tectonic plates result in new landforms Flashcards
(19 cards)
What is the Theory of Plate Tectonics?
The Theory of Plate Tectonics describes the movement of tectonic plates on Earth’s surface and explains geological phenomena.
It differs from the Theory of Continental Drift, which only focused on the movement of continents.
What are the three main plate boundary types?
- Convergent
- Divergent
- Transform/Conservative
Each type has distinct characteristics and directions of motion.
What is the direction of motion at convergent plate boundaries?
Plates move towards each other (→←)
This can lead to subduction or mountain formation.
What is the direction of motion at divergent plate boundaries?
Plates move away from each other (←→)
This often results in seafloor spreading.
What is the direction of motion at transform plate boundaries?
Plates slide past each other (horizontal motion)
This type of boundary can lead to earthquakes.
What happens to the crust at convergent plate boundaries?
Subduction occurs, where one plate is forced below another.
This can create mountain ranges and volcanic activity.
What happens to the crust at divergent plate boundaries?
Seafloor spreading occurs, creating new crust as magma rises.
This typically happens at mid-ocean ridges.
Provide a named example of a convergent boundary.
The Himalayas
This mountain range is formed by the collision of the Indian and Eurasian plates.
Provide a named example of a divergent boundary.
Mid-Atlantic Ridge
This is where the Eurasian and North American plates are moving apart.
Provide a named example of a transform boundary.
San Andreas Fault
This fault line is located in California, where the Pacific and North American plates slide past each other.
Why are some tectonic plates moving faster than others?
Some plates more faster than others because when some plates have a subduction zone on the other side and the subduction zone pulls the plate faster than the convection current moves. Where a when a plate doesn’t get pulled it moves at the same speed as the convection current underneath.
Slab-pull occurs when a denser oceanic plate sinks into the mantle.
Where do most volcanoes and earthquakes occur?
At plate boundaries along the ring of fire
Their occurrence is directly related to the interactions of tectonic plates.
Why do most large earthquakes occur at convergent plate boundaries?
From the intense pressure and stress from colliding plates lead to significant seismic activity.
This is especially true where subduction occurs.
How are tsunamis created during an earthquake?
when a sudden rise or fall of the ocean floor, caused by the earthquake, displaces the overlying water column
This can occur at subduction zones.
What are the different types of volcanoes?
- Shield volcanoes
- Stratovolcanoes
- Cinder cone volcanoes
- Calderas
Each type has distinct shapes and eruption styles.
How do volcanoes form and erupt?
Volcanoes form at plate boundaries where tectonic plates collide and spread, erupting when pressure builds up.
Eruptions can be explosive or effusive based on magma composition.
What is the link between silica levels, viscosity, explosivity, and volcano shape?
Higher silica levels increase viscosity, leading to more explosive eruptions and steeper volcano shapes.
Lower silica results in less viscous and less explosive eruptions.
What is the Ring of Fire?
A major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur.
It is associated with numerous convergent and transform boundaries.
What are hot spot volcanoes?
Volcanoes that are created by stationary regions of intense heat in the earths mantle that cause magma to rise and erupt on the surface, forming volcanoes away from plate boundaries
An example is the Hawaiian Islands.
