Trivia
Name the 4 sections of the earth (on the board)
A.Lithosphere
B.Mantle
C.Outer Core
D.Inner Core
Why is the inner core solid?
Pressure Freezing-the physical pressure caused by the great mass of rock above the inner core is high enough that the atoms making up the iner core stay close together keeping the inner core solid, despite its high temperature.
Sedimentry Rock
Earth's outermot layer of rock.
What is the lithosphere composed of?
Many independently moving plates.
The study of earthquakes is called?
The scale that measures the strength of an earthquake is called the?
Seismology
Richter Scale
What have scientists observed in order to learn about earth's interior?
Seismic Waves
What causes the earth's magnetic field?
Electrical flow in the core.
Igneous Rock
Rock that forms from molten rock.
Explain the theory of plate tectonics.
This theory relies on the idea that the earth's lithosphere is fractured and broken.
If a region of the earth has a lot of volcanic activity, what kinds of mountains do you expect to find there?
Both volcanic mountains and domed mountains.
What 2 sections of Question 1 (on board) is the Moho between?
A & B separates the lithosphere from the mantle.
What benefit do we derive from the earth's magnetic field?
It blocks cosmic rays from the sun.
Fault
The boundary between two sections of rock that can move relative to one another.
A hypothetical supercontinent that might have existed in earth' past is called?
Pangaea
What two theories attempt to explain the earth's magnetic field?
Which theory is more scientifically valid?
Dynamo Theory and the Rapid Decay Theory.
The Rapid Decay Theory.
In a survey of the deep ocean, sonar measurements detect a deep trench on the bottom that runs as far as the instruments detect. What is the most likely cause of the trench?
Most likely the trench where one plate shlides under another.
How do scientists find out about the mantle and the core?
Indirect observation
Epicenter
The point on the surface of the earth directly above an earthquake's focus.
The earthquake activity of two regions on earth is measured. The first region sits near the middle of one of the plates in the earth's crust, while the other is very near a boundary between two plates. Which will most likely have the greatest earthquake activity?
The region near the plate boundary,
What is the name of the theory that tries to explain how earthquakes occur?
Elastic Rebound Theory
Sound travels as a wave. A sound wave is just a vibration that passes through a substance. Will sound travel better through substances in which the matter is more tightly packed or less dense?
Tightly packed- a solid
The crest of the earth contains what 3 things?
Soil, Sediment and Rock
Plastic Rock
Rock that behaves like something between a liquid and a solid.
Would plate tectonics work if the mantle were made out of normal, solid rock? Why or why not?
If the mantle were normal, solid rock, the plates would not be able to move.
If an earthquake measures 6 on the Richter scale and is followed by an aftershock that measure 3, how many times more energy was released in the origianl earthquake as compared to the aftersock?
Each step on the scale means a factor of 32 in energy. Since the quake and aftershock are off by 3 units, the quake is 32x32x32=32,768 times more energetic than the aftershock.