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Introduction to Geological Process in Illinois Glacial
INTRODUCTION TO GEOLOGICAL PROCESS IN ILLINOIS GLACIAL PROCESSES AND LANDSCAPES GLACIERS A glacier is a flowing mass of ice. This simple definition covers many possibilities. Glaciers are large, but they can range in size from continent covering (like that occupying Antarctica) to barely covering the head of a mountain valley (like those found in the Grand Tetons and Glacier National Park). No glaciers are found in Illinois; however, they had a profound effect shaping our landscape. More on glaciers: http://www.physicalgeography.net/fundamentals/10ad.html Formation and Movement of Glacial Ice When placed under the appropriate conditions of pressure and temperature, ice will flow. In a glacier, this occurs when the ice is at least 20-50 meters (60 to 150 feet) thick. The buildup results from the accumulation of snow over the course of many years and requires that at least some of each winter’s snowfall does not melt over the following summer. The portion of the glacier where there is a net accumulation of ice and snow from year to year is called the zone of accumulation. The normal rate of glacial movement is a few feet per day, although some glaciers can surge at tens of feet per day. The ice moves by flowing and basal slip. Flow occurs through “plastic deformation” in which the solid ice deforms without melting or breaking. Plastic deformation is much like the slow flow of Silly Putty and can only occur when the ice is under pressure from above. The accumulation of meltwater underneath the glacier can act as a lubricant which allows the ice to slide on its base. -
LESSON PLAN #2: Creating the Driftless: a Study in Glacial Movement
LESSON PLAN #2: Creating the Driftless: A Study in Glacial Movement Overview: Glaciers are moving mountains of ice. They move like slow rivers and actually flow. Gravity and the sheer weight of the ice mass are the causes of glacial motion. Ice is softer than rock so is easily deformed by the pressure of its own weight. Movement at the underside of a glacier is slower than movement along the top. Glaciers retreat and advance, depending on snow accumulation, evaporation, or ice melt. Glaciers transport materials as they move. They also sculpt and carve the land beneath them. A glacier’s weight combined with gradual movement, reshapes the land over hundreds to thousands of years. The ice erodes the land surface and carries broken rock and soil debris far from their original places, resulting in some interesting glacial landforms. Due to the nature of land formations, some areas in northwest Illinois along with southwest Wisconsin, southeast Minnesota, and northeast Iowa were missed by the four glaciers that at different times covered the rest of these states. This area not covered by glaciers and the resulting glacial drift is called “The Driftless Area.” This Driftless Area is rich with historic and geological information free from glacial impact. Duration: 30 minutes Subject Areas: Earth Science, Physical Science, Geography Standards Addressed: 4-PS3-1 4-PS3-4 5-ESS3-1 MS-ESS3-1 MS-ESS2-5 MS-ESS2-3 MS-ESS1-C MS-PS2-4 Objectives: Gain an understanding of how glaciers move Understand the types of landforms created from glacial movement and glacial scraping Define what is meant by The Driftless Area Teacher Background: Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses. -
Gradient Approach to INSAR Modelling of Glacial Dynamics and Morphology
Gradient approach to INSAR modelling of glacial dynamics and morphology A. I. Sharov Institute of Digital Image Processing, Joanneum Research, Wastiangasse 6, A - 8010 Graz, Austria E-mail: [email protected] Keywords: differential interferometry, phase gradient, change detection, glacier velocity, geodetic survey ABSTRACT: This paper describes the development and testing of an original gradient approach (GINSAR) to the reconstruction of glacial morphology and ice motion estimation from the interferometric phase gradient that does not involve the procedure of interferometric phase unwrapping, thus excluding areal error propagation and improving the modelling accuracy. The global and stringent GINSAR algorithm is applicable to unsupervised glacier change detection, ice motion estimation and glacier mass balance measurement at regional scale. Experimental studies and field surveys proved its efficacy and robustness. Some algorithmic singularities and limitations are discussed. 1 INTRODUCTION detect and to measure quite small glacier motions and ice deformations in the centimetre range from There is a close interrelation between glacier motion spaceborne SAR interferograms with a nominal and glacial topography. Irregularities in the glacier ground resolution of several tens of meters. Accurate width, thickness, slope or direction alter the reconstruction of the configuration and external character of ice flow. On the other hand, glacial structure of the glacier surface from INSAR data is topography is dynamically supported by the moving also possible. Differential interferometry (DINSAR) ice (Fatland & Lingle 1998). Both, glacier dynamic based on differencing between two different SAR quantities and topographic variables are essential interferograms of the same glacier allows the parameters for studying the glacier mass balance and impacts of glacial topography and surface monitoring actual and potential glacier changes. -
Glacial Processes and Landforms
Glacial Processes and Landforms I. INTRODUCTION A. Definitions 1. Glacier- a thick mass of flowing/moving ice a. glaciers originate on land from the compaction and recrystallization of snow, thus are generated in areas favored by a climate in which seasonal snow accumulation is greater than seasonal melting (1) polar regions (2) high altitude/mountainous regions 2. Snowfield- a region that displays a net annual accumulation of snow a. snowline- imaginary line defining the limits of snow accumulation in a snowfield. (1) above which continuous, positive snow cover 3. Water balance- in general the hydrologic cycle involves water evaporated from sea, carried to land, precipitation, water carried back to sea via rivers and underground a. water becomes locked up or frozen in glaciers, thus temporarily removed from the hydrologic cycle (1) thus in times of great accumulation of glacial ice, sea level would tend to be lower than in times of no glacial ice. II. FORMATION OF GLACIAL ICE A. Process: Formation of glacial ice: snow crystallizes from atmospheric moisture, accumulates on surface of earth. As snow is accumulated, snow crystals become compacted > in density, with air forced out of pack. 1. Snow accumulates seasonally: delicate frozen crystal structure a. Low density: ~0.1 gm/cu. cm b. Transformation: snow compaction, pressure solution of flakes, percolation of meltwater c. Freezing and recrystallization > density 2. Firn- compacted snow with D = 0.5D water a. With further compaction, D >, firn ---------ice. b. Crystal fabrics oriented and aligned under weight of compaction 3. Ice: compacted firn with density approaching 1 gm/cu. cm a. -
Glaciers and Glaciation
M18_TARB6927_09_SE_C18.QXD 1/16/07 4:41 PM Page 482 M18_TARB6927_09_SE_C18.QXD 1/16/07 4:41 PM Page 483 Glaciers and Glaciation CHAPTER 18 A small boat nears the seaward margin of an Antarctic glacier. (Photo by Sergio Pitamitz/ CORBIS) 483 M18_TARB6927_09_SE_C18.QXD 1/16/07 4:41 PM Page 484 limate has a strong influence on the nature and intensity of Earth’s external processes. This fact is dramatically illustrated in this chapter because the C existence and extent of glaciers is largely controlled by Earth’s changing climate. Like the running water and groundwater that were the focus of the preceding two chap- ters, glaciers represent a significant erosional process. These moving masses of ice are re- sponsible for creating many unique landforms and are part of an important link in the rock cycle in which the products of weathering are transported and deposited as sediment. Today glaciers cover nearly 10 percent of Earth’s land surface; however, in the recent ge- ologic past, ice sheets were three times more extensive, covering vast areas with ice thou- sands of meters thick. Many regions still bear the mark of these glaciers (Figure 18.1). The basic character of such diverse places as the Alps, Cape Cod, and Yosemite Valley was fashioned by now vanished masses of glacial ice. Moreover, Long Island, the Great Lakes, and the fiords of Norway and Alaska all owe their existence to glaciers. Glaciers, of course, are not just a phenomenon of the geologic past. As you will see, they are still sculpting and depositing debris in many regions today. -
Short-Lived Ice Speed-Up and Plume Water Flow Captured by a VTOL UAV
Remote Sensing of Environment 217 (2018) 389–399 Contents lists available at ScienceDirect Remote Sensing of Environment journal homepage: www.elsevier.com/locate/rse Short-lived ice speed-up and plume water flow captured by a VTOL UAV give insights into subglacial hydrological system of Bowdoin Glacier T Guillaume Jouveta,*, Yvo Weidmanna, Marin Kneiba, Martin Deterta, Julien Seguinota,c, Daiki Sakakibarab, Shin Sugiyamab a ETHZ, VAW, Zurich, Switzerland b Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan c Arctic Research Center, Hokkaido University, Sapporo, Japan ARTICLE INFO ABSTRACT Keywords: The subglacial hydrology of tidewater glaciers is a key but poorly understood component of the complex ice- Unmanned Aerial Vehicle ocean system, which affects sea level rise. As it is extremely difficult to access the interior of a glacier, our Structure-from-Motion photogrammetry knowledge relies mostly on the observation of input variables such as air temperature, and output variables such Feature-tracking as the ice flow velocities reflecting the englacial water pressure, and the dynamics of plumes reflecting the Particle Image Velocimetry discharge of meltwater into the ocean. In this study we use a cost-effective Vertical Take-Off and Landing (VTOL) Calving glaciers Unmanned Aerial Vehicle (UAV) to monitor the daily movements of Bowdoin Glacier, north-west Greenland, and Meltwater plume Ice flow the dynamics of its main plume. Using Structure-from-Motion photogrammetry and feature-tracking techniques, we obtained 22 high-resolution ortho-images and 19 velocity fields at the calving front for 12 days in July 2016. Our results show a two-day-long speed-up event (up to 170%) – caused by an increase in buoyant subglacial forces – with a strong spatial variability revealing that enhanced acceleration is an indication of shallow bedrock. -
The Formation of Eskers
Proceedings of the Iowa Academy of Science Volume 21 Annual Issue Article 31 1914 The Formation of Eskers Arthur C. Trowbridge State University of Iowa Let us know how access to this document benefits ouy Copyright ©1914 Iowa Academy of Science, Inc. Follow this and additional works at: https://scholarworks.uni.edu/pias Recommended Citation Trowbridge, Arthur C. (1914) "The Formation of Eskers," Proceedings of the Iowa Academy of Science, 21(1), 211-218. Available at: https://scholarworks.uni.edu/pias/vol21/iss1/31 This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. Trowbridge: The Formation of Eskers THE FORMATION OF ESKERS. 211 -· THE FORMATION OF ESKERS. .ARTHUR C. TROWBRIDGE. Ever since work has been in progress in glaciated regions, long, nar -row, winding, steep-sided, conspicuous ridges of gravel and sand have been recognized by geologists. They are best developed and were first recognized as distinct phases of drift in Sweden, where they are called Osar. The term Osar has the priority over other terms, but in this country, probably for phonic reasons, the Irish term Esker has come into use. With apologies to Sweden, Esker will be used in the present paper. Other terms which have been applied to these ridges in various parts of the world are serpent-kames, serpentine kames, horsebacks, whalebacks, hogbacks, ridges, windrows, turnpikes, back furrows, ridge • furrows, morriners, and Indian roads . -
A Glacier Runs Through It: Effects of Late Wisconsinan Glaciation on Stream Drainage Near the Terminal Moraine Boundary in North Central Pennsylvania
University of Pennsylvania ScholarlyCommons Master of Environmental Studies Capstone Department of Earth and Environmental Projects Science May 2008 A Glacier Runs Through It: Effects of Late Wisconsinan Glaciation on Stream Drainage Near the Terminal Moraine Boundary in North Central Pennsylvania Krista Heinlen University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/mes_capstones Heinlen, Krista, "A Glacier Runs Through It: Effects of Late Wisconsinan Glaciation on Stream Drainage Near the Terminal Moraine Boundary in North Central Pennsylvania" (2008). Master of Environmental Studies Capstone Projects. 21. https://repository.upenn.edu/mes_capstones/21 Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Master of Environmental Studies 2007. This paper is posted at ScholarlyCommons. https://repository.upenn.edu/mes_capstones/21 For more information, please contact [email protected]. A Glacier Runs Through It: Effects of Late Wisconsinan Glaciation on Stream Drainage Near the Terminal Moraine Boundary in North Central Pennsylvania Abstract Stream morphology in north central Pennsylvania has been influenced yb the passage of multiple glaciers during the Quaternary period, and most recently by the Late Wisconsinan ice sheet which began to recede just 10,000 years ago. While glaciers can take a heavy erosive toll on the landscape, the Late Wisconsinan and previous glaciers stopped when they reached Pennsylvania, and as such were not as thick and did not cover the ground as long as in regions to the north. This paper examines current morphology in an area along the north central part of the state that contains both glaciated and non-glaciated regions. -
A Glacial-Process Model: the Role of Spatial and Temporal Variations in Glacier Thermal Regime
A glacial-process model: The role of spatial and temporal variations in glacier thermal regime H. D. MOOERS Department of Geology and Geophysics, 108 Pillsbury Hall and Limnological Research Center, 220 Pillsbury Hall University of Minnesota, Minneapolis, Minnesota 55455 ABSTRACT ucts of glaciation also provide important infor- there are several distinct thermal environments, mation on the physical nature and dynamics of each of which has a dominant set of erosional or Glacial landform assemblages associated the ice. Moran (1971), Clayton and Moran depositional processes. The position and charac- with the retreat of the Rainy and Superior (1974, 1977), and Moran and others (1980) teristics of these zones also vary with time during lobes of the Laurentide Ice Sheet in Minne- used field relationships to reconstruct the glacio- glacial advance and retreat. sota provide a record of spatial and temporal logical conditions necessary for the formation of The glacial sediments and landforms in Min- variations in glaciological processes. The large-scale glaciotectonic features, and they pro- nesota associated with the late Wisconsin St. two lobes advanced contemporaneously to vided a major advance in the understanding of Croix Phase provide a detailed record of the their maximum at the St. Croix moraine. The ice-marginal glacial processes. Mathews (1974) maximum and recessional events of the Superior portion of the moraine formed by the Rainy reconstructed longitudinal profiles of the Lau- and Rainy lobes. During recession, each major lobe is characterized by large frontal outwash rentide Ice Sheet and changed the way subse- lobe broke up into multiple, smaller sublobes, plains, broad ice-stagnation topography, gla- quent researchers have viewed ice lobes along its dynamically independent from one another. -
Glacial Erosion Assessment
Glacial Erosion Assessment March 2011 Prepared by: B. Hallet NWMO DGR-TR-2011-18 Glacial Erosion Assessment March 2011 Prepared by: B. Hallet NWMO DGR-TR-2011-18 Glacial Erosion Assessment - ii - March 2011 THIS PAGE HAS BEEN LEFT BLANK INTENTIONALLY Glacial Erosion Assessment - iii - March 2011 Document History Title: Glacial Erosion Assessment Report Number: NWMO DGR-TR-2011-18 Revision: R000 Date: March 2011 AECOM Canada Ltd. Prepared by: B. Hallet (University of Washington) Reviewed by: W.R. Peltier (University of Toronto), R. Frizzell Approved by: R.E.J. Leech Nuclear Waste Management Organization Reviewed by: M. Jensen Accepted by: M. Jensen Glacial Erosion Assessment - iv - March 2011 THIS PAGE HAS BEEN LEFT BLANK INTENTIONALLY Glacial Erosion Assessment - v - March 2011 EXECUTIVE SUMMARY This report examines the phenomenon of glacial erosion as it is a consideration in the safety and performance of Ontario Power Generation’s proposed Deep Geological Repository for low and intermediate level radioactive waste beneath the Bruce nuclear site located in the Municipality of Kincardine, Ontario. The report reviews currently available knowledge, insights and data that provide a basis for assessing the maximum amount of glacial erosion likely to occur during the next glacial cycle at the Bruce nuclear site. As in the Long-Term Climate Change Study of Peltier (2011), the prudent assumption will be made that the region will be subjected to major glacial cycles, recurring every ~100,000 years, much as they have over the last ~900,000 years. Accordingly, the geologic data and reconstructions of the Laurentide ice-sheet (LIS) during the last major glaciation are used to assess the amount of erosion expected over the next glacial cycle. -
The Use of Simple Physical Models in Seismology and Glaciology
The Use of Simple Physical Models in Seismology and Glaciology A dissertation presented by Victor Chen Tsai to The Department of Earth and Planetary Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the subject of Earth and Planetary Sciences Harvard University Cambridge, Massachusetts May 2009 c 2009 - Victor Chen Tsai All rights reserved. Dissertation Advisor: Author: Professor James R. Rice Victor Chen Tsai The Use of Simple Physical Models in Seismology and Glaciology Abstract In this thesis, I present results that span a number of largely independent topics within the broader disciplines of seismology and glaciology. The problems addressed in each section are quite different, but the approach taken throughout is to use simplified models to attempt to understand more complex physical systems. In these models, use of solid and fluid mechanics are important elements, though in some cases the mechanics are greatly simplified so that progress can be more easily made. The five primary results of this thesis can be summarized as follows: (1) Glacial earthquakes, which were known as enigmatic M 5 seismic sources prior to the work presented S ∼ here, are now characterized and understood as being due to coupling of gravitational energy from large calving icebergs into the solid Earth. (2) Rapid drainage events from meltwater lakes on Greenland can be understood in terms of models of turbulent hydraulic fracture at the base of the Greenland Ice Sheet. (3) The form of ‘lake star’ melt patterns on lake ice can be quantitatively modeled as arising from flow of warm water through slushy ice. -
Glaciers of the Canadian Rockies
Glaciers of North America— GLACIERS OF CANADA GLACIERS OF THE CANADIAN ROCKIES By C. SIMON L. OMMANNEY SATELLITE IMAGE ATLAS OF GLACIERS OF THE WORLD Edited by RICHARD S. WILLIAMS, Jr., and JANE G. FERRIGNO U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1386–J–1 The Rocky Mountains of Canada include four distinct ranges from the U.S. border to northern British Columbia: Border, Continental, Hart, and Muskwa Ranges. They cover about 170,000 km2, are about 150 km wide, and have an estimated glacierized area of 38,613 km2. Mount Robson, at 3,954 m, is the highest peak. Glaciers range in size from ice fields, with major outlet glaciers, to glacierets. Small mountain-type glaciers in cirques, niches, and ice aprons are scattered throughout the ranges. Ice-cored moraines and rock glaciers are also common CONTENTS Page Abstract ---------------------------------------------------------------------------- J199 Introduction----------------------------------------------------------------------- 199 FIGURE 1. Mountain ranges of the southern Rocky Mountains------------ 201 2. Mountain ranges of the northern Rocky Mountains ------------ 202 3. Oblique aerial photograph of Mount Assiniboine, Banff National Park, Rocky Mountains----------------------------- 203 4. Sketch map showing glaciers of the Canadian Rocky Mountains -------------------------------------------- 204 5. Photograph of the Victoria Glacier, Rocky Mountains, Alberta, in August 1973 -------------------------------------- 209 TABLE 1. Named glaciers of the Rocky Mountains cited in the chapter