Snow Suppresses Seismic Signals From Steamboat Geyser

Abstract

Geyser and volcano monitoring suffer from temporal, geographic, and instrumental biases. We present a recording bias identified through multiyear monitoring of Steamboat Geyser in Yellowstone National Park, USA. Eruptions of Steamboat are the tallest of any geyser in the world and they produce broadband signals at two nearby stations in the Yellowstone National Park Seismograph Network. In winter, we observe lower eruption signal amplitudes at these seismometers. Instead of a source effect, we find that environmental conditions affect the recorded signals. Lower amplitudes for 23–45 Hz frequencies are correlated with greater snow depths at the station 340 m away from Steamboat, and we calculate an energy attenuation coefficient of 0.21 ± 0.01 dB per cm of snow. More long‐term monitoring is needed at geysers to track changes over time and identify recording biases that may be missed during short, sporadic studies.

A shake and a surge: Assessing the possibility of an earthquake-triggered eruption at Steamboat Geyser

“…This yields a volume of 373 m 3 ; however, wind speeds >1 m/s can decrease the water volume that enters Tantalus Creek and thus this should be considered a minimum estimate (Reed et al 2021). In terms of both seismic spectral content and ejected water volume, the 18 September eruption was similar to other major eruptions (Reed et al 2021;Reed and Manga 2023). Cistern Spring drained and refilled as normal.…”

“…Very little has been published about hydrothermal tremor at Norris Geyser Basin since Iyer and Hitchcock (1974) Seismic spectral amplitude measurements (SSAM) are a computationally inexpensive way to represent relative signal strength in different frequency bands over time (Rogers and Stephens 1995). We compute SSAM for narrow 1 Hz bands between 0.5 to 5.5 Hz, a range chosen to match low frequency tremor observed in Yellowstone thermal areas (Wu et al 2019(Wu et al , 2021Liu et al 2023) and to avoid contamination from Steamboat's broadband (5-45 Hz) eruption signal (Reed and Manga, 2023). After selecting the raw, vertical-component seismic data for overnight hours (20:30-6:30) during August-October 2022, we remove instrument response to obtain velocity, slice the data into 1 h segments, and apply acausal, 4 corner Butterworth bandpass filters to match the bands of interest.…”