Breathe of Earth by Beth Cato

A girl geomancer was unheard of until now.

The United States and Japan are allied. Ingrid Carmichael is a girl in San Francisco who works for the geomancers that keep the earthquakes under control.  That changes with a single bomb. Ingrid  is on the run with a dashing engineer who has more to him that, meets the eye. She discovers more about herself and her considerable magic.  They are involved in a plot that will literally shake San Francisco to it’s foundations. Can they stop it or will San Francisco be reduced to rubble?