevolence —all of which sound terribly melodramatic — but which truly convey the actual feeling of Antarctica. Where else in the world are all of these descriptions really true? —Captain T.L.M. Sunter, ‘The Antarctic Century Newsletter ANTARCTIC PRIMER 2018 | 3 CONTENTS I. CONSERVING ANTARCTICA Guidance for Visitors to the Antarctic Antarctica’s Historic Heritage South Georgia Biosecurity II. THE PHYSICAL ENVIRONMENT Antarctica The Southern Ocean The Continent Climate Atmospheric Phenomena The Ozone Hole Climate Change Sea Ice The Antarctic Ice Cap Icebergs A Short Glossary of Ice Terms III. THE BIOLOGICAL ENVIRONMENT Life in Antarctica Adapting to the Cold The Kingdom of Krill IV. THE WILDLIFE Antarctic Squids Antarctic Fishes Antarctic Birds Antarctic Seals Antarctic Whales 4 AURORA EXPEDITIONS | Pioneering expedition travel to the heart of nature. CONTENTS V. EXPLORERS AND SCIENTISTS The Exploration of Antarctica The Antarctic Treaty VI. PLACES YOU MAY VISIT South Shetland Islands Antarctic Peninsula Weddell Sea South Orkney Islands South Georgia The Falkland Islands South Sandwich Islands The Historic Ross Sea Sector Commonwealth Bay VII. FURTHER READING VIII. WILDLIFE CHECKLISTS ANTARCTIC PRIMER 2018 | 5 Adélie penguins in the Antarctic Peninsula I. CONSERVING ANTARCTICA Antarctica is the largest wilderness area on earth, a place that must be preserved in its present, virtually pristine state.
    [Show full text]
  • Glaciation and Hydrogeology Workshop Proceedings
    SKI Report 97:13 SE9700378 Glaciation and Hydrogeology Workshop on the Impact of Climate Change & Glaciations on Rock stresses, Groundwater flow and Hydrochemistry - Past, Present and Future Workshop Proceedings Edited by: Louisa King-Clayton Neil Chapman Lars O Ericsson Fritz Kautsky April 1997 ISSN 1104-1374 ISRNSKI-R--97/13--SE STATENS KARNKRAFTINSPEKTION Swedish Nuclear Fuel and Swedish Nuclear Power Inspectorate Waste Management Co ML 9 ft fe 2 4 SKI Report 97:13 Glaciation and Hydrogeology Workshop on the Impact of Climate Change & Glaciations on Rock stresses, Groundwater flow and Hydrochemistry - Past, Present and Future Organised by: Nordic Nuclear Safety Research (NKS) Funding Organisations: The Swedish Nuclear Power Inspectorate (SKI) and the Swedish Nuclear Fuel and Waste Management Co (SKB) Scientific Secretariat: QuantiSci Ltd, UK Venue: Hasselby Castle Conference Centre, Stockholm, Sweden Date: 17-19 April 1996 Workshop Proceedings April 1997 Edited by: Louisa King-Clayton & Neil Chapman, QuantiSci Ltd, UK Lars O Ericsson, SKB, Sweden Fritz Kautsky, SKI, Sweden NORSTEDTS TRYCKERI AB Stockholm 1997 Workshop on the Impact of Climate Change & Glaciations on Rock Stresses, Groundwater flow and Hydrochemistry, Stockholm 1996 Contents Executive summary 2 Preface 4 1 Introduction 5 2 Workshop Structure 6 3 Background to Workshop Discussions (Day 1) 9 4 Climate Change and Quaternary Geology 23 5 Hydrogeological Aspects of Glaciation 33 6 Hydrogeochemical Aspects of Glaciation 45 7 Tectonic Aspects of Glaciation 52 8 Final Workshop
    [Show full text]
  • Korean Direct
    AAC Publications Korean Direct The First Ascent Of Gasherbrum V Insignificant against the blinding white backdrop of Gasherbrum V’s south face, we stood like silhouettes atop a moraine, the wall before us in full view. The complex glacier leading up to the face reminded me of scaly dragon’s tail. We had spotted a snaking line that would lead us to the jagged bergschrund at the foot of the wall. Once on the face, we would have to keep left to avoid a menacing serac, then move right in the upper mixed section before finishing with a direct line to the top. Seong Nak-jong and I had never really considered a route on the south side of unclimbed Gasherbrum V until we were denied passage up the northeast face. We had started our first attempt on the 7,147- meter peak from Camp 1 on the South Gasherbrum Glacier, along the normal routes to Gasherbrums I and II. We trudged through thigh-deep snow to reach the northeast face, which was covered in loose ice and snow, and was nearly impossible to protect. Falling ice and spindrift poured down from above. We finally had no choice but to evacuate from our high point of 6,400 meters. This unsuccessful attempt quashed our desire to climb. As the leader of our small team, the quandaries of a second attempt weighed heavily on my mind. Not only were we physically weakened and our confidence shot, it was already mid-July and more snow was laying siege to the camps. We had been away from home for more than a month.
    [Show full text]
  • An Investigation of the Thermo-Mechanical Features of Laohugou Glacier No.12 in Mt
    An investigation of the thermo-mechanical features of Laohugou Glacier No.12 in Mt. Qilian Shan, western China, using a two-dimensional first-order flowband ice flow model Yuzhe Wang1,2, Tong Zhang3,a, Jiawen Ren1, Xiang Qin1, Yushuo Liu1, Weijun Sun4, Jizu Chen1,2, Minghu Ding3, Wentao Du1,2, and Dahe Qin1 1State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3Insititute of Polar Meteorology, Chinese Academy of Meteorological Sciences, Beijing 100081, China 4College of Geography and Environment, Shandong Normal University, Jinan 250014, China anow at: Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA Correspondence to: Tong Zhang ([email protected]) Abstract. By combining in situ measurements and a two-dimensional thermo-mechanically coupled ice flow model, we in- vestigate the thermo-mechanical features of the largest valley glacier (Laohugou Glacier No.12; LHG12) in Mt. Qilian Shan located in the arid region of western China. Our model results suggest that LHG12, previously considered as fully cold, is probably polythermal, with a lower temperate ice layer overlain by an upper layer of cold ice over a large region of the ablation 5 area. Modeled ice surface velocities match well with the in situ observations in the east branch (mainstreammain::::::::::branch) but clearly underestimate the ice surface velocities those:::: near the glacier terminus possibly because the convergent flow is ignored and the basal sliding beneath the confluence area is underestimated. The modeled ice temperatures are in very good agreement with the in situ measurements from a deep borehole (110 m deep::::) in the upper ablation area.
    [Show full text]
  • The Ministry for the Future / Kim Stanley Robinson
    This book is a work of fiction. Names, characters, places, and incidents are the product of the author’s imagination or are used fictitiously. Any resemblance to actual events, locales, or persons, living or dead, is coincidental. Copyright © 2020 Kim Stanley Robinson Cover design by Lauren Panepinto Cover images by Trevillion and Shutterstock Cover copyright © 2020 by Hachette Book Group, Inc. Hachette Book Group supports the right to free expression and the value of copyright. The purpose of copyright is to encourage writers and artists to produce the creative works that enrich our culture. The scanning, uploading, and distribution of this book without permission is a theft of the author’s intellectual property. If you would like permission to use material from the book (other than for review purposes), please contact [email protected]. Thank you for your support of the author’s rights. Orbit Hachette Book Group 1290 Avenue of the Americas New York, NY 10104 www.orbitbooks.net First Edition: October 2020 Simultaneously published in Great Britain by Orbit Orbit is an imprint of Hachette Book Group. The Orbit name and logo are trademarks of Little, Brown Book Group Limited. The publisher is not responsible for websites (or their content) that are not owned by the publisher. The Hachette Speakers Bureau provides a wide range of authors for speaking events. To find out more, go to www.hachettespeakersbureau.com or call (866) 376-6591. Library of Congress Cataloging-in-Publication Data Names: Robinson, Kim Stanley, author. Title: The ministry for the future / Kim Stanley Robinson. Description: First edition.
    [Show full text]
  • Brief Communication: Collapse of 4 Mm3 of Ice from a Cirque Glacier in the Central Andes of Argentina
    The Cryosphere, 13, 997–1004, 2019 https://doi.org/10.5194/tc-13-997-2019 © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. Brief communication: Collapse of 4 Mm3 of ice from a cirque glacier in the Central Andes of Argentina Daniel Falaschi1,2, Andreas Kääb3, Frank Paul4, Takeo Tadono5, Juan Antonio Rivera2, and Luis Eduardo Lenzano1,2 1Departamento de Geografía, Facultad de Filosofía y Letras, Universidad Nacional de Cuyo, Mendoza, 5500, Argentina 2Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales, Mendoza, 5500, Argentina 3Department of Geosciences, University of Oslo, Oslo, 0371, Norway 4Department of Geography, University of Zürich, Zürich, 8057, Switzerland 5Earth Observation research Center, Japan Aerospace Exploration Agency, 2-1-1, Sengen, Tsukuba, Ibaraki 305-8505, Japan Correspondence: Daniel Falaschi ([email protected]) Received: 14 September 2018 – Discussion started: 4 October 2018 Revised: 15 February 2019 – Accepted: 11 March 2019 – Published: 26 March 2019 Abstract. Among glacier instabilities, collapses of large der of up to several 105 m3, with extraordinary event vol- parts of low-angle glaciers are a striking, exceptional phe- umes of up to several 106 m3. Yet the detachment of large nomenon. So far, merely the 2002 collapse of Kolka Glacier portions of low-angle glaciers is a much less frequent pro- in the Caucasus Mountains and the 2016 twin detachments of cess and has so far only been documented in detail for the the Aru glaciers in western Tibet have been well documented. 130 × 106 m3 avalanche released from the Kolka Glacier in Here we report on the previously unnoticed collapse of an the Russian Caucasus in 2002 (Evans et al., 2009), and the unnamed cirque glacier in the Central Andes of Argentina recent 68±2×106 and 83±2×106 m3 collapses of two ad- in March 2007.
    [Show full text]
  • The Physical Geography of the Illinois River Valley Near Peoria
    The Physical Geography of the Illinois River Valley Near Peoria An Updated Self-Conducted Field Trip using EcoCaches and GPS Technology Donald E. Bevenour East Peoria Community High School Illinois State University Copyright, 1991 Updated by: Kevin M. Emmons Morton High School Bradley University 2007 Additional Support: Martin Hobbs East Peoria Community High School Abstract THE PHYSICAL GEOGRAPHY OF THE ILLINOIS RIVER VALLEY NEAR PEORIA: AN UPDATED SELF CONDUCTED FIELD TRIP USING ECOCACHES AND GPS TECHNOLOGY This field trip has been written so that anyone can enjoy the trip without the guidance of a professional. The trip could be taken by student groups, families, or an individual; at least two people, a driver and a reader/navigator, are the recommended minimum number of persons for maximum effectiveness and safety. Subjects of discussion include the Illinois River, the Bloomington, Shelbyville, and LeRoy Moraines, various aspects of the glacial history of the area, stream processes, floodplains, natural vegetation, and human adaptations to the physical environment such as agriculture, industry, transportation, and growth of cities. Activities include riding to the top of a lookout tower, judging distance to several landmark objects, and scenic views of the physical and cultural environment. All along the trip, GPS coordinates are supplied to aid you in your navigation. Information on EcoCaches is available at http://www.ilega.org/ Why take a self-guided field trip? A self-guided field trip is an excellent way to learn more about the area in which one lives. Newcomers or visitors to an area should find it a most enlightening manner in which to personalize the new territory.
    [Show full text]
  • Decadal Changes in Glacier Parameters in the Cordillera Blanca, Peru, Derived from Remote Sensing
    Journal of Glaciology, Vol. 54, No. 186, 2008 499 Decadal changes in glacier parameters in the Cordillera Blanca, Peru, derived from remote sensing Adina E. RACOVITEANU,1,2,3 Yves ARNAUD,4 Mark W. WILLIAMS,1,2 Julio ORDON˜ EZ5 1Department of Geography, University of Colorado, Boulder, Colorado 80309-0260, USA E-mail: [email protected] 2Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80309-0450, USA 3National Snow and Ice Data Center/World Data Center for Glaciology, CIRES, University of Colorado, Boulder, Colorado 80309-0449, USA 4IRD, Great Ice, Laboratoire de Glaciologie et Ge´ophysique de l’Environnement du CNRS (associe´a` l’Universite´ Joseph Fourier–Grenoble I), 54 rue Molie`re, BP 96, 38402 Saint-Martin-d’He`res Cedex, France 5Direcion de Hidrologı´a y Recursos Hidricos, Servicio Nacional de Meteorologı´a e Hidrologı´a Jiro´n Cahuide No. 175 – Jesu´s Marı´a, Lima 11, Peru ABSTRACT. We present spatial patterns of glacier fluctuations from the Cordillera Blanca, Peru, (glacier area, terminus elevations, median elevations and hypsography) at decadal timescales derived from 1970 aerial photography, 2003 SPOT5 satellite data, Geographic Information Systems (GIS) and statistical analyses. We derived new glacier outlines from the 2003 SPOT images, and ingested them in the Global Land and Ice Measurements from Space (GLIMS) glacier database. We examined changes in glacier area on the eastern and western side of the Cordillera in relation to topographic and climate variables (temperature and precipitation). Results include (1) an estimated glacierized area of 569.6 Æ 21 km2 in 2003, (2) an overall loss in glacierized area of 22.4% from 1970 to 2003, (3) an average rise in glacier terminus elevations by 113 m and an average rise in the median elevation of glaciers by 66 m, showing a shift of ice to higher elevations, especially on the eastern side of the Cordillera, and (4) an increase in the number of glaciers, which indicates disintegration of ice bodies.
    [Show full text]
  • 1953 the Mountaineers, Inc
    fllie M®��1f�l]�r;r;m Published by Seattle, Washington..., 'December15, 1953 THE MOUNTAINEERS, INC. ITS OBJECT To explore and study the mountains, forests, and water cours­ es of the Northwest; to gather into permanent form the history and traditions of this region; to preserve by encouragement of protective legislation or otherwise, the natural beauty of North­ west America; to make expeditions into these regions in ful­ fillment of the above purposes ; to encourage a spirit of good fellowship among all lovers of out-door life. THE MOUNTAINEER LIBRARY The Club's library is one of the largest mountaineering col­ lections in the country. Books, periodicals, and pamphlets from many parts of the world are assembled for the interested reader. Mountaineering and skiing make up the largest part of the col­ lection, but travel, photography, nature study, and other allied subjects are well represented. After the period 1915 to 1926 in which The Mountaineers received books from the Bureau of Associate Mountaineering Clubs of North America, the Board of Trustees has continuously appropriated money for the main­ tenance and expansion of the library. The map collection is a valued source of information not only for planning trips and climbs, but for studying problems in other areas. NOTICE TO AUTHORS AND COMMUNICATORS Manuscripts offered for publication should be accurately typed on one side only of good, white, bond paper 81f2xll inches in size. Drawings or photographs that are intended for use as illustrations should be kept separate from the manuscript, not inserted in it, but should be transmitted at the same time.
    [Show full text]