Abstract: The total throw across a fault zone may not occur entirely on a single fault strand but may be distributed onto several strands or may be accommodated by distributed deformation within or adjacent to the fault zone. Here we conduct a quantitative analysis of the partitioning of throw into three components, the throw accommodated by: (a) the largest fault strand; (b) subsidiary faults; and (c) continuous deformation in the form of bed rotation in sympathy with the fault downthrow direction. This analysis is applied to seven seismic-scale fault zones at outcrop resolution (maximum throw 50 m) that were mapped over a four-year period during open-cast lignite mining within the late Miocene–Pliocene Ptolemais Basin, West Macedonia, Greece. The analysis shows that the fault zones offsetting the lignite–marl sequence are more localized at higher throws with progressively more of the total throw accommodated by the largest fault strand. Normal drag, which can account for up to 12 m of the total throw, accommodates a lower proportion of the total throw on larger faults. It appears that initial fault segmentation is the main control on the degree of, and spatial variation in, fault throw partitioning. Gold Open Access: This article is published under the terms of the CC-BY 3.0 license

Groundwater resources in Haiti are considered abundant, with greater than 2 billion cubic meters per year (2 × 10 9 m 3 /yr) of renewable resources and 56 billion cubic meters of reserves. However, groundwater is not available everywhere and many aquifers are often low yielding, discontinuous, or are at risk from saltwater intrusion, overexploitation, reduced recharge, and contamination. Economic development, population growth, and climate change are factors that will increase stress on groundwater resources. Sector leadership, capacity building mechanisms, integrated water policy, and a clear regulatory framework are urgently needed to manage, regulate, and protect Haiti’s groundwater resources to achieve long-term security. Accomplishing this requires technical support and practical references that summarize the groundwater resources and their vulnerabilities, complexities, and opportunities. This chapter includes a summary of knowledge, information, and experience to aid the development and management of Haiti’s groundwater resources, as well as provides an overview of its complex hydrogeology. Five broad hydrogeological environments are differentiated: (1) Unconsolidated alluvium accounts for 26% of Haiti’s land area—it includes a large portion of the country’s groundwater reserves and is the most exploited for irrigation, industry, and potable water; (2) interior sedimentary units account for 32% of Haiti’s land area and include up to 25% of the country’s groundwater reserves—springs from carbonate aquifers are significant sources of water supply throughout the country; (3) reef carbonate accounts for 6% of Haiti’s land area, with locally available coastal karst aquifer systems serving some of the most rural, driest, and impoverished areas of Haiti; (4) semiconsolidated units account for 21% of Haiti’s land area—their low groundwater potential limits rural and urban water use throughout the country; and (5) igneous bedrock accounts for 15% of Haiti’s land area—its discontinuous groundwater reserves are an important source of water in rural and mountainous areas.

Despite the superior energy efficiency of geothermal heat pump systems, widespread adoption of the technology is hindered by the higher initial capital cost relative to conventional heating and cooling systems. A promising avenue for reducing first costs is better characterization of salient subsurface properties and the subsequent implementation of more optimal designs for the ground heat exchange component. This study evaluates the potential for geological and pedological models to facilitate optimal design of vertical- and horizontal-based ground heat exchange systems, respectively. Data from well borings and subsurface monitoring sites in Indiana are used for geological model development and the assessment of existing pedological models. Results from performance simulations illustrate how the total design length of a conceptual, commercial-scale vertical ground heat exchange installation could be reduced by 17% as a result of better characterization of the variability in thermal properties gleaned from geological modeling. Given the abundance of publicly available well bore data, the explicit integration of geological modeling during the system design phase appears to be a feasible and promising approach for improving affordability. Results from horizontal ground heat exchange modeling at sites in Indiana that contain in situ monitoring data indicate that the use of design parameters derived from existing pedological models generally leads to overbuilt ground loops that were on average 45% longer than necessary to achieve design specifications. Despite the apparent limitations of existing pedological models, such models have utility in identifying sites that exhibit stable thermal properties and are thus most amenable for optimal design of horizontal ground heat exchange systems.

By using ground source heat pumps to exchange heat with the shallow surface, areas with minimal or no tectonic activity can still be viable resources for low-temperature geothermal energy. This study focuses on generally characterizing the potential exploitation of flooded mines as low-temperature thermal resources within Ohio. These unconventional thermal resources offer large, thermally stable bodies of water, which store relatively more heat than saturated soils and bedrock. The legacy of underground mining, predominantly in the southeastern and eastern portions of Ohio, makes ground source heat pump geothermal energy a potentially valuable resource for the state. Using geographic information system (GIS) software, mines that were either flooded or partially flooded and within 1.6 km of a population center were selected as potential candidates for ground source heat pump exploitation. Physical and thermal parameters were calculated for each of the identified geothermal sites. These include: maximum and minimum residence times of waters within the mines, maximum and minimum recharge to the mines, effective mine volumes, linear groundwater velocities, groundwater flow direction, and percentage of the mine that is flooded. The total theoretical amount of heat extraction or addition per degree change in mine water temperature (Celsius degree) was calculated for each identified mine site, as well as the potential amount of heat either entering or being dissipated in mine waters due to groundwater recharge. This study identified 147 possible mine sites spanning 21 counties that might be used for ground source heat pump installations in Ohio. The mines have an estimated average maximum residence time ranging from 6 to 15 yr and an estimated average minimum residence time ranging from 3.6 to 8.9 yr. It was estimated that, on average, 10 10 kJ °C −1 of heat energy could be extracted from the mines. Overall, this study has shown that abandoned underground mines contain enough stored heat to be used as thermal resources for ground source heat pump systems, and that the number and extent of mines within Ohio could make this type of geothermal resource valuable.

Thermal response tests are the industry standard for borehole heat exchanger design in ground-coupled heat pump systems. Two previously conducted thermal response tests in phase 2 of the district-scale ground-coupled heat pump system at Ball State University (BSU) measured a bulk “formation” thermal conductivity K T between 2.6 and 3.0 W m −1 K −1 . Meanwhile, K T from a core recovered near BSU averages 2.2 ± 0.006 and 3.5 ± 0.086 W m −1 K −1 for dry and water-saturated samples, respectively. The range in K T data from saturated samples (1.8–7.2 W m −1 K −1 ) leads to the conclusion that thermal response tests do not capture the vertical and horizontal heterogeneity of heat flux in layered sedimentary aquifers. Characterization of the hydrogeologic environment can be one tool to tune district-scale ground-coupled heat pump systems to the specific on-site conditions that may influence the magnitude and mode of heat transfer. At BSU, temperature ( T ) changes in the groundwater environment at the active phase 1 field through October 2013 support this notion. After constant heat loading, a T increase of 14–18 °C was observed in the central monitoring well. The vertical structure in the T profile of this well may correlate to “thermofacies.” For example, a T spike between 14 and 19.5 m in depth may correspond to a sand and gravel zone in the surficial glacial till, and a T dip at a depth of 70 m agrees with the position of the Brainard Shale—zones of higher permeability and lower measured K T (2.0 W m −1 K −1 ), respectively. Higher measured K T zones, such as the low siliciclastic Silurian Salamonie Limestone and the Ordovician Whitewater Formation, may be target thermofacies for heat deposition and extraction. In contrast, sand and gravel zones within the glacial till may allow for significant thermal loading; however, groundwater advection may reduce the fraction of recoverable thermal load.

Heat transfer in the subsurface can vary with depth due to variations in the thermal conductivity of the geologic medium as well as variations in groundwater flow velocity. However, traditional thermal response tests (TRTs) do not allow for evaluation of the depth variability of heat transfer. We investigate the potential for using discrete-depth heat dissipation tests in open, water-filled boreholes to evaluate variations in heat exchange rate with depth. Heat dissipation tests were initiated at target depths in a test well using an electrical resistance heater. Heat dissipation was monitored by measuring borehole water temperature through time using a fiber-optic distributed temperature sensing system. Temperature data were used to compare the thermal response at different depths in the borehole. To account for both the thermal conductivity of the geologic medium and the groundwater flow velocity, we used a numerical groundwater flow model (MODFLOW) and solute transport model (MT3DMS) to simulate heat dissipation tests. Simulation results indicate the measured response to a heat dissipation test in an open borehole is strongly dependent on the measurement location within the borehole; thus, data are ambiguous when the measurement location is uncontrolled. However, modeling results also indicate that the thermal response of a heat dissipation test as measured at the center of the borehole is sensitive to variations in thermal conductivity and groundwater flow velocity, suggesting that heat dissipation tests are a potentially useful method for characterizing depth variability in thermal properties if a centralized temperature measurement method is used to monitor the tests.

Abstract Earth construction is the oldest building material known, with documented cases of the use of earth bricks since Mesopotamia around 10 000 BC. Earth construction exists throughout most of the world in different cultures, and for some countries it continues to be the main process of construction. Around 30% of the world’s population lives in buildings made from earth materials. Earthen construction is an environmentally friendly technique with a social and cultural contribution; this advantage is increased when this type of construction is applied in developing countries where the material costs counterbalance the labour costs, and where other materials and techniques are not available. Studies of material characteristics are required in order to understand the composition and specific properties of earth buildings, their heterogeneity and their degradation mechanisms. Results from two different types of adobes that represent these material characteristics in Aveiro district are shown, owing to the importance of determining and acknowledging the main characteristics of adobe buildings in order to have sufficient information to initiate conservation and rehabilitation actions.

Abstract Airborne dust suppression is of critical importance to military operations conducted in desert environments. Airborne dust is commonly generated in the desert by surface and near-surface operations during operational, testing, and training missions. Currently, there is no standardized procedure for testing dust suppressants, and the U.S. military lacks a specific test operations procedure (TOP) designed to provide realistic testing of the performance and durability of commercial products sold for dust abatement. The primary purpose of this study is to provide recommendations for the future development of a TOP for testing dust suppressants applied to desert soils. Recommendations were developed from the evaluation of a polyvinyl-based synthetic polymer as a dust suppressant, which was tested at four test intervals over a 19–week period in the late spring and summer of 2008 at the U.S. Army Yuma Proving Ground. The dust suppressant was applied at three separate test sites having different surface characteristics and soil properties ranging from loose, sandy gravel to gravelly sand, alluvial-fan soils to soft, sandy-silt, alluvial-plain soils. Each test site was subjected to a variety of traffic impact types consisting of an increasing number of cumulative passes by different vehicle types—including a low-flying helicopter, a light-weight armored tracked vehicle, and heavy-, medium-, and lightweight wheeled vehicles, plus pedestrian foot traffic. In addition to the sites of traffic impact, three types of control plots were concurrently tested to act as reference sites, as well as to evaluate the longevity of the suppressant, which included: disturbed and static (undisturbed) baseline plots and a static benchline plot. Surface soil and dust-suppressant physical properties were measured following each traffic impact in the form of shear strength and bearing capacity, plus dust-emission flux as measured by a Portable In Situ Wind ERosion Laboratory (PI-SWERL). Results from this study show that dust-emission flux and surface-strength measurements from a layout of control and traffic impact test plots provide a quantifiable and repeatable approach in measuring the efficacy of a dust suppressant for a TOP used by the U.S. Army.

Abstract The removal of obsolete and unsafe dams for safety, environmental, or economic purposes frequently involves the exploration of sediments trapped within the impoundment and the subsequent assessment of sediment management needs and techniques. Sediment management planning requires a thorough understanding of the watershed’s surficial geology, topography, land cover, land use, and hydrology. The behavior of sediments is influenced by their age, consolidation, and stratigraphy. All watersheds have a history that helps forecast sediment loads, quality, gradation, and stratigraphy. Impounded sediment deposits may include coarse deltas and foreset slopes, fine or coarse bottom deposits, cohesive or organic matter, and wedge deposits immediately behind the dam. Some watersheds have anthropogenic pollutants from agricultural activities, mining, industries, or urban runoff. The volume and rate of sediment release during and after small dam removal can be limited by active management plans to reduce potential downstream impacts. Management strategies include natural erosion, phased breaches and drawdowns, natural revegetation of sediment surfaces, pre-excavation of an upstream channel, hazardous waste removal or containment, flow bypass plans, and sediment dredging.

Abstract Before a dam removal project is implemented, engineers are often asked to estimate the potential for impacts from the release of reservoir sediment. Field measurements, numerical models, and physical models are typically used to develop sediment impact estimates. This information helps decision makers to make informed decisions about when and how to remove the dam, whether to allow the river to erode the reservoir sediment, or to remove or stabilize the reservoir sediment prior to dam removal, or whether mitigation of the effects is needed. Although numerous dams have been removed, mostly small in size, few case studies on sediment impacts have been documented. Because there are limited case studies, dam removal regulators and stake-holders often err on the side of caution when selecting the level of pre removal analysis or determining whether the reservoir sediment needs to be removed prior to dam removal. The purpose of this paper is to increase our knowledge base for application to future dam removals. The chapter discusses sediment impacts associated with the removal of the 11.9-m-high Savage Rapids Dam on the Rogue River near Grants Pass, Oregon. A unique factor to the Savage Rapids project was the construction and operation of a new diversion facility and water intake located immediately downstream of the dam, which introduced additional consequences associated with the release of reservoir sediment.

This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California , edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description , for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a repository site.

Cultural resources are an important nonrenewable national asset that, like the mineral resources in which they can occur, are finite and need protection. In the six years since 2002, geoarchaeological research funded by English Heritage (EH) through the Aggregates Levy Sustainability Fund (ALSF) has significantly enhanced our understanding and ability to safeguard the historic environment in areas impacted by aggregate extraction. Most of the funding has been allocated toward strategic research and survey aimed at characterization of both the mineral and archaeological resources, and also toward monitoring and management of the archaeological resources. A smaller but significant contribution has been directed at development and application of new survey and specialist archaeological dating techniques, as well as unexpected discoveries. Such research is aimed at reducing irreversible damage of the archaeological resource as the result of aggregate extraction and ultimately provides the fundamental evidence on which minerals planning policies can be based, thus protecting the finite resources for future generations.