Surface of the Earth

Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. The underlying question is: Why do landscapes look the way they do? The term is derived from the Greek γη, ge, meaning Earth, and μορφή, morfé, meaning form. Geomorphologists seek to understand landform history and dynamics, and predict future changes through a combination of field observation, physical experiment, and numerical modeling. The discipline is practiced within geology, geodesy, geography, archaeology, and civil and environmental engineering. Early studies in geomorphology are the foundation for pedology, one of two main branches of soil science. Download high resolution version (3078x2203, 1905 KB)Surface of the Earth, Revised March 2000 World Data Center for Marine Geology & Geophysics, Boulder NGDC DATA ANNOUNCEMENT NUMBER: 00-MGG-05 This image was generated from digital data bases of land and sea-floor elevations on a 2-minute latitude/longitude grid... Download high resolution version (3078x2203, 1905 KB)Surface of the Earth, Revised March 2000 World Data Center for Marine Geology & Geophysics, Boulder NGDC DATA ANNOUNCEMENT NUMBER: 00-MGG-05 This image was generated from digital data bases of land and sea-floor elevations on a 2-minute latitude/longitude grid... A landform comprises a geomorphological unit. ... This article does not cite its references or sources. ... A mathematical model is an abstract model that uses mathematical language to describe the behaviour of a system. ... World geologic provinces Oceanic crust  0-20 Ma  20-65 Ma  >65 Ma Geologic provinces  Shield  Platform  Orogen  Basin  Large igneous province  Extended crust Geology (from Greek γη- (ge-, the earth) and λογος (logos, word, reason))[1] is the science and study of the solid matter of the earth, its composition, structure... It has been suggested that geodetic system be merged into this article or section. ... Archaeology, archeology, or archæology (from the Greek words αρχαίος = ancient and λόγος = word/speech/discourse) is the study of human cultures through the recovery, documentation and analysis of material remains and environmental data, including architecture, artifacts, biofacts, human remains, and landscapes. ... The Falkirk Wheel in Scotland. ... Environmental engineering is the application of science and engineering principles to improving the environment (air, water, and/or land resources), to provide healthful water, air and land for human habitation and for other organisms, and to investigate the possibilities for remediation of polluted sites. ... Pedology (pÄ›dÇ’lōgy), (from Russian: pedologiya, from the Greek pedon = soil, earth), is the study of soils and soil formation. ... Soil science deals with soil as a natural resource on the surface of the earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils per se; and these properties in relation to the use and management of soils. ...

Landforms evolve in response to a combination of natural and anthropogenic processes. The landscape is built up through tectonic uplift and volcanism. Denudation occurs by erosion and mass wasting, which produces sediment that is transported and deposited elsewhere within the landscape or off the coast. Landscapes are also lowered by subsidence, either due to tectonics or physical changes in underlying sedimentary deposits. These processes are each influenced differently by climate, ecology, and human activity. Look up anthropogenic in Wiktionary, the free dictionary. ... A tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. ... This article is about volcanoes in geology. ... Denudation is the geological process which involves the erosion and weathering of landscapes, resulting in the physical lowering of the landscape, by such processes as wind, rain, the sun, etc. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as understood by materials science, see Erosion (materials science) For erosion as an English analogy, see Erosion (figurative) Erosion is the displacement of solids (soil, mud, rock and other particles) by the agents of wind, water... Mass wasting, also known as mass movement or slope movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. ... Deposition, also known as sedimentation, is the geological process whereby material is added to a landform. ... Ernst Haeckel coined the term oekologie in 1866. ...

Practical applications of geomorphology include landslide prediction and mitigation, river control and restoration, coastal protection, and assessing the presence of water on Mars. Landslide of soil and regolith in Pakistan A landslide is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows. ... River Gambia flowing through Niokolokoba National Park A river is a large natural waterway. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ...

Paleogeomorphology is the study of the geomorphology of all or part of the earth's surface at some time in the earth's past.

History

Geomorphology was not originally differentiated from the rest of geography. The first geomorphic model was the geographical cycle or the cycle of erosion, developed by William Morris Davis between 1884 and 1899. The cycle was inspired by theories of uniformitarianism which were first formulated by James Hutton (1726-1797). Concerning valley forms, the cycle was depicted as a sequence by which a river would cut a valley more and more deeply, but then erosion of side valleys would eventually flatten out the terrain again, now at a lower elevation. The cycle could be started over by uplift of the terrain. The model is today considered too much of a simplification to be especially useful in practice. William Morris Davis (February 12, 1850 - February 5, 1934) was an American geographer, geologist and meteorologist, often called the father of American geography. He was born into a Quaker family in Philadelphia, Pennsylvania, son of Edward M. Davis and Maria Mott Davis (a daughter of the womens advocate Lucretia... Uniformitarianism, in the philosophy of science, is the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present. ... James Hutton, painted by Abner Lowe. ... The terms side valley and tributary valley refer to valleys whose brook or river is confluent to a greater one. ... Look up uplift in Wiktionary, the free dictionary. ...

Walther Penck developed an alternative model in the 1920s, based on ratios of uplift and erosion, but it was also too weak to explain a variety of landforms. G. K. Gilbert was an important early American geomorphologist. Walther Penck (August 30, 1888 – September 29, 1923), born in Vienna as son of Albrecht Penck. ...

Processes

Age of seafloor crust. Red is youngest.

Modern geomorphology focuses on the quantitative analysis of interconnected processes, such as the contribution of solar energy, the rates of steps of the hydrologic cycle, and plate movement rates from geophysics to compute the age and expected fate of landforms. The use of more precise measurement technique has also enabled processes like erosion to be observed directly, rather than merely surmised from other evidence. Computer simulation is also valuable for testing that a particular model yields results with properties similar to real terrain. Download high resolution version (1624x1020, 895 KB)Age of oceanic crust. ... Download high resolution version (1624x1020, 895 KB)Age of oceanic crust. ... Solar power describes a number of methods of harnessing energy from the light of the sun. ... The water cycle—technically known as the hydrologic cycle—is the circulation of water within the earths hydrosphere, involving changes in the physical state of water between liquid, solid, and gas phases. ... ‹ The template below has been proposed for deletion. ... Wooden mechanical horse simulator during WWI. A simulation is an imitation of some real thing, state of affairs, or process. ...

Primary surface processes responsible for most topographic features include wind, waves, weathering, mass wasting, ground water, surface water, glaciers, tectonism, and volcanism. Wind is the rough horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earths surface. ... A WAVES Photographer 3rd Class The WAVES were a World War II era division of the U.S. Navy that consisted entirely of women. ... Weathering is the process of breaking down of rocks, soils and their minerals through direct, or indirect contact with the atmosphere. ... Mass wasting, also known as mass movement or slope movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. ... Groundwater is any water found below the land surface. ... Surface water is water on the ground or in a stream, river, lake, sea or ocean; as opposed to groundwater. ... A glacier is a large, long-lasting river of ice that is formed on land and moves in response to gravity and undergoes internal deformation. ... Plate tectonics (from the Greek word for one who constructs, τεκτων, tekton) is a theory of geology developed to explain the phenomenon of continental drift, and is currently the theory accepted by the vast majority of scientists working in this area. ... This article is about volcanoes in geology. ...

Fluvial geomorphology

Rivers and streams are not only conduits of water, but also of sediment. The water, as it flows over the channel bed, is able to mobilise sediment and transport it downstream, either as bedload, suspended load or dissolved load. The rate of sediment transport depends on the availability of sediment itself and on the river's discharge. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ... Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ... Look up Discharge in Wiktionary, the free dictionary. ...

As rivers flow across the landscape, they generally increase in size, merging with other rivers. The network of rivers thus formed is a drainage system and is often dendritic, but may adopt other patterns depending on the regional topography and underlying geology. A drainage system is the pattern formed by the streams, rivers, and lakes in a particular watershed. ...

Glacial geomorphology

Glaciers, while geographically restricted, are effective agents of landscape change. The gradual movement of ice down a valley causes abrasion and plucking of the underlying rock. Abrasion produces fine sediment, termed glacial flour. The debris transported by the glacier, when the glacier recedes, is termed a moraine. Glacial erosion is responsible for U-shaped valleys, as opposed to the V-shaped valleys of fluvial origin. A glacier is a large, long-lasting river of ice that is formed on land and moves in response to gravity and undergoes internal deformation. ... Snowflakes by Wilson Bentley, 1902 Ice is the name given to any one of the 14 known solid phases of water. ... Glacially abraded rocks in western Norway near Jostedalsbreen glacier. ... Plucking, in the sense relating to glaciers, is when a glacier erodes away chunks of bedrock to be later deposited as erratics. ... The rocky side of a mountain creek near Orosí, Costa Rica. ... Rock flour consists of clay-sized particles of rock, generated by glacial erosion or by artificial grinding to a similar size. ... Moraine at Mono Lake, California, United States Moraines clearly seen on a side glacier of the Gorner Glacier, Zermatt, Switzerland. ...

See also: Glacier morphology

Glacier morphology, or the form a glacier takes, is influenced by temperature, precipitation, topography, and other factors. ...

Weathering

Main article: Weathering

This results from chemical dissolution of rock and from the mechanical wearing of rock by plant roots, ice expansion, and the abrasive action of sediment. Weathering provides the source of the sediment transported by fluvial, glacial, aeolian, or biotic processes. Weathering is the process of breaking down of rocks, soils and their minerals through direct, or indirect contact with the atmosphere. ... Look up biotic in Wiktionary, the free dictionary. ...

Taxonomy

Different geomorphological processes dominate at different spatial and temporal scales. To help categorize landscape scales some geomorphologists use the following taxonomy: Look up taxonomy in Wiktionary, the free dictionary. ...

• 1st - Continent, ocean basin, climatic zone (~10,000,000 km²)
• 2nd - Shield, e.g. Baltic shield, or mountain range (~1,000,000 km²)
• 3rd - Isolated sea, Sahel (~100,000 km²)
• 4th - Massif, e.g. Massif Central or Group of related landforms, e.g., Weald (~10,000 km²)
• 5th - River valley, Cotswolds (~1,000 km²)
• 6th - Individual mountain or volcano, small valleys (~100 km²)
• 7th - Hillslopes, stream channels, estuary (~10 km²)
• 8th - gully, barchannel (~1 km²)
• 9th - Meter-sized features

Its use, however, is rare and may be misleading - the nature of landscape change may be better viewed as a continuum of coupled processes. Color-coded regions of the world based on the seven commonly-recognised continents Dymaxion map by Buckminster Fuller shows land masses with minimal distortion as nearly one continuous continent A continent is one of several large areas of land on Earth, which are identified by convention rather than any strict... Oceans (from Okeanos in Greek) are saline waters that cover almost three quarters (71%) of the surface of the Earth. ... The Baltic Shield (or Fennoscandian Shield) is a segment of the Earths crust belonging to the East European Craton, representing a large part of Fennoscandia, northwestern Russia and the northern Baltic Sea. ... The Himalaya as seen from the International Space Station A mountain range is a group of mountains bordered by lowlands or separated from other mountain ranges by passes or rivers. ... Sea as seen from jetty in Frankston, Australia Look up maritime in Wiktionary, the free dictionary. ... See also Sahel, Tunisia, a region of eastern Tunisia. ... France, viewed from the NASA Shuttle Topography Radar Mission. ... A weald once meant a dense forest, especially the famous great wood once stretching far beyond the ancient counties of Sussex and Kent, England, where this country of smaller woods is still called the Weald. ... The Cotswolds is the name given to a range of hills in central England, sometimes called the Heart of England, a hilly area reaching over 300 m or 1000 feet. ... Lyskamm, 4 527 m, Pennine Alps A mountain is a landform that extends above the surrounding terrain in a limited area. ... Volcano 1. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing ecological, economic, cultural, and aesthetic benefits. ... Gully in El Paso County, Colorado, USA. A gully is a landform created by running water eroding sharply into a hillside. ...

See also

• Base level
• Biogeology
• Bioerosion
• Biogeomorphology
• Biorhexistasy
• Coastal erosion
• Drainage system
• Erosion prediction
• Fluvial landforms of streams
• Geologic modeling
• Hydrologic modeling, behavioral modeling in hydrology
• Landscape
• Lithosphere
• Mound
• Regolith
• Soil
• Soil conservation
• Soil mechanics
• Soil morphology
• Soils retrogression and degradation
• Stream capture
• Watershed
• Important publications in geomorphology

The base level of a river or stream is the lowest point to which it can flow, often referred to as the mouth of the river. ... Biogeology is the study of how the biosphere and the lithosphere interact. ... Bioerosion describes the erosion of hard ocean substrates by living organisms by a number of mechanisms. ... Biogeomorphology and ecogeomorphology are the study of interactions between organisms and the development of landforms, and is thus a field of geomorphology. ... The Theory of Biorhexistasy describes climatic conditions necessary for periods of soil formation (pedogenesis) separated by periods of soil erosion. ... Coastal erosion is a process which affects the landmass of an area as a consequence of the sea acting upon it. ... A drainage system is the pattern formed by the streams, rivers, and lakes in a particular watershed. ... Erosion prediction There are dozens of erosion prediction models. ... Stream beds or river valleys have various different landforms. ... Geologic modeling is the applied science of creating computerized representations of portions of the Earths crust, especially oil and gas fields and groundwater aquifers. ... Water covers 70% of the Earths surface. ... This article does not cite its references or sources. ... The tectonic plates of the Lithosphere on Earth. ... Look up mound on Wiktionary, the free dictionary. ... Regolith (Greek: blanket rock) is a layer of loose, heterogeneous material covering solid rock. ... Loess field in Germany Soil horizons are formed by combined biological, chemical and physical alterations. ... Sheep pasture with macroscale erosion, Australia Soil conservation is a set of management strategies for prevention of soil being eroded from the earth’s surface or becoming chemically altered by overuse, salinization, acidification, or other chemical soil contamination. ... Soil mechanics is a discipline that applies the principles of engineering mechanics to soil to predict the mechanical behavior of soil. ... // Soil Macromorphology Soil morphology is the field observable attributes of the soil within the various soil horizons and the description of the kind and arrangement of the horizons (Buol et al 2003). ... Retrogression and degradation are two regressive evolution processes associated with the loss of equilibrium of a stable soil. ... Stream capture is a geological or hydrological phenomenon which occurs when a stream from a neighboring drainage system erodes through the divide between two streams and captures another stream which then is diverted from its former bed and now flows down the bed of the capturing stream. ... A drainage basin is the area within the drainage basin divide (yellow outline), and drains the surface runoff and river discharge (blue lines) of a contiguous area. ... // Foundations Principles of Geology Author: Charles Lyell Publication data: 1830–1833. ...

References

• M. J. Selby, Earth's Changing Surface. ISBN 0-19-823252-7, Oxford University Press, 1985
• Richard Chorley, Stanley Schumm, and David Sugden, Geomorphology. Edition Methuen, 1984
• Bernhard Edmaier, Earthsong. A collection of breathtaking arial photographs. Phaidon, 2004.
• Adrian E. Scheidegger, Morphotectonics. ISBN 3-540-20017-7, Springer-Verlag Berlin 2004.

Oxford University Press (OUP) is a highly-respected publishing house and a department of the University of Oxford in England. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Methuen & Co Limited is a firm of British publishers, which began publishing in London in 1892. ... It has been suggested that this article or section be merged with Phaedo. ...

External links

• International Association of Geomorphologists
• British Society for Geomorphology
• Association of Polish Geomorphologists
• Model of landscape evolution by William Morris Davis (by GEOMORPHLIST)
• The Geographical Cycle, or the Cycle of Erosion (1899)

Physical geography v • d • e
	Biogeography · Climatology & paleoclimatology · Coastal/Marine studies · Geodesy · Geomorphology · Glaciology · Hydrology & Hydrography · Landscape ecology · Limnology · Oceanography · Palaeogeography · Pedology · Quaternary Studies