Exam 1 Flashcards
Compression
Action of oppositely directed forces acting towards each other at the same time.
Scientific Method
Observation
Hypothesis
Prediction
Testing
(Ex)Tension
Action of coinciding and oppositely directed forces acting away from each other.
Shear
Action of coinciding and oppositely directed forces acting parallel to each other across surface.
Earthquakes
Vibrations caused by a sudden release of energy, usually as the result of the displacement of rocks along faults.
Compression=?
Reverse Fault
Shearing=?
Strike Slip Fault
(Ex)Tension=?
Normal Faults
Fault
A fracture along which movement has occurred parallel to the fracture surface.
What causes faults to form?
When rocks experience stress.
Dip-slip faults examples
Normal
Reverse
Strike Slip Fault examples
Right, left lateral
Dip-Slip faults
Up or down direction along the fault plane.
Normal Fault
Puts stress on it and pulling rock apart.
Hanging wall moves down relative to Foot Wall.
Reverse Fault
Hanging wall moves up along Foot Wall
Strike Slip Fault has?
No vertical Displacement
Body waves
Travel through solid body of the Earth.
Surface waves
Travel along the ground surface and move slower than P and S waves, but can produce severe ground movements
Two types of Seismic Waves
Body Waves
Surface Waves
The Magnetosphere surrounds?
The Earth
What Methods do people use to study Earths Interior?
Drilling
Radar Frequencies
Earthquakes
Epicenter
The geographic location on Earth’s surface directly above the Earthquake focus.
P-waves
Can travel at 4-6 km through liquid and solids.
Side to side motion
S Waves
(Shear Waves) travel at 3-4 km/sec
Can’t travel through liquids, useful for inferring the physical state of rocks below Earths Surface
Up and Down motion
Seismometer
The instrument to record Earthquakes release of Energy as vibrations (Seismic waves)
Can Earthquakes be predicted? What methods could you use to determine the timing of a big earthquake?
Scientists use the times that the various waves arrive and their relative amplitudes as recorded on a seismogram.
Can you measure the amount of damage caused by an Earthquake?
Yes, the amplitude of the seismic wave record is proportional to the magnitude of shaking associated with the earthquake, (the greater the amplitudes the more violent the shaking).
Where do most Earthquakes occur?
Along the coast lines, near faults
Intensity
A measure of the effects of earthquakes on people and buildings.
How is Earthquake magnitude measures?
On a logarithmic scale in which each division represents a 10-fold increase in the ground motion associated with the earthquake.
The Earthquake Magnitude doesn’t have a maximum value (T or F)
True
Richter Scale
Measures amplitude of largest S-wave.
Scale is logarithmic:
Increase 1 unit=10 times greater
Increased 1 rating=30 times greater
Examples of Major Earthquakes around the world?
Loma Prieta, California Kobe, Japan New Madrid, Montana Chile Alaska
Intensity is measured using?
The Modified Mercalli Intensity Scale
Chemical Layers
Crust
Mantle
Core
Continental Crust
Granite
Oxygen, silicon, aluminum, potassium
Oceanic Crust
Basalt Oxygen Silicon Magnesium Iron
Mantle
Layer be sty crust
Composed of rock called Peridotite
Green and Black colored
Core
Beneath the mantle at the Earths center
No rock defines this layer
One feature
Metal, Iron, nickel, sulfur
Mechanical Layers
Lithosphere, Asthenosphere, Mesosphere, Lower Mantle, Outer Core, Inner Core
Order of Rigidity based on Seismic Data?
Solid/Elastic
Solid/Rigid
Liquid
Lithosphere
Crust
Uppermost most mantle
Rigid
Lower Mantle includes
Solid/rigid
Mesosphere
San Andreas Fault
Right-Lateral Strike Slip Fault
Moho Discontinuity
Boundary between the Earths Crust and the mantle
Low Velocity Zone
Occurs close to the boundary between the lithosphere and the asthenosphere in the upper mantle.
Mantle-Core Boundary
Lies between the Earth’s silicate mantle and its liquid iron-nickel outer core.
Asthenosphere
Solid/elastic
Outer Core
Liquid
Inner Core
Solid/
Earths Mechanical Layers
Lithosphere Asthenosphere Lower Mantle Outer Core Inner Core
What skill (or part of the scientific method) is a scientist using when she uses the available data to formulate an explanation of an observed event?
Developing Hypothesis
Which is an observation rather than an interpretation?
Rock around the crater are slanted upward
What quality defines a useful or meaningful hypothesis?
Testable
Scientific explanations (hypotheses) are absolute and unchanging T or F
False
In the context of science, how would you classify the following statement? Iridium is present in relative high concentrations in 65 million year old rock layers in several locations on Earth.
Observation
Which is not a characteristic of scientific explanations?
They are able to answer all questions
A hypothesis is supported by more scientific research and observation than a theory
T or F
False
The average surface temperature of the earth has increased by 0.7 degrees C. Over the last 125 years. This is an example of?
Scientific or empirical observation
NEO
Near Earth Object
NEO impacts are the only natural disaster that can actually be prevented.
T or F
True
The risks associated with NEOs are reported using a numeric scale ranging from 0 to 10 known as the Richter Scale.
T or F
False
What is false about NEOs?
The number of known asteroids in our solar system has remained unchanged over the last 100 years
The impact of a large comet or meteorite with Earth would devastate the global environment by generating air blasts, earthquakes, wild fires, tsunami, acid rain, and changes in climate.
T or F
True
Most orbit between Mars and Jupiter
Asteroids only
Long versions of this come from the Oort Cloud
Comets only
How long have asteroids been striking Earth?
Since Earth formed
Seismic Discontinuity
An abrupt change in seismic wave velocity
False statement about the Moho
The Moho separates the crust from the mantle
The highest geothermal gradients in the United States are located along our East Coast.
T or F
False
Which would have a high geothermal potential?
A region of active extension/cracking of the crust
A region containing many active volcanoes
Comets
Made out of ice and dust, lower density, lower risk, 100,000mph
Asteroid
Made out of rock and/or metal, high density, high risk 30,000mph
Comet vs. Asteroid
Comet more dangerous due to low risk due to density, high risk due to speed.
Geothermal Gradient
How the temperature of rocks changes with Depth.
25 degrees Celsius per Kilometer
Geothermal Energy
Heat from the Earth
Th act of recognizing a fact or occurrence often involving measurement with instruments. Use of the senses.
Observation
An explanation that can be tested by additional investigation or by examining data that already exist.
Hypothesis
To foretell on the basis of observation, experience, or scientific reasoning
Predicting
Scientific observation
The data (evidence) can be observed using the senses or in some cases using calibrated scientific instruments
Casual observation
Reflection alone is concerned to be evidence for the truth or falsity of some proposition.
Not an example of a scientific observation
There is an isolated mountain surrounded by relatively flat land
Asteroids that burn in the Atmosphere
Meteor
If a NEO clearly is going to collide with a Earth, what score on the Torino scale is it mostly likely to recieve
9
These are known to pass close to the Earth
Comets and Asteroids
Crust
Uppermost, lightweight, brittle layer
Earths Chemical Layers
Crust, Mantle, Core
Which rock would you be most likely to find in continental crust?
Granite
What marks the boundary between the crust and the mantle?
An increase in P-wave velocity and a change in rock type.
What is the approximate distance from the surface to the center of the Earth?
6400km
Which of the following seismic waves will arrive at a seismograph first?
P-waves
Which layer in the earth does not transmit S waves?
Outer core
Where do P waves travel fastest
Lower mantle
What makes up most of the core?
Iron
What’s the difference between the inner core and outer core?
The inner core=solid
The Outer core=liquid
Which is better? Theory or Hypothesis
Theory
How many NEOs are there?
Hella
How was the Barringer (Meteor) Crater formed in Arizona?
50,000 years ago when a 50 meter diameter meteorite crashed into Earth.
1km Diameter NEO forms what size of crater?
10-20 kilometer wide crater
10 km Diameter NEO forms what size of crater?
100-200km diameter
