SeisSeeker is a package for performing beamforming for earthquake detection. It was developed initailly for detection of icequakes at glaciers and icesheets, but could be applied to a range of earthquake detection problems.
A decription of how the package works can be found here: Thomas S. Hudson, Alex M. Brisbourne, Sofia-Katerina Kufner, J-Michael Kendall, and Andy M. Smith. (in review). "Array processing in cryoseismology". Submitted to: The Cryosphere.