[CIG-SHORT] Step18 and step 19 for multiple loads

[Sauber-Rosenber, Jeanne M. (GSFC-6980)]

Brad, Charles and Matt,

  To date I have been successfully experimenting with various parameter changes to your
Step18 and Step19 examples (for instance different rheological models, loading time history etc).
However,  when I tried introducing multiple surface loads in step18 and step19, initially,  it didn't work.
After a fair amount of experimentation with the input parameters, including trying
to use SimpleGridDB, I was successful including multiple loads IF I changed
the query_type from "linear" to "nearest" neighbor.    
      Was there something else (other parameters) I should be changing to enable me to input multiple
surface loads?  Or is this what you might expect for when using query_type = linear (for a reason I don't understand)?  

Jeanne Sauber