I absorb S-waves but allow P-waves to travel through me. What layer am I?

P and S waves are both body waves (def); however, they have very different properties. ...

Explanation:

Though, S waves (which are a type of shear wave)will travel through solids and but will be absorbed by liquids and gases. ... Having the lag time for three seismic stations allows us to determine the epicenter of an earthquake.

a physical change is being made.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products