Negative Z values in ArcScene

[BeckyOswalt]

I am trying to display earthquake depths in arcscene; however the points are appearing above the basemap instead of below. I used the field calculator to make the z values negative, but all the points are still above the land. How can I get them underneath the map?

[TimothyHales]

How are you setting up the base heights?  Are you using the option for elevations from features with the field as the expression?

About defining the z-value for a layer

You could also use Feature to 3D by Attribute to see if that feature class will display any differently.