Multiple Choice
Why does the magma from some volcanoes flow smoothly and relatively peacefully,while the magma from other volcanoes blasts forth violently and deals death over wide areas?
A) differences in the chemical and mineral makeup of magmas
B) variations in the temperature,water and gas content,and viscosity of magmas
C) different geographic positions with respect to hot spots and edges of tectonic plates
D) All of these are correct.
Correct Answer:
Verified
Correct Answer:
Verified
Q1: The dominant volcanic gas (commonly 90% or
Q3: Spreading centers are an ideal location for
Q4: At oceanic spreading centers,magmas are rhyolitic in
Q5: _ are steep-sided,symmetrical volcanic peaks built of
Q6: When magma nears the surface,gases come out
Q7: At a depth of 20 miles,basaltic
Q8: If lava reaches the sea or a
Q9: Basaltic magma has the lowest viscosity,so more
Q10: Eruptions in Hawaii are always peaceful.
Q11: Hot spots occur only under oceanic plates.