Tectonic Plates Flashcards
What are tectonic plates?
Large pieces of the Earth’s crust that float and move on the mantle
Tectonic plates consist of two types: oceanic and continental.
What is the crust?
The outer edge of the Earth, solid and composed of oceanic and continental types
Continental crust is lightweight but thick, while oceanic crust is heavier but thin.
What is the mantle?
Layer below the Earth’s crust, consisting of liquid magma over 5000°C
Convection currents occur in the mantle.
Define convection currents.
Movement of magma in the mantle driven by heat from the core
These currents help move tectonic plates in different directions.
What are hot spots?
Areas where volcanoes form not on a plate margin due to thin crust
Example: Hawaiian Islands.
What are the three main types of plate margins?
Constructive, destructive, and conservative margins
These margins are where different tectonic plates meet.
What occurs at a constructive margin?
Two plates moving apart, allowing magma to rise and form shield volcanoes
Example: Mid Atlantic Ridge.
What is ridge push?
The force that pushes tectonic plates down due to gravity
This occurs at constructive margins.
Describe shield volcanoes.
Flat volcanoes with runny lava and violent eruptions
Formed at constructive margins.
What happens at a destructive margin?
Two plates move towards each other, with the heavier oceanic plate going beneath the lighter continental plate
This results in oceanic platelets and eruptions through composite volcanoes.
Define slab pull.
The force that pulls tectonic plates into the mantle due to gravity
This occurs at destructive margins.
Describe composite volcanoes.
Steep volcanoes with sticky lava and violent eruptions
Found at destructive margins.
What characterizes a conservative margin?
Two plates sliding alongside each other, moving at different rates
Pressure builds up due to friction, released through earthquakes.
What are natural hazards?
Severe and extreme tectonic, weather, and climate events
They become disasters when they destroy lives and livelihoods.
Fill in the blank: The Pacific Ring of _____ is known for its high volcanic activity.
Fire
True or False: The San Andreas Fault is an example of a constructive margin.
False
The San Andreas Fault is a conservative margin.
