Unit 4

Question 1

Igneous Rocks

Answer 1

Formed by the cooling and solidification of magma/lava
Classified by crystal size, texture, and composition
The crystal size is influenced by the rate of cooling (rapid cooling = small/no crystals and glassy) (slow cooling = large crystals)
Composition is influenced by minerals present (granitic = lighter, less dense material) (basaltic = darker, denser materials)

Question 2

Sedimentary Rocks

Answer 2

Formed from sediments cementing together, the evaporation of seawater, or the deposition of organic material
Only type that contains fossils
Often deposited in layers in an aquatic environment

Question 3

Metamorphic Rocks

Answer 3

Formed by extreme heat and pressure
Distortion and banding

Question 4

Th theory of Plate tectonics

Answer 4

The convection currents in the mantle are what drive continental drift in the crust.
(Mantle material near the core is hotter, becomes less dense, and it rises towards the surface. The material near the surface is cooler and pushed out of the way, and the plates above are dragged along with the surface)

Question 5

Converging Plate Boundaries

Answer 5

Converging plate boundaries (two plates converging together)
Uplift: both are pushed upward
Subduction: the denser plate is pushed down and under
Features: mountains, volcanoes, islands, earthquakes, trenches

Question 6

Divergent Plate Boundaries

Answer 6

Divergent plate boundary ( two plates moving away from each other
Seafloor spreading occurs, where the seafloor is growing because new crust is being created
Features: mid ocean ridge, rift valleys, volcanoes, hydrothermal vent communities, earthquakes

Question 7

Transform Plate Boundaries

Answer 7

Transform plate boundaries (two plates sliding past each other in opposite directions)
Ex san andreas fault, where lots of earthquakes occur

Question 8

Volcanoes

Answer 8

Classified as active, dormant, or extinct. Eruptions occur when magma is released out of the crust
Some are a slow ooze of lava, others are huge explosions
Short term effects: catastrophic destructions, new land masses
Long term effects: climate change: release aerosols like fine ash are released into the atmosphere where they reflect light away from earth, lowering global temps.

Question 9

Earthquakes

Answer 9

As plates move, friction builds along the boundaries and faults. Sometimes, the plates bet stuck, and potential energy continues to build after they got stuck. An earthquake occurs when the buildup is suddenly released sending seismic waves in all directions
Types of waves: P waves(fastest, arrive first) and S waves (arrive second)
Can create massive damage around the epicenter
Are the primary cause of tsunamis

Question 10

Weather vs climate

Answer 10

Weather is the current condition of the atmosphere. Short term, changes rapidly
Climate is the general pattern of weather conditions, observed over long periods of time for a specific location. These patterns exist after 30+ years, even thousands, and change very slowly if at all

Question 11

Incoming Solar radiation

Answer 11

Can be shortened to insolation. Most of Earth’s heat/energy comes from the Sun, but it’s radiation is not evenly spread across the surface. Earth is tilted off at a 23.5 degree angle, and the equator is usually the area of highest insolation while the poles are the lowest. Depends on latitude & time of year

Question 12

Seasons

Answer 12

The angle of insolation for a particular region is influenced by the time of year. As a pole is angled towards the sun, more angle of insolation (summer). As a pole is angled away from the sun, less angle of insolation (winter).
The more horizontal an area is to the sun, the more insolation it gets

Question 13

Air and ocean currents (how they impact each other)

Answer 13

Earth receives most of the sun’s energy at the equator which creates convection currents
Water has a higher specific heat, it absorbers more of the energy from the sun. This warms up the area’s atmosphere even more (The ground can radiate this heat back as well)
This mass movement of warm air/surface water influences regional climates/biomes

Question 14

Vertical Air currents

Answer 14

Convections cells develop vertically in the atmosphere and line up along specific latitudes
These are HADLEY CELLS near the equator
FERREL CELLS at the mid latitudes
And POLAR CELLS near the poles
When two cells meet and air is sinking, there is dry, high pressure air that creates arid biomes (deserts)
Where two cells meet and air is rising, there is moist, low pressure air that creates humid/stormy biomes (rainforests)
SEE DIAGRAM 1

Question 15

global surface winds

Answer 15

Uneven heating causes air to move across the ground from areas of high pressure to low pressure. Thus, this always means winds blow from low latitudes to high latitudes. However, due to the Coriolis effect, the winds do not move in straight lines. These winds have been critical to maritime trade in the past
SEE DIAGRAM 2

Question 16

Coriolis Effect

Answer 16

The APPARENT deflection of an object’s path due to the rotation of the earth.
Because the earth is a sphere and the equator is wider than the poles, the earth is spinning faster at the equator (since it has a farther distance to cover). As the object moves from the equator north, it APPEARS to bend to the right since the earth is spinning SLOWER the further north you go (opposite in the south)

Question 17

Rain Shadow Effect

Answer 17

Air evaporates over the ocean and is moved on land by prevailing winds
As the air is pushed UP the windward side of the mountain, it cools and condenses.T his causes the moisture to fall out as precipitation. Usually leads to high productivity
The now dry air is pushed over the peak and down the leeward side causing it to warm and expand
This warming and expansion promotes evaporation, creating an arid biome
(windward faces the wind and leeward is protected from it)

Question 18

Physical Weathering

Answer 18

Water: freezes into cracks of rocks and expands, forcing the rock to split or cracked
Temperature: sometimes ice or other large changes in temperature cause a rock to crack, split, melt, etc because minerals expand or contract
Constant light pressure from wind or water can also change a rock overtime
Biological agents: like plant roots or burrowing animals also take advantage of cracks and increase surface are
oftentimes , physical weathering exposes more surface area and makes rock more vulnerable to further degradation, and increases rate of chemical

Question 19

Chemical Weathering

Answer 19

Releases nutrients from rock which is good for organisms
Occurs more rapidly on newly exposed minerals (primary minerals)
It alters primary minerals to form secondary minerals
Rain: acids in rain react with rock to form ions and particles etc
Lichen: break down rock with weak acids
Rocks containing compounds that dissolve easily weather easily
The chemical composition of rock and the pH of water that contacts it can change the reaction that occurs
Ex. carbonic acid in water flows over limestone, it dissolves the stone and makes cool cave systems
Sulfur emitted from fossil fuels forms Sulfur dioxide in atmosphere and degrades rock rapidly through acid precipitation
Acid precipitation on soil can chemical weather the soil and release elements
Because weathering certain granite consumes carbon dioxide from the atmosphere, weathering can reduce CO2 in the atmosphere

Question 20

Erosion

Answer 20

you know this

Question 21

How Soil is Formed

Answer 21

It takes hundreds to thousands of years to form, it is the result of physical/chemical weathering of rocks and accumulation of detritus (waste) from the biosphere
Young soul has less organic matter and nutrients than developed soil, while very old soils are also sometimes nutrient poor because they’ve been sucked dry
5 factors decide properties: parent material, climate, topography, organisms, time for formation

Question 22

Soil Horizonsssss

Answer 22

O horizon: Made of organic matter like leaves, and is mostly found in forests/grasslands. (Humus) The lowest layer of the O horizon, where most matter is fully decomposed and does not contain recognizable plant or animal components. “Humic material” can sometimes be sparsely found lower down as well
A horizon: Also known as topsoil, a mixed layer of both organic and mineral materials. Very important in agriculture
E horizon: Sometimes it forms in acidic soils. Where iron, aluminum and organic matter is dissolved and transported from above to the B horizon
B horizon: Also known as subsoil, mostly made of minerals but may have a bit of nutrients.
C horizon: The least weathered horizon and is very similar to parent material
SEE DIAGRAM 3

Question 23

Physical Properties of soil

Answer 23

TEXTURE, POROSITY, PERMEABILITY (all decided by the % mixture of sand, silt and clay)

Question 24

Chemical Properties of soil

Answer 24

Clay particles in a soil contribute most to chemical properties because they attract positively charged mineral ions (cations) and have a - charge themselves. cations are taken in and then used for nutrients by the plants
A soil’s ability to absorb and release cation is called its cation exchange capacity (CEC) (soils with high CEC are better for agriculture). The CEC is a function of the amount and type of clay particles present
If a soil is >20% clay, there is too much water retention for agriculture so too much CEC causes less permeability

Question 25

Soil bases vs acids

Answer 25

Soil acids are usually harmful for plants, while bases aid plant growth
All soil bases except sodium are crucial for plant nutrition
ex. bases: calcium, magnesium, potassium
ex. acids: aluminum, hydrogen

Question 26

Layers of the Atmosphere

Answer 26

TROPOSPHERE: Where most of the atmosphere’s N2, O2, and H2O is found. Has a lot of circulation within and thus is where weather occurs
Temperature decreases as it gets farther from the surface
STRATOSPHERE: Less dense than the troposphere, and holds the ozone layer, a pale blue gas made of O3 that protects the earth from most of the sun’s UV-B and UV-C radiation. The radiation is converted to infrared radiation and released as heat
The stratosphere’s temp increases as it gets higher up (more sun rays)
MESO/THERMO/EXOSPHERE: They are all less and less pressurized and dense
The thermosphere is also critical for UV protection, and is where the northern lights occur

Question 27

What is a watershed

Answer 27

A watershed is all of the land in a given landscape that drains into a particular stream lake or other body of water

Question 28

Parts of a watershed

Answer 28

The divide: line marking the highest points around a body of water. Separates one watershed from another and create an outline
Tributaries: smaller streams and river that feed into the main river
River: the main source of water flowing into the largest water feature in a region
Delta: where the largest tributaries empty into the main body of water and located at the mouth of a river.
Groundwater/aquifer: water that has infiltrated underground and is held in sediments
Source Zone: also known as headwaters, fed by precipitation or snow/ice melt
Transition zone: portion of the system between the head and mouth of river
Floodplain: usually flat and wide open space along the river, and represent where the water goes when the river floods.

Question 29

Effects of Vegetation on Watershed

Answer 29

Slow the movement of water through the soil and drastically decrease the amount of erosion that occurs

Question 30

Effects of Topography on Watershed

Answer 30

steeper slopes have faster flow of water (and permeability affects this as well) and larger watersheds collect more water

Question 31

Intermediate Disturbance Hypothesis

Answer 31

The intermediate disturbance hypothesis says that ecosystems experiencing intermediate levels of disturbance will favor a higher diversity of species than those with high or low disturbance levels
When disturbances are rare, there is intense competition and eventually only a few populations dominate the entire system. When they are large, it’s hard for a species to get an upper hand at all

Question 32

Groundwater

Answer 32

The area closest to the surface holds little groundwater, below this area there is a space where the pores are 100% filled with water. This is the zone of saturation. The top of this zone is called the water table, and it changes depending on water and human use. When an area has water ponding on the surface, it is oversaturated
Rate of infiltration and the amount of water the ground can hold is determined by the sediment size of the soil
Directly related to porosity and permeability

Question 33

Aquifers

Answer 33

Regions with deep, saturated sediments and represent a significant source of freshwater (can flow)
Unconfined: aquifer is covered in permeable soil (rechargeable)
Confined: capped with an impermeable layer and the water is under pressure (harder to recharge)
Some are renewable resources others aren’t
Pollutants are nearly impossible to remove from an aquifer

Question 34

Cone of Depression

Answer 34

As water is pumped out of an aquifer, the water table subsides near the well called the cone of depression. THe faster it is the steeper it is and it acts like a hill

Question 35

The Trade Winds

Answer 35

Northern Trade WInds (north of equator) and Southern Trade Winds (south of)
Formed due to the coriolis effect
Surface winds moving towards the equator are deflected to the west
Creates a prevailing wind: a major surface wind that blows almost constantly

Question 36

Neutral Conditions (Walker Circulation)

Answer 36

Trade winds blow across the pacific and push the warm surface off the coast of Australia (east to west)
The warm water evaporates and creates stormy conditions s in Australia and the other surrounding islands
When the air comes back to south America, its now dry and dense (descends)
This causes upwelling from deep cold water that comes to the surface, which is also nutrient rich
This addition of nutrients trigger algae blooms which support a diverse range of marine species

Question 37

El Nino conditions

Answer 37

Happens when TRADE WINDS are WEAKER than normal. The westerly winds then come in to change things up
Evaporation spreads east as well and there’s more rain in the middle of the pacific/ eastern pacific
Warm water is not fully pushed around (stays in the east). This means the warm water stays in place and upwelling is much weaker, and this brings less nutrients up to the surface and the ecosystem collapses (bad for the economy as well)
Effects (general):Warm and dry conditions in southern and eastern Australia and southeast Asia, Drier winter conditions in Brazil and South Africa, Wetter than normal along the gulf coast and the West Coast of Tropical South America, Milder winter in Alaska and Canada
DIAGRAM 4