Chapter 4 - Volcanism

Question 1

Subaqueous Eruptions

Answer 1

Magma eruptions on ocean floor (sometimes lakes)

Question 2

Subaerial Eruptions

Answer 2

Magma eruptions on land.

Question 3

Pillows

Answer 3

Hot lava that oozes into cold water - the surface of the emergent tongue cools very quickly, forming a skin. The tongue continues to lengthen and inflate with more lava, forming a lobe, until the pressure of the magma becomes sufficient to rupture the skin and start the formation of a new eruption point nearer the vent. This process produces a series of interconnecting lobate shapes that are pillow-like in cross-section.

Question 4

Mantle Plume

Answer 4

An ascending column of hot rock (not magma) that originates deep within the mantle.