Thumping Cycle Variations of Doublet Pool in Yellowstone National Park, USA

Abstract

The active Yellowstone hydrothermal system results from shallow groundwater interacting with heat from a deeper magmatic system (Smith & Siegel, 2000). Variations in heating rate, conduit geometry, and water influx control the exact surface manifestation of each hydrothermal feature (e.g., Namiki et al., 2016;Rinehart, 1980;Toramaru & Maeda, 2013). An eruptive geyser is composed of a long narrow subsurface conduit with constrictions that inhibit effective fluid convection, keep the hydrostatic pressure high, and suppress the liquid-to-vapor phase transition. With continued heat accumulation, the system eventually reaches a critical condition where a perturbation in pressure initiates a phase transition between liquid and vapor, and the resulting volume expansion will vigorously eject a liquid-vapor mixture into the air (White, 1967). A hot spring, in contrast, is a steady-state system where both heat and water influx and outflux remain balanced. At least one hot spring in New Zealand (Iodine Pool; Legaz et al., 2009) and several features in Yellowstone, however, mysteriously "thump" either periodically or episodically suggesting their heat input and output are not completely balanced and thus that they share some similarities with geysers. Doublet Pool, a hot spring composed of a main and an auxiliary pool connected by a narrow channel at the surface, in the Upper Geyser Basin (Figure 1), is famous for its persistent, approximately periodic thumping cycle (Bryan, 2008). During active thumping, the water level in the main pool vibrates visibly, ground shaking can be felt, and thumping can be heard on a quiet day near the pool. While periodic thumping resembles a geyser's eruption pattern, the thumping at Doublet Pool never evolves into an active eruption.Many previous geophysical studies, including seismic investigations aimed at understanding the eruption dynamics of geysers, have recorded hydrothermal tremor connected to the liquid/vapor phase transition processes (Kedar et al., 1998(Kedar et al., , 1996Wu et al., 2017). The spatiotemporal distribution of the tremor sources has been used to illuminate the subsurface conduit system and infer the physical state of the geyser system during each stage of the eruption cycle (

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

“…Were there any changes to the strength of ambient seismic noise? Hydrothermal areas generate tremor that has been primarily attributed to bubble collapse and nucleation (e.g., Kedar et al 1998;Legaz et al 2009;Vandemeulebrouck et al 2014;Nayak et al 2020;Liu et al 2023). 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).…”

“…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.…”