geology final exam

ORDER OF WATER STORAGE

Oceans > Glaciers > Groundwater > Lakes & Streams

WHAT IS A STREAM?

A body of flowing water confined to a channel.

WHAT IS EROSION?

The removal and transport of sediment by water, wind, or ice.

WHAT IS DEPOSITION?

The settling or dropping of sediment when water loses energy.

HIGH-ENERGY WATER CAN CARRY

Pebbles, sand, and mud (all grain sizes).

LOW-ENERGY WATER CAN CARRY

Mud and sometimes sand; cannot carry pebbles.

HOW DOES A STREAM START?

Runoff concentrates into small channels that grow into larger streams.

WHAT IS A DRAINAGE BASIN?

The land area where all water drains into the same stream system.

WHAT IS A DIVIDE?

A boundary separating drainage basins.

CHICAGO AND DRAINAGE BASINS

Chicago destroyed a natural divide to reverse the Chicago River into the Mississippi basin.

CONSEQUENCES OF REVERSING CHICAGO'S DIVIDE

Pollution transfer, invasive species, and long-term ecological impacts.

BRAIDED STREAMS

Multiple channels, high sediment load, unstable, wide and shallow.

MEANDERING STREAMS

Single winding channel with stable flow and distinct bends.

EROSION IN A MEANDERING STREAM

Occurs on the outer bend (cut bank).

DEPOSITION IN A MEANDERING STREAM

Occurs on the inner bend (point bar).

HOW MEANDERING STREAMS GROW

Bends migrate outward, forming wider floodplains and oxbow lakes.

WHAT HAPPENS AT A DELTA?

A river slows and deposits sediment where it enters a lake or ocean.

WHAT IS GROUNDWATER?

Water stored in pore spaces and fractures beneath Earth's surface.

WHAT IS POROSITY?

The amount of empty space in a rock.

WHAT IS PERMEABILITY?

How easily water can flow through a rock.

HIGH POROSITY, LOW PERMEABILITY ROCK

Has many pores but they are not connected (e.g., clay or pumice).

WHAT IS RECHARGE?

Where groundwater enters the ground.

WHAT IS DISCHARGE?

Where groundwater exits naturally (springs, rivers).

SATURATED ZONE

Below the water table; pores completely filled with water.

UNSATURATED ZONE

Above the water table; pores contain air + water.

WATER TABLE

Boundary between saturated and unsaturated zones.

HOW WATER TABLE SHAPE CHANGES

It generally follows land surface topography.

WHAT HAPPENS WHEN HUMANS DRAIN WATER TABLES?

Water tables drop, causing wells to dry and land to subside.

WHAT IS ARTESIAN WATER?

Groundwater that flows upward under natural pressure.

OGALLALA AQUIFER ISSUE

It is being pumped faster than it recharges, causing major depletion.

WHAT IS POINT-SOURCE POLLUTION?

Pollution from a single identifiable source.

POINT-SOURCE POLLUTION (MICHIGAN)

The 2010 Kalamazoo River oil spill (Enbridge Line 6B).

WHAT IS NON-POINT-SOURCE POLLUTION?

Pollution from many diffuse sources.

NON-POINT-SOURCE POLLUTION (MICHIGAN)

Agricultural runoff leading to Lake Erie algal blooms.

WHAT IS A GLACIER?

A large, moving mass of ice formed from compacted snow.

TWO TYPES OF GLACIERS

Alpine: small, in mountains, flow downhill. Continental: huge ice sheets covering land.

HOW DO GLACIERS FORM?

Snow accumulates, compacts, and begins to flow under its weight.

WHEN WERE THE ICE AGES?

Last 2.6 million years; geologically recent.

HOW DID THE ICE AGES START?

Changes in Earth's orbit reduced sunlight and cooled climate.

HOW GLACIERS SHAPED MICHIGAN

Moraines, outwash plains, and formation of many lakes.

WHAT IS AN ORE?

A rock containing valuable minerals that can be mined profitably.

WHAT IS ORE GRADE?

The concentration of valuable minerals in the ore.

WHICH HAS HIGHER GRADE?

Natural/native minerals typically have higher grade.

SURFACE MINES

Large quantities, lower grade.

UNDERGROUND MINES

Smaller quantities, higher grade, more expensive.

WHY MINES OPEN OR CLOSE

Mineral prices change.

HOW COPPER ORE FORMS

Hydrothermal fluids deposit copper in veins.

HOW IRON ORE FORMS

Bog iron (wetland precipitation) and banded iron formations (ancient oceans).

WHERE EARTH GETS MOST HEAT

The Sun.

HOW THE ATMOSPHERE CONTROLS TEMPERATURE

Greenhouse gases trap heat; fewer gases = cooling.

HOW SUNLIGHT CHANGES OVER TIME

Milankovitch cycles: orbital, tilt, and wobble changes.

EARTH TEMP WITH NO SUN

Near absolute zero.

EARTH TEMP WITH SUN & NO GREENHOUSE GAS

About 0°F (-18°C).

MODERN EARTH TEMP

About 59°F (15°C) with 0.04% greenhouse gases.

HOW GREENHOUSE GASES WORK

They absorb and re-radiate infrared heat back to Earth.

HOW PETROLEUM FORMS

Buried organic material is heated and compressed over millions of years.

MODERN CLIMATE CHANGE

Vastly faster than past cycles due to human emissions.

YEARLY CO2 CHANGE

CO2 rises in winter and falls in summer due to plant growth.

WHAT IS RENEWABLE ENERGY?

Energy that replenishes on human timescales.

WHAT IS NON-RENEWABLE ENERGY?

Energy that takes millions of years to form and is limited.

SOLAR ENERGY PROS & CONS

Pros: abundant, clean. Cons: intermittent, needs sun.

WIND ENERGY PROS & CONS

Pros: renewable, cheap. Cons: inconsistent, noisy.

HYDROPOWER PROS & CONS

Pros: reliable, consistent. Cons: disrupts ecosystems.

GEOTHERMAL PROS & CONS

Pros: constant, clean. Cons: location-limited.

BEST US AREAS FOR SOLAR

Southwest (AZ, CA, NV).

BEST US AREAS FOR WIND

Great Plains (TX to ND).

BEST US AREAS FOR HYDROPOWER

Pacific Northwest and mountain regions.

BEST US AREAS FOR GEOTHERMAL

Western US near tectonic activity (NV, CA, ID).