The CO bubble volume fraction, eruption velocity, flash depth and mass emission of CO were determined from multiple wellbore CO -driven cold-water geysers (Crystal and Tenmile geysers, in Utah and Chimayó geyser in New Mexico). At shallow depths the bubble volume fraction ranges from 0 to 0.8, eruption velocities range from 2 to 20 m/s and flash depths are predominately shallow ranging from 5 to 40 m below the surface. Annual emission of CO is estimated to be , , for Crystal, Tenmile and Chimayó geysers, respectively. These estimates are coherent with showing that the rate of CO leakage from wellbores is greater than fault-parallel or diffuse CO leakage. The geyser plumbing geometry consists of a vertical wellbore which allows for the upward migration of CO -rich fluids due to artesian conditions. The positive feedback system of a CO -driven eruption occurs within the well. Active inflow of CO into the regional aquifers through faulted bedrock allows geysering to persist for decades. Crystal geyser erupts for over 24 h at a time, highlighting the potential for a wellbore in a natural environment to reach relatively steady-state high velocity discharge. Mitigating high velocity CO -driven discharge from wellbores will, however, be easier than mitigating diffuse leakage from faults or into groundwater systems.
One geyser egg (a smooth, oval, siliceous pebble found in alkali chloride hot pools) from the siliceous sinter slope surrounding Old Faithful Geyser was examined to determine its genesis, sinter architecture and elemental composition. The multi-technique approach included Scanning Electron Microscopy (SEM), petrographic microscopy, X-Ray Diffraction, Energy Dispersive Spectroscopy, iTRAX Core Scanner and Computerised Tomography (CT) scans. The geyser egg architecture consists of alternating smooth and porous concentric bands of opal-A silica around a nucleus. These alternating bands are signatures of changes in the degree of silica oversaturation of the discharging fluid. CT scans mapped changes in density throughout the sample and also showed concentric banding of varying density around a core. SEM observations showed the geyser egg has an abiotic origin with subsequent microbial filamentous void infill creating an abiotic-biotic sinter structure. iTRAX scans revealed the geyser egg preserved signatures of changes in fluid chemistry with time, and that the core is rich in arsenic and calcium. iTRAX scans also documented significantly higher concentrations of gallium in the geyser egg compared to those documented in rhyolites and tuffs from the same area. Unravelling geyser egg formation mechanisms and their microbial content provide useful insights on fluid chemistry, water temperature, and flow conditions in these unique hot spring environments.
Geyser boiling is a complex phenomenon which may occur in heat pipes causing high temperature and pressure oscillation leading to noticeable vibration. Therefore, understanding of such process is essential to improve heat pipes thermal performance and avoid damage. In this experimental study, a comprehensive investigation of several parameters on the characteristics of the geyser boiling has been conducted during the operation of two-phase closed thermosiphon (TPCT) using water as the working fluid. The effect of different inclination angles (90, 60, 30 and 10°) at various fill ratios defined as volume of liquid in the evaporator to the volume of the evaporator (25%, 65% and 100%) on the geyser boiling has been investigated at a broad range of heat load and for various mass flow rates and inlet temperatures of the cooling water. These important parameters have been examined to report the occurrence and period of the geyser effect at each heat input. The results showed that the orientation and the liquid charge have a significant impact on the occurrence and period of the geyser boiling at low and high heat inputs. For example, at a fill ratio of 100%, the geyser boiling occurs at a lower heat input compared with that for fill ratios 25%, 65% at all inclination angles, while it happens at a higher heat load at a low inclination 10° compared with other angles at all fill ratios. In addition, at high input energies, it almost disappears at orientations of 90 and 60° for all liquid charges. Also, comparing with fill ratios of 25% and 65%, a shorter period is observed for a fill ratio of 100% at angles of 90, 30 and 10°, whereas it is longer at 60° and low heat inputs. This work highlights the effects of the operating conditions on geyser boiling in heat pipes.
Despite more than 200 years of scientific study, the internal dynamics of geyser systems remain poorly characterized. As a consequence, there remain fundamental questions about what processes initiate and terminate eruptions, and where eruptions begin. Over a one-week period in October 2012, we collected down-hole measurements of pressure and temperature in the conduit of an exceptionally regular geyser (132 s/cycle) located in the Chilean desert. We identified four stages in the geyser cycle: (1) recharge of water into the conduit after an eruption, driven by the pressure difference between water in the conduit and in a deeper reservoir; (2) a pre-eruptive stage that follows the recharge and is dominated by addition of steam from below; (3) the eruption, which occurs by rapid boiling of a large mass of water at the top of the water column, and decompression that propagates boiling conditions downward; and (4) a relaxation stage during which pressure and temperature decrease until conditions preceding the recharge stage are restored. Eruptions are triggered by the episodic addition of steam coming from depth, suggesting that the dynamics of the eruptions are dominated by geometrical and thermodynamic complexities in the conduit and reservoir. Further evidence favoring the dominance of internal processes in controlling periodicity is also provided by the absence of responses of the geyser to environmental perturbations (air pressure, temperature and probably also Earth tides).
Crystal geyser is a CO -driven cold-water geyser which was originally drilled in the late 1930’s in Green River, Utah. Utilizing a suite of temporal groundwater sample datasets, monitoring of temperature, pressure, pH and electrical conductivity from multiple field trips to Crystal geyser from 2007 to 2014, periodic trends in groundwater chemistry from the geyser effluent were identified. Based on chemical characteristics, the primary sourcing aquifers are characterized to be both the Entrada and Navajo Sandstones with a minor contribution from Paradox Formation brine. The single eruption cycle at Crystal geyser lasted over four days and was composed of four parts: Minor Eruption (mEP), Major Eruption (MEP), Aftershock Eruption (Ae) and Recharge (R). During the single eruption cycle, dissolved ionic species vary 0–44% even though the degree of changes for individual ions are different. Generally, Na , K , Cl and SO regularly decrease at the onset and throughout the MEP. These species then increase in concentration during the mEP. Conversely, Ca , Mg , Fe and Sr increase and decrease in concentration during the MEP and mEP, respectively. The geochemical inverse modeling with PHREEQC was conducted to characterize the contribution from three end-members (Entrada Sandstone, Navajo Sandstone and Paradox Formation brine) to the resulting Crystal geyser effluent. Results of the inverse modeling showed that, during the mEP, the Navajo, Entrada and brine supplied 62–65%, 36–33% and 1–2%, respectively. During the MEP, the contribution shifted to 53–56%, 45–42% and 1–2% for the Navajo, Entrada and Paradox Formation brine, respectively. The changes in effluent characteristics further support the hypothesis by Watson et al. (2014) that the mEP and MEP are driven by different sources and mechanisms.
A sloping travertine mound, approximately 85 m across and a few metres thick is actively forming from cool temperature waters issuing out of Crystal Geyser, east‐central Utah, USA. Older travertine deposits exist at the site, the waters having used the Little Grand Wash Fault system as conduits. In contrast, the present Crystal Geyser travertine mound forms from 18°C waters which have been erupting for the last 80 years from an abandoned oil well. The present Crystal Geyser travertine accumulation forms from a ‘man‐made’ cool temperature geyser system; nevertheless, the constituents are an analogue for ancient geyser‐fed carbonate deposits. The travertine primary fabric is composed of couplets of highly porous, thin micritic laminae intercalated with thicker iron oxide rich laminae. Low Mg‐calcite is the dominant mineralogy; however, aragonite is a major constituent in deposits proximal to the vent and decreases in abundance distally. Cements exhibit a variety of fabrics, isopachous being common. Constituents include micro‐stromatolites, clasts, pisoids and the common occurrence of Frutexites‐like iron oxide precipitates. Leptothrix, a common iron‐oxidizing bacterium, is believed to be responsible for the production of the dense iron‐rich laminae. Pisoids litter the ground around the vent and rapidly decrease distally in abundance and size.
Geyser eruptions are produced by a complex and poorly understood set of subsurface processes and conditions. They typically have an abundant supply of water, relatively permeable and competent subsurface material, a conduit to the surface, a driving mechanism (commonly believed to be the initiation of gas lift pumping by steam formation in the conduit), and a trigger. Here we present time series of dissolved CO2 concentrations in near-surface discharge waters of a thermal geyser in Yellowstone National Park (northwestern United States) that vary systematically over several eruption cycles. Chemical geothermometry, combined with a temperature profile in a nearby well, suggests that the geyser water ascends from non-boiling conditions (similar to 153-171 degrees C at a depth of 57-65 m). When the time series of near-surface measured CO2 concentrations are extrapolated to these subsurface conditions assuming dominantly adiabatic cooling, the additional gas pressure from dissolved CO2 is large enough to cause the total dissolved gas pressure to exceed bubbling pressure, inducing bubble formation. We postulate that CO2 is a necessary component to triggering eruptions in the geyser studied. Furthermore, unlike steam, CO2 bubbles do not completely re-condense during cooling in the geyser conduit, hence providing better sustenance for gas lift pumping than pure H2O boiling.
Geyser boiling is experimentally investigated in two-phase closed loop-thermosyphons, consisting of two parallel condensers and a shared evaporator. Heat sink conditions at each condenser vary from forced to natural convection in a multitude of thermal arrangements. A cartridge resistance provides input power ranging from 0.1 to 0.85 kW to the evaporator. Water is employed as working fluid with filling ratios of 0.5 and 0.9. The effects of thermal conditions in both condensers, filling ratio, heat flux and vapor pressure on geyser boiling phenomenon are investigated. Geyser boiling eventually yields intense evaporator vibrations inferred by acceleration measurements. The ratio of convective thermal resistances acting at each condenser affects the acceleration. Amplitudes up to 110 and 1100 m/s were observed for filling ratios of 0.5 and 0.9, respectively. In unsteady regime, geysering occurs for heat fluxes less than 20 kW/m and vapor pressures less than 25 kPa. The vapor pressure is increased with increasing heat flux, suppressing geyser boiling intensity. In steady-state regime geyser boiling occurs for heat fluxes higher than 12.5 kW/m and vapor pressures below 25 kPa.
Multiphase and multicomponent fluid flow in the shallow continental crust plays a significant role in a variety of processes over a broad range of temperatures and pressures. The presence of dissolved gases in aqueous fluids reduces the liquid stability field toward lower temperatures and enhances the explosivity potential with respect to pure water. Therefore, in areas where magma is actively degassing into a hydrothermal system, gas-rich aqueous fluids can exert a major control on geothermal energy production, can be propellants in hazardous hydrothermal (phreatic) eruptions, and can modulate the dynamics of geyser eruptions. We collected pressurized samples of thermal water that preserved dissolved gases in conjunction with precise temperature measurements with depth in research well Y-7 (maximum depth of 70.1 m; casing to 31 m) and five thermal pools (maximum depth of 11.3 m) in the Upper Geyser Basin of Yellowstone National Park, USA. Based on the dissolved gas concentrations, we demonstrate that CO2 mainly derived from magma and N-2 from air-saturated meteoric water reduce the near-surface saturation temperature, consistent with some previous observations in geyser conduits. Thermodynamic calculations suggest that the dissolved CO2 and N-2 modulate the dynamics of geyser eruptions and are likely triggers of hydrothermal eruptions when recharged into shallow reservoirs at high concentrations. Therefore, monitoring changes in gas emission rate and composition in areas with neutral and alkaline chlorine thermal features could provide important information on the natural resources (geysers) and hazards (eruptions) in these areas.