Earth Science Lab Exam 1

Seismic Amplitude

it measures the height of a seismic wave relative to its zero baseline

P-Wave

P waves arrive before S waves; it travels through solids, liquids, and gases

S Wave

S waves arrive after P waves; passes through solids only

Love Waves

love waves are surface waves; travels through Earth’s surface

Rayleigh Waves

rayleigh waves are surface waves; travels through Earth’s surface

Focus

location underground where earthquake begins

Epicenter

point on Earth’s surface directly above focus

What is the dew point?

the temperature to which air must cool to become completely saturated

When does saturation occur?

when air temp reaches it

What does Relative Humidity measure?

measures the amount of water vapor currently in the air compared to the amount of water it can hold at its temp

When does Relative Humidity change?

RH changes when there’s a shift in temperature, amount of moisture in the air, or atmospheric pressure

How can Fog form near the surface?

when the air near Earth’s surface cools down to dew point

Stages of Fog

air cools, approaches dewpoint, saturation, condensation, fog

How to find Heat index?

you need air temp (dry bulb) and relative humidity

How to find Wind Chill?

you need air temp and wind speed

Formula for Fahrenheit

F = (C * 1.8) + 32

Formula for Celcius using Fahrenheit

C = (F -32) / 1.8

Formula for K

K = C + 273.15

Formula for Celcius using Kelvin

C = K - 273.15

High Pressure System

winds circulate clockwise and surface air moves outward

Low Pressure System

winds circulate counterclockwise and surface air moves inward

Hurricanes

low pressure system; they flow counterclockwise in northern hemisphere and flow clockwise in southern hemisphere

Cold Front

replaces warm air with cold air; causes hail, strong winds, tornadoes, lightning

Warm Front

replaces cold air with warm air; causes light precipitation

Dryline

boundary between dry air and moist air

Contour Line

every point on that line has the same elevation

Contour Intervals

difference in elevation between two adjacent contour lines

Contour Crossing

may cross when showing a vertical or overhanging cliff

Slope

lines close together = steep slope
lines far apart = gradual slope
evenly spaced lines = constant slope

Closed Contours

Hill: closed contour lines with elevations increasing towards the center
Depression: closed contour lines with elevations decreasing towards the center

Streams & Valleys

contour lines form a “v” shape when crossing a stream
“V” points upstream, toward higher elevation

Hardness

minerals resistance to being scratched

Grain Size

size of individual mineral or rocks particles; helps identify what type of rock

Streak

color of mineral’s powder; surface color can vary but streaks are usually consistent

Cleavage

mineral’s tendency to break along smooth, flat planes

Fracture

how a mineral breaks when it doesn’t break along cleavage planes

Acid Reaction

small drop of hydrochloric acid if it fizzes it likely contains carbonate minerals