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Robert H. Mariner

Publications and source records attributed to Robert H. Mariner.

At least 19 recordsLinked to original sources
USGS2014

Hydrothermal monitoring in a quiescent volcanic arc: Cascade Range, northwestern United States

Ongoing (1996–present) volcanic unrest near South Sister, Oregon, is accompanied by a striking set of hydrothermal anomalies, including elevated temperatures, elevated major ion concentrations, and 3 He/ 4 He ratios as large as 8.6 R A in slightly thermal springs. These observations prompted the US Geological Survey to begin a systematic hydrothermal-monitoring effort encompassing 25 sites and 10 of the highest-risk volcanoes in the Cascade volcanic arc, from Mount Baker near the Canadian border to Lassen Peak in northern California. A concerted effort was made to develop hourly, multiyear records of temperature and/or hydrothermal solute flux, suitable for retrospective comparison with other continuous geophysical monitoring data. Targets included summit fumarole groups and springs/streams that show clear evidence of magmatic influence in the form of high 3 He/ 4 He ratios and/or anomalous fluxes of magmatic CO 2 or heat. As of 2009–2012, summit fumarole temperatures in the Cascade Range were generally near or below the local pure water boiling point; the maximum observed superheat was <2.5°C at Mount Baker. Variability in ground temperature records from the summit fumarole sites is temperature-dependent, with the hottest sites tending to show less variability. Seasonal variability in the hydrothermal solute flux from magmatically influenced springs varied from essentially undetectable to a factor of 5–10. This range of observed behavior owes mainly to the local climate regime, with strongly snowmelt-influenced springs and streams exhibiting more variability. As of the end of the 2012 field season, there had been 87 occurrences of local seismic energy densities approximately ≥ 0.001 J/m 3 during periods of hourly record. Hydrothermal responses to these small seismic stimuli were generally undetectable or ambiguous. Evaluation of multiyear to multidecadal trends indicates that whereas the hydrothermal system at Mount St. Helens is still fast-evolving in response to the 1980–present eruptive cycle, there is no clear evidence of ongoing long-term trends in hydrothermal activity at other Cascade Range volcanoes that have been active or restless during the past century (Baker, South Sister, and Lassen). Experience gained during the Cascade Range hydrothermal-monitoring experiment informs ongoing efforts to capture entire unrest cycles at more active but generally less accessible volcanoes such as those in the Aleutian arc.

California;Oregon;Washington↗
USGS2013

Springs, streams, and gas vent on and near Mount Adams volcano, Washington

Springs and some streams on Mount Adams volcano have been sampled for chemistry and light stable isotopes of water. Spring temperatures are generally cooler than air temperatures from weather stations at the same elevation. Spring chemistry generally reflects weathering of volcanic rock from dissolved carbon dioxide. Water in some springs and streams has either dissolved hydrothermal minerals or has reacted with them to add sulfate to the water. Some samples appear to have obtained their sulfate from dissolution of gypsum while some probably involve reaction with sulfide minerals such as pyrite. Light stable isotope data for water from springs follow a local meteoric water line, and the variation of isotopes with elevation indicate that some springs have very local recharge and others have water from elevations a few hundred meters higher. No evidence was found for thermal or slightly thermal springs on Mount Adams. A sample from a seeping gas vent on Mount Adams was at ambient temperature, but the gas is similar to that found on other Cascade volcanoes. Helium isotopes are 4.4 times the value in air, indicating that there is a significant component of mantle helium. The lack of fumaroles on Mount Adams and the ambient temperature of the gas indicates that the gas is from a hydrothermal system that is no longer active.

Washington↗
USGS2012

Geochemistry of thermal waters in Long Valley, Mono County, California

Thermal springs and wells in Long Valley, California, issue sodium bicarbonate‐chloride waters containing 1000–1420 mg/l of dissolved solids. Thermal waters of sodium bicarbonate‐chloride composition are usually associated with hot‐water reservoirs. Chloride concentrations and stable isotope data indicate that the thermal waters have had varied histories. All of the thermal springs issue a mixture of fluid from the thermal reservoir and less saline, cooler water from one or more shallow aquifers. The composition of springs in Hot Creek Gorge may have been further altered by minor subsurface boiling. Thermal springs between Hot Creek and Lake Crowley issue mixtures of fresh and thermal waters which have lost heat by conductive cooling and changed composition by reaction with rock in the shallow aquifer. The silica content of water from Magma Richie 5 and mixing calculations based on the concentrations of silica in thermal waters collected from springs in Hot Creek Gorge and along Little Hot Creek indicate a temperature of at least 200°C in the thermal reservoir. The sodium‐potassium‐calcium geothermometer yields a reservoir temperature estimate near 200°C for most of the thermal springs. If geothermal energy is developed in Long Valley, the high concentrations of arsenic (up to 2.2 mg/l), boron (up to 15 mg/l), and total dissolved solids in the thermal fluids will make it necessary to isolate the effluent of production wells from the freshwater system.

California↗
USGS2012

The hydrothermal system at Newberry Volcano, Oregon

Results of recent geological and geophysical studies at Newberry Volcano have been incorporated into conceptual and numerical models of a magma-based hydrothermal system. Numerical simulations begin with emplacement of a small magma body, the presumed source of silicic eruptions at Newberry that began about 10,000 B.P., into a thermal regime representing 100,000 years of cooling of a large underlying intrusion. Simulated flow patterns and thermal histories for three sets of hypothetical permeability values are compatible with data from four geothermal drill holes on the volcano. Meteoric recharge cools the caldera-fill deposits, but thermal water moving up a central conduit representing a permeable volcanic vent produces temperatures close to those observed in drill holes within the caldera. Meteoric recharge from the caldera moves down the flanks and creates a near-isothermal zone that extends several hundred meters below the water table, producing temperature profiles similar to those observed in drill holes on the flanks. The temperatures observed in drill holes on the flanks are not influenced by the postulated Holocene magma body. The elevated temperature gradients measured in the lower portions of these holes may be related to the cumulative effect of older intrusions. The models also indicate that meteoric recharge to the deep hydrothermal system probably originates within or near the caldera. Relatively low fluid velocities at depth suggest that at least a significant fraction of the thermal fluid may be very old.

Journal of Geophysical Research Solid Earth↗
USGS2012

Discharge rates of fluid and heat by thermal springs of the Cascade Range, Washington, Oregon, and northern California

Fluid and heat discharge rates of thermal springs of the Cascade Range have been determined using the chloride inventory method. Discharge rates of thermal spring groups range from 1 to 120 L s &minus;1 . Most of the fluid (50%) and heat (61%) are discharged from two hot spring groups in northern Oregon. Total discharge from thermal springs in the Cascade Range of California, Oregon, and Washington is about 340 Ls &minus;1 , which corresponds to about 8.2&times;10 4 kJ s &minus;1 of heat. This does not include hot springs developed on the flanks of Mount St. Helens after the 1980 eruption. The Cascade Range consists of geologically and technically distinct segments; rates of convective heat discharge by the thermal springs in these segments correlate with volcanic rock extrusion rates for the last 2 m. y. In Oregon and Washington, many streams without known thermal or mineral springs in their drainage basins also were sampled for chloride and sodium to detect chemical anomalies that might be associated with previously unknown thermal or mineral waters. Only three chloride anomalies not associated with known thermal or mineral springs were identified in the streams of the Cascade Range.

Journal of Geophysical Research↗
USGS2008

A landslide in Tertiary marine shale with superheated fumaroles, Coast Ranges, California

In August 2004, a National Forest fire crew extinguished a 1.2 ha fire in a wilderness area ~40 km northeast of Santa Barbara, California. Examination revealed that the fire originated on a landslide dotted with superheated fumaroles. A 4 m borehole punched near the hottest (262 °C) fumarole had a maximum temperature of 307 °C. Temperatures in this borehole have been decreasing by ~0.1 °C/d, although the cooling rate is higher when the slide is dry. Gas from the fumaroles and boreholes is mostly air with 3–8 vol% carbon dioxide and trace amounts of carbon monoxide, methane, ethane, and propane. The carbon dioxide is 14 C-dead. The ratios of methane to ethane plus propane [C 1 /(C 2 + C 3 )] range from 3.6 to 14. Carbon isotope values for the CO 2 range from −14‰ to −23‰ δ 13 C. 3 He/ 4 He values range from 0.96 to 0.97 times that of air. The anomalous heat is interpreted to be due to rapid oxidation of iron sulfide augmented by combustion of carbonaceous matter within the formation.

Geology↗
USGS2008

Assessment of Moderate- and High-Temperature Geothermal Resources of the United States

Scientists with the U.S. Geological Survey (USGS) recently completed an assessment of our Nation's geothermal resources. Geothermal power plants are currently operating in six states: Alaska, California, Hawaii, Idaho, Nevada, and Utah. The assessment indicates that the electric power generation potential from identified geothermal systems is 9,057 Megawatts-electric (MWe), distributed over 13 states. The mean estimated power production potential from undiscovered geothermal resources is 30,033 MWe. Additionally, another estimated 517,800 MWe could be generated through implementation of technology for creating geothermal reservoirs in regions characterized by high temperature, but low permeability, rock formations.

Fact Sheet↗
USGS2008

A Review of Methods Applied by the U.S. Geological Survey in the Assessment of Identified Geothermal Resources

The U. S. Geological Survey (USGS) is conducting an updated assessment of geothermal resources in the United States. The primary method applied in assessments of identified geothermal systems by the USGS and other organizations is the volume method, in which the recoverable heat is estimated from the thermal energy available in a reservoir. An important focus in the assessment project is on the development of geothermal resource models consistent with the production histories and observed characteristics of exploited geothermal fields. The new assessment will incorporate some changes in the models for temperature and depth ranges for electric power production, preferred chemical geothermometers for estimates of reservoir temperatures, estimates of reservoir volumes, and geothermal energy recovery factors. Monte Carlo simulations are used to characterize uncertainties in the estimates of electric power generation. These new models for the recovery of heat from heterogeneous, fractured reservoirs provide a physically realistic basis for evaluating the production potential of natural geothermal reservoirs.

Open-File Report↗
USGS2006

Comparison of circulation times of thermal waters discharging from the Idaho batholith based on geothermometer temperatures, helium concentrations, and 14C measurements

Circulation times of waters in geothermal systems are poorly known. In this study, we examine the thermal waters of the Idaho batholith to verify whether maximum system temperatures, helium concentrations, and 14C values are related to water age in these low-to-moderate temperature geothermal systems. He/N2 values of gas collected from thermal waters that circulate solely through distinct units of the Idaho batholith correlate linearly with Na-K-(4/3)Ca geothermometer temperatures, showing that both variables are excellent indicators of relative water age. Thermal waters that circulate in early Tertiary (45-50 Ma) granite of the Sawtooth batholith have 3.5 times more helium than thermal waters of the same aquifer temperature that circulate through the main Cretaceous granite (average 91 Ma). Hot spring waters circulating in hydrothermally altered parts of the batholith have very little dissolved helium and no correlation between He/N2 values and geothermometer temperatures. Thermal waters discharging from the Idaho batholith are more depleted in deuterium than modern precipitation in the area. Recharge to these geothermal systems occurred from at least 10,000 BP for the cooler systems up to about 33,000 BP for the hotter systems.

Geothermics↗
USGS2006

Chemical and isotopic database of water and gas from hydrothermal systems with an emphasis for the western United States

Chemical and isotope data accumulated by two USGS Projects (led by I. Barnes and R. Mariner) over a time period of about 40 years can now be found using a basic web search or through an image search (left). The data are primarily chemical and isotopic analyses of waters (thermal, mineral, or fresh) and associated gas (free and/or dissolved) collected from hot springs, mineral springs, cold springs, geothermal wells, fumaroles, and gas seeps. Additional information is available about the collection methods and analysis procedures . The chemical and isotope data are stored in a MySQL database and accessed using PHP from a basic search form below. Data can also be accessed using an Open Source GIS called WorldKit by clicking on the image to the left. Additional information is available about WorldKit including the files used to set up the site.

Data Series↗
USGS2005

Systematics of halogen elements and their radioisotopes in thermal springs of the Cascade Range, Central Oregon, Western USA

This study quantifies the cycling of halogen elements through the Cascadia subduction zone based on the chemistry of thermal springs in the Central Oregon Cascade Range and of a mineral spring in the forearc (Willamette Valley). Considerations based on mass balances, element ratios, and 36 Cl/Cl and 129 I/I ratios suggest that halogens discharged through the thermal springs in the Cascade Range are probably derived from magma degassing. Our results indicate that < 35% of the subducted Cl and < 20% of the subducted Br and I could be transported through arc volcanism and the thermal springs, a considerably lower percentage than estimated for other volcanic arcs along the Pacific Rim. A likely explanation for this difference is that a large fraction of the halogens is released from the slab at shallow depths into the serpentinized sub-forearc mantle because of the relatively high temperatures in the subducting Juan de Fuca plate. The small fraction of halogens subducted to depth probably also indicates a low rate of water transport, which is consistent with the observation that the Cascade Range sub-arc mantle is relatively dry and has a low degree of volcanic vigor, compared with other arcs.

Oregon↗
USGS2004

Magmatic intrusion west of Three Sisters, central Oregon, USA: The perspective from spring geochemistry

A geochemical investigation of springs near Three Sisters volcanoes was conducted in response to the detection of crustal uplift west of the peaks. Dilute, low-temperature springs near the center of uplift show 3 He/ 4 He ratios ≥7 R A ( R A is the ratio in air), and transport in total ∼16 MW of heat and ∼180 g/s of magmatic carbon (as CO 2 ). These anomalous conditions clearly reflect the influence of magma, but they seemingly predate the onset of the present uplift and derive from a previous event. Episodes of intrusion may thus be more common in this area than the age of eruptive vents would imply.

Geology↗
USGS2003

Excess nitrogen in selected thermal and mineral springs of the Cascade Range in northern California, Oregon, and Washington: Sedimentary or volcanic in origin?

Anomalous N 2 /Ar values occur in many thermal springs and mineral springs, some volcanic fumaroles, and at least one acid-sulfate spring of the Cascade Range. Our data show that N 2 /Ar values are as high as 300 in gas from some of the hot springs, as high as 1650 in gas from some of the mineral springs, and as high as 2400 in gas from the acid-sulfate spring on Mt. Shasta. In contrast, gas discharging from hot springs that contain nitrogen and argon solely of atmospheric origin typically exhibits N 2 /Ar values of 40–80, depending on the spring temperature. If the excess nitrogen in the thermal and mineral springs is of sedimentary origin then the geothermal potential of the area must be small, but if the nitrogen is of volcanic origin then the geothermal potential must be very large. End-member excess nitrogen (δ 15 N) is +5.3‰ for the thermal waters of the Oregon Cascades but is only about +1‰ for fumaroles on Mt. Hood and the acid-sulfate spring on Mt. Shasta. Dissolved nitrogen concentrations are highest for thermal springs associated with aquifers between 120 and 140°C. Chloride is the major anion in most of the nitrogen-rich springs of the Cascade Range, and N 2 /Ar values generally increase as chloride concentrations increase. Chloride and excess nitrogen in the thermal waters of the Oregon Cascades probably originate in an early Tertiary marine formation that has been buried by the late Tertiary and Quaternary lava flows of the High Cascades. The widespread distribution of excess nitrogen that has been generated in low to moderate-temperature sedimentary environments is further proof of the restricted geothermal potential of the Cascade Range.

Cascade Range↗
USGS2002

Report of hydrologic investigations in the Three Sisters area of central Oregon, Summer 2001

An ongoing episode of crustal uplift centered in the Separation Creek drainage of the Three Sisters area, central Oregon Cascades, may result from a magmatic intrusion that began in 1998. An investigation of springs in this drainage in summer 2001 revealed slightly elevated water temperatures and chloride (Cl-) concentrations of up to about 5?C and 20 milligrams per liter (mg/L), respectively, above background. The total discharge of anomalous Cl- in Separation Creek was 9.2 grams per second, which in combination with the temperature-Cl- relation in the springs results in a total advective heat discharge of 16 MW (megawatts). Comparison with similar findings obtained a decade earlier suggests that total Cl- and heat discharges in the groundwater drainage are unaffected by the current uplift. However, the isotopic composition of the dissolved inorganic carbon (DIC) in the spring waters (delta carbon-13 (13C) = -9.03 to -11.6?; carbon-14 (14C) <25 pmC) combined with helium-3/helium-4 (3He/4He) ratios near 8 RA and C/3He ratios <1010 in two of the springs are indicative of a magmatic source. The high 3He/4He ratios indicate that the magmatic gas is derived from a relatively recent, if not ongoing, intrusion. The concentration of magmatic carbon is low, a few millimoles per liter (mmol/L) at most, with an average value of 1.53 mmol/L for all the springs sampled in the drainage. Combining this average with the late-summer water flow in Separation Creek suggests a discharge of 21 tonnes/day of magmatic carbon dioxide (CO2). The presence of magmatic carbon in the shallow groundwater system, and the fact that DIC is uncorrelated with Cl-, suggests that some magmatic gas could escape diffusely through the soils.

Water-Resources Investigations Report↗
USGS2002

Mantle helium and carbon isotopes in Separation Creek geothermal springs, Three Sisters area, central Oregon: Evidence for renewed volcanic activity or a long term steady state system?

Here we present the helium and carbon isotope results from the initial study of a fluid chemistry-monitoring program started in the summer of 2001 near the South Sister volcano in central Oregon. The Separation Creek area which is several miles due west of the volcano is the locus of strong crustal uplift currently occurring at a rate of 4-5 cm/yr (Wicks, et. al. , 2001). Helium [R C /R A = 7.44 and 8.61 R A (R C /R A = ( 3 He/ 4 He) sample-air corrected /( 3 He/ 4 He) air ))] and carbon (δ 13 C = -11.59 to -9.03 ‰ vs PDB) isotope data and CO 2 / 3 He (5 and 9 x 10 9 ) show that bubbling cold springs in the Separation Creek area near South Sister volcano carry a strong mantle signal, indicating the presence of fresh basaltic magma in the volcanic plumbing system. There is no evidence though, to directly relate this signal to the crustal uplift that is currently taking place in the area, which started in 1998. The geothermal system in the area is apparently much longer lived and shows no significant changes in chemistry compared to data from the early 1990s. Hot springs in the area, which are relatively far removed from the volcanic edifice, do not carry a strong mantle signal in helium isotope ratios (2.79 to 5.08 R A ), unlike the cold springs, and also do not show any significant changes in helium isotope ratios compared to literature data for the same springs of over two decades ago. The cold springs of the Separation Creek area form a very diffuse but significant low temperature geothermal system, that should, due to its close vicinity to the center of up uplift, be more sensitive to changes in the deeper volcanic plumbing system than the far removed hot springs and therefore require much more study and consideration when dealing with volcano monitoring in the Cascade range or possibly with geothermal exploration in general.

Oregon↗
USGS2001

Time-variation of hydrothermal discharge at selected sites in the Western United States: Implications for monitoring

We compiled time series of hydrothermal discharge consisting of 3593 chloride- or heat-flux measurements from 24 sites in the Yellowstone region, the northern Oregon Cascades, Lassen Volcanic National Park and vicinity, and Long Valley, California. At all of these sites the hydrothermal phenomena are believed to be as yet unaffected by human activity, though much of the data collection was driven by mandates to collect environmental-baseline data in acticipation of geothermal development. The time series average 19 years in length and some of the Yellowstone sites have been monitored intermittently for over 30 years. Many sites show strong seasonality but few show clear long-term trends, and at most sites statistically significant decadal-scale trends are absent. Thus, the data provide robust estimates of advective heat flow ranging from ~130 MW in the north-central Oregon Cascades to ~6100 MW in the Yellowstone region, and also document Yellowstone hydrothermal chloride and arsenic fluxes of 1740 and 15-20 g/s, respectively. The discharge time series show little sensitivity to regional tectonic events such as earthquakes or inflation/deflation cycles. Most long-term monitoring to date has focused on high-chloride springs and low-temperature fumaroles. The relative stability of these features suggests that discharge measurements done as part of volcano-monitoring programs should focus instead on high-temperature fumaroles, which may be more immediately linked to the magmatic heat source.

Journal of Volcanology and Geothermal Research↗