Question

What do you notice about the average seismic wave speeds at a depth of 90 km in the locations where volcanoes have occurred? Does this support or refute the idea that the heat for volcanic magma is a deep feature?

Answer 1

The average seismic wave speeds at a depth of 90 km in locations where volcanoes have occurred vary with material rigidity. P-waves have faster speeds indicating magma originating from a deep, rigid layer, while S-waves travel slower through less rigid sediments above the magma source. This supports the idea that the heat for volcanic magma is a deep feature.

Step-by-step explanation:

The average seismic wave speeds at a depth of 90 km in locations where volcanoes have occurred vary depending on the rigidity of the medium. P-waves have speeds of 4 to 7 km/s, while S-waves range from 2 to 5 km/s. Both waves travel faster in more rigid material.

This information supports the idea that the heat for volcanic magma is a deep feature. The faster speed of the P-waves suggests that the magma originates from a deeper, more rigid layer, while the slower speed of the S-waves indicates the presence of less rigid sediments above the magma source.