msharrisonweiss.weebly.commsharrisonweiss.weebly.com/.../12.0_-_complete_student_notes.do… ·...
TRANSCRIPT
Chapter 1212.1
Evidence for Continental DriftP. 506-509
Vocabularysupercontinent pangaea continental drift theory continental shelfpaleoglaciation
Continental Drift
Current map of the world:
The world did not always look like this!
Alfred Wegner, a scientist in the 1900’s, began to notice something when he studied the world map: some continents fit together like puzzle pieces. He began to research a bit more into the matter and found a few things:
1. There are the same types of rocks and mountains on different continents.2. There are the same fossils on different continents3. There were very old glaciers all over the world
These observations lead him to come up with the ___________________________1. A very long time ago (~200 million years) the continents were joined together in a
________________________________ called ______________.2. Continents _________ around the world
1 Gu 2016
Continental Drift
Evidence Notes
1. The shape of the continents
The shape of the continents fit together like jigsaw pieces. the continents fit together even better if we include the
___________________________
2. Matching geological structures
3. Matching Fossils
2 Gu 2016
4. Paleoglaciation
Some scientists opposed Wegner’s theory of continental drift1. The age of the Earth is debated. Continental drift takes a VERY long time and many scientists believe the
Earth is ________________.2. Wegener could not explain how continental drift occurs. How can huge pieces of land move?
3 Gu 2016
Chapter 1212.2
The EarthP. 518-522
Geological Structurescrust upper mantle lithosphere rift valleycontinental crust lower mantle asthenosphere subduction zoneoceanic crust outer core spreading ridge trenchmantle inner core
Geological Processesmantle convection seafloor spreading ridge push subductionslab pull
Other Wordsgranite basalt thermal energy
The Layers of the Earth
The Earth is not a solid ball, but made of complex layers. Some of these layers are solid, while others are liquid! Read P. 519-520 and fill in the following table.
Layers Thickness State Main Elements Temperature(oC) Other
The
Crus
t ContinentalRock type:
_____________ (Less dense)
OceanicRock Type:
_____________(More dense)
Man
tle
Upper(lithosphere &
asthenosphere)
Includes the asthenosphere and
part of the lithosphere
Lower
Outer Core rotates
Inner Core very high pressure and rotates
4 Gu 2016
5 Gu 2016
___________________
state: _________ composition: _______________________ temperature: _______________________
___________________
state: _________ composition: _______________________ temperature: _______________________
___________________
state: __________________ composition: _________________________________ temperature: _____________
__________________Made of tectonic plates that float on the asthenosphere
___________________
state: _______________________ composition: _________________ temperature: __0 - 400°C__
__________________ composition: ________
______________________________________
upper mantle
does not include the crust state: ________________________ composition: __________________
_____________________________ temperature: _____________
mantle
crust
___________________
state: _______________________ composition: _______________________ temperature: __0 - 400°C__
Tectonic Plates
Tectonic plates are like giant pieces of rock floating on top of the ___________ asthenosphere. They float on ____________
there are ______ major tectonic plates and many smaller ones
continents are ____________ to the tectonic plates tectonic plates are always ______________
Convection
Convection is a process where hot material _________ and cool material _________. Tectonic plates are always moving due to convection. They move at a rate of ______________!
6 Gu 2016
Chapter 1212.1/12.2
Diverging BoundariesP. 523-526
Vocabularydiverging boundary continental plate oceanic plate spreading ridge ridge push seafloor spreading rift valley rift eruption Plate Tectonic Theory mountain range Unifying Theory of Geology
Boundaries
A diverging boundary occurs where two tectonic plates move ________ from each other or are spreading apart. What happens depends on whether the plates involved are _____________ or _____________.
Two Oceanic Plates (under water) Two continental plates (on land)
1. ______________________________________2. The magma _________ and ______________3. ________________: the magma is pushed
aside by new magma coming from below4. The entire process is called seafloor spreading
1. There is a weakened spot on the plate2. _________________________________________
_________________________________________
For both cases, large amounts of magma can be released (called a ___________________) through the crack. This may result in the creation of a _____________.
7 Gu 2016
Diverging Boundaries/Plates ( ← → )
Plate Tectonics Theory In the mid-1960s, Canadian geologist J. Tuzo Wilson came up with the Plate Tectonics Theory to explain continental drift.
People call the Plate Tectonics Theory the ___________________________________ because it can explain so many things:
how earthquakes happen and why they appear in certain regions how volcanoes are made and why they appear in certain regions how valleys are made and why they appear in certain regions how mountains are made and why they appear in certain regions rock layers why different continents have the same fossil paleoglaciation records on different continents
8 Gu 2016
Plate Tectonics Theory
1. There are huge slabs of rock called tectonic plates around the world that float on top of partly molten rock (magma in the mantle).
2. Continents are on top of different tectonic plates.3. The tectonic plates move on partly molten rock by _____________________, where old
rock is pushed by new rock.
Chapter 1212.2
Convergent and Transform BoundariesP. 523-526
Vocabulary & Conceptsconverging boundary subduction slab pull trenchfracture fault shield volcano transform boundary
Converging Boundaries/Plates ( → ← ) A converging boundary occurs where two tectonic plates move __________ each other and ___________. What happens depends on whether the plates involved are continental or oceanic.
Continental → ← Continental Convergence
When two continental plate collide: continental plates have similar ______________ the two plates push against each other
Can result in ______________ and _________________ eg. Himalayas are the world’s youngest and
tallest mountain range, and is still growing taller today
Oceanic → ← Oceanic Convergence
When two oceanic plates collide, the ________ more ________ plate will sink under the __________ less dense plate.
the area where the “sinking” occurs is called a _________________________
the subducting plate is pulled down by gravity in a process called ___________
at the subduction zone, there is a deep depression called a ___________o eg. Mariana’s Trench
9 Gu 2016
Can result in: earthquakes and volcanoes
Oceanic → ← Continental Convergence
Oceanic plates (made of ____________) are heavier and more dense than continental plates the oceanic plate will subduct under the continental plate
Transform Boundaries/Plates (↑↓) A transform boundary occurs where two tectonic plates ________________________ against each other.
usually found near ________________ can be found on land too (San Andreas Fault in California)
Only sliding, no colliding no mountains are formed no composite volcanoes are formed results in breaks or _____________ in rock called ___________
10 Gu 2016
Can result in: earthquakes, mountains
ranges, and volcanoes
Chapter 1212.2
EarthquakesP. 526-534
Vocabulary & Conceptsearthquake focus epicenter shallow focusintermediate focus deep focus seismic wave primary (P) wavesecondary (S) wave surface (L) wave seismograph seismometerRichter scale perpendicular friction
What is an Earthquake?
Earthquake: shaking of the ground as a result of a ____________________________ in Earth’s crust often occurs as a result of _________ between moving tectonic plates that builds-up ____________ about 80% of earthquakes occur in a ring bordering the ________________________ the Juan de Fuca convergent plate boundary West of Vancouver Island has many earthquakes
Focus: _____________ where the pressure is finally released as an earthquake
Epicenter: the point on the ____________ ____________ _________ the focus
Earthquakes occur at various depths, depending on the plates involved. earthquakes at the surface usually cause more damage
Seismic Waves
Seismic wave: _______________ energy released by earthquakes can tell us the ___________ of an earthquake (where an earthquake happened) can tell us the ____________ of an earthquake
11 Gu 2016
Classification of EarthquakesClassification Depth of FocusShallow Focus 0 to 70 kmIntermediate Focus 70 to 300 kmDeep Greater than 300 km
Types of Seismic Waves
Seismic Wave Description Ground Motion
Where: ______________________ (body)
Travel through: _________, _____________, and _________Speed: ______________ (~6km/s) When to arrive: _______Direction: ________ direction as the wave’s motion
Analogy: spring
Where: ______________________ (body)
Travel through: _________Speed: _____________ (~3.5km/s) When to arrive: ______ Direction: _________________________ the wave’s motion
Analogy: Rope
Where: _______________________
Travel through: ________Speed: ___________When to arrive: ______________ Direction: _________________________ the wave’s motionCause more _____________________________ than P-waves.
Analogy: Ocean wave
12 Gu 2016
Measuring Earthquakes
Seismometer: a machine that measures and records seismic wave energy
Seismograph: a graph that shows _______________ of seismic waves how __________ an earthquake lasted an earthquake’s ________________ (strength)
The Richter ScaleThe magnitude (size) of an earthquake is the size of the line on the seismograph
The magnitude is measured by the Richter Scale an increase of ____ in magnitude = _______
stronger
13 Gu 2016