Section 2 ReviewSection 2 Review1. Seismic waves carry the energy of an EQ away from the focus. 1. Seismic waves carry the energy of an EQ away from the focus. Some of those waves reach the surface and become surface waves.Some of those waves reach the surface and become surface waves.

2…2…•P-waves-compress and expand; move through solids and liquids; P-waves-compress and expand; move through solids and liquids; fastests waves. fastests waves. •S-waves- side to side and up and down; solids only; slower than P-S-waves- side to side and up and down; solids only; slower than P-waves. waves. •Surface waves- When p or s waves reach the surface; most Surface waves- When p or s waves reach the surface; most destructive and slowest moving.destructive and slowest moving.

3. Data from electronic seismographs rate the strength of the EQ on 3. Data from electronic seismographs rate the strength of the EQ on the moment magnitude scale.the moment magnitude scale.

4. Energy released from the focus can travel very far. The type of 4. Energy released from the focus can travel very far. The type of rock and soil around the epicenter can affect how much the ground rock and soil around the epicenter can affect how much the ground shakes.shakes.

Earthquake Hazards Earthquake Hazards and and

SafetySafety

1- What kinds of damage can 1- What kinds of damage can earthquakes cause?earthquakes cause?

The severe shaking produced by The severe shaking produced by seismic waves can damage or seismic waves can damage or destroy buildings and bridges, destroy buildings and bridges, topple utility poles, and fracture topple utility poles, and fracture gas and water mains.gas and water mains.

2- How do local soil conditions 2- How do local soil conditions affect earthquake damage?affect earthquake damage?

Loose soil will allow more violent Loose soil will allow more violent shaking than solid rock surfaces.shaking than solid rock surfaces.

3- What is liquefaction and 3- What is liquefaction and how does it cause damage how does it cause damage during an earthquake?during an earthquake?

Liquefaction is when the shaking from an earthquake causes soft soil to turn to mud. Liquefaction can cause landslides.https://www.youtube.com/watch?v=2WoKu5VxKgs

4- What is an aftershock?4- What is an aftershock?

An aftershock is an earthquake that An aftershock is an earthquake that occurs after a larger earthquake in occurs after a larger earthquake in the same area. They can occur the same area. They can occur hours, days, or months after the first hours, days, or months after the first earthquake.earthquake.

5- What is a tsunami and how 5- What is a tsunami and how can it cause damage during an can it cause damage during an

earthquake?earthquake?A tsunami is a large wave caused A tsunami is a large wave caused by the displacement of water by the displacement of water during an under water earthquake. during an under water earthquake. They cause damage along They cause damage along coastlines.coastlines.

https://www.youtube.com/watch?v=yN6EgMMrhdI Alaska Alaska

https://www.youtube.com/watch?v=w3AdFjklR50 Japan (1:17) Japan (1:17)

6- What types areas should be 6- What types areas should be avoided when building a avoided when building a

structure?structure?

When building, areas that should When building, areas that should be avoided are near steep slopes, be avoided are near steep slopes, filled land, soft soil and near filled land, soft soil and near faults.faults.

7- How can buildings be made to 7- How can buildings be made to better withstand earthquakes?better withstand earthquakes?

Buildings can be reinforced, Buildings can be reinforced, strengthened and made flexible or strengthened and made flexible or anchored to solid rock. anchored to solid rock.

Base isolated buildings are a type of Base isolated buildings are a type of building that is designed to reduce the building that is designed to reduce the amount of energy that reaches the amount of energy that reaches the building during an earthquake.building during an earthquake.

8- What is the main danger 8- What is the main danger during an earthquake?during an earthquake?

The main danger during an The main danger during an earthquake is from falling objects earthquake is from falling objects and flying glass.and flying glass.

9- If you are INSIDE during an 9- If you are INSIDE during an earthquake, what should you do?earthquake, what should you do?

Drop, cover and holdDrop, cover and hold Crouch under a table or desk to Crouch under a table or desk to

protect yourself from falling objectsprotect yourself from falling objects Avoid windows, mirrors, wall Avoid windows, mirrors, wall

hangings and furniture that may hangings and furniture that may topple.topple.

10- If you are OUTSIDE during an 10- If you are OUTSIDE during an earthquake, what should you do?earthquake, what should you do?

Move to an open areaMove to an open area Avoid vehicles, power lines, Avoid vehicles, power lines,

trees, buildings or other things trees, buildings or other things that can topple onto you.that can topple onto you.

11- What are the 2 MOST 11- What are the 2 MOST important things for you to do to important things for you to do to stay safe during an earthquake?stay safe during an earthquake?