| A | B |
|---|
| earthquakes | ____ are the shaking of the earth. 地震 |
| Mercalli | It measures the total amount of damage done by an earthquake. |
| seismologists | are scientists who study earthquakes. 地震学家 |
| secondary | The ___ waves cause the ground to move side to side. |
| primary | The ___ waves cause the ground to move up and down. |
| secondary | This wave causes the most damage during an earthquake. |
| P | the __ waves are the first to arrive during an earthquake. |
| S | The __ waves are the second to arrive during an earthquake. |
| seismograph | We use this instrument to record earthquake waves. 地震仪 |
| seismogram | The paper on which earthquake waves are recorded are called __. 地震波纪录 |
| tsunamis | Earthquakes can cause large waves called __. 海啸 |
| epicenter | The point at the surface of the earth where earthquake begins is __. 震中 |
| focus | The point where the earthquake happens is __. 震源 |
| tectonic | Most earthquakes are caused by the movement of __ plates. |
| west | Most earthquakes in the US happen on the __ coast. |
| ring of fire | The area of earthquake and volcanoes the encircles the Pacific Ocean is the _ _ _. |
| magnitude | It's the measurement of the total amount of engergy released by an earthquake |
| intensity | It's a measure of the damage done by an earthquake. |
| Richter | It measures the total amount of energy released by an earthquake. |
| energy | Large and sudden release of ___ cause earthquakes. 能量 |
