Earth Science Final Flashcards
What type of weather is most associated with each of the types of weathering?
chemical- warm, wet climates
mechanical- cold and wet or dry climates
What is the difference between mechanical and chemical weathering?
mechanical weathering is the breakdown of rock that takes place when a rock is broken into smaller pieces of the same material without changing its composition. chemical weathering is the breakdown of decomposition of rock that takes place when minerals are changed into different substances
what causes ice wedging?
when water freezes in the cracks of a rock and wedges it apart (because it expands)
How do plants mechanically weather rocks?
the roots plant themselves into the dirt in the cracks in a rock and as they expand it mechanically weathers the rock
How does particle size affect weathering rate
smaller particles will weather faster than larger particles because they have more surface area
describe the relationship between particle size and settling rate
if the particle size increases, then the amount of time it takes to settle in water decreases
what is found in each horizon of a soil profile
A Horizon- top soil, gray to black, contains humus decaying organics
B Horizon- subsoil, red/brown, clay and other minerals leach (wash) down from above
C Horizon- partly weathered bedrock
How is the thickness of a soil layer related to the weathering rate of the bedrock beneath it?
the faster the rate of weathering, the thicker the soil will be
What are the 4 agents of erosion?
gravity, wind ,ice (glaciers) water
What are the 3 ways that a river can carry sediment? What type of material is carried in each way?
solution-dissolved material
Suspension- fine material in turbulence
Bedlad- heavy particles dragged along bottom
Why do different areas of rock experience differential rates of erosion
A rocks resistance to weathering affects how fast it weathers. Limestone is easily weathered while granite and sandstone are much harder
What are the 3 stages of river development? What are the characteristics of each stage?
young, narrow Straight, v shape, fast water,, potholes, steep slope
mature, valley widens, flood plains starts , meanders begin, slower water, less slope
old, wide flood plains, slow water, bromeanders oxbow lakes, yazoos
Where do caverns form in Virginia? What is the bedrock in this area? What is the name for this type of top[ography?
caverns are in the valley and ridge province of virginia. the bedrock is limestone and it is known as karst topography
What is a divide? What is the largest basin in the United States and where are its divides?
high land that separates drainage basin
What are the layers of the groundwater system from the surface down?
zone of aeration, water table, zone of saturation
How does the type of surface material affect the rate of rainfall runoff
rainfall runoff is greatest for impermeable surfaces (like pavement and urban areas) and less for permeable surfaces (like farmland and forests)
Where do most earthquakes and volcanoes occur?
at plate boundaries (the ring of fire on the edges of the pacific plate)
WHat is evidence for plate tectonics?
earthquakes and volcanoes, sea floor spreading, pattern of magnetic reversal on the sea floor
What is the difference between a focus and an epicenter?
the point where an earthquake occurs is called the focus (origin)
an epicenter is the point on the surface above this place
What are the 2 types of seismic body waves? How did each one move?
P (primary) wave travels the fastest through any material.
Push-pull (compression)
S (Secondary) wave only travels through solids. Side to side
What causes plate movement? How does this behave at a divergent boundary? At a convergent boundary?
Convection currents ause plate movement. The currents rise an move plates apart at a divergent boundary.
They sink and pull plates together at a convergent boundary