Geomorphology

Geomorphology isstudypresent-day landforms, including their classification, description, nature, origin, development,relationshipsunderlying structures, as well ashistorygeologic changes as recorded by these surface features. The termsometimes restrictedfeatures produced only by erosiondeposition. Although geomorphology tendsfocus on terrestrial landforms,surfaces ofMoonMarsnow sufficiently well-knownmorphological analysisbe applied there as well.

Geomorphologyfundamentally inspired byshapes ofterrain we see every day;meandering course ofriver,rounded shapessome hills andpointed shapesothers,seemingly-random capesbays ofcoastline. While itgenerally accepted that,instance, water erodes rock overlong periodtime, that doesn't answerquestionwhether any particular landform was created by water erosion, howago, whether wind playedrole also,so forth. Geomorpology delves into these questionsdepth, seeking bothexplain origins,soprovide predictive power that can be usedactivities such as civil engineering.

Some geomorphologists identifytaxonomylandforms, sorted by magnitude:

• 1st - continent, ocean basin, climatic zone (~10,000,000 kmē)
• 2nd - Baltic shield, mountain range (~1,000,000 kmē)
• 3rd - isolated sea, Sahel (~100,000 kmē)
• 4th - Massif Central, Weald (~10,000 kmē)
• 5th - river valley, Cotswolds (~1,000 kmē)
• 6th - individual mountain or volcano, small valleys (~100 kmē)
• 7th - hillslopes, stream channels, estuary (~10 kmē)
• 8th - gully, barchan (~1 kmē)
• 9th - meter-sized features

Different kindsprocesses tenddominate at different magnitudes.

Tablecontents

1 History 2 Processes 3 References

History

Geomorphology was not originally differentiated fromrestgeology. The first geomorphic model was"cycleerosion", developed by William Morris Davis between 18841899. The cycle was inspired by theoriesevolution,was depicted assequence by whichriver would cutvalley moremore deeply, but then erosionside valleys would eventually flatten outterrain again, now atlower elevation. The cycle could be started over by uplift ofterrain. The modeltoday considered too much ofsimplificationbe especially usefulpractice.

Walther Penck developed an alternative model in1920s, based on ratiosuplifterosion, butwas also too weakexplainvarietylandforms.

Processes

Modern geomorphology focuses onquantitative analysisinterconnected processes, such ascontributionsolar energy,ratessteps ofhydrological cycle,plate movement rates from geophysicscomputeageexpected fatelandforms. The usemore precise measurement technique has also enabled processes like erosionbe observed directly, rather than merely surmised from other evidence. Computer simulationalso valuabletesting thatparticular model yields resultsproperties similarreal terrain.

(add specific landform processes here)

References

• M. J. Selby, Earth's Changing Surface (Oxford University Press, 1985) ISBN 0198232527
• Richard Chorley, Stanley Schumm,David Sugden, Geomorphology (Methuen, 1984)