EXAM 6 Flashcards
Resources that can be replenished over relatively short timespans
Renewable Resources
Significant deposits that take millions of years to form
Nonrenewable Resources
How much World** Energy consumption comes from non-renewable resources
90%
How much US Electricity Consumption comes from non-renewable resources
60%
Fuel sources derived from remains of marine plants and animals
Oil & Natural Gas
Solid fuel source formed mostly from plant material
Coal
Useful metallic minerals that can be mined at a profit.
Ore
Most minerals have very ___ concentrations in ore rocks
Low
Separation of heavy minerals that crystallize early
Magmatic Segregation
Metal-rich fluids that are remnants of late stage magmatic processes. Moves along fractures, cools, and precipitates metallic ions to produce vein deposits.
Hydrothermal solutions
Concentrating metals into economically valuable concentrations.
Secondary Enrichment
Deposits formed when heavy metals are mechanically concentrated by currents
Placers/Placer Deposits
Glaciers in mountainous areas that flow down a valley from an accumulation center at its head.
Valley (alpine) glaciers
Ice flows out in all directions from one or more snow accumulation centers
Ice Sheets
Which form of glacier is bigger?
Ice Sheets
Movement of Glaciers
Flow
Flow occurring within the ice
Plastic flow
Entire ice mass slipping along the ground
Basal Slip
Area where a glacier forms
Zone of accumulation
Area of a glacier where there is net loss
Zone of wastage
2 ways that glaciers erode the land:
Plucking and Abrasion
Tall u-shaped glacial valley structure
Hanging valley
A thin, jagged crest that separates—or that once separated—two adjacent glaciers.
Arete
Bowl-shaped depression on the side of or near mountains.
Cirque
Pointed peaks bound on at least 3 sides by glaciers
Horn
Most glacial valleys have a characteristic __ shape.
U
unsorted glacial sediment.
Till
comprised of layered deposits of sand, gravel, silt and clay laid down thousands of years ago by glacial meltwaters.
Stratified drift
a mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity.
Moraine
A ______ moraine forms along the sides of a glacier. As the glacier scrapes along, it tears off rock and soil from both sides of its path.
Lateral
A ______ moraine is found on top of and inside an existing glacier. _____ moraines are formed when two glaciers meet.
Medial
A _____ moraine is also sometimes called an end moraine. It forms at the very end of a glacier
Terminal
_________ moraines are often observed as a series of transverse ridges running across a valley behind a terminal moraine.
Recessional
A _________ moraine consists of an irregular blanket of till deposited under a glacier.
Ground
formed of glaciofluvial deposits due to meltwater outwash at the terminus of a glacier.
Outwash plains
________ form when a block of ice leaves the glacier, submerges into the ground and melts.
Kettles
Smooth elongated parallel hills that can be used to identify the direction of glacial movement.
Drumlins
Formed by glaciers pushing inwards on the earth’s crust
Crustal subsidence
Proper reforming of crust after glaciers causing crustal subsidence has stopped.
Crustal rebound
Possible cause of glaciation explained by variations in earth’s orbit.
Milankovitch Hypothesis
Methods for detecting changes in earth’s climate
Either temperature or precipitation
3 most important factors in the atmosphere.
Water vapor, aerosols, and CO2
____ & ____ absorb ultraviolet radiation given off by earth.
Water vapor & CO2
______ act as surfaces for condensation, also serving as good absorbers & reflectors.
Aerosols
Process where radiant energy that is absorbed heats Earth and is eventually redirected skyward.
Natural Greenhouse Effect
__% of incoming solar radiation is actually absorbed by the earth’s surface
50%
Natural occurrences that can have an effect on earth’s climate
Plate tectonics, variations in earth’s orbit, volcanic activity, changes in Sun’s output.
Changes that reinforce initial changes are called:
Positive-feedback mechanisms
Produce results that are the opposite of the initial change and tend to offset it:
Negative-feedback mechanisms
Difference between Instrumental records and proxy measurements
Instrumental - Comparative data collected over the last ~100 years; Proxy - Environmental happenings that give clues to history.
Approximate concentration of CO2 currently present in our atmosphere
440 ppm
