Exam Flashcards
Earthquakes
shaking of the ground caused by movement along a fault or by the movement of magma
Primary Wave
compression waves; the fastest wave and can move through solids and liquids
Secondary Waves
transverse waves that are slower moving
Surface waves
transverse waves; slowest moving wave
Seismograph
tool to measure seismic waves
Focus
area underground where the plates shifted
Epicenter
need three seismograph readings to find epicenter of Earthquake which is the location where the quake originated
Richter scale
magnitude and strength of earthquake; 1-7
Modified Mercalli Scale
measures the damage done by the earthquake i-xii
Tsunami
seismic sea wave caused by an earthquake
Glaciers
large masses of moving ice and snow
Alpine/Valley Glacier
move due to gravity
Continental/Ice sheets
huge ice sheets that cover large parts of land
Why glaciers move
due to gravity, extremely slowly
Conditions needed to form
have more annual snowfall than snow melt
Steps in the formation of glacial ice
- Accumulation of snow
- Compression of snow into firn
- Compression of firn into ice
Moraines
deposits of rock and snow left by glaciers
Terminal Moraine
rock left in front of glacier
Lateral Moraines
rock deposited on the sides of a glacier
Medial Moraine
rock found in the middle of glaciers
Till
mixture of rock, sand, and soil deposited by a glacier
Outwash
very small particles deposited by glacial melt water
Erratics
large boulders moved by glaciers
Fiords
flooded glacial valley
Crevasses
a deep crack in a glacier
U shaped valleys
carved out by glaciers
Striations
parallel grooves carved into bedrock by glaciers
Terminus
front or lower end of the glacier
North shore of LI
terminal moraine
South shore of LI
outwash plane
Lake Ronkonkoma
Kettle lake formed by chunks of ice that melted
Causes of ice ages (6)
- elevation of large areas of land
- decrease in solar output
- change in earths orbit
- Increase in volcanic ash
- decrease in carbon dioxide
- continents moving towards the poles
