Question

What type of magma has the lowest velocity?

Answer 1

Mafic magma has the lowest velocity due to its low silica content and high fluidity, which allows it to flow quickly and over large distances, as seen in basaltic lava flows from eruptions like those at Kilauea in Hawaii.

Step-by-step explanation:

The type of magma with the lowest velocity is the mafic magma, which is rich in magnesium and iron. Its low silica content makes the magma more fluid, allowing it to flow quickly. This is evident in basaltic lava flows that can extend over 20 kilometers from a basaltic eruption due to their fluidity. For example, a flow from Kilauea in Hawaii is a demonstration of how swiftly mafic magma can travel, which is the resultant of an interplay between heat, pressure, composition, and the presence of volatiles.

Additional factors such as decompression melting, flux melting, and the addition of heat can also influence the fluidity and velocity of magma. Rocks melt at diverging tectonic plates when pressure is reduced, and at converging plates, water released from subducting oceanic crust lowers the melting point of the mantle, forming magma that can emerge as basaltic lava flows or gabbro when cooled.

Answer 2

Final Answer:

Magma with the lowest velocity is associated with: Basaltic magma

Step-by-step explanation:

The velocity of magma depends on its viscosity, which is influenced by its composition. Basaltic magma, characterized by a low silica content, has the lowest viscosity among magma types. As a result, it flows more easily, exhibiting lower velocity compared to more viscous magmas.

Basaltic magma is often associated with effusive volcanic eruptions, where lava flows relatively smoothly due to its low viscosity. In contrast, magmas with higher silica content, such as andesitic and rhyolitic magmas, have higher viscosity and flow less easily, leading to more explosive eruptions.

Basaltic magma, known for having the lowest velocity.