EES1 Exam #1
Who discovered each of the layers of the Earth?
a. Crust/mantle boundary - Andrija Mohorovicic b. Core/mantle boundary - Beno Gutenberg c. Inner core/outer core boundary - Inge Lehmann
What types of stress are associated with each type of fault?
a. Normal faults-extensional stress b.Reverse faults- compressional stress c. Strike slip faults- shear stress
What are the top four earthquakes ever recorded? Know the locations, dates, and magnitudes.
a.Chile 9.5 1960 b.Alaska 9.2 1964 c.Sumutra/Idonesia 2004 9.1 d.Japan 2011 9.0
What are the physical properties of minerals?
cleavage, hardness, density, luster, streak, color, tenacity, magnetism, and taste.
What is the importance of the outer core?
it is responsible for the magnetic field
The _________ of the Earth does not transmit S waves.
outer core
Which region in the Earth is molten?
outer core
What was Andrija Mohorovicic's major contribution to geology?
provided Evidence that the earth was layered
What are reflected and refracted waves?
reflected- waves bounce back refracted- waves travel through materials of different density and change direction speed changed and direction changed (bend)
The _____________________ magnitude scale is a measure of the energy released. It does not measure the extent of building damage.
richter or moment magnitude
What kind of fault is the San Andreas Fault? How large of an earthquake (magnitude) can the San Andreas produce?
right lateral strike-slip fault. it can produce a magnitude of 8
Who designed the first seismometer?
the Chinese
What is a dip-slip fault?
viewed in cross-section fault plane dips into crust normal and reverse
How well can scientists predict earthquakes?
we cant
What is the minimum number of seismograph stations needed to locate the epicenter of an earthquake?
3
What is the approximate distance from the surface to the center of the Earth?
6400km
The energy released during a magnitude 8 earthquake is approximately _________ times greater than the energy released during a magnitude 6 earthquake.
900
What is the definition of a mineral?
A homogenous naturally occurring solid inorganic substance with a definable chemical composition and an internal structure characterized by an orderly arrangements of atoms, ions , or molecules in a lattice.
What is the relationship between earthquakes and plate boundaries? i.e. what types of faults occur at each boundary?
A. Convergent-reverse B. divergent - normal C. transform-strike slip
What are the four pieces of evidence that Arthur Wegener used for continental drift?
A. Puzzle -piece of the continents B. Plant and animals fossils across continents were the same C. Rock assemblages across continents were the same D. Glacial striations. E. he wasn't taken seriously because he couldn't provide a mechanism
What is an anticline? Why are they important?
An anticline is a fold with an arch like shape in which the limbs dip away from the hinge.
What is the S-wave shadow zone?
Area 103 degrees from an epicenter where s waves are not recorded.
The partially molten layer beneath the lithosphere is called the
Asthenosphere
Which foundation material is most stable during earthquake shaking?
Bedrock
What is the California state gemstone?
Benitoite
Know the difference between ductile and brittle deformation
Brittle deformation - Rocks break by fracturing. Like faults Ductile deformation creates folds like anticlines and synclines
Although diamond and graphite are the same chemical composition, they are on opposite ends of the hardness scale. What accounts for this?
Carbon atoms are structured differently and different crystal structures (chemical bonding; diamonds are covalent; graphite covalent +cancer Waals force
What happens when two continental plates collide? Two oceanic plates?
Continent- continent collision= mountain building (himalaya) Oceanic -oceanic collision= volcanic island arc (Aleutian islands) Continent-ocean =volcanic arc (Andes , cascades)
Why are the Himalaya Mountains so high?
Continent- continents collision, continents are buoyant
Which crust is more dense, continental or oceanic?
Continental crust is less dense than oceanic crust
Which chemical bond is the strongest?
Covalent bonds are the strongest because the difference in electronegativity of two atoms creating a bond is small, so attraction of electrons is strong from both sides of the bond.
What is the relationship between earthquakes and plate boundaries? i.e. what types of faults occur at each boundary?
Divergent boundary- normal faults- mod magnitude (3-6) Transform boundary- strike slip faults- Fairslarge (7-8) Convergent- Reverse Faults- Large mag (8+)
What is the relationship between plate boundaries and earthquake depth?
Divergent- shallow Convergent -deep Transform- immediate
What is the California state mineral?
Gold
What is a seismic profile? How are they created?
Image of subsurface using geophones, hydrophone hammer impact source, data analyzer
Which region in the Earth consists primarily of solid iron?
Inner core
What element makes up most of the Earth's core?
Iron
What is an isotope?
Isotopes are different versions of a given element that have the same atomic number but different atomic weights.
Know how to figure out the magnitude using Richter's method (see slide in Earthquakes Powerpoint)
M= Log A - LogA0
What particles are found in an atom?
Neutron , Electrons and Protons
How thick is the crust? Which crust is thicker, continental or oceanic?
Oceanic Crust (underlies the sea floor) is only 7-10 km thick & Continental Crust ( underlies continents) 5-80 km.
Which of the following types of seismic waves arrive at a seismometer first?
P waves
What two plates does the San Andreas Fault separate?
Pacific and North American plates
What are magnetic anomalies? What would likely occur if the magnetic field reversed today?
Periods in the rock record that show reversed magnetism from today, so magnetic north is at the South Pole. If one occurred skin cancer might increase but disaster is unlikely.
What was Harry Hess' contribution to plate tectonics?
Proposed sea floor spreading
What is the difference between Richter Magnitude, Moment Magnitude, and the Modified Mercalli Intensity scale (MMI)?
Richter-based on P-S interval and wave amplitude Moment Magnitude- considers the shear modulus based on rock properties MMI- is subjective includes damages and responses
What kind of fault is the San Andreas Fault? How large of an earthquake (magnitude) can the San Andreas produce?
Right lateral strike slip mag 8.2
Given what you know about plate tectonics, is the seafloor likely to be older or younger than the continental crust?
Sea floor is younger than continental crust
Be able to recognize a fault and name the type.
See diagram at right
How do we know about the earth's interior?
Seismic Waves
What types of things occur during an earthquake?
Shaking,liquefaction, fires, tsunami
Given that the epicenter was more than 200 miles away, why was there such massive damage during the Mexico City earthquake?
The Subsurface Geology-built on an ancient lake bed
Why is there an area of "creep" along the San Andreas near Parkfield?
The base of san andres fault contains serpentinite which degrades to talc.
Know how to read a seismogram, i.e. the P-S arrival times and amplitude.
The difference between seconds read the time lapse amplitude highest wave
What does magnetic inclination tell us about where a rock formed?
The latitude at which a rock solidifies
In which region of the Earth does convection take place?
The mantle
Which layer in the Earth does not transmit S-waves?
The outer core (were P-waves are found).
How does sedimentation contribute to the evidence for seafloor spreading?
The thinnest sediment is located near the mid ocean ridge suggesting that the seafloor in that area has not been exposed long near continents sediments is thicker indicating longer exposure
Know who your LAB instructor is! NOT ME!
Yvan Mendoza
