TY - RPRT TI - S/P amplitude ratios derived from single-component seismograms and their potential use in constraining focal mechanisms for micro-earthquake sequences AU - David R. Shelly AU - Robert John Skoumal AU - Jeanne L. Hardebeck PY - 2022 DO - 10.1785/0320220002 UR - https://pubs.usgs.gov/publication/70242085 ID - 70242085 ER -