. Fissure eruptions take place when .
a. volatiles effervesce prior to lava flow
b. groundwater interacts with magma
c. basaltic lava clogs the eruptive vent
d. lava erupts out of a long crack in the ground forming a curtain of lava

d. lava erupts out of a long crack in the ground forming a curtain of lava

Explanation: Fissure Eruptions does not occur with an explosion which is caused by gas pressure. Fissure eruptions occurs as a result of magma flowing up through cracks in the ground and leaks out to the earth surface. Fissure eruptions are identified by a curtain of fire, a curtain of lava flowing out to a small height above the ground. Fissure eruptions can produce heavy flows, but the lava is slow moving.

answer conditional instability;

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