11. What is the difference between magma and lava? Magma is molten rock beneath the earth’s surface, and lava is molten rock on the earth’s surface.
VISCOSITY 12. Which lava is more viscous: slow-moving lava or runny lava? Name one other liquid that you consider to be very viscous. Slow-moving lava is more viscous. Corn syrup would be very viscous.
13. Describe how each volcano type forms and what it looks like. Include a sketch. a. It forms from alternating eruptions of viscous lava and ash. It is tall and steep near the summit.
b. It forms when cinders accumulate around a volcanic vent. It is small and cone shaped.
c. It forms from eruptions of runny lava. It is wide and broadly sloping.
14. How does the heat content of a substance affect the way it flows? Heating a liquid causes it to be less viscous (more runny).
DESTRUCTION 15. What are some of the destructive (bad) effects of volcanoes? Give at least 2. Volcanic ash can cause suffocation, contaminate water supplies, and collapse roofs. Earthquakes, flash floods, rockfalls, and mudflows. Eruptions can cause tsunamis. Eruptions can destroy homes and cause death.
RISING MAGMA…FLOWING LAVA 19. Describe how rising magma and flowing lava can create the following; a. New land or rock When molten rock cools, it hardens into new rock/land. b. Volcanic Islands Over time, the buildup of cooled magma that erupts under wat er can create volcanic islands. c. Underwater pillow lava Hot magma erupts onto the cold ocean floor and immediately cools in the water. d. Bulges in the earth’s surface Magma under the earth’s surface rises and pushes upward on the overlying rock.
20. What are some of the ways volcanologists predict volcanoes? Scientists look for the following changes in a volcano: emission of sulfur dioxide gas, growth of lava domes, increased seismic activity, cracks in the earth, steam and ash clouds.
21. Describe how each type of rock forms. a. Igneous rock – It forms when magma or lava cools and crystallizes on or below the earth’s surface.
b. Sedimentary rock – It forms from compacted or cemented sediments or particles of various sizes.
C. It forms when any rock type is changed by the earth’s high temperature and pressure.