Geol Lab

• The shaking or trembling caused by the sudden release of energy in the Earth's rock. Usually associated with faulting or breaking of rocks.
• Continuing adjustment of position results in aftershocks.

• Explains how energy is stored in rocks:
• Rocks bend until the strength of the rock is exceeded
• Rupture occurs and the rocks quickly rebound to an undeformed shape
• Energy is released in waves that radiate outward from the fault

The point within Earth where faulting begins; also called hypocenter

Focus

The point directly above the focus on the surface

• 80% of all earthquakes occur in the circum-Pacific belt
• most of these result from convergent margin activity
• more than 150,000 quakes strong enough to be felt are recorded each year

• Building collapse
• Fire
• Tsunami
• Ground Failure

Response of material to the arrival of energy fronts released by rupture

P and S waves

• Primary waves
• Fastest waves; travel through solids, liquids and gases; compressional waves

material movement is in the same direction as wave movement; P-waves

• Secondary waves
• slower than P waves; travel though solids only; shear waves

move material perpendicular to wave movement; S-waves

R and L waves

travel just below or along the ground's surface; slower than body waves, rolling and side-to-side movement; especially damaging to buildings

Reaction of P-wave to dilation and compression detected at seismic stations

pulling rocks apart (first movement down on a seismograph)

squeezing rocks together (first movement up on a seismograph)

• By seismic wave behavior:
• P waves arrive first, then S waves, then L and R
• Average speed for all these waves is known
• After an earthquake, the difference in arrival time at a seismograph station can be used to calculate the distance from the seismograph to the epicenter

showing the average travel times for P and S waves. The farther away a seismograph is from the focus of an earthquake, the longer the interval between the arrivals of the P and S waves

Three seismograph stations

by intensity and magnitude

subjective measure of the kind of damage done and people's reaction to it

intensity

magnitude

ground shaking

amplitude, duration, and damage increases in poorly consolidated rocks

by Earthquake precursors

changes in elevation or tilting of land surface, fluctuations in groundwater levels, magnetic field, electrical resistance of the ground; seismic dilatancy model; seismic gaps

the existence of year-round ice in the landscape

Continental and alpine

glaciers form whenever snowfall exceeds snowmelt year after year. The snow accumulates incrementally, pressure increases, and it is changed into never and then ice by this pressure.

a semicirculr or amphitheater-shaped bedrock feature created as glaciers scour back into the mountain. This is where the snow and ice forming the glacier first accumulates; it is the "headwaters" of a glacier.

Steep-sided, sharp-edged, bedrock ridge formed by two glaciers eroding away on opposite sides of the ridge.

Greenland and Antarctica

• 1.a graphical representation of the three dimensional shape of the earth's surface
• 2. a reduced, simplified, categorized/classified, symbolized and annotated representation of the earth's surface which has been projected on a horizontal plane

a family of lines drawn on the globe parallel to the equator

circles drawn on the globe that pass through the two poles

the process of constructing a map, the transferring of the meridians and parallel to a flat sheet of paper

a means of showing the relationship between the size of an object or feature indicated on a map and the actual size of the object on the ground.

Fractional, graphical, verbal

a contour line is an imaginary line on the surface of the earth connecting points of equal elevation

the difference in elevation between any two adjacent contour lines

a diagram that shows the change in elevation of the land surface along any given line

the water which is contained within the saturated zone beneath the Earth's surface

a process by which water is transported from one part of the Earth to another.

comprised of water and air filled spaces

a process by which water is returned to the atmosphere by the transpiration of living plants.

every pore space is completely saturated/filled with water.

upper surface of the saturated zone which divides the saturated zone from the unsaturated zone.

an underground unit of soil/rock/sediment that can yield a significant quantity of groundwater

the capacity of rock/unconsolidated material to transmit a liquid

measure of the volume of pore space per volume of rock/sediment

aquifers which are bound above and below by a confining layer.

layer of sediment/rock which has a lower permeability than the aquifer that is confines

confining layers

does not have a confining later above it

unconfined aquifer

when a well is excavated the level to which the water rises within the well

when the potentiometric surface is above the surface of the ground

pollution which has a single identifiable source of pollution

pollution that may come from a variety of sources and has no apparent source

the times is takes a given particle of water to traverse a given distance in a stream

all water molecules travel along similar parallel paths

individual water particles take irregular paths

• the amount of water flowing in a stream, which is the volume of water passing any point in a given time interval
• Area x Average Velocity

the rock particles and dissolved ions carried by the stream

particles that are carried along with the water in the main part of the streams

coarser and denser particles that remain on the bed of the stream most of the time but move by a process of saltation (jumping) by a result of collisions between particles, and turbulent eddies

ions that have been introduced into the water by chemical weathering of rocks. this load is invisible because the ions are dissolved in the water.

characterized by water flowing in a channel of some sort

relates to stream

the area of land that contributes water to stream; drainage basin

the upstream part of a stream near its origin

the downstream end of a stream where it empties into another stream or body of water

a smaller stream that joins a larger, mainstem stream

a larger stream that is joined by smaller tributaries

the steepness of the slope of the stream bed, generally steeper near headwaters and becoming gentler towards the mouth.

pools are deep and smooth. steps are formed by water running over a shallow rocky area (a bar) and down into a pool. Due to high gradient channels with rocky sediments.

riffles are shallow and turbulent of water flows over a bar

the bottom of the stream channel

the sides of the stream channel

gently sloping sediment deposited on the inside of the bend.

the deepest part of the stream channel

the movement of sediment from its source to another location

the width of a stream channel when the water just fills the channel but does not overlap the banks

The level are near a stream channel constructed by stream overflow during flood events.

abandoned floodplains and usually have a higher elevation that the present floodplains

resembles the branching of a tree, many tributaries flowing into the mainstream of the stream

channels that form right angle bends

channel flow outwards from the center, resembles the spokes of a wheel

channels flow to a center point

streams form concentric rings connected by short radical channels

the mainstream is intersected by angular tributaries, resembles a vine

random pattern

when the water level of a river is below the river's banks

when the water level is even with the banks

when the water level exceeds the banks

difference in elevation

rectangular sections of Earth's surface bound by lines of latitude and longtiude

true north

magnetic north

difference between MN and GN, is exact only for the year listed on the map

how maps are updated through aerial photographs to discover changed in the landscape

topographic maps are made from overlapping pairs of photos

lines marked with numbers

the elevation

a permanent marker, labeled as an X symbol on the map

measure of the steepness of a slope

the difference in elevation between the highest and lowest point a topo map

stripes of longitude having a width of 6 degrees

compass direction

rain that soaks into the ground

water in lakes and streams

melting snow

flow continuously through the year

flow only during certain times of the year

where sediments are deposited

entire stream drainage system

lines boundaries that separate stream drainage system

the small valleys in a drainage basin occur at it's highest elevation

point of origin of stream

process of form v-shaped erosion

end of river valley

the slope of the water surface

a distinctive topography that indicates dissolution of underlying soluble rock

surface depression formed by the collapse of caves or other larger undergrounf void spaces

valley-like depressions formed by a linear series of sink holes or collapse of the roof of a linear cave

places where water flows naturally from the ground

streams that terminate abruptly by seeping into the ground

icicle-like masses of chemical limestone that hang from ceillings

water flows naturally from the top of the well

winter accumulation of snow and ice exceeds the summer ablation

the loss of snow and ice by melting and sublimation to gas

direct change from ice to water vapor, without melting

regions of permanent snow cover

as snow and ice collect they become compacted and highly recrystallized under their own weight

ice melts or sublimes faster than new ice forms

the boundary between the zone of accumulation and ablation

the bottom end of the glacier

when a glacier melts, it appears to retreat up the valley from which it flowed

deposits of rocky gravel, sand, silt, and clay accumulate where there once was ice

drift that accumulates directly from the melting ice is unstratified

drift that is transported by the melt water becomes sorted by size

wind-transported glacial material

long glaciers that flow down stream valleys in the mountains

mergers of two or more valley glaciers at the foots of a mountain range

a vast, pancake-shaped ice mound that covers a large portion of a continent and flows independent of the topographic features beneath it

the upper end of the glacier is the large part that separates the flowing ice from the relatively immobile portion of the snowfield

the other cracks or open fissures that form when the velocity of ice flow is variable

perpendicular to the flow direction

aligned with direction of flow