Earth systems

Hominids

extinct members of the human lineage

3 Milankovitch cycles

Eccentricity - shape of earths orbit around the sun

Obliquity - angle of earths tilted axis

Precession - changes in earths wobble

Diagenesis

loose sediment derived from erosion, compacting into sedimentary rock through physical, chemical and biological processes

Orogenesis

the geological process of natural mountain building resulting from the structural deformation, folding, faulting, and uplift of the Earth's lithosphere

Accretionary prism

a mass of deformed sediment scraped off a subducting oceanic plate and piled up against the overriding plate at a convergent boundary

Flysch

a sequence of alternating hard and soft sedimentary rock layers that accumulate in deep marine environments during the early stages of mountain building

Denudation

overall process of wearing away and removing surface material from the Earth's crust (weathering and erosion combined)

Amelioration

fixing or making a bad environmental situation better for ecological balance, human or agricultural use

Regolith

in situ weathered products e.g. rock fragments that overlay fresh rock, may eventually become soil

Spheroidal weathering

a form of chemical weathering that causes jointed or fractured metamorphic bedrock to decay into concrete spheres

Insolation weathering

a form of physical weathering caused by the repeated heating and cooling of rock surfaces from solar radiation over daily cycles

Tafoni

small, rounded hollows in rocks like sandstone and limestone

Honeycomb weathering

geological process that creates a network of small hollows on a rock surface, giving the appearance of honeycomb

Aspect

the compass direction that a slope or terrain surface faces

Stalactites

icicle shaped mineral deposit that hangs from the ceiling of a cave, cavern or man-made structure

Stalagmites

a mound or column rising from the cave floor where the water drips, depositing calcium salts

Karren

ribbed and fluted rock surface that forms due to differential solution

Karst

a distinctive landscape type characterised by solutions weathering, most is limestone

Solution doline

a closed, low surface depression formed by the chemical dissolution of soluble bedrock from the surface downward

Dinural

a process that completes a full cyclical change over a 24 hour period

Brackish

water with a salinity higher than freshwater but lower than seawater

Null points

a hypothetical location in nearshore waters where a specific grain of sediment experiences no net movement landward or seaward (local dynamic equilibrium)

Homogenised water column

a vertical section of water from the surface to the seafloor that has uniform physical and chemical properties throughout its entire depth

Stratification

formation of stable, distinct horizontal water layers

Sill

a submerged, relatively shallow seafloor barrier that restricts movement of water between 2 basins

Anoxia

an environmental condition where dissolved oxygen is completely depleted in a body of water or sediment

Autotrophs

primary producers, most plants, harness solar energy to form biomass from simple inorganic sources

Heterotrophs

reliant upon other organisms for energy (consumers)

Insolation

the amount of incoming solar energy that reaches a given area of earths surface

Vegetation communities

groups of plant species that occur together in a specific area, forming distinct and recognisable ecological units

Ecosystem

community of living organisms (plants and animals) interacting with each other and their non-living environment, including communities, geology, topography, soils, hydrology and microclimate

Biomes

A major ecological community extending over large areas where the dominant plants have a similar overall growth form, these are strongly correlated with regional climate e.g. savannah in Africa

Ecological niche

The position occupied by individual species within an ecosystem, in terms of function, space and time, determined by its functional role and its position along environmental gradients

Vegetation zones

large-scale geographical regions with similar types of plant life, primarily determined by variations in climate (temperature and precipitation) across latitudes and altitudes

Glacial refugia

plants that survived during the ice ages continue to grow in the holocene

Biogeochemical cycles

The cyclical movement of elements between living organisms (biotic phase) and their non-living (abiotic) surroundings e.g. rocks, water, air.

Geochemical cycles

Cycles of physical erosion and return to reserves, operating on a long time scale

Haber-Bosch process

converts atmospheric nitrogen to ammonia by a reaction with hydrogen using a metal catalyst under high pressure and temperature - led to creation of wartime explosives and synthetic fertilisers

Nitrate vulnerable zones

land that drains into nitrate polluted waters, or water which could become polluted by nitrates

Biogeography

the study of the past and present geographic distribution of life and earth

Island biogeography

the study of the distribution and dynamics of species in island environments, islands provide a natural laboratory for studying the effects of environmental factors on biodiversity due to relative isolation from continental species

Adaptive radiation

a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches

MacArthur and Wilson’s theory

Species presence depends on distance from mainland and the richness of the source

Edemism

the distribution of a species that is limited to a small geographical area

Dynamic equilibrium in biogeography

through time, the number of species present balance out as the rates of colonisation and extinction stabilise

Conservation in biogeography

knowledge on islands helps preserve biodiversity in these environments

Atmosphere structure (upwards)

Trophosphere, stratosphere, mesosphere, thermosphere

Aerosols

suspended particulates (microscopic droplets) in the air

What is sensible heat?

changing the temperature of material without changing its state

What is latent heat?

changing the phase of a material

Absolute humidity

Mass of water vapour per volume of air

Saturated humidity

maximum absolute humidity, it decreases with temperature

Relative humidity

absolute divided by saturated

tells us how close air is to being saturated with water vapour

Radiation

energy that travels through space or matter

Absorption

uptake of radiative energy (shortwave or longwave radiation) by gases or particulate matter in the atmosphere

Heat

transfer of energy from one body to another driven by a difference in temperature

Temperature

measure of the average seed of atoms and molecules

Convection

transport of heat through vertical motion of air

How much water is in the oceans?

97% / 1.4 billion cubic km

Sea

smaller than an ocean, partially or completely enclosed by land

Gulf

a body of water with a narrow opening into a larger body

Strait

A narrow passage of water connecting two larger bodies of water

What does the suffix ‘cline’ indicate?

a region of rapid property change e.g. thermocline

Thermohaline circulation

The global ocean circulation system driven by differences in temperature (thermo) and salinity (haline), which together determine seawater density.

Cryosphere

consists of all parts of earth where water is present as ice permanently or recurrently

Snow cover

seasonal snow on land not otherwise covered by ice

Permafrost

ground continually frozen for 2 or more consecutive years