Glossary
A
Albedo — The amount of solar radiation that is reflected back off a surface.
Altitude — Height above sea level.
Aquifer — One of many types of permeable rock. Pore spaces (tiny holes) between the grains, or fractures (cracks) allows water to flow through and accumulate in an aquifer rock.
Aquiclude — An impermeable layer of rock which water cannot flow through because there are no pore or fracture voids, or such voids are not connected together.
Aquitard — A rock with limited permeability that allows some water to pass through it, but at a very reduced rate.
Atmosphere — The atmosphere is a thin layer of gas and suspended particles surrounding the Earth and is composed mainly of nitrogen and oxygen but also small quantities of argon, carbon dioxide, neon, helium, methane, krypton, nitrous oxide, hydrogen, xenon and ozone (in order of decreasing amounts). The atmosphere has four layers: the troposphere up to an altitude of about 18 km, the stratosphere from 18 km to about 50 km, and the mesosphere from about 50 km to 82 km, beyond which is the thermosphere. Above 80 km the gases begin to thin out eventually leaving just oxygen in its atomic form.
B
Basin mires — Developed in a waterlogged basin which may be completely enclosed or only a very restricted through-flow of water.
Blanket mires — Formed on extensive flat or gently sloping ground usually in 'upland' ground.
C
Carbonaceous — A rock or sediment that is rich in carbon.
Carbon cycle — The natural cycling of carbon atoms between rocks, vegetation, oceans and the atmosphere.
Carbon sink — A part of the carbon cycling where carbon accumulates such as in calcium carbonate rocks.
Cement — The material, usually a very fine-grained mineral growth, which forms after a rock is deposited and bonds the grains of sediment together.
Climate — Average atmospheric conditions of an area. This is controlled by the latitude of the area, which determines how much solar radiation it receives, the distribution of land masses and oceans, the altitude and topography of the area, and the influence of ocean currents. See weather.
Crust — The outermost solid layer of the Earth up to about 70 km thick. There are two types: continental crust (which is older and thicker) and oceanic crust (which is younger and much thinner).
D
Diatoms — Single celled algae that have interlocking cell walls made of silica.
E
Eccentricity — The Earth's orbit around the sun changes from being almost circular to elliptical in shape every 100 000 years.
Enhanced Greenhouse effect — 'Greenhouse gases' are actually crucial to keeping our planet at a habitable temperature, without them the Earth would be about minus 17 degrees! Anthropogenic or human release of carbon dioxide is what is contributing to an additional or enhanced greenhouse effect.
Eustasy — A global change in sea level. Compare with Isostasy.
Evolution — The change in the characteristics of living organisms over successive generations, it occurs through the mechanism of natural and sexual selection.
F
Floodplain mires — Developed on waterlogged, periodically inundated river and stream floodplains and on coastal plains behind beach barriers and salt marsh. Often very extensive and include one or more buried peat sequences.
Foraminifera — Single-celled organisms (protists) with a hard shell
Fossil — Originally meaning anything dug from the ground, the term fossil is now restricted to naturally preserved evidence of an ancient organism. These include preserved parts of the original organism (such as bones, skin, hair, shell, teeth, leaves, bark, pollen), an imprint of a body part (such as the hollow left by a dissolved shell, or a footprint), or some other trace (such as mineralised dung, worm-casts or burrows).
Fossil fuels — A stored energy source, originally of organic (living) origin, that can be used as a fuel; includes coal, oil, natural gas, and peat.
G
Glacial — Characterised or produced by the presence or action of ice. A period of glaciation. See Interglacial.
Glacier — A mass of ice and snow which can deform and flow under its own weight.
Greenhouse effect — The natural 'trapping-in' of heat by greenhouse gases present in the atmosphere.
Greenhouse gas — A greenhouse gas is so-called because it absorbs infrared radiation emitted by the Earth's surface (the original energy source for this radiation is solar radiation), the absorbed radiation is trapped as heat in our atmosphere. Greenhouse gases in our atmosphere are: carbon dioxide, water vapour, methane, nitrous oxide, ozone and CFCs.
Groundwater — Water found underground within porous soils and rocks.
H
Holocene — The time period from 10 000 years ago to the present day.
Hydrological cycle — The movement of water through the environment by the processes of evapotransporation, condensation, wind transportation, precipitation, runoff, infiltration and interception.
I
Ice Age — A long period of glaciation.
Ice sheet — A glacier of more than 50 000 km2 with a flattened dome that buries the landscape.
Infilitration — The downward flow of surface water into the soil.
Interglacial — A phase of relatively warm temperatures between glacials. See glacial.
Interpolation — The process by which software invents new data to fill gaps in an image or grid.
Isostasy — The theoretical equilibrium that tends to exist in the Earth's crust; this can alter sea level on a local scale. For example, glacial ice can push down the crust so that when it melts the crust will uplift thus causing sea level in the area to decline. Compare with Eustasy.
Isotopes — Atoms of an element that have the same number of electrons and protons but different numbers of neutrons.
J
K
L
Latitude — Circles drawn around the Earth parallel to the equator; their diameters diminish as they approach the poles. These parallels have an angle provided from the angle from the equator i.e. 0 degrees at the equator and 90 degrees at the poles.
M
Maine transgressions — Advances of the sea over the land
Mantle — Inside the earth, the layer below the earth's crust but above the core
Marine regressions — Retreats of the sea over the land
Metamorphism — When a pre-existing rock is chemically or physically altered by heat, pressure or chemically active fluids.
N
Negative feedback — A process that is triggered by an initial change in an environmental variable so that the original 'normal' condition is restored. See positive feedback.
O
Obliquity — Earth rotates around an axis; the angle of this axis changes from 22.1 to 24.5 degrees.
Ombrogenous mires — Have a high-water table maintained by precipitation.
Open water transition mires — Developed from encroachment of vegetation around bodies of open water.
Orogeny — The process of mountain formation, especially by a folding and faulting of the earth's Crust.
Oxidised — A chemical reaction with oxygen or where electrons are lost. See reduced.
P
Photosynthesis — The process by which plants convert light energy to chemical energy. Carbon dioxide and water are changed into carbohydrates and oxygen in the presence of light and chlorophyll.
Plate tectonics — The Earth's surface (crust) is divided into huge fragments called tectonic plates which carry the continents on top of them. They move very slowly over the globe, past each other, away from each other or colliding and taking the continents with them.
Pleistocene — The period from 2 500 000 to 10 000 years ago, during which continental glaciers periodically expanded to cover sub-polar regions in both hemispheres.
Pore space — Spaces or voids between grains in the rocks in which air, water, other fluids or fine-grained mineral cements can be present.
Positive feedback — A process that is triggered by an initial change in an environmental variable which causes that variable to deviate further from the original condition. See negative feedback.
Precession — The slow circular movement, or 'wobble', of the Earth's axis of rotation around another axis.
Primary porosity — Porosity a rock has when it forms.
Q
R
Raised mires — Developed from another mire type, commonly from a basin or floodplain mire to be above the general groundwater influence.
Recharge — The natural process in which aquifers are replenished by rainwater reaching the water table.
Reduced — The loss of oxygen or gain of electrons in a chemical reaction. See oxidised.
Residence time — The length of time an element spends in a storage place (sink).
Respiration — The breakdown or organic compounds which releases energy and produces carbon dioxide and water.
Rock head boreholes – Boreholes that record rock head (RH) prove the base of the superficial deposits. These boreholes go all the way through the superficial and into the bedrock geology below.
S
Sea level — Sea level or mean sea level as it is sometimes known, is the average height of the ocean's surface between high and low tide. Changes in tides and wave conditions over time are averaged out to determine a 'still water level' that can be used to identify a real change in sea level or a change in the height of the land that a tidal gauge is measuring. In the UK, height above sea level is defined as 'Ordnance Datum' and this is the mean sea level at Newlyn Bay in Cornwall.
Schwingmoor — Floating rafts of peat.
Secondary porosity — Porosity that results from processes that occur after the rock has formed , such as fracturing or the more soluble grains dissolving.
Soligenous mires — Have a high-water table maintained by lateral water movement.
Spatial — The location of an object, its size, shape and relationship to other objects.
Spring mires — Often small, developed downslope of springs and seepage lines.
Subpolar — Latitudes of the Earth adjacent to the Arctic and Antarctic circle.
Subtropical — Latitudes of the Earth adjacent to the tropics.
T
Temperate forests — Forests in the temperate (mild, not extreme) climate zones.
Terminal depth borehole — Boreholes that record terminal depth (TD) are boreholes that end before going through the base of the superficial deposits. These boreholes can't prove the base of the superficial deposits, but can provide a minimum value for thickness.
Topogenous mires — Have a high-water table maintained by the generally low lying ground.
U
Unconsolidated — A sediment is unconsolidated if the particles are not attached together at all. As a sediment becomes more rock like it becomes more consolidated.
V
Valley mires — Elongate in form, developed on the lower slopes and floors of small valleys and channels with a through-flow of water along the main drainage axis. The water table is maintained, at least partly, by springs and seepage along the valley sides.
W
Water table — The level below which the pore spaces of the soil or rocks are completely saturated with water.
Weather — The physical conditions of the atmosphere (mainly the troposphere) with regard to wind, temperature, cloud cover, fog and precipitation (rain, hail, snow) at a specific time and place. It is highly variable and can be unpredictable. Compare with climate.
X
Y
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