function trm=velz(ffreqs,dirs,wns,z,depth,xpos,ypos)

Kz=sinh(z*wns)./sinh(depth*wns);
%include a maximum cuttoff for the velocity response function
Kz(find(Kz<0.1))=0.1;
Kz(find(isnan(Kz)))=1;
trm=-i*(ffreqs.*Kz)*ones(size(dirs));