Geophysics: Applications typically involve material in sections 74: Mechanics of Solids and 76: Fluid Mechanics, but for large-scale problems (this subject deals with a very big solid and a large pool of fluid!) With the advent of Global Positioning Systems there has been a good deal of interest in geodesy and triangulation, which is included here.
See also 76U05, 76V05
Simple spherical geometry (and trigonometry) is treated in 52A55: Spherical Geometry.
This image slightly hand-edited for clarity.
There is only one division (86A) but it is subdivided:
This is one of the smallest areas in the Math Reviews database.
Browse all (old) classifications for this area at the AMS.
There is a sci.geo.* hierarchy of newsgroups (e.g. sci.geo.satellite-nav) which may be relevant in general. For geodesy there is an additional newsgroup comp.infosystems.gis.
Software and Data for Thermodynamics and Phase Equilibrium Calculations in Geology
Relevant packages from the Computer Physics Communications package library.