Preliminary isotope assessment, La Grange Groundwater Area

The Department of Agriculture and Food, Western Australia (DAFWA) is currently undertaking a Royalties for Regions funded project in the La Grange Groundwater Area south of Broome. The focus is on providing improved confidence about soil suitability and water availability for potential expansion of irrigated agriculture in the region. Groundwater in the Broome Sandstone Aquifer (BSA) is the target water resource, however before the La Grange project commenced little was known about the physical and chemical attributes of the aquifer. This report provides the results of estimated groundwater recharge and residence times using environmental tracer techniques. Sampling of 12 existing bores in the Broome Sandstone Aquifer during October 2014 has shown that the major ion chemistry is similar to that found previously in the LaGrange area. The Na-Ca-Cl-HCO3 to Na-Cl compositions are consistent with a source of solutes from aerosols in rainfall of marine origin, followed by minimal water-rock interaction. Measured carbon-14 activities have been converted into apparent groundwater ages. After using several of the most widely used corrections schemes, which account for the addition of ‘dead’ carbon to groundwater by carbonate mineral weathering, most samples appear to be modern. Considering potential errors in sampling and analysis, and assumptions required for the correction schemes, these ‘modern’ waters may be up to 500 years old. The fact that these groundwater samples are so young in a regional groundwater system reflects the shallow depth of the bores compared to the total thickness of the aquifer, as well as the dominance of episodic recharge mechanisms across different soils and landforms. In contrast, waters sampled from Munro Springs and the nearby outstation bore are in the order of 3000-5000 years and 10 000-12 000 years old, respectively. A recent AEM survey has been interpreted to suggest that structural controls and/or local topographic effects, plus potential coincidence of palaeochannels, may mean this water has been sourced from deeper parts of the Broome Sandstone originating further east. The full range of groundwater carbon-14 ages and the steady-state chloride mass balance suggest long-term average recharge rates are in the range 5-15 mm/y. This range should now be tested through the proposed numerical groundwater flow model(s) for the region. Stable hydrogen and oxygen isotope compositions of groundwater samples are all relatively depleted in the heavy isotopes compared to the composition of bulk rainfall samples, particularly rainfall in the dry season. This data supports a conceptual model of recharge only occurring after very intense monsoonal rainfall events in the wet season. These results are also similar to previous work in the West Canning Basin, the Dampier Peninsula, and the Fitzroy River catchment

Broome Sandstone aquifer, La Grange groundwater area: a preliminary report on the hydrochemistry and groundwater recharge rates, with recommendations for future drilling and environmental tracer sampling

Innovative Groundwater Solutions has been engaged by the Department of Agriculture and Food, Western Australia (DAFWA) to assist with the initial planning and design of the drilling and groundwater sampling program for the Broome Sandstone aquifer in the La Grange groundwater area. There are multiple objectives of the drilling program, including defining aquifer stratigraphy and position of the salt-water interface; assessing groundwater recharge, residence time, lateral flow velocity and the source of water to culturally significant sites; enabling long-term monitoring of water level and water quality; and, ultimately, developing a groundwater model for the aquifer. The following four tasks were considered important preparatory steps for the drilling program, the results of which are detailed in this report: review DAFWA’s preliminary interpretation of groundwater chemistry data collected from existing bores in 2013 derive preliminary estimates of recharge rate for shallow groundwater using the steady-state chloride mass balance method with best available data. work with DAFWA to determine suitable locations and completion details for new bores along 4-6 potential transects. recommend a suite of chemical and isotopic analytes for each of the proposed new bores, and the existing bores for which completion details are known along each transect

A hydrochemical assessment of groundwater recharge and flow in the Broome Sandstone Aquifer, La Grange area, Western Australia

The Department of Agriculture and Food Western Australia has undertaken a four-year Royalties for Regions funded project in the La Grange Groundwater Area south of Broome. The purpose of the project was to provide improved knowledge and confidence about soil suitability and water availability for potential expansion of irrigated agriculture in the region. A range of complementary techniques have been used to assess the groundwater resources in the Broome Sandstone aquifer, including contemporary approaches such as drilling and aquifer pumping tests, and state-of-the-art approaches such as airborne geophysical surveys and hydrochemistry investigations. This report presents a synthesis of all hydrochemistry data collected from about 200 existing and recently drilled bores over three campaigns from 2013 to 2015. Major ion chemistry data, stable hydrogen and oxygen isotopes of the water molecule, chlorofluorocarbons and radiocarbon have all been used to address key knowledge gaps in the context of future irrigation development and water allocation planning. Most groundwater in the Broome Sandstone aquifer is exceptionally good quality with salinity less than 500 mg/L as total dissolved salts. Major ion compositions are consistent with a source of solutes from aerosols in rainfall of marine origin, followed by minimal water-rock interaction including weathering of soil carbonates. Stable hydrogen and oxygen isotope compositions of groundwater samples indicate that recharge to the aquifer only occurs after intense monsoonal rainfall events in the wet season. Three different environmental tracer based methods for estimating recharge rates have produced remarkably consistent results, despite differences in the spatial and temporal scales over which they apply. There are no apparent spatial trends in recharge rate, which indicates that recharge is driven by large episodic events associated with tropical cyclones rather than mean annual rainfall. Residence times of groundwater flow in the Broome Sandstone range from ‘modern’ for shallow bores to more than 20 000 years for deep bores in down-gradient parts of the aquifer. These residence times correspond to flow path lengths ranging from only a few kilometres for groundwater in the shallowest bores, to more than 150 km for groundwater in the deep bores near the coast

Hydrogeology and drilling phase 1 for Scott Creek catchment

Scott Creek Catchment is the first of a number of catchments that will be used as case studies to investigate the sustainability of groundwater resources in the Mount Lofty Ranges over the next 45 years. This report provides a collation of background information for the Scott Creek Catchment including geological, hydrological, meteorological and surface water quality data. Site selection criteria, drilling methods, construction details and lithological logs are presented for the first phase of drilling in this catchment. A total of nine wells (one completed in the Quaternary alluvium and eight in the fractured Woolshed Flat Shale) were drilled at strategic locations on either side of Scott Creek upstream of the weir at Scott Bottom. These wells will be used for a variety of hydraulic and hydrochemical tests to define the local hydrogeology in terms of streamaquifer interactions and groundwater recharge and flow rates.repor

Early Science with the Large Millimeter Telescope: COOL BUDHIES I - a pilot study of molecular and atomic gas at z~0.2

An understanding of the mass build-up in galaxies over time necessitates tracing the evolution of cold gas (molecular and atomic) in galaxies. To that end, we have conducted a pilot study called CO Observations with the LMT of the Blind Ultra-Deep H I Environment Survey (COOL BUDHIES). We have observed 23 galaxies in and around the two clusters Abell 2192 (z = 0.188) and Abell 963 (z = 0.206), where 12 are cluster members and 11 are slightly in the foreground or background, using about 28 total hours on the Redshift Search Receiver (RSR) on the Large Millimeter Telescope (LMT) to measure the $^{12}$CO J = 1 --> 0 emission line and obtain molecular gas masses. These new observations provide a unique opportunity to probe both the molecular and atomic components of galaxies as a function of environment beyond the local Universe. For our sample of 23 galaxies, nine have reliable detections (S/N$\geq$3.6) of the $^{12}$CO line, and another six have marginal detections (2.0 < S/N < 3.6). For the remaining eight targets we can place upper limits on molecular gas masses roughly between $10^9$ and $10^{10} M_\odot$. Comparing our results to other studies of molecular gas, we find that our sample is significantly more abundant in molecular gas overall, when compared to the stellar and the atomic gas component, and our median molecular gas fraction lies about $1\sigma$ above the upper limits of proposed redshift evolution in earlier studies. We discuss possible reasons for this discrepancy, with the most likely conclusion being target selection and Eddington bias.Comment: MNRAS, submitte

Design tools for complex dynamic security systems.

The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle

Suitability of external controls for drug evaluation in Duchenne muscular dystrophy

OBJECTIVE: To evaluate the suitability of real-world data (RWD) and natural history data (NHD) for use as external controls in drug evaluations for ambulatory Duchenne muscular dystrophy (DMD). METHODS: The consistency of changes in the 6-minute walk distance (Δ6MWD) was assessed across multiple clinical trial placebo arms and sources of NHD/RWD. Six placebo arms reporting 48-week Δ6MWD were identified via literature review and represented 4 sets of inclusion/exclusion criteria (n = 383 patients in total). Five sources of RWD/NHD were contributed by Universitaire Ziekenhuizen Leuven, DMD Italian Group, The Cooperative International Neuromuscular Research Group, ImagingDMD, and the PRO-DMD-01 study (n = 430 patients, in total). Mean Δ6MWD was compared between each placebo arm and RWD/NHD source after subjecting the latter to the inclusion/exclusion criteria of the trial for baseline age, ambulatory function, and steroid use. Baseline covariate adjustment was investigated in a subset of patients with available data. RESULTS: Analyses included ∼1,200 patient-years of follow-up. Differences in mean Δ6MWD between trial placebo arms and RWD/NHD cohorts ranged from -19.4 m (i.e., better outcomes in RWD/NHD) to 19.5 m (i.e., worse outcomes in RWD/NHD) and were not statistically significant before or after covariate adjustment. CONCLUSIONS: We found that Δ6MWD was consistent between placebo arms and RWD/NHD subjected to equivalent inclusion/exclusion criteria. No evidence for systematic bias was detected. These findings are encouraging for the use of RWD/NHD to augment, or possibly replace, placebo controls in DMD trials. Multi-institution collaboration through the Collaborative Trajectory Analysis Project rendered this study feasible

CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

CMB-S4---the next-generation ground-based cosmic microwave background (CMB) experiment---is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semi-analytic projection tool, targeted explicitly towards optimizing constraints on the tensor-to-scalar ratio, $r$, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2--3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments given a desired scientific goal. To form a closed-loop process, we couple this semi-analytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for $r > 0.003$ at greater than $5\sigma$, or, in the absence of a detection, of reaching an upper limit of $r < 0.001$ at $95\%$ CL.Comment: 24 pages, 8 figures, 9 tables, submitted to ApJ. arXiv admin note: text overlap with arXiv:1907.0447