kb/data/en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)-11.md

title	chunk	source	category	tags	date_saved	instance
Glossary of geography terms (N–Z)	12/21	https://en.wikipedia.org/wiki/Glossary_of_geography_terms_(N–Z)	reference	science, encyclopedia	2026-05-05T08:06:30.234613+00:00	kb-cron

shield volcano A class of volcano that resembles an inverted warrior's shield, with long gentle slopes produced by multiple eruptions of fluid lava flows.

shoal Also sandbank, sandbar, or gravel bar. A natural submerged ridge, bank, or bar that consists of or is covered by sand or other unconsolidated material and rises from the bed of a body of water to just below or above the surface.

shore Also shoreline. The fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. Compare coast.

shore platform See wave-cut platform.

shoulder

1. A rounded spur on a mountainside; or a bench on the side of a glacier-deepened U-shaped valley, demarcating an abrupt transition between the gentle upper slopes which have been largely unaffected by glacial erosion and the steep lower slopes of the heavily eroded inner valley.
2. The part of a roadway between the edge of the graded or paved driving surface and the top of the foreslope of an adjacent ditch or embankment.

shoulder drop See topographic prominence.

side valley A valley whose mouth opens onto a larger, lower-order valley to which its drainage is tributary.

sighting compass A handheld magnetic compass fitted with a sighting device that permits the user to accurately determine the bearing or azimuth of a specified target with respect to their own position. The sighting instrument may make use of a simple notched protrusion akin to a gunsight, an image of the target reflected in a mirror, or a prismatic or lensatic system.

sinkhole A crater formed when the roof of a cavern collapses, usually found in areas of limestone rock.

site The features of a place related to the immediate environment in which the place is located (e.g. terrain, soil, subsurface, geology, groundwater, etc.).

situation The features of a place related to its location relative to other places (e.g., accessibility, hinterland quality).

skerry A small, rocky islet or reef, often one of a series lying just offshore and parallel to the main trend of the coastline, over which large waves may break at high tide or in stormy weather.

sky island An isolated mountain, mountain range, or high plateau characterized by conspicuous elevational gradients in geology, climate, and/or biodiversity, so that environments and ecosystems near the summit differ greatly from those of the adjacent slopes or the surrounding lowlands. This effectively cuts off the ecosystems of the highest areas, turning them into "islands" in a "sea" of dissimilar landscapes.

slack A shallow hole or hollow among coastal sand dunes or mud banks.

slack water Also slack tide or simply slack. The brief period of time during which a body of water susceptible to tides is completely unstressed because the tidal stream is almost still, i.e. there is no movement in either direction in the tidal current, usually occurring twice daily at the high and low water marks prior to the tide reversing direction.

slant range The line-of-sight distance along the relative direction between two points, especially two points which are not at the same elevation relative to a specific datum. If the two points are at the same elevation, the slant range equals the horizontal distance.

slash

1. In the southeastern United States, a low-lying swampy or boggy area, overgrown with shrubs and cane grasses and favorable for the growth of the slash pine and related trees.
2. The debris of felled trees, especially in a forest that has been subjected to slash-and-burn agriculture.

slide

1. A noticeable track of bare rock or furrowed earth left by the mass movement of soil, mud, snow, or rock under shear stress down a steep slope, as in a landslide or avalanche.
2. The mass of material moved or deposited by such an event, and which has become fixed or settled upon the landscape.

slip-off slope The more gently sloping of the two banks of a river or stream, usually on the inside bend of a meander, as opposed to a cut bank.

slope The upward or downward inclination of a natural or artificial surface (e.g. a hillside or a road), or the degree or nature of such an incline; a deviation from the perpendicular or horizontal direction (these directions generally being assigned with respect to the direction of the force of gravity). See also grade.

slough A type of wetland – usually a swamp, a shallow lake, or a backwater branching from or feeding into a river – in which water tends to be stagnant or flows only very slowly on a seasonal basis.

slum A residential settlement or neighborhood associated with extreme poverty and overpopulation, usually in or near an urban area. Slums are characterized by densely packed and poorly built or dilapidated housing units and a deterioration or lack of civic infrastructure such as reliable water, electricity, sanitation, law enforcement, and other basic services.

smog A mixture of particulate matter and chemical pollutants which has accumulated in the lower atmosphere, usually over urban areas.

smooth sheet Also smooth chart, fair sheet, and fair chart. A sheet on which field control and hydrographic data such as soundings, depth curves, and regions surveyed with a wire drag are plotted or drawn during the creation of a hydrographic chart.

snout Also terminus or toe. The lowermost margin or extremity of a glacier, always either gradually advancing or retreating, sometimes partially hidden by morainic material, and commonly featuring a cave from which meltwater flows.

snowline The lowest elevation at which snow remains throughout the year if the summer warmth does not completely melt the winter accumulation, e.g. on a high mountain. This elevation varies widely with latitude, local climate, directional aspect, and steepness of slope, such that the snowline may be very different on different mountains in the same range, on different faces of the same mountain, or on the same face in different years.

social trail See desire path.

society A group of people living in an organized community.