GLS Final Exam

Porosity

Fraction of material that consists of open spaces (pores)

Permeability

A measure of how interconnected the pores are (how easily water can flow through the material)

Aquifer

A layer of high permeability

Aquitard

A layer of reduced permeability

Aquiclude

A layer of no permeability

Confined Aquifer

An aquifer that has an aquiclude above and below it (an aquiclude sandwich)

Common contaminated sources

• Sewage

• Agricultural fertilizers

• Pesticides

• Landfills

• Highway salt

• Underground storage tanks (gas stations)

• Mine tailings

• Preventing groundwater from contamination

• Containment methods: landfill rests on top of impermeable material, contaminants are contained

• Remove & treat: pump out bad water, clean the water, and the use the clean water or reinject

Landscape features that groundwater systems create

• Caves

• Speleothems

• Sinkholes

• Natural bridges

• Tower karst

What is a Karst? How does it form? Examples.

Landforms that form from interactions between carbonated rocks (limestone) and groundwater

• Caves

• Sinkholes

What is the relation between glaciers and sea levels?

If glaciers melt, sea levels rise; Glaciers store frozen water on land and when they melt, that water flows into the ocean which increases sea levels

Main factors that cause glaciation or general climate change

• Plate tectonics

• Orbital changes

• Impact events

• Big volcanic eruptions

• Human activity

How do plate tectonics affect global climate?

Causes widespread glaciation; opens seaways and can change the positions of mountains

Milankovitch Cycles

• Eccentricity

• Obliquity

• Precession

How do Earth’s orbital motions, also known as Milankovitch cycles, affect glaciation (or climate in general)?

Glaciation cycles appear to be directly or indirectly related to changes in the distribution of solar adiation as a result of variations in the Earths orbit around the sun

Isostatic Rebound Theory

The rise of land after the weight of glaciers is removed; glaciers make the land push down, but when removed the land rises

Albedo Effect

A measure of how much sunlight a surface reflects and helps control how warm or cool Earth becomes; light colors surfaces = cooler while dark colored surfaces = hotter

How do we know about past climate conditions? What kind of geological records do we examine to study past climate? 

• Sedimentary rocks, deep sea, and ice cores tells us past climate

• Isotopes

What are “greenhouse gasses”?

• Water vapor

• Carbon dioxide

• Methane

• Nitrious oxide

• Ozone

• Chlorofluorocarbons

How do greenhouse gasses affect the climate?

Sunlight passes through the atmosphere and warms the Earths surface, then heat then radiates back toward space, with most of the outgoing heat is absorbed by greenhouse gas molecules and re-emitted in all directions, warming the surface of the Earth and the lower atmosphere

How can oxygen isotopes be helpful?

Oxygen-16 evaporates more easily and is stored more in ice during glacial periods, leaving oceans enriched in oxygen-18

Where is the extra heat energy going from climate change?

In oceans!

Why is the extra heat going into oceans?

Oceans are dark in color and cover the majority of Earth

What are some geoengineering solutions proposed to “fix” global warming? 

• Increased reflectivity from low clouds 

• Ocean fertilization 

• Increased reflectivity from the oceans 

• Thinning high clouds 

• Biomass energy with capture and storage 

• Increased reflectivity of crops 

• Afforestation 

• Increased reflectivity from aerosols pumped into atmosphere 

• Increased reflectivity from deserts 

• Biochar 

• Direct capture and storage of CO2 

True or False? Freshwater is abundant on the Earth.

False. It is not abundant.

Which reservoir constitutes the largest fraction of the global FRESH water supply?

Glaciers

The percentage of total volume of rock or sediment that consists of pore spaces is called:

Porosity

If a low permeability layer overlies an aquifer, the aquifer is said to be:

Confined or a confined aquifer

An artesian well is free-flowing because the well surface is:

Beneath the water table

Which state does NOT use water from the Ogallala High Plains aquifer?

California

Which of the following rocks would make the best aquifer?

Highly fractured granite

A cone of depression is caused by:

Pumping a well in an unconfined aquifer

Which of these rock types is susceptible to karst formation?

Limestone

Which of the following is not a landscape created by groundwater?

Point bars

Which of the following is a factor that has an influence on climate?

The intensity of the sun, the distribution of water and land masses, ocean circulation, AND wind circulation

Types of rocks/materials that geologists study for past climate include:

• Ice cores

• Deep sea sedimentary cores

• Fossiliferous limestone

• Cave deposits

Increased uptake of CO2 by the oceans is currently causing ocean:

Acidification

A precise estimate of paleotemperature can be measure from marine sediments and ice cores using:

18O/16O Ratio

What is NOT a greenhouse gas?

Oxygen