Hammer was an undergraduate at
Dartmouth College, where she graduated in 1993 with a bachelor's thesis on the formation of Himalayan
leucogranite, supervised by C. Page Chamberlain. She continued her studies at the
University of Oregon, where she completed her Ph.D. in 1998. Her doctoral dissertation was
Magma vesiculation, degassing, and crystallization: Case studies and results from analog experiments, with
Katharine Cashman as her
doctoral advisor. She became an NSF Postdoctoral Fellow and researcher at
Brown University from 1999 until 2002, when she joined the University of Hawaiʻi as an assistant professor. She was promoted to associate professor in 2006 and full professor in 2013. ==Recognition==