Determining basins and seamounts using GMT spatial:

Hello,

I am trying to locate basins in the Carpentaria Gulf off the coast of Australia.
I have been previously using gmt spatial commands like: gmt spatial -Qe -fg, to locate closed polygons, ‘seamounts’ in a sense.
Would anyone know of a way to locate the centroid location of a basin, for example, an area in which the depth starts as 60m and then decreases to 80m over 5 miles then back up to 60m?

I have looked through the documentation on GMT but cannot find much about it.
Any ideas or thoughts would be greatly appreciated.

Thank you :slight_smile:
Hannah