Exam 2 Flashcards
What is the definition for weathering?
Weathering is the physical, chemical, and biological breakdown of rocks.
What is the difference between physical and chemical weathering
Chemical weathering is the change in composition (form) while physical weathering is the mechanical/physical breakdown.
What are the different types of physical weathering?
Freeze-thaw - water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
Exfoliation - cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.
What are the different types of chemical weathering?
Oxidation, hydration, hydrolysis, and acid reaction.
Which mineral dissolves in carbonic acid?
calcite (mainly composed of limestone and marble)
How do we get carbonic acid?
mix carbon dioxide and water
In what type of climate is chemical weathering most affective?
warm and humid
What is mass wasting?
It’s a type of gravity erosion. (erosion by gravity)
What is the main driving force behind mass waisting?
gravity
What slopes are unstable when it comes to mass waisting?
The steeper the slope, the more unstable the slope. Horizontal is the most stable
What are the agents of erosion on the surface of the earth?
Gravity, water, wind and glaciers
Define creep.
The slow and perceptibly slow movement of material downslope
Define slide.
A translational movement of material downslope.
What is devine slump?
The rotation movement of material downslope.
The rotation movement of material downslope
The rotation movement of material downslope (usually in clay).
Define avalanche
A very fast chaotic movement of material downlope.
Define fall?
Fast movement of material down vertical slopes
What triggered the massive avalanche/landslide in Peru in 1970 that killed 25,000 people?
earthquake
What is bed load, dissolved load, and suspended load?
Bed load is the bottom of channel.
suspended load is the solids that make the water cloudy.
dissolved load is ions and solution.
What are point bar deposits
They are deposits of the edges (insides) of the meandering.
What is saltation?
The jumping of material in the channel.
What is river discharge?
The amount of water that passes through a channel per unit time.
On which side of the dam are sediments deposited, upstream or downstream?
Upstream
What is a delta?
A deposit at the mouth of the river.
Which is the largest river in north america?
The Mississippi river.
What is the factor that determines river velocity?
The gradience, then the amount of water in the channel, (which is the discharge) followed by the shape of the channel. gradience, channel roughness and what????
Volume of Water (gradience). The volume of water that flows through a river within a given amount of time – known as the discharge – also affects its velocity. As the volume of water in a river increases, through smaller streams flowing into it, for example, the velocity of the river increases.
What is a meandering river?
Forms seamless curves
Rivers flowing over gently sloping ground begin to curve back and forth across the landscape.
What is an oxbow lake?
a cutoff meander
a curved lake formed at a former oxbow where the main stream of the river has cut across the narrow end and no longer flows around the loop of the bend.
Which factor determines the whether a river is going to erode or deposit?
The speed, aka the velocity
What increases erosion downstream and decreases the balance of the ecosystem?
A dam
What is a water table?
The boundary the zone of aeration and the zone of saturation.
What is stalactite?
Deposits from the ceilings of the cave
What is porosity?
the percentage of void space in a rock. It is defined as the ratio of the volume of the voids or pore space divided by the total volume.
What is permeability?
a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.
What is an aquifer?
A porous permeable layer that can carry/hold water
What is stalagmite?
a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings.
What is an aquiclude?
It is the impermeable layer that doesn’t carry water.
What is carbonic acid?
Carbon dioxide mixed with water that causes limestone to dissolve
What is an artesian well?
Water that comes up naturally without being pumped.
karst topography?
A landscape that is characterized by numerous caves, sinkholes, fissures, and underground streams. Karst topography usually forms in regions of plentiful rainfall where bedrock consists of carbonate-rich rock, such as limestone, gypsum, or dolomite, that is easily dissolved.
What is a cone of depression?
occurs in an aquifer when groundwater is pumped from a well.
When you suck out a lot of ground water and it creates a downward cone
What causes of ice ages?
Fluctuations in the amount of insolation (incoming solar radiation).
Plate tectonics, atmospheric changes
What has been happening with the glaciers in the last 200 years?
They’re melting
What kind of glaciers are found in greenland and antarctica?
Continental glaciers
Where is the largest glacier in the world today?
Antarctica
What is a moraine?
a mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity.
A pile of sediments left behind by receding glaciers.
What is a terminal moraine?
The southern most marks the maximum advance of the glacier.
What is a medial moraine?
a ridge of moraine that runs down the center of a valley floor
What type of a moraine is found in Long island in the south fork? Terminal, minimal or recessional?
terminal moraine.
What is the name of the last ice age?
The Pleistocene Epoch
What kind of information do the ice cores provide? Like epica, why do we drill the ice cores in antarctica?
The oxygen isotopes which give us information of the past climate.
What shape are glacial valleys?
The fjords of Norrway, are U shaped.
When did the last ice age peak?
10,000 years ago
When we have a lot of ice on land, ice age what happens to sea level?
It decreases/lowers
What are wind processes are called?
aeolian
What is Loess?
It is wind blown dust
What is a deflation surface?
It’s when the wind removes the sand and leaves behind larger particles.
What is the name of the coastal dunes that are found near beaches?
parabolics
What is desertification?
Transformation of semi-arid regions into deserts.
Which is slowest and which is fastest?(creep or avalanche)
Creep is slowest. falls and avalanches are the fastest.
