What Happens
A(n) _____________ is trembling of the ground when energy is suddenly released along a moving fault.
What is an earthquake?
The point underground where the first motion of an earthquake occurs.
What is the focus?
Waves of energy that travel through rock.
What are seismic waves?
Most of the earthquakes in Japan are the result of one plate sinking under another.
What is a convergent boundary?
These extremely fast and long waves are formed when underwater earthquakes displace enormous amounts of water.
What is a tsunami?
Earthquakes are caused by sudden motion along a _________.
What is a fault?
The point directly above the focus on the surface of the Earth.
What is the epicenter?
A device that scientists use to collect and record seismic-wave data.
What is a seismograph?
The African Rift Valley is a location where plates are moving apart.
What is a divergent boundary?
This many earthquakes occur worldwide each year: 50,000 or 500,000, or 5,000,000.
What is 500,000?
______________ is the sudden return of deformed rock to its undeformed state.
What is elastic rebound?
Most earthquakes occur near _________________________________.
What is tectonic plate boundaries?
P waves travel through what states of matter?
What are solids, liquids, and gasses?
The San Andreas fault is a location where tectonic plates move horizontally past each other.
What is a transform boundary?
This common, everyday item, is a simple model of elastic rebound.
What are rubber bands or hair elastics?
Stress causes land to bend, tilt, or break. These changes in shape are called __________________.
What is deformation?
Earthquakes occur at ______________, which are breaks in Earth's crust where blocks of rock move.
What is a fault?
S waves travel through this state of matter.
What is solids?
Normal faults occur at these boundaries where tension stress stretches rock and makes it thinner.
What is a divergent boundary?
Most earthquakes last for several ______________. (nanoseconds, seconds, or minutes)
What are seconds?
Earthquakes cause injury and loss of life, mostly from _____________________________________.
What is buildings or structures collapse?
This state has the most Earthquakes of any in the United States - over 10,000 each year!
What is Alaska?
Both P and S waves travel faster through matter that is more __________________.
Strike-slip faults are common at boundaries where rock is distorted by shear stress.
What is a transform boundary?
The strongest earthquake on record occurred in this country.
What is Chile?