Quiz

Question 1

Rocks beneath the seafloor that were once melt within a mid-ocean ridge magma chamber are called:

Answer 1

gabbro

Question 2

two kinds of lava flows on the seafloor are called:

Answer 2

pillow flows and sheet flows

Question 3

the oceans cover what percent of the earth:

Answer 3

70%

Question 4

convection occurs where:

Answer 4

cold seawater is heated by underlying magmetic rocks

Question 5

novel organisms that thrive beneath the seafloor live

Answer 5

at temperatures in excess of 200 F (121 C), in the absence of oxygen, appear to multiply rapidly following seafloor eruptions, utilize toxic metals

Question 6

Hydrothermal vents, or black smokers as they are commonly called, form at the seafloor as a result of:

Answer 6

extraction of metals from the ocean crust, heat extracted from magma chambers, precipitation of fine-grained metal sulfides, and rise of acidic fluids and mixing with seawater.

Question 7

magma chambers typically occur at depths of

Answer 7

1-8 km beneath the seafloor

Question 8

submarine volcanoes erupt because

Answer 8

they are enriched in carbon dioxide

Question 9

seafloor volcanism accounts for what percent of the volcanic activity on the planet?

Answer 9

70%

Question 10

Draw an idealized cross section of the oceanic crust showing a magma chamber

Answer 10