Trying to make it easy for a non-GIS savy person to view the 3D data I produced in ArcScene. I can't seem to get Google Earth to view underground/below the standard imagery.
Yes it can.
Here is a video of heat index from Texas geothermal BHT using Google Earth view below the surface: https://www.youtube.com/watch?v=CeYyJIXOo6Y
You can also access the KML or KMZ files here: http://hitechmex.org/kml_examples/. This link also has examples in Cesium using KMZ.
This paper title includes two examples (earthquakes and geothermal) of subsurface in Google Earth: "Geological and hydrological visualization models for Digital Earth representation"