Primary seismic waves a. Are slower than secondary b. Are the result of shearing forces c. Can travel through solids, liquids and gases d. Causes Earth’s to roll up and down *Please have Tier 1 Out

When is the vocabulary sheet due?

Quiz the person sitting next to you, then switch!!!

Focus is in the point beneath the earth surface where the rock breaks. Epicenter is above it. The Epicenter is the point beneath the earth where the rock breaks. The focus is above it.

 Squeezes the rocks of the crust  Pushes in opposite direction  Pulls the rocks  Decreases volume  Increases volume  Increases density  Decreases density  Tear and twist

When plates slide past one another this is what type of boundary?

Transform

When plates collide this is what type of boundary?

Convergent

What happens to a rock if it’s undergoing shearing?

Bends and breaks

What is it called when that Earth BENDS?

Folding

Squeezing an object describes what kind of stress?

Compression

Before Lava hits it is called:

Magma

A volcanic belt that circles the Pacific Ocean is called:

Ring of Fire

All you need to know about Earthquakes Today: seismic waves

Seismic waves ripple like when you throw a stone into a lake or pond

Snap Your Fingers and observe what is happening. When you snap your fingers, imagine that each finger is a big chunk of rock deep inside the earth's surface. Like your fingers, one rock mass is forced against another.

Extra: Seismic Waves Deep inside the earth, rocks are constantly being pressured to move until the strain is so great the rocks can no longer bear the tension. Suddenly, there is a movement that releases all the energy--some of which has been building up for years. This released energy travels through rocks in the form of vibrations called seismic waves. Blue primary waves followed by red secondary waves move outward in concentric circles from the epicenter of an earthquake off British Columbia and Washington State.

Three Seismic Waves The energy of all three types of waves is passed from one rock particle to another in the same way one domino hits another and then another in a line of falling dominoes. These seismic waves cause back-and-forth, side-to-side, and up-and-down motions in the earth. These motions are what people sense during a earthquake.

▪ Fastest waves ▪ P waves ▪ Moves through solids, liquids, and gases ▪ Speeds up in denser material ▪ Push and pull waves

What it Looks like! Primary waves travel the fastest. P-waves are the first waves to reach the Earth's surface after an earthquake.

▪ S waves ▪ Slower than P waves ▪ Travels through solids but not liquids and gases ▪ Speeds up in denser material ▪ Movement is side to side

What it Looks Like!

I need 10 volunteers!  S waves: do "the wave" as they would in a football stadium, raising their arms and lowering them as the next person raises his or hers.  P Waves: gently grip each other's shoulders and having one pull or push the next person in line.

▪ L waves (*think Land) ▪ Slowest waves ▪ Originates at the epicenter ▪ Creates the wave movements on the Earth’s surface ▪ Causes the most damage

Let’s watch it!

Match the following into three separate categories: P, S, L waves  Slowest  Fastest  Primary  Surface  Secondary  Causes the most damage  Travels through solids, liquids, and gases

III. Seismograph – a. is an instrument that detects and measures seismic b. Waves *typo in spacing! c. Seismologist – scientists who study earthquakes, can determine the strength of them

Seismograph This is an image of a seismograph, an instrument used to record the energy released by an earthquake. When the needle is moved by the motion of the earth, it leaves a wavy line.

When you look at a seismogram, there will be wiggly lines all across it. These are all the seismic waves that the seismograph has recorded. Seismogram

The Surface waves are the other, larger waves marked on this seismogram. Surface waves travel slower than S waves (which are slower than P waves) so they arrive at the seismograph after the S waves. The Surface waves are the other, larger waves marked on this seismogram. Surface waves travel slower than S waves (which are slower than P waves) so they arrive at the seismograph after the S waves. Surface Waves Arrive Last

There are at least 20 different types of measures 3 of them are the Mercalli scale, Richter scale, and the Moment Magnitude scale Magnitude is a measurement of earthquake strength based on seismic waves and movement along faults

rate earthquakes according to their intensity The intensity of an earthquake is the strength of ground motion in a given place Is not a precise measurement But, the 12 steps explain the damage given to people, land surface, and buildings The Mercalli scale uses Roman numerals to rank earthquakes by how much damage they cause

is a rating of the size of seismic waves as measured by a particular type of mechanical seismograph All over the world, geologists used this for about 50 years Electric seismographs eventually replaced the mechanical ones used in this scale Provides accurate measurements for small, nearby earthquakes Does not work for big, far ones

 Since the P waves travel faster than the S waves, scientists can use the difference in arrival times to see how far away the earthquake occurred.  It does not tell the direction however.

 One station can only learn how far away the quake occurred.  They would draw a circle at that radius.  If three stations combine their data, the quake occurred where the three circles overlap.

The severe shaking provided by seismic waves can damage or destroy buildings and bridges, topple utility poles, and damage gas and water mains With their side to side, up and down movement, S waves can damage or destroy buildings, bridges, and fracture gas mains.

What is the measurement of an earthquakes strength?

Option 1: Create a radio announcement for an earthquake warning Option 2: Letter to the editor

 Help give yourself an outline  Make sure you have incorporated the vocabulary

Part 1: Vocabulary (9 points each) Did you accurately communicate the following vocabulary 1. Focus 2. Epicenter 3. Stress (Tension, shearing, compression) 4. Seismic waves (P waves, s waves, surface waves) 5. Plate Boundaries 6. Faulting 7. Folding 8. Seismograph 9. Richter Scale 10. Plate tectonics Part 2: Presentation (10 points) Is your project neat, legible, creative, and organized