Untitled Flashcards Set

Chapter 1: Introduction to Geology
What is Geology

-        Science that examines earth and its form and composition

-        Science that pursues an understanding of planet earth and beyond

The two branches of geology

1.     Physical: materials, processes (subsurface and surface)

2.     Historical: origin of Earth, chronological order of different stages of earth, how past informs us of future

Importance of geology

-        Natural hazards

o   Volcanoes, earthquakes, mass wasting (landslides, mudslides), flooding, fire dangers

o   Urbanization: increased population growth, results in more influence of natural disasters/hazards

§  Ex: Ecuador earthquake; Pacifica, CA erosion

-        Understanding global climate change and implications of climate change

Catastrophism vs uniformitarianism

-        Catastrophism: earth was created by some great catastrophe; estimated to be 4004 yrs old, estimated by calculating genealogy in Bible; fit with Christian belief of Great Flood

-        Uniformitarianism: “present is the key to the past”

o   Occasional catastrophe

o   Mountains constantly eroding, sediment from mountains transported via gravity/water, sediments deposited/solidified into rock

What is the law of uniformitarianism

-        “Present is the key to the past”

-        Earth is old

-        Physical and chemical and biological operations observed today have operated in geologic past in the same way

How old is the Earth

-        4.6 billion years old

What is the scientific method?

-        Observation (collect background data), construct a hypothesis, test the hypothesis, analyze data from the hypothesis, make a prediction, hypothesis either supported or not

What is a theory vs a hypothesis?

-        Theory: well-tested and widely accepted view that the scientific community agrees best explains observable facts

What is a system?
What are the three Earth Systems? And how do they work?
What is the Big Bang?
What is the age of Universe?
How were the elements formed?
What is Solar nebular theory?
What is chemical differentiation?

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Chapter 12: Earth’s Interior
Name the three main chemical layers of the Earth and their characteristics DONE
Name the five main physical layers of the Earth and their characteristics DONE KINDA
The differences between oceanic crust (characteristics) and continental crust (characteristics)
What is the Moho?
What are the main parts of the mantle? What are their characteristics with depth?
What are the differences between the inner vs outer core?
How are seismic waves used to understand Earth’s interior?

-        They travel through different materials at different speeds which helps to identify the layers and distinguish them

What are the two main types of waves?

-        S waves and P waves

What provides heat to the Earth? How is it transferred?

-        The sun provides heat through sun waves

How is heat transferred through the earth?’

-        It’s stored through the greenhouse effect

What is the geothermal gradient?

-        The rate at which the earth’s temp. increases with depth; how much temp. rises as you go deeper into the earth’s crust

Why does gravity vary across the earth?

-        Earth isn’t a sphere

What gives earth its magnetic field?

-        The rotation of the inner and outer core

Chapter 2: Plate Tectonics
What is plate tectonics?

-        The movement of lithospheric plates that shift continents

What is continental drift and what is its relationship to plate tectonics?

-        Scientific theory by Alfred Wegner that earth’s continents have moved over time

What are the three types of plate boundaries?

-        Convergent: 2 plates collide

-        Divergent: plates spreading

-        Transform: plates grind against eachother

What are three lines of evidence for plate tectonics?

-        Continental jigsaw

-        Paleontological evidence

-        Geologic evidence

What are characteristics of divergent boundaries?

-        2 plates moving apart

-        New crust; crust things, magma upwells due to lower pressure

-        Ocean ridge

-        Contains rift valleys

What are characteristics of convergent boundaries?

-        2 plates move toward each other

-        One plate (denser) will move under, or subduct, below less dense plate

-        Old crust returned to mantle

What are characteristics of transform boundaries?

-        2 plates slide past eachother

-        No volcanoes

-        Transform faults

-        Shallow earthquakes, not very strong.

-        Connect spreading centers to convergent boundaries

Are two geophysical lines of evidence for plate tectonics?

-         

What are the two main mechanisms for what causes plate tectonics?

-        Ridge push, slab pull

Chapter 10: Crustal Deformation
What are the three main stresses?

-        Compression, tension, shearing

What do these stresses do to rock?

-        Causes strain, which changes shape of rock that is measurable

What are the four factors that cause brittle versus ductile deformation?

-        Temperature, confining pressure, rock type, time

What are the two main types of folds?

-        Anticline, syncline

What are the different components of a fold?

-        Hinge-line, axial plane, limb

What types of plate boundaries do folds occur in?

-        Convergent boundaries

How do domes form versus how do basins form

-        Domes: upwarping of rock

-        Basins: downwarping of rock/strata

What is a monocline? How do they form?

-        Single fold in rock layer; result from faults

What are the main types of faults?

-         

What is a hanging wall versus a foot wall?

-         

What types of faults occur at different plate boundaries?

-         

What are different structures associated with faults?’’

-         

What are joints and how do they form?

-         

Chapter 11: Earthquakes
What is an earthquake?

-        Groundshaking caused by sudden/rapid movement of one rock block slipping past another

What is the difference between a hypocenter, an epicenter, and a fault trace?

-        Hypocenter: location of initial slippage (focus)

-        Epicenter: point of hypocenter but at surface

-        Fault trace: surficial trace or offset visible of the fault (line where fault intersects earth’s surface)

What is elastic rebound?

-        Sudden release of stored strain in an object

Where do earthquakes occur?

-       Mostly at plate boundaries

-       Convergent boundaries, thrust faults, megathrusts

What are the two main types of body waves?

-       P-waves (primary waves, compressional, fast, travel through all material)

-       S-waves (secondary waves, back&forth/up&down, slower, change volume of rock material it moves through, only travels through solids)

What are the two main types of surface waves?

-       Rayleigh waves

o   Vertical rolling motion; ocean wave

o   Rotation of a particle

-       Love wave

o   Horizontal motion

o   Particles move side to side

Be able to label parts of a seismogram

-       P waves are fastest

-       S waves slower

-       Surface waves slowest

-       Speed: P > S > surface

-       Strength: surface > S > P

Which is faster P waves S waves or surface waves?

-       P waves

How are earthquakes located?

-       Triangulation method: 3 seismograms from 3 locations, determine time b/t 1^st P wave and 1^st S wave

What are different methods and scales of determining the strength and magnitude of an
earthquake?

-       Intensity: scale uses observed property damage to estimate ground shaking

-       Magnitude: uses data from seismograms & ground measurements to determine energy release

What are five different destructive forces that occur due to earthquakes?

1.    Groundshaking

2.    Liquefaction

3.    Landslides and rockslides

4.    Fire

5.    Tsunami

How can earthquake hazards be mitigated?

-        

How accurate are earthquake predictions?

Chapter 5: Volcanoes
How do different compositions of magma effect eruption?
What are the two main types of eruptions?

-       Effusive: “liquid-y” fluid-like; mafic magmas, high melting temp

-       Explosive: “sticky” viscous; felsic, low melting temp

What are the two main types of lava flows and types of pyroclastic material?

-       AA flow: slow & cool lava with rising gas content

-       Pahoehoe: “ropey”; mafic, lower gas content, higher temp.

Label parts of a volcano

-       Fissure

-       Conduit

-       Vent

-       Crater

-       Volcanic cone

-       Calclera

-       fumaroles

What are the three main types of volcanoes?

1.    Shield volcanoes

2.    Cinder cones

3.    Composite volcanoes

What types of eruptions are associated with each type of volcano?

-       Shield: effusive

-       Cinder: Effusive

-       Composite: explosive

What are other volcanic hazards associated with volcanoes?

-       Pyroclastic flows:

-       Lahars

-       Tsunami

-       Ash

-       Gases

What are other landforms associated with volcanoes?

-       Caldera

-       Crater

-       Vent

How do plate tectonics control volcanoes, their occurrence, and their type?

-        

What is a caldera versus a crater versus a vent?

-       Caldera: circular and deepsided depression; form from collapse of overlying rock due t o explosion and emittable of rock

-       Crater: depression, smaller; occurs when material is ejected

-       Vent: can be center of a crater and represents the termination of a conduit

What are the three main types of calderas?

1.    Crater

2.    Hawaiian – “shield-type"

3.    Yellowstone – “resurgent-type”

What types of volcanoes occur at convergent versus divergent boundaries?

-       Convergent: composite volcanoes a

-       Divergent: shield volcanoes

What is a large igneous province?

-       Lava erupted in a short term

How are volcanoes monitored and can we predict eruptions?