A high-frequency, phased array was deployed for one year over the Reelfoot fault, New Madrid Seismic Zone (NMSZ), to detect signals at ground motion levels equivalent to ML -2. We hypothesize that recently identified nonvolcanic tremor in NMSZ consists of temporally-energetic swarms of micro-earthquakes at the ML -1 to -2 level occurring at mid-crustal levels in the NMSZ. The array consists of 19 stations deployed in an L-shape with a station spacing of ~500 m. Stations were deployed in mid-November, 2009