Human activities such as undercutting the base of the slope, adding weight to the upper part of the slope by building large structures, removing vegetation, and saturating the ground with water increase the risks of mass wasting. Most mass wasting events are actually caused by the natural processes of erosion as well as precipitation and infiltration of water. Formerly, the term mass wasting referred to a variety of processes by which large masses of crustal materials are. Mass wasting erosion features exceeding 50 m 2 in a map view were observed in sandstone bedrock at four locations along the coast at tusan. Although failures are inevitable in a region with steep slopes, larger ones happen less frequently than smaller ones, and the consequences vary depending on the downslope conditions, such as the presence of people, buildings, roads, or fishbearing streams. Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, sand, regolith, and rock move downslope typically as a solid, continuous or discontinuous mass, largely under the force of gravity, frequently with characteristics of a flow as in debris flows and mudflows.
Fall is the fastest type of mass wasting where rock falls freely. Three major types of mass wasting are classified by the type of downslope movement. Hughes, 2003 gros ventre landslide, wyoming there are many types of slope failure. Its important to classify slope failures so that we can understand what causes them and learn how to mitigate their effects.
Types and causes of mass wastingmass movement of rocks. If the surficial and sometimes subsurface geology is unstable, mass wasting often occurs. To a geologist, earths landscape is an ephemeral surface expression of the more. Slope failure, also referred to as mass wasting, is the downslope movement of rock debris and soil in response to gravitational stresses. Rapid flow of mass wasting a rapid dorm of mass wasting that involves the flow of soil and regolith with water tends to occur more frequently in semiarid mountainous regions sudden rainfall or snowmelt washes large quantities of sediment into rivers. Weathering, mass wasting, erosion, and landscape change. Formerly, the term mass wasting referred to a variety of processes by which large masses of crustal materials are moved by gravity from one place to.
Mass movements affect the following elements of the environment. Mass movement, also called mass wasting, bulk movements of soil and rock debris down slopes in response to the pull of gravity, or the rapid or gradual sinking of the earths ground surface in a predominantly vertical direction. Tectonics, local geology, and weathering intensity all contribute to the generation of materials susceptible for movement. Start a free trial of quizlet plus by thanksgiving lock in 50% off all year try it free. Formerly, the term mass wasting referred to a variety of processes by which large masses of crustal materials are moved by gravity from one place to another. The definition excludes material transported downslope by streams, winds, or glaciers. It could be rapid snowmelt, intense rainfall, earthquake shaking, volcanic eruption, storm waves, rapidstream erosion, or human activities, such as grading a new road. That includes all earth materials, rock and regolith. Slope failure landslides, mudflows, earthflows, and other mass wasting processes read chapter 5 in your textbook keller, 2000 geol g406 environmental geology s. Erosion, transportation, and deposition while landslides are a normal part of erosion and surface processes, they can be very destructive to life and property. This is particularly dangerous when the underlying rock layers slope towards the area figure 8.
Careful evaluation of slopes and geologic evidence can help prevent consequences of mass wasting. Mass movements are an important part of the erosional process, as it moves material from higher elevations to lower elevations where. Processes of downslope movement of surficial earth materials under the pull of gravity are collectively termed mass wasting. Erosion is the removal of sediments by natural processes e. Gravity pulls rocks, soils and debris on a downward.
Gravity pulls rocks, soils and debris on a downward slope naturally without any chemical change. Information on these locations, dimensions, and key characteristics of the features are presented in table 4, and shown in photographs in fig. Imprints of volcanic, erosional, depositional, tectonic and masswasting processes in the morphology of santa maria insular shelf article pdf available in marine geology. A little bit of water helps to hold grains of sand or soil together. Varieties of these are called earthflows, mudflows, and debris avalanches.
Types of mass wasting include creep, slides, flows, topples, and falls, each with its. The national map of mass wasting activity shows areas with greatest potential for. Mass movements and mass movement processes tulane university. The rate of movement how quickly the material moved. Mass wasting is the downhill movement of rock and soil material due to gravity. California state university, long beach 1250 bellflower boulevard, long beach, california 90840. Mass wasting, which is sometimes called mass movement or slope movement, is defined as the large movement of rock, soil and debris downward due to the force of gravity. Weathering, disintegration or alteration of rock in its natural or original position at or near the earths surface through physical, chemical, and biological processes induced or modified by wind, water, and climate. Prevention of mass wasting human activities such as undercutting the base of the slope, adding weight to the upper part of the slope by building large structures, removing vegetation, and saturating the ground with water increase the risks of mass wasting.
In recent years, the definition of mass movement has been enlarged to include mass wasting processes or natural erosion and the slow submerging of the earths ground surface. Sep 12, 2019 see also see more ideas about geology, natural disasters and department of. The various kinds of down hill movement of coherent masses of rock debris occurring under the pull of gravity are collectively known as mass movement or mass wasting. If people dig into the base of a slope to create a road or a homesite, the slope may become unstable and move downhill. Slope failure, also referred to as mass wasting, is the. In situations where we cant predict, prevent, or delay masswasting hazards, some effective measures can be taken to minimize the associated risk.
Deposition is the process by which weathered and eroded materials. Mass movements and mass movement processes mass movements and their human impacts mass movement is defined as the down slope movement of rock and regolith near the earths surface mainly due to the force of gravity. Research geological sciences department california state. Overview of the effects of mass wasting on the natural. When earth material moves down a hillside as a fluidlike mass, it is called an earthflow.
The other side of the coin is that we must be careful to avoid activities that could make mass wasting more likely. As terrain becomes more mountainous, the hazard increases in developed nations impacts of masswasting or landslides can result in millions of dollars of damage with some deaths in less developed nations damage is more extensive because of population density, lack of stringent zoning laws. Erosion, driven by gravity, is the inevitable response to that uplift, and various types of erosion, including mass wasting, have created slopes in the uplifted regions. Mass movement causes regolith and rock to move downslope where sooner. Slope instability and mass wasting at fargo, north dakota. Mass movement or mass wasting is a natural phenomenon initiated by the force that attracts any object with mass.
This is one of the central concepts of this course. Increased water content within the slope is the most common masswasting. These flows typically occur in humid areas on steep slopes with thick. Mass wasting is the downslope translation of weathered and bedrock materials under the influence of gravity. The three criteria used to describe slope failures are. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Oct 11, 2015 3 dollar tree diy farmhouse rustic decor dollar tree diy home decor duration. If your web browser has the proper plugin installed, clicking on the pdf will bring the file into your web browser from which you can then print the notes. And, can you mentally image how weathering, mass wasting, and erosion would operated in such diverse landscapes. Increased water content within the slope is the most.
Understanding the geology is critical to understanding mass wasting. Delaying mass wasting is a worthy endeavor, of course, because during the time that the measures are still effective they can save lives and reduce damage to property and infrastructure. Slope the steeper the slope, the downslope pull angle of repose steepest angle at which a pile of unconsolidated grains remains stable. Largescale carbonate submarine masswasting along the. Mass wasting is the transfer or movement of rock or soil down slope primarily by gravity. Knowledge about the relationships between local geology and mass movement. Start a free trial of quizlet plus by thanksgiving. Geologically, a landslide is a general term for mass wasting that involves fastmoving geologic material. Environmental geology gly 50 gly 550 homework 3 mass wasting complete the following exercises.
Gravity the force of gravity provides the energy that causes material to move downhill. Masswasting is a unique geomorphological process destabilizing the surface rocks and soil mass. The general term landslide is used to describe all rapid forms of mass wasting. Environmental geology ge ol 406506 module 4 landslides, slope failure, and other mass wasting processes. It is a significant part of the process of erosion because it moves material from high elevations to lower elevations. Worst case scenario mass wasting coupled with flooding present the worst of geologic settings in our region. Wasting is the movement of rock and soil down a slope due to the force of gravity. The features are shown in a map view and a crosssection view in fig. Mass wasting is also known as slope movement or mass movement. It has a strong emphasis on examples from western canada, especially british. Mass wasting, sometimes called mass movement, is the downward movement by gravity of rock, regolith loose, weathered rock andor soil on the sloped top layers of the earths surface.
I a which material will have a steeper angle of repose, a dry granular material or the same material damp. The pdf portable document format versions of the lecture notes are optimized for printing. It can be described as the potency by which certain landforms like soil. Factors that control slope stability mass wasting happens because tectonic processes have created uplift. Definition the bulk movement of weathered and broken rock. Mass wasting is the geologic term used to describe the natural downward movement of landforms e. This material is offten poorly sorted, only crudely bedded if at all, and can. Physical geology is a comprehensive introductory text on the physical aspects of geology, including rocks and minerals, plate tectonics, earthquakes, volcanoes, glaciation, groundwater, streams, coasts, mass wasting, climate change, planetary geology and much more.
An introduction to geology free textbook for college. Mass wasting is the downslope movement of masses of earth materials. Mass wasting comes in a great variety of forms largely dependent on the character of the material moving, and the mechanisms of movement. Chapter 15 mass wasting physical geology 2nd edition. Proper design during construction projects can eliminate the potential for increased mass wasting. Flow is when unconsolidated sediments comes down the slope and it flows. A search of the document itself finds only three standards related to weathering, mass wasting, erosion, and landscape change. We cant always predict or prevent the occurrence of masswasting events, a knowledge of the processes and their relationship to local geology can lead to intelligent planning that will help reduce losses of life and property controls and triggers of mass wasting important factors include. Mass wasting processes read chapter 5 in your textbook keller, 2000 geol g406 environmental geology s. The term landslide is often used as a synonym for mass wasting, but mass wasting is a much broader term referring to all movement downslope. During the weathering process the translocation of disintegrated or altered. Apr 10, 2019 mass wasting, sometimes called mass movement, is the downward movement by gravity of rock, regolith loose, weathered rock andor soil on the sloped top layers of the earths surface. Introduction mass wasting the downslope movement of.
The types of movement, falls, slides, and flows, will be covered in this module. There are several factors that increase the chance that a landslide will occur. Yet people have been allowed to build on these vulnerable land surfaces. An introduction to geology free textbook for collegelevel. Mass wasting can be defined as a geomorphic process. Mass wasting represents the downslope movement of material under the influence of gravity. A geomorphic process is a natural course of weathering, erosion and deposition that causes alteration of the surface materials and landforms of the earth. Mass wasting is a unique geomorphological process destabilizing the surface rocks and soil mass.
Slide is when rock breaks down along fracture and is slides down. Mass wasting, which is sometimes called mass movement or slope movement, is defined as the large movement of rock, soil and debris downward due to. Pdf file ch 12 geologic time pdf file ch 14 energy resources pdf file ch 15 mineral resources pdf file ch 16 mass movements pdf file ch 17 streams pdf file ch 18 oceans and coasts pdf file ch 19 groundwater pdf file ch 21 deserts pdf file ch 22 glaciers pdf file ch 23 global change. It constitutes an important process in denudation of the continental surface. Most mass wasting events are actually caused by the natural processes of erosion as. Internal cohesion strength the characteristic property of a. Gravity the force of gravity provides the energy that causes. Mass wasting mass wasting the process by which materials e.
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