Presentation on theme: " List the names of the interior layers of the Earth beginning with the core. But wait, we didn’t learn that…… where ever could we find such information?"— Presentation transcript:
List the names of the interior layers of the Earth beginning with the core. But wait, we didn’t learn that…… where ever could we find such information?
Using the copy of page 10 in the ESRT, count how many interior layers there are inside Earth and take a colored pencil for each layer. Color each layer a different color. With you partner, answer the questions about the layers.
How is it possible for us to know all of this about the inside of Earth?
Interior Layers of the Earth:
An earthquake is the vibration of Earth produced by rapid release of energy. Focus is the point within Earth where the earthquake starts. Epicenter is the location at the surface directly above the focus.
Faults are fractures in Earth where movement has occurred.
Earthquakes are caused when the strength of the rock is exceeded. It suddenly breaks causing the vibrations of an earthquake.
These vibrations travel in the form of seismic waves.
There are two kinds of seismic waves Body waves travel through the Earth. When body waves reach the surface of the Earth they are called surface waves. There are two types of body waves travel through Earth: 1.P waves 2.S waves
P waves (compression) can travel at the fastest speed and can move through solid, liquid, and gas! S waves (shear) travel slower and can only move through solids!
Which interior layers of Earth can S waves move through? (Use your ESRT) Why?
A Tsunami is an underwater earthquake. When there is a shift in the ground underwater, it displaces or moves the water. The water waves travel trough the deep water. When they approach shallow depths, the energy in the wave is conserved by increasing wave height.
Let’s meet Patty and Sarah!
A seismograph is an instrument used to detect and record seismic waves. A seismogram is the actual recording on paper. How do we know that P waves (compression) travel faster than S waves (shear)?
-How do we know that P waves (compression) travel faster than S waves (shear)?
-Because they always show up first on a seismogram.
According to the graph of Earthquake P-wave and S- wave Travel Time in the reference information, what is the approximate total distance traveled by an earthquake’s P-wave in its first 9 minutes? 2,600 km 5,600 km 7,600 km 12,100 km
Let’s have some fun with numbers!!!
What can the difference in P wave and S wave travel time can tell us about an earthquake? Let’s figure it out together…….. Turn to page 11 in your ESRT!
Earthquakes Seismograms at three stations
Earthquakes *Which Station is closer to the earthquakes epicenter? *What information did you use to figure that out?
Station A: San Francisco, California P-Wave arrival 3:02:20S-Wave arrival 3:06:30 What is the time difference between P and S wave arrivals?
Station B: Denver, Colorado P-Wave arrival 3:01:40S-Wave arrival 3:05:00 What is the time difference between P and S wave arrivals?
Station C: Missoula, Montana P-Wave arrival 3:01:00S-Wave arrival 3:03:00 What is the time difference between P and S wave arrivals?
San Francisco: 4:10 Denver, Colorado: 3:20 Missoula, Montana: 2:00
Time to…. Surf the wave!
TAKE A PIECE OF PAPER, AND MARK OFF THE DIFFERENCE IN ARRIVAL TIME
MOVE THE PAPER UNTIL THE TWO TICK MARKS LINE UP WITH THE P AND S CURVES WHEN TICK MARKS LINE UP, GO STRAIGHT DOWN AND READ THE EPICENTER DISTANCE EPICENTER DISTANCE OF 2800 KM
San Francisco: 4:10 Denver, Colorado: 3:20 Missoula, Montana: 2:00 Try the other two on your own.
The diagram shows data received at a seismic station following an earthquake. The distance from this seismic station to the epicenter of the earthquake is approximately….. a.1,300 km b. 2,600 km c. 3,400 km d. 5,000 km
Let’s practice with Epicenter Info!
So what does this distance we get from the ESRT tell us anyway?
San Francisco: 4:10 =2,800km 1,000 2,000 3,000 4,0005,000 Open your compass to the EXACT distance on the scale.
We know that P and S waves are the body waves that travel through Earth. Surface waves only travel along Earth’s surface. We describe surface waves as either Love waves or Raleigh waves. Check this out geo.mtu.edu/UPSeis/waves.html
But wait, how do P and S waves behave? Time to play with the slinky!!! How can we get the slinky to behave like a P wave? An S wave? Recall the terms compressional and shear.
Team Challenge: Each class will be timed!! Make a human P wave in order to get “energy” to travel from one side of the room to the other! Then make a human S wave!!! Ready….Set…..Go
Recall: When traveling through the same material P waves move faster than S waves. Recall: S waves can only travel through solids while P waves travel through solids and liquids! -Waves refract (change direction) and speed up as density increases. -Since density increases with depth, the wave path looks something like this…….