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15) a. Composite Volcano page 257 b. Rift Eruption c. Sheild Volcano _________________________________________________________________________________________________________________________ Pg 538 12) The Plate Tectonics and Continental Drift Theories.

13) a. Convergent Boundary b. Divergent Boundary c. Transform Fault

14) because that when the plates colide (oceanic plates and continental plates) the oceanic plate sinks below the lighter continental plate. The ocean plate sinks into the mantle creating and melts into hot magma with a greater concentration of gas that bubbles up a few kilmotres away from where the plate sunk or the fault line.

15) The mountain ranges in differnt countries are similar in composition and size to ones on the other side of an ocean this proves continental drift in some ways.

16) the continents would stop moving which would mean no more earthquakes or volcanoes. This would have its pros and cons. For instance, if they ceased then humans could build large cities without being threatened. However, this would stop all of the fertile lands around volcanoes that so many ecosystems need to survive. This may cut out some of our food sources that we need to survive.

17) When a volcano erupts it excretes the magma that has built up the pressure inside of the volcano. This magma (which is now called lava when it flows onto Earth's surface). This magma travels all over the earth due to the mantles convection currents so it is comprised of the core material.

18) Most volcanic activity happens near plate boundaries because when the heavy plate (oceanic plate) dives underneath the lighter plate (continental plate) when they meet, it melts into magma (or molten rock). This melting releases gases that aren't usually found in the mantle and causes that magma to rise into cracks in the plates above usually a few kilometers way from the plate boundary in the form of a volcano.

19) The richly forested southwest of BC would be greatly altered. The magma would destroy much of the forests as well as all the ecosystems which include plants and animals and even cities in the area. Large amounts of toxic gas and ash would be blown into the air contaminating it and greatly dropping the temperature below the gas to even colder then what it is.

20) volcanoes erupt they send vast amounts of toxic gas, molten rock and ash into the air that fly several miles away from the actual volcano. The liquid rock or lava is so hot that it could burn you if you stand near it without proper protection. This is why it is hard to study active volcanoes.

21) a. trench b. volcanic island arc c. lithosphere d. crust e. asthenosphere