Exam 3

Rock Elasticity

-Higher elasticity results in higher velocities

Rock Density

-higher density results in higher velocities

What would be the angle of inclination of rocks in Ecuador (equator)

0º

Nuclear Fission

1) Neutrons bombard the Uranium atom 2) Uranium atom splits and emits neutrons and heat energy 3) Chain Reaction

Frequency of flooding is measured by:

1) Recurrence interval 2) Exceedence probability

Continent-continent collisions result in:

1. Closing of an ocean basin 2. Increasing the surface area of a continent 3. Thickening the crust -->high topography 4. If crust becomes TOO thick it collapses

What temperature do organic rich sediment need to achieve to transform into oil?

100-120º

The angle of inclination is ___________ at the magnetic north pole.

90º

Seismograph

A device that records ground movements caused by seismic waves as they move through Earth

continental shelf

A gently sloping, shallow area of the ocean floor that extends outward from the edge of a continent

Meander cutoff

A new, shorter channel across the narrow neck of a meander.

P Wave

A type of seismic wave that compresses and expands the ground.

S Wave

A type of seismic wave that moves the ground up and down or side to side

Discharge

An outflow of water from a stream, pipe, groundwater aquifer, or watershed. The rate of flow = volume / unit time (e.g. cubic feet/second, ft3/s)

Hydraulic Radius calculated by

Area / Perimeter

Mature Stage

Atlantic Ocean

Earthquake Belts

Bands around the edges of the continental plates and in areas where two plates come together. The belt is that connection of the plates. The Pacific Ring of Fire is all the edges of these plates.

Change in magnetic inclination

Changes with latitude

Where do we have the highest velocity of Seismic Waves?

Core

How do we calculate Discharge?

Discharge (Q) is measured using a simplified form of the Continuity Equation: Q = V x A V = average flow velocity A = cross sectional area of water (channel)

Embryonic Stage

E African Rift Valley

Tsunami

Earthquake produced Tidal Wave • Long wavelength to short wavelength • Low Amplitude to high amplitude

Richter scale

Earthquakes are classified according to their magnitude, a measure of the amount of energy released during the EQ.

Mercalli Intensity Scale

Earthquakes classified by their intensity which is based on the observed damage to various structures

Where do Earthquakes Occur?

Earthquakes occur along faults where the temperature of the crust is "low" ~300o and below

Where do earthquakes occur?

Earthquakes occur along faults where the temperature of the crust is "low" ~300o and below

Velocity of Seismic Waves varies with rock properties

Elasticity & Density

Faults Move (Slip) Two Different Ways

Fault creep and stick-slip

Stick-Slip

Fault stays "locked" storing up elastic energy, then suddenly slips, releasing the stored energy. Big EQs

Oil Traps

Geologic environments that allow economically significant amounts of oil and natural gas to accumulate underground All oil traps consist of a reservoir rock and a cap rock.

Resovoir rock

HIGH porosity & permeability

Crest (wave)

Highest point of a wave

Suture Stage

Himalayan Mountains

Wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Cap Rock

LOW porosity & permeability

Greenhouse effect is caused by?

Long wavelength

Trough (wave)

Lowest point of a wave

polar wandering curves

Magnetic record trail that can be used to determine movement of a plate over time

Remnant Stage

Mediterranean Ocean

Greenhouse effect

Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases

Immature Stage

Red Sea

Earth's layered structure

Seismic waves tell us about the shape and composition of the interior of the Earth:

Compression results in:

Shortening and thickening of the crust

Fault Creep

Slow, gradual displacement (motion) Small EQs

What is forming the S wave Shadow Zone?

Something opaque to shear waves - i.e. something liquid

Alluvial streams

Streams that cut within reworked stream-deposited material

Drainage Basin

The area from which a single stream or river and its tributaries drains all of the water

Seismic Refraction

The bending of seismic waves as they pass from one material to another.

Falling Limb (Hydrograph)

The decrease in river discharge as the river returns to its normal level

Paleomagnetism

The study of natural remnant magnetization preserved in rocks in order to determine the intensity and direction of the Earth's magnetic field in the geologic past

S-Wave Shadow Zone

Those areas more than 103 degrees from an earthquake focus where no S-waves are recorded.

Lag Time (Hydrograph)

Time between peak rainfall and peak discharge

Manning's Equation

V = (1.5 R ^(2/3) x S^(1/2) / n V = Average Water Velocity n = Mannings Roughness Coefficient ( a measure of the resistance to flow) R = Hydraulic Radius ( a measure of the efficiency of the channel cross section) S = Slope of the Energy Gradient (approximated by the slope of the channel)

What two values do we use to measure Discharge

Velocity and Area

Earthquake

Vibration of the Earth caused by the rapid release of energy. Often, earthquakes are caused by slip on faults.

Geomagnetic reversal

When the north magnetic pole becomes the south magnetic pole and vice versa

Fe-rich minerals become magnetized ____?

When they cool below their curie point and become magnetized in the direction parallel to the existing magnetic lines of force.

Oxbox lake

a cresent-shaped body of water formed when sediments deposited by a river cut off a meander from the river.

Hydrograph

a graph which shows the the discharge of a river, related to rainfall, over a period of time

Triangulation Earthquakes

a method that utilizes the arrival time difference of S&P waves at three seismograph stations to locate the focus point of an earthquake

Epiccenter

a point on Earth's surface right above the focus of an earthquake

Fault scarp

a small step on the ground surface where one side of a fault has moved vertically with respect to the other

continental slope

a steep incline of the ocean floor leading down from the edge of the continental shelf

Meandering Stream

a stream with a channel that curves or loops back and forth on a wide floodplain

recurrance interval

average number of years (n) between events of similar or greater magnitude (m) RI = N + (1 / m)

Point bar

deposit of sediment build up by a river on the inside bend of a meander

Cutbank

eroded stream bank on the outside of a meander curve

meander scrolls

indicate historical migration of meander bends

The Earth's magnetic field has reversed polarity throughout geologic time. Evidence for this phenomenon is

magnetic seafloor stripes

Magnetic Stripes

provide evidence of sea floor spreading when they show the reversal of magnetic fields

Nuclear Energy

radioactive materials (Uranium) release energy by the process of Nuclear Fission.

Gravitational collapse results in

stretching and thinning of the crust

angle of inclination

the angle that the line of force makes on the horizon the angle between the Earth's magnetic field and its surface.

continential rise

the gently sloping section of the continental margin located between the continental slope and the abyssal plain

Amplitude (wave)

the height of a wave's crest

Hydrologic cycle

the movement of water through the biosphere

Seismogram

the record of an earthquake's seismic waves produced by a seismograph

Elastic Rebound

the sudden return of elastically deformed rock to its undeformed shape

Curie point

the temperature at which a mineral become magnetized (~580 C).

Period (wave)

the time that elapses between passing crests (or troughs)

Rainfall

the total rain, snow, or sleet that falls in a period of time

hypocenter

the underground focus point of an earthquake.

abyssal plain

very level area of the deep-ocean floor, usually lying at the foot of the continental rise

Runoff

water that flows over the ground surface rather than soaking into the ground = Rainfall - Infiltration

Components of a wave

wave length, trough, crest, amplitude

Seismic Survey

when a shock wave is sent into the ground surface, and the reflected sound waves are recorded

What Determines the Volume of Floodwaters at a Specific Location?

• Amount of Rainfall (inches or cm.) • Amount of Infiltration (inches or cm.) • Area of the Drainage Basin (mi2 or km2)

The Wilson Cycle

• Embryonic Stage • Immature Stage • Mature Stage • Declining Stage • Remnant Stage • Suture Stage

Streams can move by one of the following processes:

• Lateral Migration • Meander Cutoff

Isostasy

• Less dense crust floats on top of the denser and deformable rocks of the mantle • Concept of floating crust in gravitational balance is called isostasy • If weight is added or removed from the crust, isostatic adjustment will take place as the crust subsides or rebounds

Lateral migration

The sideways shift in the position of a stream channel over time

Sinuosity

The sinuosity of a stream is a measure of how much it is meandering.

Waves Speed

P: Fast S: Intermediate Surface: Slow

Waves Period

P: Shortest S: Intermediate Surface: Longest

Waves Amplitude

P: Smallest S: Intermediate Surface: Largest

Waves Medium

P: Solid, liquid, gas S & Surface: only solids

Declining Stage

Pacific Ocean

Flood peak

The highest level that a river reaches during a flood.

Rising Limb (Hydrograph)

The increase in river discharge as rainwater flows into the river

Exceedence Probability

The probability (p) of an event of a particular magnitude being equaled or exceeded any given year is. P = 1 / RI