Spectral analysis of vertical temperature profile time-series data in Yellowstone Lake sediments

Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Water Resources Research 57(4), (2021): e2020WR028430, https://doi.org/10.1029/2020WR028430.We use yearlong vertical temperature profile time-series (seven thermistors at evenly spaced depth intervals from 10 to 70 cm) from five sites in and around the Deep Hole thermal area, southeast of Stevenson Island, Yellowstone Lake, to investigate heat and mass fluxes across the lake floor. The records demonstrate that thermal gradients in surficial sediments are modulated by a rich spectrum of bottom water temperature variations generated by hydrodynamic processes, and that sites inside the thermal area also respond to hydrothermal variations. We develop and implement a new method for estimating the sediment effective thermal diffusivity and pore fluid vertical flow rate that exploits the full spectrum of observed temperature variations to generate the parameter estimates, uncertainties, and metrics to assess statistical significance. Sediments at sites outside thermal areas have gradients of ∼7.5°C/m, in situ thermal diffusivities of ∼1.6 × 10−7 m2/s consistent with highly porous (80–90%) siliceous sediments, and experience hypolentic flow in the upper ∼20 cm. Sites inside the Deep Hole thermal area exhibit considerable spatial and temporal variability, with gradients of 1–32°C/m, and higher thermal diffusivities of ∼2–12 × 10−7 m2/s, consistent with hydrothermal alteration of biogenic silica to clays, quartz, and pyrite. Upward pore fluid flow at these sites is observed across multiple depth intervals, with maximum values of ∼3 cm/day. The observed spatial and temporal variability within the thermal area is consistent with upward finger flow combined with short wavelength convection within the porous sediments above a steam reservoir.This research was supported by the National Science Foundation Grants EAR-1516361 to Robert A. Sohn and EAR-1515283 to Robert N. Harris, and by the Independent Research and Development Program at the Woods Hole Oceanographic Institution (Robert A. Sohn). All work in Yellowstone National Park was completed under an authorized Yellowstone research permit (YELL-2018-SCI-7018)

Reply to comment by T.J. Osborn and K. R. Briffa on "Mid-Latitude (30?-60?N) climatic warming inferred by combining borehole temperatures with surface air temperatures"

Journal ArticleWe thank Osborn and Briffa [2002] for their comment regarding our use of the climatic reconstruction of Overpeck et al. [1997]. We [Harris and Chapman, 2001] had taken a proxy, Arctic wide summer-weighted annual temperature reconstruction [Overpeck et al., 1997], given in dimensionless sigma units (i.e., normalized deviation from the 1901?1960 proxy mean in units of standard deviation of the new series for the period 1901?1960) and represented the reconstruction in our Figure 3 and Table 1 in terms of dimensional temperature units ?C

Geothermics and climate change: 1. Analysis of borehole temperatures with emphasis on resolving power

Journal ArticleTemperature-depth data from six boreholes in western Utah and nine boreholes in southeastern Utah are reanalyzed for evidence of ground surface temperature (GST) histories. We invert the temperature-depth data using the functional space inverse algorithm of Shen and Beck [1991, 1992] which we prefer over previous inversions of these data because of its greater sophistication and flexibility in suppressing noise. GST histories for western and southeastern Utah are generally consistent and suggest that temperatures in the mid-1800s are, on average, cooler than previous centuries, followed by about 0.6°C of warming in this century. Attention is given to the temporal resolution of our GST solutions showing the time-smearing effects of heat conduction on the solutions. GST solutions represent an average ground temperature over a time window that expands as we look farther into the past. The size of the time window is a function of measurement and geologic noise and limits the ultimate resolution of GST reconstructions

Geothermics and climate change: 2. Joint analysis of borehole temperature and meteorological data

Journal ArticleLong-period ground surface temperature variations contained in bore hole temperature-depth profiles form a complementary climate change record to high-frequency, but noisy surface air temperature (SAT) records at weather stations. We illustrate the benefits of jointly analyzing geothermal and meteorological data for two regions in Utah where both high-quality temperature-depth measurements and century long SAT records exist

Default resolution and access to fresh credit in an emerging market

We examine loan defaults by firms and identify the factors that influence both the default resolution process and firms' access to fresh credit after firms exit default. Using a dataset of all commercial loans made in Pakistan from 2006 to 2013, we find an important role for collateral. Collateral expedites both the default resolution process and access to fresh credit after exiting default. Higher interest rates increase the default duration. Relationships with multiple lenders as well as those with multiple branches of one lender are associated with obtaining fresh credit at the post default stage

Comparison of Landing Variables between Countermovement Jump Landings and Drop Vertical Jump Landings from Equal Heights

The countermovement jump (CMJ) and drop vertical jump (DVJ) are often used as a measurement of physical ability or performance potential, while analysis of landing can provide crucial information regarding injury risk. In theory, similar landing strategies should be employed when CMJ jump height and DVJ drop height are controlled, yet we know of no studies have investigated this possibility. PURPOSE: to examine and compare landing characteristics between CMJ and DVJ when flight height is controlled. METHODS: Forty (20 males; 20 females; 22.5 ± 4.3 years, 1.7 ± 0.1 m, 73.2 ± 13.3 kg) recreationally active individuals performed three CMJ and three DVJ trials, each from the same height which was controlled using a Vertec. Vertical ground reaction force (VGRF) data was obtained from a portable force platform. Landing momentum, landing time, and peak vGRF were obtained from the processed vGRF data using a custom analysis program. Variables were compared between jumps (CMJ, DVJ) using paired samples t-tests (α = 0.05). Cohen’s d is used to supplement statistical outcomes by demonstrating the magnitude of mean differences. RESULTS: Landing momentum was 4.8% greater during DVJ than during CMJ and the difference was small (DVJ = -193.6 ± 52.2, CMJ = -184.4 ± 52.5; P=0.049, d = 0.4), indicating slightly greater landing heights during DVJ. Landing time during DVJ was 52% shorter than the CMJ landing time and the difference was very large (DVJ = 0.4 ± 0.2, CMJ = 0.7 ± 0.2; P\u3c0.001, d =1.7), while DVJ peak impact force was 14.7% less than CMJ peak impact force and the difference was moderate (DVJ = 3.5 ± 1.0; CMJ = 4.1 ± 0.7; P=0.002, d = 0.6). CONCLUSION: While the significant difference in landing momentum was not random, the magnitude of mean difference was small, indicating relatively similar landing momentum between jumps. Thus, the present study shows that, even when controlling jump height between the CMJ and DVJ, the tasks do not have similar landing demands, defined by momentum, time, nor peak impact force. Due to the differences observed, the CMJ and DVJ should not be used interchangeably or as a comparison between one another when examining these specific landing variables. Finally, the DVJ might expose performers to lesser overuse injury risks related to impact forces

Automatic Detection of Seizures with Applications

There are an estimated two million people with epilepsy in the United States. Many of these people do not respond to anti-epileptic drug therapy. Two devices can be developed to assist in the treatment of epilepsy. The first is a microcomputer-based system designed to process massive amounts of electroencephalogram (EEG) data collected during long-term monitoring of patients for the purpose of diagnosing seizures, assessing the effectiveness of medical therapy, or selecting patients for epilepsy surgery. Such a device would select and display important EEG events. Currently many such events are missed. A second device could be implanted and would detect seizures and initiate therapy. Both of these devices require a reliable seizure detection algorithm. A new algorithm is described. It is believed to represent an improvement over existing seizure detection algorithms because better signal features were selected and better standardization methods were used

CMS search plans and sensitivity to new physics with dijets

CMS will use dijets to search for physics beyond the standard model during early LHC running. The inclusive jet cross section as a function of jet transverse momentum, with 10 inverse picobarns of integrated luminosity, is sensitive to contact interactions beyond the reach of the Tevatron. The dijet mass distribution will be used to search for dijet resonances coming from new particles, for example an excited quark. Additional sensitivity to the existence of contact interactions or dijet resonances can be obtained by comparing dijet rates in two distinct pseudorapidity regions.Comment: 10 pages, 4 figures, accepted for publication in J. Phys. G: Nucl. Part. Phy

Best Practice Guidelines for Regional Development Strategies

The grids project GRIDS is an INTERREG IIIC project that is focused on developing a series of best practice guidelines for regional development and spatial planning. It is especially concerned with identifying and promoting good practice within some of the smaller countries of the European Union. Project partners are based in Ireland, Wales, Belgium, Latvia and Lithuania and include national, regional and local public administrations as well as academic institutions. The project has also attracted interest and involvement from government organisa- tions in Scotland and Estonia. The project has focused on exchanging experience between partners

Observations and modeling of a hydrothermal plume in Yellowstone Lake

Author Posting. © American Geophysical Union, 20XX. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 46(12), (2019): 6435-6442, doi:10.1029/2019GL082523.Acoustic Doppler current profiler and conductivity‐temperature‐depth data acquired in Yellowstone Lake reveal the presence of a buoyant plume above the “Deep Hole” hydrothermal system, located southeast of Stevenson Island. Distributed venting in the ~200 × 200‐m hydrothermal field creates a plume with vertical velocities of ~10 cm/s in the mid‐water column. Salinity profiles indicate that during the period of strong summer stratification the plume rises to a neutral buoyancy horizon at ~45‐m depth, corresponding to a ~70‐m rise height, where it generates an anomaly of ~5% (−0.0014 psu) relative to background lake water. We simulate the plume with a numerical model and find that a heat flux of 28 MW reproduces the salinity and vertical velocity observations, corresponding to a mass flux of 1.4 × 103 kg/s. When observational uncertainties are considered, the heat flux could range between 20 to 50 MW.The authors thank Yellowstone National Park Fisheries and Aquatic Sciences, The Global Foundation for Ocean Exploration, and Paul Fucile for logistical support. This research was supported by the National Science Foundation grants EAR‐1516361 to R. S., EAR‐1514865 to K. L., and EAR‐1515283 to R. H. and J. F. All work in Yellowstone National Park was completed under an authorized Yellowstone research permit (YELL‐2018‐SCI‐7018). CTD and ADCP profiles reported in this paper are available through the Marine Geoscience Data System (doi:10.1594/IEDA/324713 and doi:10.1594/IEDA/324712, accessed last on 17 April 2019, respectively).2019-11-0