Geology Final Exam Study Guide - Vocabulary

Flashcards of key vocabulary terms and definitions from the lecture notes.

Magnitude

Numerical measure of the size of an earthquake determined from seismic records and related to the energy released by the earthquake.

Isostasy

Equal standing, adjacent blocks of crust are equal in terms of pressure beneath them even if they are at different elevations.

Craton

Interior region of a continent stable for more than 500 million years with low elevation.

Dynamic Topography

Surface elevation affected by mantle convection.

Precious water

The small fraction of Earth's water that is accessible and usable for life, emphasizes the scarcity and value of usable water.

Quarrying

Process of lifting and removing large chunks of rock from the bed or banks of a stream.

Abrasion

The grinding or swirling action of sediment and rock fragments carried by the stream scraping against the channel bed and walls.

Corrosion

The dissolving of rock by chemical reactions with the water.

Dissolved load

Ions and minerals dissolved in water and carried in solution.

Suspended load

Fine particles like silt and clay suspended in water.

Bedload

Large grains that roll, bounce, and slide along the bottom of a stream channel.

Settling velocity

The speed at which a particle falls through water when the water is calm.

Bedrock channels

Streams cutting into solid rock near headwaters.

Alluvial channels

Bed and banks are composed largely of unconsolidated sediment (alluvium) that was previously deposited in the valley.

Meandering channels

A single main channel that has various loops and curves down its path.

Braided channels

A series of small channels that are interwoven into a larger one.

Oxbow lake

Curved, crescent-shaped lake next to a river, formed when a meander is cut off.

Delta

Forms where sediment-laden streams enter the relatively still waters of a lake, inland sea, or the ocean.

Natural levees

Raised banks along the sides of a river made naturally by sediment deposition.

Alluvial fans

Fan-shaped deposits of sediment that form at the base of mountains where a river suddenly slows down on flatter land.

Regional floods

Seasonal rapid melting of snow, heavy rain, happens slowly over large areas after long periods of heavy rain and snowmelt.

Flash floods

Often occurs with little warning and are potentially deadly because they reduce rapid rises in water levels and can have devastating flow velocities.

Ice Jam Floods

Happen when floating ice blocks a river, causing water to back up and flood.

Dam Failure Floods

Happen when a dam breaks, sending a huge rush of water downstream which can result in a flash flood.

Shoreline

The line that marks contact between the land and sea.

Rip currents

Flow in the opposite direction of breaking waves, concentrated movement of backwash that moves along the surface instead of along the bottom.

Hurricanes

The greatest storms on Earth, also called typhoons, or cyclones.

Storm surge

Dome of water 65-80 km wide that sweeps across the coast near the point where the eye makes landfall.

Track forecasts

Predicted paths of hurricanes.

Hot towers

Very tall warm cloud formations inside the hurricane that can signal that the storm is strengthening.

Groundwater

Water that is not held as soil moisture percolates downward until it reaches a zone where all the pore spaces are refilled with water.

Water table

Upper limit of the zone of saturation.

Saturated zone

Area underground where all the pores and spaces are completely filled with water.

Unsaturated zone

Area above the saturated zone where pores contain both air and water.

Gaining stream

Receive water from groundwater systems.

Losing stream

Provide water to the groundwater system.

Artificial recharge

The practice of using injection wells or infiltration ponds to assist groundwater recharge.

Porosity

The amount of empty space pores in a rock or sediment where water can be stored.

Permeability

How easily water can flow through a rock or sediment.

Aquifers

Rocks or sediments with high porosity and high permeability.

Aquitards

Rocks or sediments with low permeability.

Well

A hole bored into the zone of saturation.

Perched water table

Small localized water table above the main one, often on a layer of impermeable rock.

Artesian system

Water is confined to an aquifer that is inclined so that one end can receive water.

Spring

A natural outflow of groundwater that occurs when the water table intersects the surface.

Geysers

Intermittent hot springs or fountains in which columns of water are ejected with great force at various intervals.

Geyserite siliceous sinter

Water contains dissolved silica.

Calcareous tufa

Water contains dissolved calcium carbonate.

Stalactite

Hang from the ceiling of caves.

Stalagmite

Grow up from the floor of caves.

Karst Topography

Formed by the dissolution of soluble rocks, especially limestone.

Karst towers

Isolated, steep limestone hills left behind as surrounding rock is dissolved away.

Proxy Data

Air bubbles trapped in ice cores.