GEO110 1-5

System

any order/interrelated set of componenets and their attributes, linked by flows of energy and matter

Endogenic system

includes internal processes that produces flows of heat and material from deep below the earths crust

Exogenic system

operates at the earth’s surface, it involves external processes that set into motion air, water and ice, all powered by solar energy

principle of superposition

rock and sediment are arranged such that the youngest layer of rock/sediment is pushed or superposed to the top, and the oldest rock is at the base

mineral

inorganic (nonliving) natural compound having a specific chemical formula and possessing a crystalline structure

Rock

assemblage of minerals bound together, or a mass of a single mineral, or solid organic material, all bound together

Igneous

it’s formed through volcanic molt (fire-formed)

Sedimentary

made by settling out in water

Metamorphic

altered by heat and pressure

Plate tectonics

Theory that the lithosphere is divided into a number of plates and the activity of such plates creates earthquakes and builds new mountains

Convergent boundaries

occur in areas of crustal collision and subduction, where areas of continental and oceanic lithosphere meet, crust is compressed and then lost in a destructional process as it moves downward into the mantle

Divergent Boundaries

occur in areas of seafloor spreading, where upwelling material from the mantle forms new seafloor and lithospheric plates spread apart in a constructional process

transform boundaries

occur when plates slide past one another, usually at right angles, to a seafloor spreading center

Topography

term for shape of earth’s surface

relief

vertical elevation differences in the landscapes

first order of relief

coarsest level, consists of continental landmasses and ocean basins

second order of relief

intermediate level, mountain passes, plains, lowlands, mid ocean ridges and oceanic trenches

third order of relief

most detailed level, includes individual mountains, cliffs, valleys, hills, and other smaller scale landforms

craton

nucleus on which continent grows is an old and stable part of the continental crusts

continental shield

region with a craton that is exposed at the surface

platform

continental area covered by relatively flat or gently tilted sedimentary strata

tension stress

causes stretching strain

compression stress

causes shortening strain

shear stress

causes twisting laterally strain

Rocks become deformed or folded(bend) when they are:

subjected to compressional forces

Anticline

the rock strata slopes upwards away from the hypothetical center axis

syncline

the rock strata slopes downwards away from the center axis

faulting

occurs when rocks on either side of the fracture shift relative to the other side

strike slip fault

sides of the fault are displaced horizontally

dip slip fault

sides of the fault are displaced vertically

orogeny

means mountain building

Energy released from an earthquake:

magnitude of the earthquake

intensity of shaking is:

ground motion

focus of an earthquake:

subsurface area along a fault plane where the motion of seismic waves is initiated

epicenter:

area at the surface directly above the focus

aftershock

may occur after the main shock

foreshock

precedes the main shock

Richter’s scale

based of amplitude of seismic waves, which is related to energy released

Moment Magnitude scale

based on the amount of fault slippage produce, size of surface area that ruptured, and the nature of the materials that faulted, which is more accurate than richter’s scale

A slope is stable if

the strength exceeds the weathering and erosion processes(gentle slope, clay soil)

A slope is unstable if

the slope materials are weaker than the weathering and erosion processes

Weathering processes

break down rock at earth’s surface and to some depth below the surface, either disintegrating rock into particles or dissolving it in water

physical weathering (mechanical weathering)

process of rock breakage without any chemical alteration

Chemical weathering process

refers to decomposition and decay of the constituent minerals in rocks due to chemical reaction, it is always done in the presence of water

regolith

broken up rock due to weathering

joints

fractures or seperations in rock that occur without displacement of the sides

Karst topography

refers to a limestone region with a specific landscape of pitted, bumpy surface topgraphy, poor drainage and well developed solution channels underground, due to chemical weathering

sinkholes

created by the weathering of limestone landscapes

Mass movement

process involved in mass movement and erosion of the landscape

angle of repose

represents a balance between the driving force (gravity) and resisting force (friction and cohesion)

geomorphic threshold

in any mass movement, gravity pulls on a mass until the critical shear failure point is reached, the material can then fall, slide, or flow

Fluvial

means River

Two driving forces of fluvial systems:

insolation and gravity

high drainage density

associated with humid climate

low drainage density

associated with a typical desert

dendritic drainage

dendron as in tree, energy expanded by this drainage system is efficient because the overall length of the branches is minimized

trellis

drainage pattern is characteristic of dipping or folded topography

radial drainage

pattern results when streams flow off a central peak of dome of a hill or mountain

parallel drainage

associated with steep slopes

rectangular drainage

formed by a faulted and jointed landscape which directs stream courses in patterns of right angle turns

annular drainage

pattern of stream flow in which the stream tends to form a circular path around the hill

deranged drainage

often in areas with disrupted surface patterns, such as the glaciated shield regions of Canada, no clear geometry

gradient of a stream

defined as the drop in elevation per unit distance

base level

level below which a stream cannot erode its valley