We are applying moment-tensor inversion to microseismic events emanating from hydrofractures to learn what information can be obtained from limited-view receiver geometries (for example, single boreholes, few instruments, etc.). Our first dataset is from the GRI/DOE M-Site near Rifle, Colorado. The receiver geometry is a single borehole with a string of 17 3-component accelerometer pods spaced 30 feet (10 m) apart and spanning the depth range of 4280 to 4760 feet (1305–1450 m). The hydrofracture occurred in well located about 300 feet (100 m) away and produced microseismic events within the depth range of 4400 to 4600 feet (1340–1400 m). The accelerograms clearly record P and S waves, which can be reliably rotated into the SV and SH components for many traces. Several of the microseismic events produce relatively simple pulses of both P and S waves. We target these events in our initial investigation.