ES Terminologies for 2nd Quarter Prelims

Chapters 7 & 8

Soil

is a dynamic body of natural materials capable of supporting a vegetative cover.

Pedosphere

soils are sometimes considered a separate subsystem called ____

Soil water, inorganic materials, soil air, and organic matter

major soil components

Soil fertilization

is the process of adding nutrients or other constituents in order to meet the soil conditions that certain plants require.

Capillary water

serves as a stored water supply for plants.

Hygroscopic water

does not move through the soil, nor does it supply plants with the moisture they need.

Gravitational water

water that percolates down through a soil under the force of gravity

water table

the level below which all available spaces are filled with water.

Leaching

the depletion of nutrients in the soil by the through-flow of water.

Eluviation

downward removal of soil components by water.

Illuviation

deposition by water in the subsoil.

Humus

the decayed remains of plant and animal materials, partially transformed by bacterial action.

light brown or gray

color of soils with low humus content

black or brown

soils rich in humus

Soil texture

refers to the particle sizes that make up a soil.

clayey, clay

In ____ soils, the dominant size consists of ____ particles; defined as having diameters of less than 0.002 millimeters.

silty, silt

In _____ soils, the dominant _____ particles are defined as being between 0.002 and 0.5 millimeters.

sandy, sand-sized

______ soils have mostly __________ particles, with diameters between 0.05 and 2.0 millimeters.

Soil peds

In most soils, particles clump into masses known as _____, which give a soil a distinctive structure.

Porosity

the amount of space that may contain fluids.

Permeability

the rate at which water can pass through.

acidic, alkaline

Low pH values indicate an _______ soil, and high pH indicates ____ conditions.

Parent material

soil development begins when plants and animals colonize rocks or deposits of rock fragments, the ___ on which soil will form.

Soil profile

the vertical cross-section of a soil from the surface down to the parent material.

Soil horizons

well-developed soils typically exhibit distinct layers in their soil profiles called ___

O horizon

layer of organic debris and humus

A horizon

referred to as “topsoil”, contains decomposed organic matter.

E horizon

named for the action of strong eluviation.

B horizon

where much of the materials removed from the A and E horizons are deposited.

C horizon

is the weathered parent material from which the soil has developed.

R horizon

is unchanged parent material, either bedrock or transported deposits of rock fragments, and is the lowest layer.

Weathering

refers to the many natural processes that break rocks down into smaller fragments.

Hans Jenny

observed that soil development was a function of climate, organic matter, relief, parent material, and time.

Residual parent material

the accumulation of weathered rock particles through the physical and chemical breakdown of bedrock directly beneath the soil.

Transported parent material

the deposition of rock fragments that form a soil by streams, waves, winds, gravity, or glaciers.

Slope aspect

has a direct effect on microclimates and vegetative cover in areas outside of the equatorial tropics.

Laterization

is a soil-forming regime that occurs in humid tropical and subtropical climates as a result of high temperatures and abundant precipitation.

Laterite

these soils are generally reddish in color from iron oxides; and means “brick-like.”

Podzolization

occurs mainly in the high midlatitudes where the climate is moist with short, cool summers and long, severe winters.

Calcification

occurs in regions where evapotranspiration significantly exceeds precipitation.

Salinization

the concentration of salts in the soil, and is often detrimental to plant growth.

Gleization

occurs in poorly drained areas under cold and wet environmental conditions.

Exogenic processes

Geological phenomena and processes that originate externally to the Earth's surface. It breaks down rocks and erode fragments from higher energy, transporting them to locations of lower energy

Mass wasting

Gravity induced downslope movement of a rock material that happens without the assistance of a geomorphic agent is called ___

Erosion

The process that moves rock, soil, or other materials from one place to another, usually after it has been broken down by weathering. ____ involves the transport of materials by agents like water, wind, ice, or gravity.

Clasts

broken fragments of rock that detach from the original rock mass, can be large or small.

Physical weathering

Also known as mechanical weathering, disintegrates rocks, breaking larger blocks or outcrops of rock into smaller clasts.

Unloading

the process where rocks that were once buried deep beneath the Earth's surface are exposed to the surface and undergo pressure release.

Exfoliation

the successive removal of outer rock sheets; the process by which curved layers or sheets of rock peel off from the surface

Exfoliation Dome

an unloaded exfoliating outcrop of rock with a domelike surface form

Thermal Expansion & Contraction

A process in physical weathering where rocks expand and contract due to changes in temperature

Granular disintegration

The breaking free of individual mineral grains from a rock

Freeze-thaw

a type of physical weathering that happens when water repeatedly freezes and thaws inside cracks in rocks. Over time, this process causes the rock to crack and eventually break apart

Salt Crystal Growth

A type of physical weathering that occurs when salty water enters cracks or pores in rocks and then evaporates, leaving behind salt crystals.

Hydration

Water molecules attach to the crystalline structure of a mineral without causing a permanent change in that mineral’ s composition.

Chemical Weathering

Ions from a rock are either released into water or recombine with other substances to form new materials, such as clay materials

Oxidation

The chemical union of oxygen atoms with another substance to create a new product.

Solution

A chemical reaction causes mineral-forming ions to dissociate and the separated ions are carried away in the water

Carbonation

A common type of solution that involves carbon dioxide and water molecules reacting with, and thereby decomposing rock material.

Hydrolysis

Water molecules alone, rather than oxygen or carbon dioxide in water, react with chemical components of rock-forming minerals to create new compounds, of which the H and OH ions of water are a part.

Biological weathering

The process by which living organisms contribute to the breakdown of rocks and minerals, altering their structure over time

Joint

fractures in rocks along which there has been little or no displacement

Fault

fractures along which there has been displacement.

Folds

bends or curves in rock layers that form due to compressive forces in the Earth's crust.

Bedding planes

the surfaces that separate individual layers or beds of sedimentary rock.

Spheroidal weathering

is a type of chemical weathering that affects rock masses, causing them to take on a rounded or spherical shape. This process occurs primarily in jointed rock formations, where weathering begins along fractures and edges, gradually rounding the rock over time.

Differential Weathering

Occurs when softer or less resistant rock layers weather (break down) more quickly than harder, more durable layers. For example, softer sedimentary rocks like shale may weather rapidly, while harder rocks like sandstone or granite resist weathering.

Differential Erosion

After weathering, the eroded material is carried away by wind, water, or ice, and the same pattern occurs where softer rocks erode faster than harder ones. This process shapes landscapes, leading to features like cliffs, ridges, and valleys where the more resistant rock remains as elevated areas while the less resistant rock forms lower, eroded zones.

Friction

increases the roughness and angularity of a rock fragment and the roughness of the surface on which it rests

Rock strength

depends on physical and chemical properties of the rock and is reduced by any kind of break or gap in the rock

Soil

a thin layer of predominantly fine-grained, unconsolidated surface material; Soil moving downslope by gravity could involve only particles at the ground surface, or it could extend beneath the surface by no more than a couple of meters.

Debris

specifies a mass of sediment composed of a wide range of grain sizes, at least 20% of which is gravelsized.

Mud

indicates saturated sediment composed mainly of clay and silt, which are the smallest particles sizes.

Earth

where mass wasting involves a thicker unit of fine-grained, unconsolidated material, often tens of meters thick.

Slow mass wasting

a type of mass movement that happens so slowly, that no can watch the motion occuring, and, we can only measure the movement and observe its effects over long periods of time.

Fast mass wasting

the motion of this can be witnessed directly by people.

Creep

Slow, gradual, and almost imperceptible downslope movement of soil, rock, and debris under the influence of gravity.

Solifluction

Literally means “soil flow”; the downslope movement of water-saturated soil or regolith.

Active layer

lies above the permafrost layer; Freezes during winter but thaws during summer.

Falls

Mass wasting events that consist of Earth materials plummeting downward freely through the air

Avalanche

a type of mass movement in which much of the involved material is pulverized and then flows rapidly as an airborne density current along the Earth’ s surface.

Slides

a cohesive or semicohesive unit of Earth material slips downslope in continuous contact with the land surface

Slumps

rotational slides where earth (a thick block of fine-grained material) moves along a concave, curved surface

Landslides

large, rapid mass wasting events that are difficult to classify because they contain elements of more than one category of motion or because multiple types of material are involved in a single massive slides.

Flows

Masses of water-saturated unconsolidated sediments that move downslope because of the pull of gravity.

Earth flows

occur when a relatively thick unit of predominantly fine-grained, unconsolidated hillside sediment or shale becomes saturated and mixes and tumbles as it moves.

Debris flow

is a fast-moving flow of a mixture of soil, rock, and water. It typically occurs after intense rainfall or rapid snowmelt saturates loose material on steep slopes, causing it to flow downslope.

Mudflow

is a specific type of debris flow where the material is primarily composed of fine particles like silt and clay, with a high water content. ___ are highly fluid and can travel quickly, covering large areas.

Lahars

Mudflows composed of volcanic ash are called ___