1. Sonar and the beginning of seafloor spreading By: Vanessa and Micaela

2. Definition of Sonar A device used for finding things that are underwater by using sound waves A method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects A device for detecting the presence of a vessel (as would a submarine by the sound it emits in water

3. How sonar works Sonar is something both animals like Whales or Dolphins and or special equipment like submarines can use, It sends out sound waves into the environment. These waves bounce of objects and reflect back to whatever made the noise. Sonars are simply just making echoes, that can sense their shape and movement.

4. Dolphins or Whales can actually tell how small an object is, Like as small as a BB pellet from 50 feet away, And they usually use sonar to find their food, families, and direction.

5. Theory of seafloor spreading Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earths mantle. Convection currents carry heat from the lover mantle and core to the lithosphere. Convection currents also “recycle” lithospheric materials back to the mantle.

6. Seafloor spreading- is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. A long, seismically active submarine ridge system situated in the middle of an ocean basin and marking the site of the upwelling of magma associated with seafloor spreading known as the mid ocean range. The mid ocean range is a range on mountains created be the hot magma that flows from within earths crust.

8. Sources: www.exploratorium.edu/theworld/sonar/sonar.html www.education.nationalgeographic.com/encyclopedia/seaflo or-spreading www.education.nationalgeographic.com/encyclopedia/seaflo or-spreading