1. Earth and Space Science
Changing Earth’s Surface

2. Natural events, human actions
1. Most environments are constantly changing. Environmental changes can be caused by ___________ ____________ or _____________ _______________.

3. floods, storms, volcanoes, droughts
2. Natural events include natural disasters and changes
caused by organisms other than humans. Natural disasters such as earthquakes, _____________, _______________, _____________ and ________________ can drastically alter environments.

4. sudden, violent, dams
3. Natural disasters can cause _________________ and _________________ changes to Earth’s surface. These changes greatly affect the plants, animals, and people living where these disasters occur. Beavers, for example, build _________. Their dams can cause flooding, but the dams can also be beneficial by creating new habitats.

5. People, habitats, pesticides, polluting
4. ______________________ can also cause changes to the environment by destroying __________________, using __________________, and _________________.

6. Tsunami, tsunami
5. One of the most damaging natural disasters is a _______________. A __________________ is a series of huge waves caused by an earthquake or volcanic eruption beneath the ocean.

7. Increases, slow 6. The speed of a tsunami depends on the depth of the
water. As the waves reach shallow water, the height of the wave _________________ and the waves ___________ down.

8. Richter Scale
7. On December 26, 2004, and earthquake measuring between 9.0 and 9.3 on the ______________ _____________ occurred in the Indian Ocean. The earthquake triggered a tsunami that sent a series of waves crashing into coastlines of Asia destroying whole villages and killing hundreds and thousands of people

9. warn
8. Tsunamis often take hours to travel across the ocean. It may be possible to __________ people before the waves reach the shore.

10. large, rain
9. Floods are usually caused by a ____________ amount of ___________ that falls in a short period of time.

11. force
10. Floods are dangerous to nearby inhabitants because of the ____________ of flowing flood water and people sometimes driving through floodwater.

12. levees
11. In areas that are in a river’s flood plain, people try to control the water’s flow by building dams or structures called _________________.

13. levee, Levees, more water
12. A _____________ is a wall or a large amount of Earth built along a river to prevent it from flooding. _________________ raise or extend the banks of a river so that _______________ _______________ than usual can flow in the river.

14. power, gas
13. When earthquakes occur in an area populated with people, _____________ and ________________ lines can be broken which can cause destructive fires.

15. landslide, volcanoes, earthquakes
14. A _________________________ can occur from heavy rainfall, rapid snowmelt, ____________ and _______________. A landslide can carry buildings down a hillside or bury highways under debris

16. natural disasters
15. The sudden changes caused by _________ _______________ can have long-term effects on Earth and its habitats.

17. volcanoes, climate
17. Some natural disasters, such as ___________________, can affect the _______________ for both short or long periods of time.

18. floods, landslides
18. __________________ and ____________________ can add to the soil by leaving behind nutrient-rich mud.

19. positive changes
19. Natural disasters cause harm, but they can also bring about _____________ ____________

20. Volcanoes (island chains)
tsunami
flooding