71 terms

Lab Final

shows differences in elevation
Topographic Map differs from regular map
the difference in elevation between two points
true or false, index contours are not actual contour lines
Ratio scale used for larger numbers
difference between ratio scale and fractional scale
magnetic declination
caused by a slight misalignment between the Earth's rotational axis and the global magnetic field
true or false: magnetic declination does not change over time at a given location
quadrant bearing
expressed as degrees east or west of true north or south (with respect to)
azimuth bearing
expressed in degrees between 0 and 360 (N 0 or 360, E 90, S 180, W 270)
the slope of a stream along a selected segment
base level
the lowest level to which a stream can theoretically erode
the rate of stream flow at a given time and location
the amount of material transported by a stream
oxbow lake
formed when the outer edge of a meander is cut off
yazoo tributary
formed when a tributary cannot breach a river's levee, and flows parallel to the river
created when the water velocity decreases dramatically, such as when entering a lake, ocean or dry basin
channel pattern that occurs where rocks are fractured or faulted in two main directions that are perpendicular
channel pattern that develops on flat lying or homogenous rocks
drainage basin
the area of land that is drained by one stream
oxbow lake
crescent shaped lake (like a half moon)
point bar
the inside point of a river pointing to the direction the river turned
cut bank
the outside point of a river where it turns directions
the direction of a line formed by the intersection of the surface of an inclined rock layer and a horizontal plane
the angle between a horizontal plane and the inclined (tilted) stratum, fault or fracture
normal fault
fault that results from the hanging wall moving down with respect to the footwall (footwall doesn't move)
-caused by tension
reverse fault
fault which results from the hanging wall moving up with respect to the footwall (footwall doesn't move)
-caused by compression (rock shortening)
strike-slip fault
fault that results from the horizontal movement along the fault plane (vertical fault plane)
-caused by shear and involve motions of rocks
block diagram
a combination of the geologic map and two cross sections; small 3D model of a portion of earth's crust
hanging wall
the top surface of the fault
the bottom surface of the fault
boundaries between plates (oceanic and continental)
where most earthquakes occur
limbs dip away from center (hinge); oldest rocks are in the middle, youngest on the outside
limps dip toward the hinge (center); oldest rocks are on the outside, youngest on the inside
underground origin of the earthquake, in bedrock
the point of earth's surface directly above the focus
Richter scale
logarithmic scale, uses actual numbers
Mercalli scale
scale that is a set of definitions based upon what people in the area feel
P waves
the fastest waves
L waves
the slowest waves; cause most of the generally recongnizable earthquake surface effects
S - P time interval
the time it takes for the secondary waves of an earthquake to hit after the primary waves hit
the amount of seismographs needed to determine the exact location of an earthquake
P wave
moves up and down continuously
S wave
moves up and down and also in a slinky motion
L wave
huge waves
rocky coasts
ocean waves strike shores with immense energy
soft sediment coasts
eroded much more easily on a human scale, but slower on a geologic scale
wave energy
builds as it reaches the shoreline; intersects at oblique angles
longshore drift
the movement of sedimentary materials along the coast created by swash and backwash
-flow parallel to the coastline and move vast amounts of sedimentary material
beach budget
the amount of sedimentary material carried to and removed from the beach
rip currents
form at right angles to the shoreline and carry material out to deeper water
moves material a minor amount
bring sediments to the beach usually the same amount as removed (no gain or loss)
terrigenous sediments
the most significant supply of new material entering the beach budget
-sediments from land surface carried by river to the coast
coastal control
a continuous project, seawalls can damage beaches and hurt the turtles because they try to clim up the walls when laying eggs and fall over and get stuck on their backs
parts of a coastline
barrier island, estuary, headland, longshore current, marine terrace, sea stack, spit, hook, wave-cut cliff
barrier island
a long, narrow deposit of sand, parallel to the coast and raised above sea level, by the action of waves
-formed by either sand dunes drowned by rising sea level, or spits and bars formed by the refraction of waves
part of the sea where saltwater is mixed with freshwater, often in a drowned river valley
projection into the sea, usually by land underlain by rock resistant to erosion (generally associated with uplifted coasts)
longshore current
a current in the near shore surf zone created by the action of wind and waves
marine terrance
a flat surface eroded by the action of waves that is often uplifted and exposed above sea level on coasts that have been tectonically uplifted
sea stack
a pinnacle of rock isolated from the coast by the erosion of a headland
a long, narrow stretch of sand deposited by longshore drift and longshore currents when the land ends at a bay
a spit that is turned inward at its outermost end by the action of currents, waves, and tides
wave-cut cliff
a steep cliff facing the ocean that has been cut by the ocean
a structure built to protect an offshore area, such as a harbor, from the action of waves
a structure build to protect a portion of th eshore from loss of sand and to prevent erosion
a structure erected to retain current velocity in channels and entrances to harbors in order to diminish siltation of the filling in of the channel by sediments
a structure erected at the shore to stop erosion or extend the shore
if a seismogram's first motion is upwards, is the block on with the seismograph is attached undergoing compression or dilation?