Question

1. s-waves stop at this layer because it is a liquid. 1 point gutenberg boundary moho boundary outer core boundary between outer core and inner core 27. p-waves dramatically decrease speed because there is a change in density of composition (peridotite/olivine to iron/nickel) and state of matter (solid to liquid). 1 point gutenberg boundary moho boundary outer core boundary between outer core and inner core

Explanation:

For question 26: S-waves (shear waves) cannot travel through liquid materials. The Outer Core is Earth's only liquid layer, so S-waves stop here.
For question 27: The Gutenberg Boundary is the transition between the solid lower mantle and the liquid outer core. Here, there is a sharp change in both composition (from silicate-rich rock to iron-nickel alloy) and state of matter (solid to liquid), which causes P-waves to slow dramatically.

Answer:

1. Outer Core
2. Gutenberg Boundary