DOCSLIB.ORG

Tillery, Chapter 22

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tillery, Chapter 22 6/29/2007 1 • Shaping Earth’s Surface Tillery, Chapter 22 2 • Weathering, Erosion, and Transportation 3 • The Earth is constantly undergoing gradual changes • The Earth is moved by weathering, erosion, and then transported to different areas on the Earth. 4 • Weathering 5 • Importance of Weathering – Participates in the rock cycle – Used in the formation of soils – Helps in the movement of rock material over the Earth’s surface. 6 •Erosion – Weathering breaks the rocks into fragments – Erosion then transports the material to new places of the Earth – This is the physical process of removing the weathered material. 7 • Transportation – The movement of eroded materials by rivers, glaciers, wind, or waves. – As material is transported the weathering and erosion process continues 8 • This famous natural bridge is an example of a landform created by the sculpturing power of weathering and erosion. It is Rainbow Bridge in the Rainbow Bridge National Monument, Utah. 9 • The piles of rocks and rock fragments around a mass of solid rock is evidence that the solid rock is slowly crumbling away. This solid rock that is crumbling to rock fragments is in the Grand Canyon, Arizona. 10 • Mechanical Weathering – The physical breaking of rock material without any change to their chemical composition – Exfoliation • Spalling off layers of rock • Caused by reduced pressure on rocks as material is removed from above. – Frost wedging • Caused as pores or cracks become filled with water and then freeze and thaw. • As the process repeats cracks and pores become larger • Eventually the rock will break off. 11 • (A)Frost wedging and (B) exfoliation are two examples of mechanical weathering, or disintegration, of solid rock. 12 • Growing trees can break, separate, and move solid rock. (A) Note how this tree has raised the sidewalk. (B) This tree is surviving by growing roots into tiny joints and cracks, which become larger as the tree grows. 13 1 6/29/2007 • Spheroidal weathering of granite. The edges and corners of an angular rock are attacked by weathering from more than one side and retreat faster than flat rock faces. The result is rounded granite boulders, which often shed partially weathered minerals in onion-like layers. 14 • Chemical Weathering – The alteration of materials by chemical reactions which do change the chemical composition of the material. –Oxidation • When oxygen reacts with minerals in rocks –Carbonation • A reaction between carbonic acid and minerals in rocks – Hydration • A reaction between water and the minerals in rocks. • Dissolves material • Water combines with the mineral to form a hydrate 15 • Limestone caves develop when slightly acidic groundwater dissolves limestone along joints and bedding planes, carrying away rock components in solution. (A) Joints and bedding planes in a limestone bluff. (B) This stream has carried away less-resistant rock components, forming a cave under the ledge. 16 • Soils 17 • Soils – Soil is a mixture of unconsolidated weathered Earth materials and humus • Humus – Decayed organic matter •Bedrock – Solid rock below the soil •Loam – A soil that is a mixture of sand, silt, and clay – Also referred to as topsoil 18 •Erosion 19 • Mass Movement – Criteria •Material –bedrock that has been weathered and eroded –debris that is carried away during the mass movement. •Rate –The speed at which the movement occurs •Type –Fall –Slip »Slump »Slide –Flow 20 – Creep • The slow downhill movement of soil down a steep slope –Fall 2 6/29/2007 • material moves in free fall down a cliff – Slip - materials moving together along a surface • Slump - Movement along a curved surface • Slide - Movement along a plane parallel to the surface. – Flow – Mass movement of a liquid 21 • The slow creep of soil is evidenced by the strange growth pattern of these trees. 22 • Running Water – Stream Channels • Move materials in 3 ways. –As dissolved material in a solution –As materials carried in suspension –As sand and larger materials rolled, bounced, and slid along with a stream • Most of the erosion that a stream does is done by the larger material that moves along with it on the stream bed. 23 • Moving streams of water carry away dissolved materials and sediments as they slowly erode the land. 24 – Stream Erosion and Deposit Features • Floodplain –The wide, level floor of the valley adjacent to a stream that has been built by the stream over time. –This is the area that the stream will begin to move into when moisture is high (flood). –A young stream usually has a v shaped flood plain whereas a mature stream has a flattened floodplain. •Delta –Where the stream empties into an ocean or a lake it loses all of its sediment carrying ability –The sediments are deposited at the mouth of the stream and form a deposit 25 • A river usually stays in its channel, but during a flood it spills over and onto the adjacent flat land called the floodplain. 26 • Three stages in the aging and development of a stream valley, (A) youth, (B) maturity, and (C) old age. 27 • The waterfall and rapids on the Yellowstone River in Wyoming indicate that the river is actively down cutting. Note the V-shaped cross-profile and lack of floodplain, characteristics of a young stream valley. 28 • (A)Delta of Nooksack River, Washington. Note the sediment-laden water, and how the land is being built outward by river sedimentation. (B) Cross section showing how a small delta might form. Large deltas are more complicated than this. 29 • Glaciers – A mass of ice on land that moves under its own weight. – Origin of Glaciers • As snow melts and refreezes it is turned into ice. • After years of repeated thawing of snow and refreezing into ice, the weight above begins to pack down the ice below. 3 6/29/2007 • The increased pressure drives out air and reforms the ice into a crystalline structure of interlocking ice crystals with a very high mass • Alpine glaciers form in high elevations • Valley glaciers form and flow downhill through a valley • Continental glaciers cover large areas of a continent. 30 • Valley glacier on Mount Logan, Yukon Territory. 31 – Glacial Erosion and Deposition • A glacier erodes material by: –Bulldozing –Abrasion –Plucking • Material; that is deposited by a glacier forms a moraine • Plucking material produces a depression called a cirque • As abrasion continues material becomes ground into fine sediment called rock flour. 32 • (A)A stream-carved mountainside before glaciation. (B) The same area after glaciation, with some of the main features of mountain glaciation labeled. 33 •Wind – Wind Erosion and Transportation • Wind abrasion is the sandblasting process that occurs as material is carried along with wind. • Deflation is the picking up of loose materials from the Earth’s surface. – Wind Deposits • Dunes –A low mound or ridge of material sediments –Form where the wind that is carrying the sediment encounters some obstruction •Loess –Very fine dust or silt that is deposited over large areas. –The source of the material is thought to be rock flour from glacier action 34 • Ventifact formation by abrasion from one or several directions. 35 • Development of Landscapes 36 • Rock Structure –Type of rock •igneous •metamorphic • Sedimentary – If they have been disturbed by faulting or folding 37 • Weathering and Erosion Process – Controlled by climate and elevation • State of Development – How effectively the landscape has been attacked by erosion processes 38 • This melting glacier (A) is the source for a stream (B) that flows through a valley in the youth stage. 4.
Load more

Recommended publications
  • Name These Glacial Features 1.) 1
    Name these Glacial Features 1.) 1.)____________________________________ 2.) 2.) ___________________________________ 3.) 3.)_____________________________________ 4.) 4.) ____________________________________ Name these types of Glaciers 5.) 5.)___________________________________________ 6.) 6.) __________________________________________ 7.) 7.) __________________________________________ 8.) 8.) __________________________________________ True or False 9.) __________ The terminus marks the farthest extent of a glacier. 10.) _________ An arête is a bow or amphitheater shape in a glacier. 11.) _________CO2 levels are higher during glacial episodes. 12.) _________ Methane Hydrate breaks down into H20. 13.) _________ Glaciers exist on every continent. 14.) _________ The Great Lakes were created by glaciation. 15.) _________ Calving is a process that creates icebergs. 16.) ________ Glacier National Park is in Alaska 17.) ________ Alaska has 100 glaciers. 18.) ________ 75% of the world’s glaciers are retreating. 19.) ________ A glacier can move forward and retreat at the same time. 20.) ________ Ogives are alternating wave crests and valleys that appear as dark and light bands of ice on glacier surfaces. 21.) ________ A drumlin field east of Rochester, New York is estimated to contain about 100 drumlins. Short Answer 22.) Give a general definition of the milankovitch cycles. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
    [Show full text]
  • 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.
    [Show full text]
  • Geotechnical and Geologic Constraints on Tsunamigenic Submarine Landslides
    GEOTECHNICAL AND GEOLOGIC CONSTRAINTS ON TSUNAMIGENIC SUBMARINE LANDSLIDES H.J. LEE U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 USA Abstract Modeling submarine-landslide-induced tsunamis requires many simplifications of the landslide process, although the real world is much more complicated. Clearly tsunami modelers cannot consider all facets, but there is value in being aware of the complications. This paper describes the many environments in which submarine landslides can occur and the triggers that typically initiate them. Earthquakes acting on continental or canyon slopes comprise probably the most common scenario but many other combinations of environments and triggers are possible. Surprisingly, many sediment-covered slopes in highly seismically active areas have not failed. A possible explanation for this phenomenon is a process called “seismic strengthening.” The existence of such a process reduces somewhat the risk of landslide tsunamis along active margins while maintaining the risk along passive margins. Once a trigger has initiated a landslide in one of the vulnerable environments, failed masses begin to move downslope. Depending upon initial density state, the masses may convert into fluid-like sediment flows or even more dilute turbidity currents. A model for quantifying the tendency to flow is provided. Finally, a case study of the landslides and landslide tsunamis that occurred in Port Valdez, Alaska, during the 1964 Great Alaska Earthquake is provided. The excellent data base, including before and after bathymetry, shows that both large rigid block motion and mobilized sediment flows can occur near each other during the same event. The intact blocks are more efficient in producing tsunamis but the sediment flow can move farther and can erode and entrain considerable bottom sediment as they progress across the seafloor.
    [Show full text]
  • 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 .
    [Show full text]
  • Mass-Wasting, Classification and Damage in Ohio C
    MASS-WASTING, CLASSIFICATION AND DAMAGE IN OHIO C. N. SAVAGE Department of Geography and Geology, Kent State University, Kent, Ohio The sudden and often spectacular free fall, slide, flow, creep or subsidence of earth materials may be costly in terms of human lives and property damage. Phenomena of this type, variously called "landslide, earthflow or subsidence" are assigned by geologists to gravity controlled movement or referred to collectively as "mass-wasting." This category also includes movement of dry or hard-frozen masses, or snow-laden debris when moved by gravity. Figure 1 illustrates some of these types of movement. This paper is intended to bring to the attention of laymen and professional men the importance and widespread occurrence of these destructive forces. A brief discussion of damage, origin, prevention and classification is presented, followed by examples in Ohio. It is hoped that the suggested classification will prove useful as an aid to the recognition of different types of mass-movement. Annually, many highways are blocked or destroyed, soils are ruined and buried in rubble, forest lands are ripped apart, and bridges, dams, buildings and other structures are wrecked or buried by landslides. Every year, especially in southern and eastern Ohio, many thousands of dollars are lost because of this type of calamity. There is scarcely a spring which does not bring reports of landslides in the local press. It seems obvious that this is a subject of grave concern to construction engineers, soils experts, conservation men and many others including the tax paying citizen. Wherever there are slopes that are steep enough, and wherever there is loose rock material, mass-wasting is a potential threat.
    [Show full text]
  • Geotechnical Investigation and Geologic Landslide Hazard Assessment, Proposed Single-Family Residential Home Site, Tax Lot No
    REDMOND GEOTECHNICAL SERVICES · Geotechnical Investigation and Geologic Landslide Hazard Assessment Proposed Single-Family Residential Home Site Tax Lot No. 300 4th Avenue and Ganong Street Oregon City (Clackamas County), Oregon for Iselin Architects Project No. 1477.003.G December 6, 2017 REDMOND .GEOT.ECHNICAL SERVICES January 6, 2017, Mr. Todd lselin lselin Architects ( 1307 Seventh Street I' Oregon City, Oregon 97045 Dear Mr. lselin: Re: Geotechnical Investigation and Geologic Landslide Hazard Assessment, Proposed Single-Family Residential Home Site, Tax Lot No. 300, 4th Avenue and Ganong Street, Oregon City (Clackamas County), Oregon . · ':,,, ''\ T ' ' Submitted herewith is our report entitled "Geotechnical Investigation and Geologic Landslide Hazard Assessment, Proposed Single-Family.Residential Home Site, Tax Lot No. 300, 4th Avenue and Ganong Street, Oregon City (Clackamas County), Oregon". The scope of our services was outlined in our formal proposal to Mr. Todd lselin dated October 24, 2016. Written authorization of our services was provided by Mr. Todd lselin on November 1, 2016. 1 During'the course of our investigation, we have kept you and/or,others advised of our schedule and preliminary finding~. We appreciate the oppori unity to assist you with this phase of the project . .. Should you have any questions regardlng'this report, please do not hesitate to call. : Sincerely, ,,, Daniel M. Redmond, P.E ., G.E. ;,."" ; '. President/Prim:ipal Engineer PO BQX 20547 • PORTL.AND, OREGON 9729~ • FAX 503/286-7176 • PHONE 503/285-0598 TABLE OF CONTENTS . ' j Page No. INTRODUCTION 1 PROJECT DESCRIPTION 1 SCOPE OF WORK 2 SITE CONDITIONS 3 Site Geology 3 Surface Conditions 3 Subsurface Soil Conditions ' 4 Groundwater ..
    [Show full text]
  • Geology 1 Questions for Chapter 19 2) ___Have Rainfall Amounts
    Geology 1 Questions for Chapter 19 2) ________ have rainfall amounts and soil moisture contents between those of true deserts and humid lands. A) Tundras B) Steppes C) Sundras D) Sabkhas 3) Most dry lands lie between ________ degrees north and south of the equator. A) 40 and 50 B) 20 and 30 C) 5 and 10 D) 0 and 5 4) Which one of the following statements concerning rock weathering is true? A) Warm temperatures and high soil moisture contents accelerate chemical weathering. B) Low temperatures and high soil moisture contents accelerate chemical weathering but inhibit mechanical weathering. C) Warm temperatures and low soil moisture contents both promote rapid rates of mechanical weathering. D) Temperature has no effect on rock weathering. 5) A ________ is an intermittent stream channel in the dry land areas of the western United States. A) rivulet B) playa C) rill D) wash 6) ________ refers to the "bouncing" mode of sand transport in a windstorm or stream. A) Saltation B) Ventifaction C) Siltation D) Deflation 7) Which one of the following will effectively limit further deflation in a given area? A) sea level B) desert pavement C) a hanging valley D) the repose level 8) Which one of the following statements is correct? A) Alluvial fans typically rim desert valleys; playas form in the lowest, interior parts of the valleys. B) Inselbergs are low, circular depressions on gently sloping pediments and bajadas. C) Playas are typically covered with gravel-sized desert pavement and loess deposits. D) Saline sediments and evaporites are common in inselbergs and pediments of desert landscapes.
    [Show full text]
  • Chapter 8. Glacioaeolian Processes, Sediments, and Landforms
    CHAPTER GLACIOAEOLIAN PROCESSES, SEDIMENTS, AND LANDFORMS 8 E. Derbyshire1 and L.A. Owen2 1Royal Holloway, University of London, Surrey, United Kingdom, 2University of Cincinnati, Cincinnati, OH, United States 8.1 INTRODUCTION The frequently strong association of aeolian processes with present and former glaciation has been recognized for over 80 years from field observations (Hogbom, 1923). Bullard and Austin (2011) point out that the interaction between glacial dynamics, glaciofluvial, and aeolian transport in proglacial landscapes plays an important role, not only in local environmental systems, but also in the global context by affecting the amount of dust generated and transported. Moreover, glacial outwash plains have been cited as a significant source of dust in the Southern Hemisphere (Sugden et al., 2009) and must also have been important dust sources in the northern hemisphere (Bullard and Austin, 2011). Cold climate aeolian processes and landforms have been widely acknowledged in proglacial and paraglacial geomorphology (e.g., Ballantyne, 2002; Seppa¨la¨, 2004). However, relatively little work has been undertaken on glacioaeolian processes, sediments, and landforms compared to other glacial systems. The ISI Web of Science does not even provide one reference to the term ‘glacioaeolian’ and Google Scholar provides a mere 61 references. Variations on the spell- ing of glacioaeolian, including glacioeolian, glacio-aeolian, glacio aeolian, and glacio-eolian yield less than 40 citations. Even the international journal Aeolian Research provides only one reference to the term glacioaeolian. A search of glacial aeolian yields 924 and 35,300 citations in the ISI Web of Science and Google Scholar, respectively. However, this includes reference to aeolian sedi- ments that are not of glacial origin, but were deposited during a glacial event.
    [Show full text]
  • Chapter 9: Weathering and Erosion
    530-S1-MSS05_G6_IN 8/17/04 3:33 PM Page 258 Academic Standard —3: Students collect and organize data to identify relationships between physical objects, events, and processes. They use logical reasoning to question their own ideas as new information challenges their conceptions of the natural world. Also covers: Academic Standard 2 (Detailed standards begin on page IN8.) Weathering and Erosion What happened to his face? sections Well, how would you feel if wind, sand, and 1 Weathering and Soil Formation rain blew in your face for over 5,000 years? Lab Classifying Soils Don’t forget the blistering sun and nightly chill! Would you feel weathered and torn? 2 Erosion of Earth’s Surface Two processes help shape Earth’s surface— Lab Measuring Soil Erosion weathering and erosion. Virtual Lab How are Earth’s materials broken down? Science Journal Describe a place—a home, a park, river, or mountain. What would happen in a year, a hundred years, even 5,000 years? 258 Carmen Redondo/CORBIS 530-S1-MSS05_G6_IN 8/17/04 3:33 PM Page 259 Start-Up Activities Weathering and Erosion Make the following Foldable to compare and contrast weath- Water’s Force ering and erosion. The Grand Canyon is 446 km long, up to 29 km wide, and up to 1,829 m deep. The water STEP 1 Fold one sheet of paper lengthwise. of the Colorado River carved the canyon out of rock by wearing away particles and carry- ing them away for millions of years. Over time, erosion has shaped and reshaped STEP 2 Fold into thirds.
    [Show full text]
  • California Glacial Till and the Glaciated Valley Landsystem: Engineering Classification and Properties
    San Jose State University SJSU ScholarWorks Master's Theses Master's Theses and Graduate Research Fall 2013 California Glacial Till and the Glaciated Valley Landsystem: Engineering Classification and Properties Matthew Mark Lattin San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/etd_theses Recommended Citation Lattin, Matthew Mark, "California Glacial Till and the Glaciated Valley Landsystem: Engineering Classification and Properties" (2013). Master's Theses. 4392. DOI: https://doi.org/10.31979/etd.npfw-e78s https://scholarworks.sjsu.edu/etd_theses/4392 This Thesis is brought to you for free and open access by the Master's Theses and Graduate Research at SJSU ScholarWorks. It has been accepted for inclusion in Master's Theses by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. CALIFORNIA GLACIAL TILL AND THE GLACIATED VALLEY LANDSYSTEM: ENGINEERING CLASSIFICATION AND PROPERTIES A Thesis Presented to The Faculty of the Department of Civil and Environmental Engineering San José State University In Partial Fulfillment of the Requirements for the Degree Master of Civil Engineering by Matthew M. Lattin December 2013 © 2013 Matthew M. Lattin ALL RIGHTS RESERVED The Designated Thesis Committee Approves the Thesis Titled CALIFORNIA GLACIAL TILL AND THE GLACIATED VALLEY LANDSYSTEM: ENGINEERING CLASSIFICATION AND PROPERTIES by Matthew M. Lattin APPROVED FOR THE DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING SAN JOSÉ STATE UNIVERSITY December 2013 Dr. Laura Sullivan-Green Department of Civil and Environmental Engineering Dr. Kurt McMullin Department of Civil and Environmental Engineering Martin M. McIlroy, P.G., P.E. Vice President, Taber Consultants ABSTRACT CALIFORNIA GLACIAL TILL AND THE GLACIATED VALLEY LANDSYSTEM: ENGINEERING CLASSIFICATION AND PROPERTIES by Matthew M.
    [Show full text]
  • Coastal Impressions
    CoastalA Photographic Journey Impressions along Alaska’s Gulf Coast i Exhibit compiled by Susan Saupe, Mandy Lindeberg, and Dr. G. Carl Schoch Photographs selected by Mandy Lindeberg and Susan Saupe Photo editing and printing by Mandy Lindeberg Photo annotations by Dr. G. Carl Schoch Booklet prepared by Susan Saupe with design services by Fathom Graphics, Anchorage Photo mounting and laminating by Digital Blueprint, Anchorage Digital Maps for Exhibit and Booklet prepared by GRS, Anchorage January 2012 Second Printing November 2012 Exhibit sponsored by Cook Inlet RCAC and developed in partnership with NMFS AFSC Auke Bay Laboratories, and Alaska ShoreZone Program. ii Acknowledgements This exhibit would not exist without the vision of Dr. John Harper of Coastal and Ocean Resources, Inc. (CORI), whose role in the development and continued refinement of ShoreZone has directly led to habitat data and imagery acquisition for every inch of coastline between Oregon and the Alaska Peninsula. Equally important, Mary Morris of Archipelago Marine Research, Inc. (ARCHI) developed the biological component to ShoreZone, participated in many of the Alaskan surveys, and leads the biological habitat mapping efforts. CORI and ARCHI have provided experienced team members for aerial survey navigation, imaging, geomorphic and biological narration, and habitat mapping, each of whom contributed significantly to the overall success of the program. We gratefully acknowledge the support of organizations working in partnership for the Alaska ShoreZone effort, including over 40 local, state, and federal agencies and organizations. A full list of partners can be seen at www.shorezone.org. Several organizations stand out as being the earliest or staunchest supporters of a comprehensive Alaskan ShoreZone program.
    [Show full text]
  • Alphabetical Glossary of Geomorphology
    International Association of Geomorphologists Association Internationale des Géomorphologues ALPHABETICAL GLOSSARY OF GEOMORPHOLOGY Version 1.0 Prepared for the IAG by Andrew Goudie, July 2014 Suggestions for corrections and additions should be sent to [email protected] Abime A vertical shaft in karstic (limestone) areas Ablation The wasting and removal of material from a rock surface by weathering and erosion, or more specifically from a glacier surface by melting, erosion or calving Ablation till Glacial debris deposited when a glacier melts away Abrasion The mechanical wearing down, scraping, or grinding away of a rock surface by friction, ensuing from collision between particles during their transport in wind, ice, running water, waves or gravity. It is sometimes termed corrosion Abrasion notch An elongated cliff-base hollow (typically 1-2 m high and up to 3m recessed) cut out by abrasion, usually where breaking waves are armed with rock fragments Abrasion platform A smooth, seaward-sloping surface formed by abrasion, extending across a rocky shore and often continuing below low tide level as a broad, very gently sloping surface (plain of marine erosion) formed by long-continued abrasion Abrasion ramp A smooth, seaward-sloping segment formed by abrasion on a rocky shore, usually a few meters wide, close to the cliff base Abyss Either a deep part of the ocean or a ravine or deep gorge Abyssal hill A small hill that rises from the floor of an abyssal plain. They are the most abundant geomorphic structures on the planet Earth, covering more than 30% of the ocean floors Abyssal plain An underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m.
    [Show full text]