VERTCRS["Unknown_height_system_(meters)",
    VDATUM["Unknown_height_system_(meters)"],
    CS[vertical,1],
        AXIS["gravity-related height (H)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Not known."],
        AREA["World."],
        BBOX[-90,-180,90,180]],
    ID["ESRI",115807]]