Earth Science Exam 3

Erosion

The incorporation and transportation of material by a mobile agent, usually water, wind, or

ice

Weathering

The disintegration and decomposition of material at or near the surface

Mass Wasting

The tranfer of rock mterial downslope under the influence of gravity

Mechanical Weathering

Breaking of rocks into smaller pieces

Chemical Weathering

Alters the internal structures of minerals by removing or adding elements

Differential Weathering

Caused by variations in rock composition; Can create unusual and spectacular rock

formations and landforms

water

the most important agent of chemical weathering

Oxygen dissollved in water oxidezes materials

How oxygen contributes to weathering

What effect does carbon dioxide have on weathering?

It forms carbonic acid, which alters the material

In what conditions is chemical weathering most effective?

In areas of warm temperatures and abundant moisture

What influences natural rates of soil erosion?

Soil characteristics, climate, slope, and type of vegetation

What is the primary controlling force of mass wasting?

Gravity

What is one triggering factor for mass wasting?

Saaturation of the material with water

what happens when slopes are oversteepened?

They become unstable and may lead to mass wasting

What is the angle of repose?

The stable slope angle that unconsolidated granular particles assume

What characterizes a slump in mass wasting?

Rapid movement of material along a curved surface

What occurs during a rockslide?

Blocks of bedrock move rapidly down a slope

What is liquefaction?

A special type of earthflow where high-energy vibrations cause solids to behave like fluids.

What is solifluction?

Slow movement of saturated upper soil layers over a frozen surface below, primarily in permafrost areas.

Desert Pavement

A surface layer of closely packed, interlocking gravel or stones that forms in arid environments.

Hanging Valley

A valley that is cut across by a deeper valley or a cliff, often formed by glacial activity.

glacial trough

A U-shaped valley formed by the erosion of a glacier, characterized by steep sides and a flat bottom

Horn

A sharp peak formed by glacial erosion, typically where three or more glaciers meet.

Cirque

A bowl-shaped depression formed at the head of a glacier, often containing a small lake.

Arête

A sharp ridge that forms between two glacial valleys, created by the erosion of glaciers on either side.

Esker

A long, winding ridge of stratified sand and gravel, formed by sediment deposited by meltwater streams beneath a glacier.

Kame

A mound or hill of sand and gravel deposited by glacial meltwater, often found near the edges of glaciers.

Glacial Till

Unsorted sediment deposited directly by a glacier, consisting of a mixture of clay, silt, sand, gravel, and boulders.

Stratified Drift

Sediment that has been sorted and deposited by glacial meltwater, typically forming layers based on particle size.

Slump

A type of mass wasting that involves the downward movement of a block of soil or rock along a curved surface.

Earthflow

A type of mass wasting characterized by the slow, viscous flow of saturated soil and debris down a slope.

Creep

The slow, gradual movement of soil and rock down a slope, often imperceptible over short periods.

Gradient

The slope or steepness of a river or stream, typically expressed as a ratio of vertical drop to horizontal distance.

Discharge

The volume of water flowing through a river or stream at a given point over a specific period, usually measured in cubic meters per second

Drainage Patterns

The arrangement of streams and rivers in a particular area, influenced by the landscape and underlying geology

Trellis Pattern

A drainage pattern characterized by parallel tributaries that flow between ridges of resistant rock.

Rectangular Pattern

A drainage pattern defined by right-angle stream junctions, often due to a well-developed joint structure in the bedrock.

Dendretic pattern

The most common pattern, characterized by tree-like, random branching. It develops on uniform, flat-lying rock where erosion is consistent.

Radial pattern

Streams flow outward from a central high point, such as a volcano or dome, resembling spokes on a wheel.

Parallel pattern

Develops on steep slopes or in regions of parallel, elongated landforms, where tributaries flow in a parallel fashion.

Centripetal pattern

Streams flow inward toward a central, low-lying basin or depression

Deranged

An irregular pattern with no coherent structure, usually found in areas disrupted by recent glaciation.

Karst Landscapes

Landforms created by the dissolution of soluble rocks such as limestone, characterized by features like sinkholes and caves.

Stalactites

Icicle-like formations that hang from the ceilings of caves, formed by the deposition of minerals from dripping water.

Stalagmites

Column-like formations that rise from the floor of a cave, formed by the accumulation of minerals from dripping water.

Unsaturated zones

Area above the water table containing both water and air. This includes the soil-water zone (surface to plant roots) and the capillary fringe (water pulled up from the saturated zone).

Saturated Zone

Subsurface area where all openings and cracks are completely filled with water. This is where usable groundwater exists.

Aquifier

A porous, permeable geologic formation (sand, gravel, fractured rock) that stores and transmits usable groundwater

Water Table

The upper surface of the zone of saturation in the ground, where the soil or rock is fully saturated with water.

Physical Boundaries

Geological features like non-porous rock layers, fault lines, or the edge of a sedimentary basin.

Hydraullic Boundaries

Dynamic boundaries formed by changing water levels, such as rivers, lakes, or groundwater divides.

Groundwater protection zones

Surface areas delineated (e.g., source water protection areas) to prevent contamination of drinking water sources.

capillary fringe

acts as a transition zone between the saturated and unsaturated zones.

Confined Aquifiers

bounded above and below by impermeable layers, often putting water under pressure (potentiometric surface).

Global Distribution of Glacial Ice

The spread and extent of glaciers and ice sheets across the Earth, primarily found in polar regions and high mountains.

Wind Erosion Processes

The removal and transportation of soil and rock particles by wind, which can shape landscapes in arid environments.

Desert Landforms

Geological features found in desert environments, including arroyos (dry riverbeds), bajadas (sloping alluvial fans), and alluvial fans (depositional landforms).

Arroyos

dry riverbeds or stream channels that temporarily carry water s=during periods of heavy rain or snowmelt

bajadas

sloping allluvial fans formed where multiple smaller streams converge and deposit sediment at a base of a mountain or hill

alluvial fan

a geological formation made up of sediment deposited by flowing water, typically found at the base of a mountain or hill where a stream exits a narrow valley and spreads out to form a cone-shaped, fan-like structure.