Eartquakes Quiz Flashcards
What is seismology?
The study of earthquakes
Name the three places where earthquakes occur.
Near the edges of tectonic plates
Along fault lines where blocks of crust slide relative to one another
Volcanoes
What causes earthquakes?
Deformation
Faults
What is deformation? What are the two kinds of deformation?
Deformation is the change in shape of rock due to stress
Plastic
Elastic
Describe plastic deformation.
Changes shape like molding clay. Doesn’t lead to earthquakes.
Describe elastic deformation
Leads to earthquakes. When rock stretches and breaks and releases energy, returning to its original shape. Similar to a rubber band. Some energy is released as seismic waves causing earthquakes.
What is an earthquake zone?
Places where a large number of faults are located
What are seismic waves
Waves of energy that travel through
What are body waves
Seismic Waves that travel through earths interior
Surface waves
Travel along earths surface.
What do P wave travel through?
Solids
Liquids
Gases
P waves are primary waves which means what.
Always first detected
What can S waves travel through?
Not liquids
When do secondary waves arrive
After p waves
What are the two types of surface waves.
Up, Down, and Around
Back and Forth
Surface waves move more than body waves and are more ?
Slowly
Destructive
What is a seismographs?
A machine that creates a seismogram
What is a focus? A epicenter?
Focus-point inside the earth where the earthquake begins
Epicenter-point on earths surface directly above the focus
What is an earthquake hazard?
Measures how likely an area is to have a damaging earthquake based on past and present seismic activity
How many great earthquakes are there a year? Minor?
1 great
365,000 minor
What is the gap hypothesis?
Sections of active faults that have had relatively few earthquakes are likely to be the sites of strong earthquakes in the future
What is a seismic gap?
Fault areas where few earthquakes have occurred
What is a foreshock? Aftershock?
Foreshock-a smaller earthquake that precedes the main quake.
Aftershock-smaller quake that co es after a large quake in the same area
How are tsunamis 🌊 happen?
Subduction areas Plates get caught, which makes pressure They slip which causes an earth quake which make the water move Water hits shore and slows down Wall of water
