Download Who was the father of plate tectonics? Alfred Wegener Who was the

Who was the father of plate tectonics?
Alfred Wegener
Who was the first to propose the idea of
continental drift?
The theory of plate tectonics proposed that all
of the continents on Earth were once a single
landmass called _____________.
According to the theory, this landmass broke
apart how long ago?
What three types of evidence supported the
Pangaea hypothesis?
Alfred Wegener
Pangaea
about 200 million years ago
1. rock formations (same rock layers were found on
mountains in US and Europe)
2. fossils (similar plant/animal fossils found on widely
separated continents)
3. climatic (coal found in Antarctica, so continent must
have once been closer to equator)
(glacier deposits found in India & South America, so
continents must have once been closer to south pole
True or False? Alfred Wegener died before his
ideas about continental drift were recognized.
What types of devices can detect small changes
in the ocean floor’s magnetic field?
What are ocean ridges?
What are ocean trenches?
True
1. Sonar
2. Magnetometers
Ocean mountain ranges where earthquakes and
volcanic eruptions take place
long, narrow depressions in the ocean floor
What is the deepest trench? Where is it
located? How deep is it?
Does the age of the oceanic crust increase or
decrease with distance from a ridge?
Is ocean sediment thickest near trenches or far
from trenches?
The Earth’s magnetic field is created by the
movement of molten _______ in the outer core.
What is it called when the Earth’s magnetic field
changes direction?
What causes changes in the Earth’s magnetic
field?
What is the study of the Earth’s magnetism?
Marianas Trench/Pacific Ocean/6 miles deep
What theory explains how new ocean crust is
formed at ocean ridges and destroyed at deep
sea trenches?
This theory explains how landmasses move in
_________ drifting.
What theory describes how plates move and
shape the Earth’s surfaces?
What are tectonic plates?
seafloor spreading
increase
near trenches
iron
magnetic reversal
changes in iron flow
paleomagnetism
continental drifting
plate tectonics
Huge pieces of crust and upper mantle that fit
together at their edges to cover the Earth’s
surface
How many major plates are there?
12
Name two types of boundaries
1. divergent boundaries
2. convergent boundaries
divergent boundary
This type of boundary is a region where plates
move away from each other forming new crust
This type of boundary occurs when plates move
toward each other destroying crust
This type of boundary occurs when plates slide
past each other creating cracks
What is subduction?
What are the three types of convergent
boundaries and what do they form?
convergent boundary
transform boundary
When one plate moves under the other one after
colliding
1. oceanic-oceanic
(forms trenches, destroys basins)
2. oceanic-continental
(forms trenches & volcanoes along edge of continental plate)
3. continental-continental
(forms large mountain ranges)
An example of this type of boundary is the
Marianas Trench
An example of this type of boundary is the
Andes mountain range
An example of this type of boundary is the
Himalaya Mountains
An example of this type of boundary is the San
Andres Fault
What cycles heat from the core to the crust?
oceanic-oceanic boundary
Describe how convection currents work
- cooler mantle sinks (sinking current), is heated
as it moves towards the core, then rises (rising
current) and is cooled again
divergent
What type of boundaries form above rising
currents in the mantle?
What type of boundaries form above sinking
currents?
Ridge push = pushes plates _______ trenches.
oceanic-continental boundary
continental-continental boundary
transform boundary
convection currents
convergent
towards
Slab pull = pulls plates _______ trenches
down
All the processes associated with the discharge
of magma, hot fluids, and gases
Where do most volcanoes form?
volcanism
True or False? Volcanic eruptions at convergent
boundaries are nonexplosive.
True or False? Volcanic eruptions at divergent
boundaries tend to be explosive.
What do you call huge piles of lava formed by
nonexplosive volcanic eruptions
false
at plate boundaries
false
pillow lava
Anatomy of a Volcano
1.___________= bowl-shaped area that forms
around the vent
2. __________= the opening at the surface
where lava leaves the pipe
3. __________= side opening of volcano where
lava leaves the pipe
4. __________= tubelike structure that lava
flows through to reach the surface
5. _________= large, underground pocket that
holds magma; located at the base of the pipe
What is a caldera?
Name the types of volcanoes, what they look
like, and how they are formed
As the amount of gases in magma increases, the
magma’s ________ increases.
What is viscosity?
The higher the _________ content, the greater
the viscosity.
Rising magma can form _______, which are
intrusive rocks.
What are intrusive rocks?
What are extrusive rocks?
1.
crater
2. vent
3. side vent
4. pipe (conduit)
5. magma chamber
A caldera is formed when volcanic structure
collapses into emptied magma chamber
(lakes form when water collects)
1. shield volcanoes
look like: gentle sloping sides, largest
formed: nonexplosive eruptions
2. cinder cone volcanoes
look like: steep sides, smallest
formed: buildup of small magma pieces
3. composite volcanoes
look like:
formed: buildup of large magma chunks from
explosive eruptions
explosivity
a material’s resistance to flow
silica
plutons
Rocks formed from cooled magma WITHIN the
crust
Rocks formed when magma cools and crystallizes
on the surface of the Earth