The eight-digit grid coordinates for spot elevation 85 are -85° -120°.
The eight-digit grid coordinates for spot elevation 85 can be determined using the shading on Figure 1.9.
Using the given coordinates, we can see that spot elevation 85 falls between -85° and -80° latitude and between -125° and -120° longitude.
Therefore, the eight-digit grid coordinates for spot elevation 85 are -85° -120°.
To generate accurate eight-digit grid coordinates, you would need a map or a geographical reference that includes the relevant coordinate system and details about the specific location you are interested in.
Spot elevations are typically associated with specific geographical points on a map, and their coordinates can be determined using a variety of mapping tools.
If you have a specific location or map in mind, please provide more details, and I can guide you on how to obtain the appropriate grid coordinates for spot elevation 85 within that context.