acclivity

First attested in 1614. From Latin acclīvitās, from acclīvis (“ascending”), from ad + clīvus (“slope”).

how gaily vineyards and olives alternately chequer the acclivities

she would walk […] as far as to the point where the acclivity from the valley began its first steep ascent to the outer world.

1891, Thomas Hardy, Tess of the d'Urbervilles:

Just below it leaned a tottering crag that would have toppled, starting an avalanche on an acclivity where no sliding mass could stop.

1912 January, Zane Grey, chapter 8, in Riders of the Purple Sage […], New York, N.Y., London: Harper & Brothers Publishers, →OCLC:

(geomorphology) A slope or inclination of the earth, as the side of a hill, considered as ascending, in opposition to declivity, or descending; an upward slope; ascent.

ylämäki

slope or inclination considered as "ascending"


dune

Partly from a dialectal form of down; and partly from French dune (from Old French dune), or from Middle Dutch dūne (modern Dutch duin), or from Middle Low German dûne; all ultimately from Proto-West Germanic *dūn, *dūnā, probably from Proto-Celtic *dūnom (“stronghold, rampart”), from Proto-Indo-European *dʰuHnom (“enclosure”), from *dʰewh₂- (“to finish, come full circle”). Doublet of down (which see).

der

Heavy line segments (lengthened for clarity) indicate locations of deep-sea dunes.

1975, Texas A & M University. College of Geosciences, Contributions in Oceanography:

In the early 2000s, space probes [confirmed Mars as] having dunes […] Their shapes are identical to their Saharan cousins', but they are ten times bigger. In contrast, underwater dunes are a hundred times smaller than their counterparts on solid ground. This universality of dunes is a blessing for physicists: their comparative study confirmed the models that describe the formation of dunes on Earth.

2021 February 23, Etienne Guyon, Jose Bico, Etienne Reyssat, Benoit Roman, Hidden Wonders: The Subtle Dialogue Between Physics and Elegance, MIT Press, →ISBN, page 257:

(geomorphology) A ridge or hill of sand piled up by currents of wind or water.

dunë

a ridge or hill of sand piled up by the wind

བྱེ་མའི་རི (bye ma'i ri, literally “mountain of sand”)

བྱེ་རི

abbr. of བྱེ་མའི་རི

བྱེ་ཕུང (bye phung, literally “sand pile”)


erg

From French erg, from Algerian Arabic, from Arabic عِرْق (ʕirq).

(geomorphology) A large desert region of sand dunes with little or no vegetation, especially in the Sahara.


striation

en-noun

striation (countable and uncountable, plural striations)

The energy raised the temperature of the snow a couple of degrees, and the friction carved striations high in the icy sides of the canyon walls.

2012, John Branch, “Snow Fall : The Avalanche at Tunnel Creek”, in New York Time:

(countable, geomorphology) One of a number of parallel scratch lines in rock outcrops, formed when glaciers dragged rocks across the landscape.


peneplain

peneplains (plural)
peneplane (alternative)

(geomorphology) A low-relief plain representing the final stage of fluvial erosion during times of extended tectonic stability.


fall line

LL-Q1860 (eng)-Flame, not lame-fall line.wav

(geomorphology) A geomorphologic unconformity marking a boundary between an upland region and a plane; sometimes marked by a series of waterfalls on rivers that cross it.

Fall Line

geomorphology: A line marking a boundary between an upland region and a plane


declivity

1610s, from French déclivité, from Latin declivitatem, dēclīvitās,
from dēclivis (“a sloping downward”), from de (“down”) + clīvus (“a slope”), from Proto-Indo-European *ḱleywo-, from Proto-Indo-European *ḱley- (“to lean”) (English lean).

The Declivity was ſo ſmall, that I walked near a mile before I got to the Shore, which I conjectur'd was about eight a-clock in the Evening.

1726 October 28, [Jonathan Swift], “The Author Gives Some Account of Himself and Family, His First Inducements to Travel. […]”, in Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume I, London: […] Benj[amin] Motte, […], →OCLC, part I (A Voyage to Lilliput), page 6:

1780, Theodore Augustine Mann, A Treatise on Rivers and Canals, Philosophical Transactions of the Royal Society of London, Volume 69: For the Year 1779, Part II, 582,
The velocity of flowing waters is very far from being in proportion to the quantity of declivity in their bed: […] .

[…]whoever takes the trouble of observing how the water runs longitudinally in the ruts on a convex road, although the declivity down the sides be incomparably greater than in the direction which it is compelled to take in the ruts, will soon see the propriety of constructing roads so as to have the water rim length-ways upon them, instead of attempting to gain a declivity, by making it run from the middle to the sides.

1809, Alexander Cumming, Observations on the Very Important and Contrary Effects which Carriage Wheels, with Rims of Cylindrical, and of Conical Shape, Have on the Roads, page 30:

[…]a line was measured down the hill on the right of 420, and the angle of declivity is 23°, which shortens the line 33 links;[…].

1812, John Ainslie, Comprehensive Treatise on Land Surveying, page 117:

A rocky cliff appeared, mounds of turned–up earth by the shore, houses on a hill, others with iron roofs, amongst a waste of excavations, or hanging to the declivity.

1899 February, Joseph Conrad, “The Heart of Darkness”, in Blackwood’s Edinburgh Magazine, volume CLXV, number M, New York, N.Y.: The Leonard Scott Publishing Company, […], →OCLC, part I:

1908 [Charles Griffin & Company], John Harvard Biles, The Design and Construction of Ships, Volume I: Calculations and Strength, 2009, Europāischer Hochschulverlag (Salzwasser-Verlag), page 216,
The declivity of the keel blocks varies slightly with the size of the vessel. The larger the vessel, the less the declivity.

Companion woodcut of "inclined plane on the railway from South Hetton to Seaham Harbour, showing the manner in which a loaded train of waggons pulls an empty one up the declivity"

1948 May and June, “The South Hetton Railway in 1835”, in Railway Magazine, page 184, image caption:

(geomorphology) The downward slope of a curve.


epeirogenesis

Borrowed from Ancient Greek ἤπειρος (ḗpeiros, “land”) + -genesis.

(geomorphology) Formation of continents, ocean basins and plateaus via movements of earth's crust.

ηπειρογένεση

formation of continents, etc via movements of earth's crust


badlands

badlands (plural)
badland (alternative)
Bad Lands (alternative archaic)

→ Esperanto: badlandoj

→ German: Badlands

→ French: badlands

→ Spanish: badlands

From earlier Bad Lands, calque of Canadian French mauvaises terres à traverser (“bad lands to cross”), itself a calque of Lakota Makhóšiča from makhó (“land”) and šiča (“bad”).

calque

Not only do the Bad Lands present a most attractive field to the student of erosion and of the origin of earth forms, but their deathlike solitudes have been made to yield the most wonderful procession of strange extinct animals yet unearthed by geologists.

1904, Israel C. Russell, North America, New York: D. Appleton and Company, page 111:

No one has ever described better the shaggy badlands and cabbage-patches round the edges of a city, where the debris of civilization piles up ramshackle suburbs in which starve and scheme all manner of human detritus.

1922, John Dos Passos, “A Novelist of Revolution”, in Rosinante to the Road Again, New York, N.Y.: George H[enry] Doran Company, →OCLC, page 85:

(geomorphology) An arid terrain characterized by severe erosion of sedimentary rocks.

وَعْر

arid terrain with severely eroded sedimentary rocks


glacis

Borrowed from French glacis (“slippery surface”), derived from Old French glacier (“to glide; freeze”), the former from Latin glaciāre (“to freeze”), from glaciēs (“ice”), of uncertain origin.
Cognates
* Medieval Latin glatia (“incline in front of a fortification”)

cog

(geomorphology) A gentle sloping landform created by the deposition or erosion of material.


orography

en-noun

orography (usually uncountable, plural orographies)

orographies (plural)
oreography (alternative)

Orography: A description of mountains.

1846, Joseph Emerson Worcester, A universal and critical dictionary of the English language: to which are added Walker's Key to the pronunciation of classical and Scripture proper names, much enlarged and improved, and a pronouncing vocabulary of modern geographical names, Boston: Wilkins, Carter, and Company, published 1849, page 501:

A knowledge of the Hydrography of a country aids as much in determining its geology as does its Orography, — that is, a description of its mountains.

1853, Edward Hitchcock, “The Geology of the Globe”, in Outline of the Geology of the Globe and of the United States in Particular with Sketches of Characteristic American Fossils., Boston: Phillips, Sampson & Company, page 10:

(geomorphology) The scientific study, or a physical description of mountains.

լեռնագրություն

the scientific study, or a physical description of mountains


flatiron

flatirons (plural)
flat iron (alternative)
flat-iron (alternative)

LL-Q1860 (eng)-Flame, not lame-flatiron.wav

(geomorphology) A steeply sloping triangular landform created by the differential erosion of a steeply dipping, erosion-resistant layer of rock overlying softer strata.


cuesta

Borrowed from Spanish cuesta (“slope”). Doublet of coast.

At that point the cuesta is 10 miles wide but the hilltops have an eastward descent of only about 62 feet. In its general eastward slope the surface of the cuesta is exactly that of one made by weathering and stream erosion, acting upon a gently-dipping limestone bed in a region never glaciated.

1965, Lawrence Martin, The Physical Geography of Wisconsin, Univ of Wisconsin Press, →ISBN, page 217:

In eastern Wisconsin the cuesta is drift-covered and less noticeable; permanent settlement came later; lead and zinc mining was absent; and industrial development took a different course.

1986, Gwen Schultz, Wisconsin's Foundations: A Review of the State's Geology and Its Influence on Geography and Human Activity, Univ of Wisconsin Press, →ISBN, page 127:

(geomorphology) A hill or ridge with a gentle slope on one side, and a steep slope on the other.


pingo

From Greenlandic pingu or Inuktitut pingu (“hummock, small hill”).

The greatest variation in cover thickness, as determined from collapsed pingos, is in irregularly shaped pingos, or those with asymmetrically located ice-cores.

1963, J[ohn] Ross Mackay, The Mackenzie Delta Area, N.W.T. (Memoir (Geographical Branch, Department of Mines and Technical Surveys, Canada); 8), Ottawa, Ont.: Department of Mines and Technical Surveys, →OCLC, page 74:

Considerable progress has been made on the discovery and mapping of many open system pingos in central Alaska and Yukon Territory[…], as well as the discovery of pingo-like mounds in the shallow waters of the Beaufort Sea north of the mouth of the Mackenzie River. The greatest advance in pingo research in the last decade has been a consideration and understanding of theory and rate of pingo growth […]

1973, Roger J. E. Brown, Troy L. Péwé, “Distribution of Permafrost in North America and Its Relationship to the Environment: A Review, 1963–1973: 13–28 July 1973, Yakutsk, U.S.S.R.”, in Permafrost: North American Contribution: Second International Conference, Washington, D.C.: National Academy of Sciences, →ISBN, page 80, column 2:

With the exception of small pingos, most pingo ice cores have several ice types. The bulk of the core can be segregated ice, intrusive ice formed from the freezing of bulk water, or any combination of the two types. In addition, dilation-crack ice (tension-crack ice, Brown and Kupsch, 1974) is commonly the main ice type beneath the summit of pingos with craters.

1983, J[ohn] Ross Mackay, “Oxygen Isotope Variations in Permafrost, Tuktoyaktuk Peninsula Area, Northwest Territories”, in Current Research Part B = Recherches en Cours Partie B (Geological Survey Paper; 83-1B), Ottawa, Ont.: Geological Survey of Canada, →ISBN, page 68:

Larger scale frost-heave features, such as pingoes, are rare because there is insufficient water available, generally, for the growth of large ice bodies.

1987, I. B. Campbell, G. G. C. Claridge, Antarctica: Soils, Weathering Processes and Environment (Developments in Soil Science; 16), Amsterdam, New York, N.Y.: Elsevier, →ISBN, page 106:

(geomorphology) A conical mound of earth with an ice core caused by permafrost uplift, particularly if lasting more than a year.


periglacial

/pɛɹɪˈɡleɪʃəl/

* During the Anglian glaciation, the ice caps were smaller than during earlier glacial events, but conditions in the periglacial areas around the ice were far more severe.

2018, Tim Flannery, Europe: A Natural History, page 167:

(geomorphology) Of or pertaining to the area around the edge of a glacier.


lithal

(informal, geomorphology) A pingo or hydrolaccolith; a mound of earth-covered ice found in the Arctic and subarctic environments that can reach up to 70 m in height and up to 600 m in diameter.


palsa

From Finnish palsa, from Northern Sami balsa.

Peat plateaux are larger landforms formed by the coalescence of palsas. String bogs, also called patterned fens, occur in muskeg. They are alternations of thin, string-like strips or ridges of peat, mainly Sphagnum moss, which may[…]

2003, Richard J. Huggett, Fundamentals of Geomorphology, Psychology Press, →ISBN, page 244:

These basin bogs are generally associated with Picea mariana or are treeless. Species in these wetlands are similar to those found in other palsas in Canada.

2013 March 9, Dennis F. Whigham, D. Dykyjová, S. Hejný, Wetlands of the World I: Inventory, Ecology and Management, Springer Science & Business Media, →ISBN, page 480:

(geomorphology) A hummock rising out of a bog with a core of ice; similar in appearance to a pingo but due to different structure palsas cannot grow as big as pingos.


intracrater

an intracrater dune formation

(geomorphology, astronomy) Occurring within a crater


lichenometry

In lichenometry, a lichen is presumed to grow radially at a specific, constant rate: this rate is used to estimate the age of the largest lichen on a rock surface, and thus the length of time the rock has been exposed.

The sophistication of approach to lichenometry has increased markedly in the last decade or two.

2004, Jean M. Grove, Little Ice Ages: Ancient and Modern, Volume 1, 2nd edition, Taylor & Francis (Routledge), page 7:

Lichenometry is a surface-exposure dating method that uses lichen-growth rates to infer the age of young ([a] few thousand years old or younger) glacial landforms, typically bouldery deposits such as moraines.[…]Several approaches have been employed to measure lichens, and a distinct advantage of lichenometry over other techniques is its simplicity (Bradwell, 2009).

2011, Jason P. Briner, “Dating Glacial Landforms”, in Vijay P. Singh, Pratap Singh, Umesh K. Haritashya, editors, Encyclopedia of Snow, Ice and Glaciers, Springer, page 177:

Lichenometry is a dating method which is based upon the direct relationship between lichen diameter and age.

2012, Matti Saarnisto, “I.4: Time-scales and dating”, in B. Huntley, T. Webb III, editors, Handbook of vegetation science, Volume 7: Vegetation history, Kluwer Academic, page 102:

(archaeology, paleontology, geomorphology) A geomorphic method of geochronologic dating that uses lichen growth to determine the age of exposed rock.

lichenometrie

geochronologic dating method that uses lichen growth


orology

Their orology however is extremely indeterminate and obscure, and must remain so until the actual survey of experienced engineers shall reduce them to distinct chains or groups.

1810, Joseph Wilson, A History of Mountains: Geographical and Mineralogical:

(geomorphology, obsolete, rare) The study or science of mountains and their formation.


antidune

(geomorphology) A bedform found in fluvial environments, opposing the direction of flow.

antiduna

a bedform opposing the direction of fluvial flow


epeirogeny

epeirogeny (usually uncountable, plural epeirogenies)

(geomorphology) Broad regional upwarp of the cratonic portions of continents.

造陆运动

broad regional upwarp of the cratonic portions of continents


inselberg

inselberg (plural inselbergs or inselberge)

/ˈɪnsəlˌbɜːɡ/

/ˈɪnsəlˌbɝɡ/

From German Inselberg, from Insel (“island”) + Berg (“mountain”).

Click: forest elephant, stern and alert. Click: humpback whale, breaching skyward like a frisky trout. Click: Gaboon viper, its big coppery head so close to the lens you could almost feel the flick of its tongue. Click: granite inselberg, like a great igneous gumdrop, protruding above forest canopy. Click: bulge-eyed hippopotamus, almost unrecognizably strange and serene, riding a wave along the Atlantic coast.

2003, David Quammen, “Saving Africa's Eden”, in National Geographic, volume 204, number 3:

From the north, the road into Nigeria’s purpose-built capital is strewn with inselbergs, vast monolithic stone outcrops that rise abruptly out of the lush savannah. At the centre of the country, the city became the seat of government in 1991 after Lagos had become too crowded and chaotic.

2015 July 24, William Wallis, “What is next for Nigeria?”, in Financial Times:

Ground penetrating radar can map the foundation of Gulem menhir and establish its identity either as a natural geological oddity, a natural inselberg or a manmade menhir.

2016 December 4, “Archaeological Mystery of Gulem Menhir”, in The Navhind Times:

(geomorphology) A monadnock (isolated mountain).


terracette

(geomorphology) A type of landform, a ridge on a hillside formed when saturated soil particles expand, then contract as they dry, causing them to move slowly downhill.


downhill creep

(geomorphology) The slow downward progression of rock and soil down a low-grade slope.


soil creep

soil creep (countable and uncountable, plural soil creeps)


drainage system

drainage system (plural drainage systems)

(geomorphology) pattern formed by the streams, rivers, and lakes in a particular drainage basin


knickpoint

knickpoints (plural)
nickpoint (alternative)

(geomorphology) Part of a river or channel where there is a sharp change in slope, such as a waterfall or lake.


palaeoaeolian

en-adj

palaeoaeolian (comparative more palaeoaeolian, superlative most palaeoaeolian)

more palaeoaeolian (comparative)
most palaeoaeolian (superlative)
paleoeolian (alternative)
palaeo-aeolian (alternative)
paleo-eolian (alternative)
paleoaeolian (alternative)
palaeo-eolian (alternative)

For quotations using this term, see Citations:palaeoaeolian.

(geomorphology, climatology) Relating to, or caused by, ancient winds

muinaisten tuulten (+ agent participle of a verb; literally "by ancient winds")


paleoplain

paleoplains (plural)
palaeoplain (alternative)

(geology, geomorphology) A buried erosion plain; a particularly large and flat erosion surface.


etchplanation

Deep weathering and etchplanation can occur in the humid sub-tropics (Tricart, 1972) and a humid sub-tropical Britain in Tertiary times is possible.

1985, Richard Hugh Johnson, The Geomorphology of North-west England, page 52:

(geology, geomorphology) The process of subsurface weathering or etching which creates etchplains.


etchplain

Lateritized etchplains are surfaces of low relief underlain by extensive primary laterite deposits.

1969, Michael Frederic Thomas, Environment and land use in Africa, page 127:

(geology, geomorphology) A plain (area of land, not necessarily flat) where bedrock has been subject to extensive etching or subsurface weathering.


mouth bar

1980 [Burgess Publishing], George deVries Klein, Sandstone Depositional Models for Exploration for Fossil Fuels, 2nd Edition, 1982, International Human Resources Development Corp., page 111,
The best targets for exploration for oil and gas in deltas are the distributary mouth bar sand complexes and the destructive-phase, transgressive barrier sands.

In the axial zone of delta mouth bars, fluvial processes dominate.

1991, D. J. P. Swift, S. Phillips, J. A. Thorne, “Sedimention on continental margins, IV: lithofacies and depositional systems”, in D. J. P. Swift, G. F. Oertel, R. W. Tillman, J. A. Thorne, editors, Shelf Sand and Sandstone Bodies: Geometry, Facies and Sequence Stratigraphy, Blackwell Scientific, page 110:

2017, Yong He, Chen Lu, Jiaquan Deng, Yugui Yang, Liuzhu Yang, Evolution of Modaomen Bar at Pearl River Esuary, Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden (editors), River Sedimentation: Proceedings of the 13th International Symposium on River Sedimentation, Taylor & Francis (CRC Press), page 212,
The mouth bar is located at the key part of the river estuary. […] At the beginning of the 20th century, the mouth bar is at the Hengzhou-Dajingjiao Gorge. […] At present, the mouth bar is located at the south side of the Jiaobeisha-Shilansha line.

(geomorphology) A bar that forms in the middle of an estuary or of a channel in a river delta.


glacial trough

(geomorphology) A valley that resembles the letter U, that is formed by the process of glaciation.


pressure ridge

(geomorphology) An oceanic or coastal area, composed of ice fragments within pack ice, forms as sea ice floes accumulate due to convergence.


gramadulla

the word “gramadulla” […] seemed to express just the bleak desolation of those grey-capped masses of rock and the wild labyrinth of those innumerable gorges and ravines.

1958, Henno Martin, translated by Edward Fitzgerald, The Sheltering Desert, New York: Thomas Nelson, pages 65-66:

1971, Jillian Becker, The Union, London: Chatto & Windus, Chapter 4, p. 248,
Perhaps it was Lisa, who had become a huntress, who chased him on; across the plains and down the gramadulla gorges, and through the shade of granite dykes.

ephemeral rivers like the Swakop are deeply incised into the plains, producing gorges and areas of badlands (locally called gramadullas)

2002, Andrew Goudie, chapter 6, in Great Warm Deserts of the World: Landscapes and Evolution, Oxford University Press, page 155:

(geomorphology, Namibia) Arid terrain characterized by numerous alternating canyons and gorges.


through valley

(geomorphology) A valley eroded between larger valleys by glacial ice or meltwater.


moundfield

(geomorphology) An area of land covered in mounds, often produced by animals.


V-shaped valley

en-noun

V-shaped valley (plural V-shaped valleys)

(geomorphology) A valley that resembles the letter V and is formed by erosion from a river or stream over time.