Chapter 3 info earth science

At the equator, is salinity low or high? How about 20-30 N and S? How about at the poles when sea ice is forming?

At the equator salinity is low, at 20-30 N and S Salinity is High. At high latitudes cold water increases in salinity when ice forms and sinks.

1. What kinds of rocks do we find on Mars? What else do we find evidence of?

Basalt and volcanic rocks

What is a biofuel? What are some examples of different biofuels? What are some disadvantages to using biofuels in your engine?

Biofuel: fuel derived from biomass (recently living organisms or their metabolic byproducts); Pros: Biofuels are a renewable resource; Cons: Combustion produces carbon dioxide and other greenhouse gases

What kind of deposits do we find copper in, in Utah?

Bornite and Chalycopite

1. How can glaciers impact drainage systems?

Changes in stream courses: the advance and retreat of ice sheets can significantly alter a region's topography and thus, its drainage system.

What are our two types of weathering processes? Can they occur at the same time? What are our three kinds of chemical weathering?

Chemical and Mechanical Weathering , yes.

How do the two different stable isotopes of oxygen that we discussed in class today differ in terms of their physical behavior? How are they fractionated during evaporation?

Chemical and biological processes can sort the light from heavy isotopes. Results in the change in ratio of heavy to light. Often Temperature dependent.

What is a proxy, in general? What are some of our proxies, and how do they work/what do they tell us about, specifically?

Climate Proxies • General proxies: - Glacial extent - Leaf shape - Dendrochronlogy - Pack rat middens • Stable isotopes: a really precise temperature proxy • Ice cores: another really precise proxy (especially for CO2

1. What do glaciers do to the underlying land? You should be able to explain why glacial rebound happens, and what this process is. Where is it currently happening in North America?

Crustal subsidence and rebound results from the addition and removal of the emense weight of continental ice sheets. Example: Since the last North American glaciers retreated (18,000 years ago), sites in Canada are rebounding at rates of 5 mm/year, while sites in the US south of the Great Lakes have largely stabilized, tipping the water in the Great Lakes.

What are our three Milankovitch cycles and what do they impact?

Eccentricity ,Tilt, Precession (wobble). The earths rotation.

2. How has resource use changed in the last 100 years (both in terms of total amount used, and in terms of what we are using to produce energy)?

Energy consumption has increased significantly over the last 100 years. 75% from fossil fuels.

What are gas hydrates, and where do we find them? What is the big downside of potentially utilizing them as a fuel source?

Gas Hydrate: a solid form of water that contains a large amount of methane within its ice-like crystals; - Exists at low temperature and high pressure; - Natural deposits on ocean floor and in permafrost; Cons: Methane is an even more efficient greenhouse gas than carbon dioxide.

1. How much of Earth's surface was covered by glaciers during the Pleistocene (and when was the Pleistocene)? How did this impact sea level, and what happens to sea level when glaciers melt?

Glaciers covered 30% of the ground surface in the Pleistocene. Sea level change: melting glaciers releases water into oceans, raising sea level.During the last ice age the sea level was about 400 feet lower than it is today.

What are PGEs? What are they associated with?

Group Elements, platinum.

6. What is the Zachos curve, and how far back in time does it extend?

His seminal work on a multi-site compilation of stable isotopes measurements throughout the Cenozoic resulted in an iconic graph, now known as the "Zachos curve", which has become the standard view on climate change throughout the Cenozoic. His high-resolution measurements enabled the study of orbital variations showing clear eccentricity pacing of the carbon cycle and climate changes prior to the onset of Northern Hemisphere glaciations.

How do we get oil out of shales? Why do we need sand to do this?

Hydrofracking, When the high-pressure water stream forces the small perforations to become larger fractures, frac sand holds these fractures open to continue releasing fossil fuels.

How do diamonds reach the surface?

In conduits within ultramafic rocks called kimberlite pipes

What do phytoplankton need to bloom, and how does this relate to upwelling?

Iron rich/ limiting nutrients cause agal and fishery booms, but upwellings can bring these nutrients to the surface and cause these blooms as well.

1. What was Glacial Lake Missoula, and what happened there?

Lake Missoula was a prehistoric proglacial lake in western Montana that existed periodically at the end of the last ice age between 15,000 and 13,000 years ago. The lake measured about 7,770 square kilometres and contained about 2,100 cubic kilometres of water, half the volume of Lake Michigan.

Varves

Layers found in sedimentary rocks that show seasonal variations

How do we optimize placement of wind farms?

Location and orientation of turbines and wind farms are optimized with climate and atmospheric circulation data.

. What happened during the PETM, and why (what was our source of greenhouse gases)?

Methane clathrates built up by archaebacteria • 5‐8°C warmer • VERY rapid warming (maybe in as little as 6,000 year

Recognize the different types of nonmetallic mineral resources.

Natural aggregates (crushed stone, sand, gravel); • Gypsum (plaster and wallboard); • Clay (tile, bricks, and cement).Fertilizers (nitrate, phosphate, and potassium compounds); • Sulfur (sulfuric acid to manufacture phosphate fertilizers); • Salt (used in chemical industry, "softening" residential water, and keeping streets ice-free

What are the primary types of fossil fuels, and what are they derived from?

Oil (petroleum) and natural gas consist of hydrocarbon compounds; • Derived from the remains of marine plants and animals; • Both are formed over millions of years in similar environments. Oil Sand: a mixture of clay and sand combined with water and bitumen (a viscous, degraded form of oil); Oil shale: fine-grained, dark sedimentary rock with enough organic material to yield oil or combustible gas upon distillation; Gas Hydrate: a solid form of water that contains a large amount of methane within its ice-like crystals;

What are oil sands, and what are some of the pros and cons of using them as a fuel source? Where do we find them, worldwide?

Oil Sand: a mixture of clay and sand combined with water and bitumen (a viscous, degraded form of oil); Pros: There are several substantial oil sand deposits around the world; Cons: Obtaining oil from oil sands is difficult and expensive to extract and has major environmental drawbacks

What major deposits do we find in Iowa, associated with limestones?

Pb-Zn deposits, and Galena.

3. What are the three primary energy sources today?

Petroleum, Natural Gas, Coal.

What are the two processes by which glaciers flow? How fast can they move?

Plastic Flow: movement of ice within a glacier when, under pressure, ice behaves as a plastic material; typically occurs below 50 meters of ice (where ice is unfractured). Basal Slip: mechanism of glacial movement in which the ice mass slides over the surface below; most glaciers are thought to move by this proce

How do tectonic processes facilitate the formation of economically valuable mineral deposits

Plate tectonics & Minerals • To form an ore deposit: collect element, transport to one place, deposit it. --Divergent & Convergent Plate Boundaries- Most important for mineral deposits: major cause of magmatism which drives most fluid flow Convergent Plate Boundaries Ocean-Ocean Subduction zone: Island Arc -Convergent Plate Boundaries Continent-Ocean Subduction zone: Continental Arc: e.g. Cascades, Andes

Be able to identify positive vs. negative feedback cycles.

Positive feedback cycles amplify warming and cooling trends Negative feedback cycles provide checks and balances on warming and cooling

What is albedo, and how can it drive changes in climate? You should know, given a comparison like soil vs. snow, which surface has a higher albedo.

Reflectivity, Higher albedo means higher reflectivity and thus more energy is sent back to space. Snow has a higher albedo than soil.

What kinds of deposits are associated with divergent margins?

Seafloor spreading at ocean ridges, creation of new oceanic crust, and constructive plate margin.

What is "peak production", in terms of petroleum? When do we think peak oil might happen? What is the Hubbert Curve, and what does it show?

The Hubbert peak theory is based on the observation that the amount of oil under the ground in any region is finite, therefore the rate of discovery which initially increases quickly must reach a maximum and decline. In the US, oil extraction followed the discovery curve after a time lag of 32 to 35 years.

11. What is the IPCC, and what is their job?

The Intergovernmental Panel on Climate Change is an intergovernmental body of the United Nations that is dedicated to providing the world with objective, scientific information relevant to understanding

What is the Coriolis Effect, and what part of the ocean does it impact?

The deflection of moving objects due to Earth's Rotation. The Earth is moving faster at the equator than it is at higher latitudes. Particles that start moving north or south from any location on Earth are going to retain their horizontal, rotational speed, that their location gives them, but they will be moving to a part of the Earth that has a different horizontal, rotational speed. These winds drive our large scale patterns in surface ocean currents.

What are mineral resources? What is an ore (how is it defined)?

The naturally occurring variety of useful and essential minerals from Earth's crust, ultimately available commercially according to value. An ore is A rock containing useful metallic minerals that make it valuable for mining; also used to refer to some nonmetallic minerals such as fluorite and sulfur.

zone of accumulation

The part of a glacial system where snow and ice are accumulating faster than they are melting away.

How does the shape of the ocean floor impact circulation?

There are physical barriers like continental shelves, shelf breaks, ocean floor/abysmal plains, mid ocean ridges, deep trenches, and hot spots that enhance/funnel/ restrict the flow of bodies of water.

What is the name of the Earth's ocean circulation pattern and what two factors that impact density drive it?

Thermohaline Circulation System, impacted by heat and salt.

What is a glacier, and what cycles are they a part of? How much of the Earth do they cover?

Thick mass of ice originating on land from the accumulation, compaction, and recrystallization of snow. • Glaciers are part of both Earth's Hydrologic Cycle and Rock Cycle; • Glaciers cover nearly 10% of Earth's lands

What are our three different kinds of hydrothermal deposits?

Vein Deposits: Solution moves along fractures, cools, and precipitates within cracks; Disseminated Deposits: ores precipitated as minute masses throughout entire rock mass. Surface Deposit: Where magma is near surface, dissolved metals precipitate when water cools in air.

You should be familiar with the major and most important greenhouse gases as well as the greenhouse effect from earlier in the semester. You should also know that carbon (part of carbon dioxide) moves into and out of reservoirs over both long and short time scales. Know additionally what combustion does (how does it generate carbon dioxide?).

Water Vapor, C02, CH4, NO2, Flourinated Gases. Combustion sets trapped and organic material free.

4. What information about climate can we get from ice cores? What is the temporal resolution of this record?

We can directly measure CO2 and methane concentration in the ice! • Oxygen Isotopes: temperature when snow fell

1. How does climate differ from weather?

Weather: minutes‐to‐ months changes in the atmosphere - Climate is: "...the description of the long‐ term pattern of weather in a particular area. " • Temperature, precipitation, humidity, sunshine, wind velocity, et

What is countershading, how does it work, and why do animals use it?

a lot of organisms are dark on top and light on the bottom. This includes great white sharks, because it is good to be able to hide... from organisms that see you as dinner.

What is bitumen?

a thick type of petroleum formed in clay and sand

8. What is a poililotherm, and what happens to poikilotherms when temperatures go up?

body temperature is dependent on ambient temperature. And size is dependent on this, too.

Crevasses

deep cracks in the brittle surface of a glacier

How do we build 10,000 year old chronologies using tree rings if the oldest tree is only 5,000 years old?

dendrochronology: (dendron = tree, chronos = time, logos = the study of) - The science that uses tree rings dated to their exact year of formation to analyze climate.

. What is a placer deposit? What are the physical characteristics of minerals associated with these types of deposits?

deposits formed when heavy minerals are mechanically concentrated by currents, most commonly streams and waves; typically heavy and durable minerals. Examples: Gold, tin, platinum, diamonds.

Firn

granular snow, especially on the upper part of a glacier, where it has not yet been compressed into ice.

Ice Shelf

ice shelves occur when glaciers flow into surrounding oceans. These are large, relatively flat masses of glacial ice extending seaward from the coast that are attached to land on at least one side. In shallow water, these touch bottom but in deep water they float. They also thin seaward.

Why do scientists think dumping iron in the southern ocean could slow climate change?

it's a limiting nutrient for phytoplankton growth= . Phytoplankton bloom. Phytoplankton are (eaten and turned into fecal matter) and sink, taking their little carbon bodies to the deep, deep ocean for perhaps millions of years Net result: less atmospheric carbon. WE SOLVED CLIMATE CHANGE!

3. During glaciations, would you expect the global oceans to be isotopically heavy, or light? Why? What about the shells of organisms that form in the oceans, assuming that these organisms passively record ocean composition?

light, because they percipitate out.

tillite

rock formed when glacial till is lithified

How do we work out a glacial budget (what happens if we have more or less accumulation relative to loss)?

the balance (or lack of balance) between accumulation at the upper end of the glacier, and loss at the lower end. Advance: = accumulation exceeds loss; Retreat: = loss exceeds accumulation; Balance: = accumulation roughly equivalent to loss (glacial front is stationary).

zone of wastage

the part of a glacier beyond the zone of accumulation where all of the snow from the previous winter melts, as does some of the glacial ice

11. What is a packrat, and how can they help us learn about climate?

• Can weigh up to 1 lb • Builds middens • Will put anything and everything into midden‐plant material, bones, shells, reptile scales • Super viscous urine:

What are some environmental consequences of using coal to generate power?

• Coal takes millions of years to form, non-renewable resource; • Mining can result in major environmental damage; • Coal combustion results in significant air pollution, Acid Rain, and Increased Green House Gases.

. How do oxygen stable isotopes work? To understand this, you should know the differences in behavior between 16O and 18O, what fractionation is, and how this changes with temperature. When there are lots of glaciers, will oceans be heavy or light?

• Light isotope evaporates faster • Heavier isotope precipitates out faster • Precipitation starts out light, and gets lighter as you move away from coastlines • Colder temperatures lead to stronger sorting

Given images of two leaf assemblages, be able to assess which group likely grew in a warmer climate.

• Shape can be indicative of climate • Can use fossil leaves

. What do you need to capture oil and natural gas? You should be able to recognize and define source rocks, cap rocks and trap rocks, and should also know the different kinds of common traps. What are oil and gas made of?

-Cap rock that is virtually impermeable to oil and gas; • A porous, permeable reservoir rock. -Anticlinal Trap: Rising oil and gas collect at a fold apex in an up-arched series of sedimentary strata; -Salt Dome Trap: Rising oil and gas accumulate in deformed, upturned sandstone beds adjacent to salt dome; -Stratigraphic Trap: Rising oil and gas is trapped by an original sedimentary structure: a sloping bed of reservoir rock thins to point of disappearance (pinches out). -Fault Trap: Upward migration of oil and gas is trapped where displaced strata bring a dipping reservoir rock opposite an impermeable bed. -Oil and Gas Are made of Petroleum

How do renewable and non-renewable resources differ? You should know, given a resource, which category it falls within.

-Nonrenewable Resources form or accumulate over millions of years, so quantities are considered fixed. Examples: coal, natural gas, iron. -Renewable resources are either virtually inexhaustible or can be replenished relatively quickly (months, years, decades). Examples: Sun, wind, tides.

1. What are the two different types of glaciers? Under what conditions will a glacier form?

-Valley (Alpine) Glacier: glacier confined to flow down a mountain valley (typically a former stream valley) from an accumulation center at its head. -Ice Sheet: very large, thick mass of glacial ice flowing outward in all directions from one or more accumulation centers; Continental ice sheets because they exist on such a large scale.

1. When can we form a glacier (what process needs to outweigh wastage), and how do we make glacial ice (4 steps)?

1) Snowflakes become smaller, thicker, & more spherical; 2) Air is forced out of pore spaces; 3) Snowflakes recrystallized into denser masses of small grains called firn; 4) Under pressure, firn fuses into solid mass of interlocking ice crystals (glacial ice).

You should be able to talk about our large-scale drivers of global climate and how they work.

1. Changes in incoming solar insolation 2. Configuration of continents 3. Changes in albedo 4. Changes in atmospheric composition (reservoirs) 5. Milankovitch cycles

2. What factors impact local climate variation (local climate drivers in notes)?

1. Latitude (incoming solar insolation) 2. Proximity to large bodies of water 3. Elevation 4. Topography

What are the two different ways by which magmatic segregation can concentrate minerals?

1. Separation of heavy minerals that crystallize early; 2. Enrichment of rare elements in the residual melt.

1. What 5 fundamental sources provide energy on Earth?

1. Solar 2. Gravity 3. Nuclear fission reactions 4. Earth's internal energy 5. Energy in chemical bonds

When did we start using oil widely?

1980's

How Deep does Light Penetrate the Ocean, and how does it impact where animals live?

200-1,000m but light barely penetrates below the euphotic zone which is 200m. Most animals live in the euphotic zone where photosynthesis can occur, providing an abundant food source.

Where does Iowa rank in terms of using wind energy in the United States?

2nd

. What percentage of greenhouse gases are absorbed by the oceans and forests?

55%

1. If we melted the Antarctic ice sheet, by how much would sea level rise?

60-70 meters

How can weathering cause secondary enrichment of ore deposits?

: Concentration of scattered, minor amounts of metals by weathering processes. Two Types: 1. Chemical weathering and water percolation remove undesirable elements from decomposing rock, leaving desirable elements; 2. Desirable elements found near surface are carried to lower zones, and concentrated.