What Important Physical and Chemical Process Occurs to Subducted Seafloor

question 123

Multiple Choice

What important physical and chemical process occurs to subducted seafloor as it reaches a depth of 100 kilometres depth in the upper mantle?

• A)It experiences nearly a doubling in its density as the subducted basalt recrystallizes to peridotite.
• B)The subducted seafloor entirely melts generating a line of explosive volcanoes.
• C)Heat from the surrounding mantle drives off water and other volatiles from the slab, which escape upwards, lowering the melting point of the overlying asthenospheric mantle.
• D)The cooling of the ocean crust from the cold, deep ocean water of the trenches causes the subducted crust to freeze the mantle, cracking and freezing it to generate the largest earthquakes.

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Definitions:

Gantt Chart

A graphical display of the scheduling of tasks required to complete a project.

One-Time Events

Occurrences or activities that happen once and are not repeated, often unique or significant in nature.

Defined Time Period

A set duration, clearly specified, within which activities, processes, or events are to be initiated and completed.

Nodes

Points or intersections within a network where lines, paths, or edges meet or cross, often referring to a specific location in a network topology.