EXAM 1 GEOLOGY

Basic Climate Concepts

Q: What is the difference between weather and climate?
A: Climate is the long-term average of daily weather conditions.

Q: What are Koppen Climate Zones?
A: A climate classification system that divides the Earth into different climate regions based on temperature, precipitation, and vegetation patterns.

Climate Change Evidence

Q: What are three recently observed climate-related trends?
A: Glacial melting, surface temperature increase, and sea level rise.

Q: What are sediment cores and what do they reveal?
A: Sediment cores are samples taken from ocean floors or lake beds that contain evidence of past climate conditions, including elements and isotopes that help reconstruct historical climate patterns.

Causes of Climate Change

Q: What are natural causes of climate change?
A: Changes in positions/shapes of landmasses, blocking of incoming solar radiation, changes in solar energy (sun spots), and Milankovitch cycles.

Q: What is the Milankovitch Theory?
A: Theory stating that climate variations are predicted by cyclical changes in Earth's orbital geometry, including eccentricity (~100,000 year cycle), obliquity (~41,000 year cycle), and precession (~23,000 year cycle).

Q: What is insolation?
A: Solar radiation energy received on a given surface in a given time.

Q: What is anthropogenic climate change?
A: Climate change caused by human activities, particularly greenhouse gas emissions.

Earth System Science

Q: What are the four main components of the Earth system?
A: Geosphere, atmosphere, hydrosphere, and biosphere.

Q: What is the carbon cycle?
A: The process by which carbon moves between different Earth system components (atmosphere, oceans, land, organisms).

The Greenhouse Effect

Q: What is the greenhouse effect?
A: The process where short wavelength solar radiation reaches Earth, while long wavelength terrestrial radiation is absorbed and reemitted by greenhouse gases, warming the planet.

Q: Why is the greenhouse effect necessary?
A: It's necessary for life on Earth as we know it by maintaining temperatures suitable for life.

Q: What are examples of greenhouse gases?
A: Carbon dioxide, methane, and water vapor.

Climate Modeling

Q: What is a Global Climate Model/General Circulation Model?
A: Mathematical models that use equations to represent Earth processes (atmosphere, ocean, land, organisms) to predict changes that may occur with changing inputs.

Q: What are Representative Concentration Pathways (RCPs) in IPCC reports?
A: Different greenhouse gas concentration scenarios used to model possible climate futures, including RCP 8.5 (emissions continue rising), RCP 4.5 (emissions peak mid-century then decline), and RCP 2.6 (emissions peak 2010-2020 then decline substantially).

Climate Change Impacts

Q: What changes in precipitation are projected due to climate change?
A: Overall precipitation increase, changing precipitation patterns, and more droughts and flooding.

Q: What is projected to happen with sea levels according to climate models?
A: Sea levels are projected to rise relative to 1985-2005 baseline, with different amounts depending on the RCP scenario.

Climate Action

Q: What are the main goals of the Paris Agreement (2016)?
A: Keep global temperature rise this century below 2 degrees Celsius above pre-industrial levels (with an additional goal of below 1.5 degrees C) through nationally determined contributions and financial/technological support for developing countries.

Q: What are examples of proposals to minimize carbon emissions?
A: Raising taxes on electricity/gasoline, tax breaks for nuclear power, tax breaks for cleaner coal electricity generation, and tax breaks for renewable energy (wind, water, solar).

Individual Climate Action

Q: What are examples of actions that can reduce an individual's carbon footprint?
A: Replacing incandescent light bulbs with energy-efficient ones, adjusting home temperature settings, washing clothes in cold water, line-drying clothes, recycling, reducing meat consumption, and driving less.

Geoengineering

Q: What is geoengineering?
A: Large-scale technological interventions in Earth's climate system to counteract climate change.

Q: What are examples of geoengineering possibilities?
A: Ocean fertilization, carbon dioxide removal methods (modified crops, forest planting, carbon capture and storage), and solar radiation management (cloud creation, space mirrors/sun-shields, injecting sun-blocking particulates).

Q: What did statistician George E.P. Box say about models?
A: "All models are wrong, but some are useful."

# Earth Formation, Plate Tectonics, and Minerals Flashcards

## Universe and Solar System Formation

Q: What were the three main stages in forming the universe?

A: The Big Bang (14 billion years ago), light element formation (hydrogen and helium atoms), and the forming of galaxies and stars.

Q: How did the solar system and Earth form?

A: About 5 billion years ago, from an initial nebula of gas and space dust that contracted due to gravity, forming a disk-shaped nebula with a hot center that eventually became the sun, with planetesimals forming into planets.

Q: What are the key differences between inner and outer planets?

A: Inner planets have less mass, are denser, and are smaller than outer planets.

## Earth's Interior Structure

Q: What are the three main chemical layers of Earth's interior?

A: The crust (outermost layer), the mantle (82% of Earth's volume), and the core (iron-rich sphere).

Q: What are the two types of crust and how do they differ?

A: Continental crust: thicker, lower density, felsic (silica-rich); Oceanic crust: thinner, higher density, mafic (contains iron and magnesium).

Q: What is the composition of the mantle?

A: Ultramafic (iron and magnesium-rich) rock, primarily peridotite.

Q: What are the key characteristics of Earth's core?

A: An iron-rich sphere with a radius of 3,471 km; the outer core is liquid while the inner core is solid. Evidence comes from seismic waves and Earth's magnetic field.

Q: How is Earth divided in terms of physical properties?

A: Lithosphere (rigid outer layer that breaks under stress), asthenosphere (bends under stress), mesosphere, and core.

## Plate Tectonics

Q: What is a lithospheric plate?

A: The rigid outer layer of Earth consisting of the crust and upper mantle that move as solid units on top of the asthenosphere.

Q: What are the three main types of plate boundaries?

A: Divergent (plates move apart), convergent (plates come together), and transform (plates slide past each other).

Q: What happens at divergent plate boundaries?

A: Plates move apart, creating rift valleys on land or mid-ocean ridges in oceans, with new crust forming from rising magma.

Q: What are the three types of convergent boundaries?

A: Continent-continent collision (forming mountain ranges like the Himalayas), ocean-ocean convergence (subduction with volcanic island arcs), and continent-ocean convergence (subduction with continental volcanic arcs like the Andes).

Q: What are transform boundaries characterized by?

A: Shear zones between plates with little mountain building or volcanic activity but lots of seismic activity.

## History of Plate Tectonic Theory

Q: Who was Alfred Wegener and what theory did he propose?

A: A German meteorologist and polar explorer who wrote "The Origins of Oceans and Continents" in 1915, proposing Continental Drift.

Q: What evidence did Wegener use to support Continental Drift?

A: Matching geologic structures across continents, fossil localities, and evidence of ancient climates.

Q: Why was Continental Drift initially rejected?

A: Wegener couldn't explain the driving force (incorrectly suggested Earth's rotation, centrifugal force, and tidal influences), and "anti-mobilists" believed Earth's features were due to heating and cooling cycles.

Q: What ocean floor observations helped develop the theory of plate tectonics?

A: Echo sounding measurements, thin ocean floor sediment, discovery of the global mid-ocean ridge, and magnetic variations across the ocean floor.

Q: What is paleomagnetism and how did it contribute to plate tectonic theory?

A: The natural remnant magnetism in rocks. Iron minerals preserve the Earth's magnetic field direction at the time of formation, showing magnetic reversals in seafloor rocks that supported sea floor spreading.

Q: What is sea floor spreading and who proposed it?

A: Proposed by Hess in 1960, it's the theory that new seafloor is produced between two diverging plates, with magma rising to fill the gap and creating new oceanic crust.

Q: How do magnetic "stripes" on the ocean floor relate to plate tectonics?

A: Magnetic polarity reversals are imprinted in sea-floor rock as the sea floor continues to spread. Normal polarity creates positive magnetic anomalies, reversed polarity creates negative anomalies, allowing estimation of sea-floor spreading rates.

Q: What modern evidence supports plate tectonic theory?

A: Earthquake and volcano locations (concentrated at plate boundaries), direct GPS measurements of plate movement, and apparent polar wander.

Q: What are the potential driving mechanisms for plate tectonics?

A: Convection in the mantle, ridge push (gravity forcing plates away from elevated mid-ocean ridges), and slab pull (dense subducting plates pulling the rest of the plate down).

## Minerals

Q: What are the five characteristics of minerals?

A: Naturally occurring, solid, crystalline structure, definite chemical composition, and mostly inorganic.

Q: What are five ways minerals can form?

A: Solidification from a melt, precipitation from a solution, solid-state diffusion, biomineralization, and precipitating directly from a gas.

Q: How do minerals grow?

A: Minerals grow from clusters of ions called seed crystals or crystal nuclei. If seed crystals are far apart, well-formed crystals develop. If seed crystals are close together, an interlocking aggregate of grains forms.

Q: What are three ways minerals can be destroyed?

A: Melting (heat breaks atomic bonds), dissolving (solvents break bonds), and chemical reactions (reactive minerals break bonds).

Q: What physical properties are used to identify minerals in hand samples?

A: Crystal form (habit), luster, color, streak, hardness, cleavage, fracture, taste, feel, magnetism, and effervescence.

Q: What is crystal form or habit?

A: The external expression of a mineral's internal orderly arrangement of atoms, typically bounded by flat surfaces (crystal faces).

Q: What is mineral hardness and how is it measured?

A: Resistance to being scratched, measured on the Mohs scale from 1 (softest) to 10 (hardest).

Q: What is the difference between cleavage and fracture?

A: Cleavage is the tendency of a mineral to break along planes of weak bonding, while fracture is any breaking that's not along cleavage planes.

Q: What are two advanced methods of mineral identification?

A: Optical mineralogy (studying minerals with a polarizing light microscope) and X-ray techniques (X-Ray Diffraction and X-Ray Fluorescence).

Q: How are minerals classified?

A: By the anion or anion complex they contain, such as silicates (silicon-oxygen tetrahedron), sulfides (sulfur anion), and carbonates (carbonate group).

## Rocks and Magma

Q: What is a rock?

A: An aggregate of one or more minerals.

Q: What are the three main rock types and how do they form?

A: Igneous (magma cools and consolidates), sedimentary (cementation of mineral grains or chemical/biochemical precipitation), and metamorphic (rock transformed by pressure/temperature).

Q: What is the difference between magma and lava?

A: Magma is melted rock below the ground surface, while lava is melted rock above the ground surface.

Q: What are three ways magma/melt can form?

A: Heating (increasing temperature), decompression (decreasing pressure), and adding water (flux melting).

Q: What are the sources of Earth's internal heat?

A: Remnant heat (planetesimal and meteorite accretion, gravitational compression, early collision with planetoid) and ongoing heat generation (decay of radioactive minerals).

Q: What is the geothermal gradient?

A: The increase in temperature with depth in the Earth.

Q: How does decompression melting work?

A: The base of the crust is hot enough to melt mantle rock but doesn't melt due to high pressure. When pressure decreases (such as at divergent boundaries), melting occurs.

Q: How does water contribute to melting in the mantle?

A: Water under high pressure breaks the silicon-oxygen bonds in minerals, causing them to liquefy at lower temperatures than they would when dry.

Here are study flashcards based on the provided lecture slides:

Glaciers

1. What is a glacier?

   • A mass of ice that moves over land due to its own weight.

2. Where do glaciers form?

   • Where more snow falls in winter than melts in summer.

3. What are the two main types of glaciers?

   • Mountain (Alpine) Glaciers – occur on mountain slopes.

   • Continental Glaciers – larger, covering most of the underlying ground.

4. How do glaciers move?

   • Plastic Flow – internal deformation of ice (creep).

   • Basal Slip – glacier slides along its base.

5. What is the glacial budget?

   • The balance between accumulation (snow gain) and ablation (snow loss).

6. What are some erosional features created by glaciers?

   • Cirque – bowl-shaped depression.

   • Horn – sharp peak formed by multiple cirques.

   • Arete – thin ridge between two glaciers.

   • U-Shaped Valley – carved by glacial movement.

7. What are the different types of glacial deposition?

   • Till – unstratified drift, deposited by moving glaciers.

   • Moraines – accumulations of glacial debris.

   • Outwash Plains – sediment carried by meltwater.

Melt and Igneous Rocks

8. What is the geothermal gradient?

   • The increase in temperature with depth in Earth's crust.

9. What are the three ways melt forms?

   • Heating – increasing temperature.

   • Decompression – reducing pressure.

   • Adding water – flux melting.

10. What are the major types of magma?

• Felsic (~70% silica)

• Intermediate (~60% silica)

• Mafic (~50% silica)

• Ultramafic (~40% silica, Fe and Mg rich)

11. What is Bowen’s Reaction Series?

• A sequence that explains the order of mineral crystallization and melting.

12. What are the two main igneous environments?

• Intrusive – below Earth's surface (plutons, sills, dikes).

• Extrusive – above Earth's surface (lava flows, volcanic eruptions).

13. How does cooling rate affect igneous rock texture?

• Slow cooling → Large crystals (coarse-grained).

• Fast cooling → Small crystals (fine-grained).

Volcanoes

14. What is a volcano?

• A vent in the Earth's crust where molten rock and gases erupt.

15. What are the three main types of volcanoes?

• Shield Volcanoes – large, broad, low viscosity lava (e.g., Hawaii).

• Cinder Cones – small, steep, made of tephra.

• Stratovolcanoes – tall, explosive, alternating lava and ash layers (e.g., Mt. Fuji).

16. What are the two main eruptive styles?

• Effusive – lava flows steadily.

• Explosive – pyroclastic material erupts violently.

17. What volcanic hazards exist?

• Lava flows – destructive but slow.

• Pyroclastic flows – fast-moving, superheated ash clouds.

• Tephra – volcanic ash and rock fragments.

• Lahars – mudflows mixing volcanic material with water.

• Earthquakes & tsunamis – triggered by eruptions.

• Gases – release of water vapor, CO₂, SO₂.

18. How do scientists monitor volcanoes?

• Seismic activity (earthquakes).

• Heat flow (temperature changes).

• Gas emissions (SO₂ levels).

• Ground deformation (bulging, tilting).

19. What is the Volcanic Explosivity Index (VEI)?

• A scale (1–8) measuring eruption size based on ejected material volume.

20. How can volcanic hazards be mitigated?

• Evacuation – moving people away from danger zones.

• Lava flow diversion – using explosives or seawater to redirect lava.

Glaciers:

• Glacial Consequences:

  • Subsidence & Rebound – Ice sheets depress the Earth's crust, which rebounds when ice melts.

  • Sea Level Variations – More ice = lower sea level, less ice = higher sea level.

• Glacial Episodes (Ice Ages):

  • Precambrian Ice Age (2.3 BYA) – Oldest known ice age.

  • Pleistocene Ice Age (2 million to 10,000 years ago) – Most recent and significant ice age.

Melt & Igneous Rocks:

• Partial Melting:

  • Magma is usually more felsic than the original rock because low-melting minerals melt first.

• Crust & Mantle Composition:

  • Crust – Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), Magnesium (Mg).

  • Mantle – Magnesium (Mg), Iron (Fe), Silicon (Si).

  • Core – Iron (Fe), Nickel (Ni).

• Igneous Rock Classification Based on Composition & Texture:

  • Felsic (Granite/Rhyolite) – Light-colored, high silica.

  • Mafic (Gabbro/Basalt) – Dark-colored, low silica, high Fe/Mg.

  • Intrusive vs. Extrusive Rocks – Intrusive (large crystals), Extrusive (small crystals).

Volcanoes:

• Volcanic Landforms:

  • Caldera – Large volcanic depression formed when a magma chamber empties and collapses.

  • Crater – Smaller, bowl-shaped depression at the volcano’s summit.

  • Fissure Eruptions – Linear cracks where lava erupts (e.g., Icelandic volcanoes).

• Lava Types:

  • Pahoehoe – Smooth, ropy lava.

  • A’a’ – Jagged, blocky lava.

• Volcanic Gases and Climate Effects:

  • Sulfur Dioxide (SO₂) – Forms aerosols that block sunlight, causing temporary cooling.

  • Carbon Dioxide (CO₂) – Contributes to greenhouse warming.

  • Example: Mt. Pinatubo (1991) – Lowered global temperature by ~0.5°C for a year.