I think mm is not a unit of pressure
Africa is the answer. Here is the packet, https://cms.springbranchisd.com/Portals/280/staff/robertsh1/exptra%20practice%20KEY.pdf?ver=2012-11-...
The answer is a strike-slip. More specifically a right-lateral strike-slip.
Pressure varies in the atmosphere because air molecules are being pulled down towards the center of the earth-hope this helps!