Earthquakes and Seismic Waves
Earthquakes and Seismic Waves Earthquake-is violent shaking of Earth's crust
Focus-exact point within the crust where the fist movement occurs
Epicenter-point on Earth's crust directly above the focus
Types of Seismic Waves P Wave
Primary-1st
Fastest
Accordion-in and out
S Wave
Secondary
Snake-like
Can't travel through liquid
Surface Wave-roll through the top of the crust creating the most damage
Measuring Earthquakes
Mercalli scale
-measures damage
The Richter Scale
-magnitude
-seismograph-needle and paper
The Moment Magnitude Scale
-measures energy
Comparing Magnitudes
-1 point = 32x energy
Locating the Epicenter
-time the difference between P and S waves
-plot time on graph to determine distance
-use compass to encircle station
-repeat with 2 other stations
-epicenter is where all 3 meet
The Richter scale measures an earthquake based on the size of the seismic waves that it produces.
The focus is the point beneath Earth’s surface where rock that is under stress breaks, triggering an earthquake. The epicenter is the point on the surface directly above the earthquake’s focus.
P waves compress and expand the ground they travel through, whereas S waves thrust the ground from side to side and up and down. S waves are not as fast as P waves, and they cannot travel through liquids as P waves can.
A tiltmeter measures vertical movement along a fault. Tiltmeters work much like a carpenter’s level. They consist of two bulb containing liquid. A scale allows scientists to determine any changes in to volume of liquid in either bulb.
The Global Positioning System, or GPS, consists of a network of satellites that can be used to locate points on Earth’s surface with great precision. This satellite network allows scientists to measure tiny movements of receivers placed on the ground on opposite sides of a fault. GPS satellites can be used to detect horizontal movements along a fault as well as
Focus-exact point within the crust where the fist movement occurs
Epicenter-point on Earth's crust directly above the focus
Types of Seismic Waves P Wave
Primary-1st
Fastest
Accordion-in and out
S Wave
Secondary
Snake-like
Can't travel through liquid
Surface Wave-roll through the top of the crust creating the most damage
Measuring Earthquakes
Mercalli scale
-measures damage
The Richter Scale
-magnitude
-seismograph-needle and paper
The Moment Magnitude Scale
-measures energy
Comparing Magnitudes
-1 point = 32x energy
Locating the Epicenter
-time the difference between P and S waves
-plot time on graph to determine distance
-use compass to encircle station
-repeat with 2 other stations
-epicenter is where all 3 meet
The Richter scale measures an earthquake based on the size of the seismic waves that it produces.
The focus is the point beneath Earth’s surface where rock that is under stress breaks, triggering an earthquake. The epicenter is the point on the surface directly above the earthquake’s focus.
P waves compress and expand the ground they travel through, whereas S waves thrust the ground from side to side and up and down. S waves are not as fast as P waves, and they cannot travel through liquids as P waves can.
A tiltmeter measures vertical movement along a fault. Tiltmeters work much like a carpenter’s level. They consist of two bulb containing liquid. A scale allows scientists to determine any changes in to volume of liquid in either bulb.
The Global Positioning System, or GPS, consists of a network of satellites that can be used to locate points on Earth’s surface with great precision. This satellite network allows scientists to measure tiny movements of receivers placed on the ground on opposite sides of a fault. GPS satellites can be used to detect horizontal movements along a fault as well as