| A | B |
| What is the thin layer of solid rock that makes up the outermost part of the Earth? | crust |
| Scientist have developed a theory called ______ to explain how forces underground move. | plate tectonics |
| The ocean floor spreads to a rate of 1.5 inches every year. After 200 years, what is the total amount the floor has spread? | 300 inches |
| What is a force that causes rocks to break along the transform boundaries and move continents? | shearing |
| When plates move apart they are called _____ boundaries. | divergent |
| A volcano that is not currently erupting but may erupt again is ______. | dormant |
| The amount of damage an earthquake causes depends partly on the earthquake's ______. | focus |
| What type of wave moves the fastest? | primary |
| Secondary waves move only through Earth's _____ layers in the mantle. | solid |
| The distance to an epicenter is measured by the distance between the arrival of ___ and ___ waves. | primary, secondary |
| What type of scale measures magnitude? | Richter |
| If one earthquake is measured at 5.9 on the Richter scale, how much more energy is realesed if a second earthquake is measured at 7.6 on the Richte scale? | 900 |
| A tsunami occurs near _____. | oceans |
| The layer of gases called _________ is what surrounds the Earth. | atmosphere |
| The layer of gases closest to the Earth's surface is called ______. | troposphere |
| Climate is the average ____ for a given place. | weather |
| The climate of a place near the ocean is usually ____ than a place inland. | milder |
| The biggest difference between a sea breeze and a land breeze is ______. | which direction the breeze is coming from |