earth quiac Flashcards
(11 cards)
What is an earthquake?
An intense shaking of Earth’s surface caused by movements in Earth’s outermost layer.
Earthquakes are characterized by sudden movements at fault lines.
What layers make up the Earth?
Four basic layers:
* Solid crust
* Hot, nearly solid mantle
* Liquid outer core
* Solid inner core
These layers contribute to the geological activity of the Earth.
What is the lithosphere?
The solid crust and top, stiff layer of the mantle.
The lithosphere is not continuous and is broken into tectonic plates.
What are tectonic plates?
Giant puzzle pieces that make up the lithosphere, constantly shifting on the mantle below.
Their movement causes stress on the Earth’s crust.
What causes an earthquake?
Sudden movement of Earth’s crust at a fault line due to stress from shifting tectonic plates.
Faults are cracks that form when stresses become too large.
What is the epicenter of an earthquake?
The location where an earthquake begins.
It is often where the most intense shaking is felt.
How do we measure earthquakes?
Using instruments called seismometers that detect and record seismic waves.
Seismometers provide information on the time, location, and intensity of an earthquake.
What are seismic waves?
Vibrations that travel through the Earth during an earthquake.
They are recorded by seismometers as zig-zag patterns.
Do earthquakes only happen on Earth?
No, seismic activity has been measured on the Moon and evidence exists on Mars, Venus, and several moons of Jupiter.
Marsquakes are studied by NASA’s InSight mission.
What is the purpose of the InSight mission?
To study seismic activity on Mars and understand its internal structure.
It helps scientists learn about the geological history of Mars.
Fill in the blank: Earthquakes are caused by shifts in the outer layers of Earth, called the ______.
lithosphere.
The lithosphere is made up of tectonic plates.
