Vocab Earthquake study guide Flashcards
What is a Earthquake
A vibration in the ground. There is stress along faults when rocks are pushed together. When a rock suddenly slips or breaks, it creates releases energy.
What is a Focus
An area in the crust or the upper mantle where seismic waves move outward in all directions. This area is underground. This area can also be where earthquakes occurs.
What is a seismic wave
An energy wave that travels from the focus.
What is a epicenter
An area on the surface directly above the focus.
What is a primary wave/ P wave?
A type of seismic wave that travels the fastest. The wave can go through all states of matter. Push and pull rock depending on the way the wave is moving. The primary wave moves from the focus.
What is a secondary wave?
A type of seismic wave that moves from the focus. Slower than the primary wave and can only go through rock. Causes rock the move at right angles to primary waves. Movs rock side to side, As well as up and down.
What is a surface wave
A type of seismic wave that moves out from the epicenter. This causes the ground to shake by making the rock sway side to side. Surface waves are what cause most of the damage in an earthquake.
What is a seismograph
A machine that shows how much energy is released. The higher the jagged line on a piece of paper, the more energy is released. The P wave reaches the seismograph first then the second wave and the surface wave. Scientists measure the time of arrival between the p wave and the secondary wave. Then they figure what’s the distance of the epicenter. Multiple readings from a seismograph can determine where an earthquake is.
What is magnitude
The energy released by the earthquake. Determined by a seismograph and compared to the earthquakes using the Richter scale.
What is the Richter Scale
A scale that measures the magnitude of an earthquake from a scale of 1-10. Each number going up is 10 times as much magnitude.
What is the Mercalli Scale?
A scale that measures the damage done by an earthquake in a specific location. Uses the scale I-XII
What is a tsunami
An earthquake that reaches the ocean floor creates seismic sea waves called tsunamis. When tsunamis reach shallow water near land the tsunami grows in height.
