Resonance Mode Analysis of Devils Tower, Wyoming, USA

We deployed a Nanometrics Trillium Compact 20-s, three-component broadband seismometer on the summit of Devils Tower between October 12-13, 2024. The instrument was hauled and carried to the summit by a team of climbers under an approved permit from the National Park Service. The seismometer (labelled station D) was located on the northern portion of the tower summit. It was placed on bare bedrock, with a dab of adhesive putty under each foot to aid coupling, leveled and oriented north, and then covered to prevent wind buffeting. The seismometer was paired with a 24-bit Nanometrics Centaur datalogger recording continuous data at 100 Hz. Two additional identical seismometer setups were also deployed: station C on bedrock near the base of the tower's south wall, and station A on a large flat boulder embedded in colluvium ~200 m south of the tower. The various instruments had different run times: station D on top of the tower ran the longest for 21 hours from afternoon to late morning, while the overlapping duration of the three sensors was 19 hours (10/12 20:00 to 10/13 15:00 UTC).