The World Stress Map database release 2016 : Crustal stress pattern across scales

Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, and biogeochemical stores and fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, and ESM developers, to explore how hillslope structures may modulate ESM grid‐level water, energy, and biogeochemical fluxes. In contrast to the one‐dimensional (1‐D), 2‐ to 3‐m deep, and free‐draining soil hydrology in most ESM land models, we hypothesize that 3‐D, lateral ridge‐to‐valley flow through shallow and deep paths and insolation contrasts between sunny and shady slopes are the top two globally quantifiable organizers of water and energy (and vegetation) within an ESM grid cell. We hypothesize that these two processes are likely to impact ESM predictions where (and when) water and/or energy are limiting. We further hypothesize that, if implemented in ESM land models, these processes will increase simulated continental water storage and residence time, buffering terrestrial ecosystems against seasonal and interannual droughts. We explore efficient ways to capture these mechanisms in ESMs and identify critical knowledge gaps preventing us from scaling up hillslope to global processes. One such gap is our extremely limited knowledge of the subsurface, where water is stored (supporting vegetation) and released to stream baseflow (supporting aquatic ecosystems). We conclude with a set of organizing hypotheses and a call for global syntheses activities and model experiments to assess the impact of hillslope hydrology on global change predictions.

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Hillslope Hydrology in Global Change Research and Earth System Modeling

Tectonic Regimes of the Central and Southern Andes: Responses to Variations in Plate Coupling During Subduction

Structural, sedimentological, and provenance data from Paleogene synorogenic deposits of the east-central flank of the Bighorn Mountains provide new information about the development of footwall growth synclines, the evolution of fault-related folds, and the erosional unroofing history of intraforeland uplifts. Three conglomerate units, the upper conglomerate member of the Fort Union Formation and the Kingsbury and Moncrief Members of the Wasatch Formation, are incorporated within an asymmetric, east-verging growth syncline in the footwall of the main range-bounding thrust system. Three stages of footwall deformation are recorded within these conglomerates. Analysis of mapped progressive unconformities, retrodeformed balanced cross sections, and conglomerate clast composition data define these stages as part of a continuum of deformation associated with the development of footwall growth synclines. Development of an anticline-syncline pair marked the earliest stage of growth syncline formation (stage I). Rotation of the shared fold limb resulted in amplification of the growth syncline. Fine-grained, synorogenic sediment derived from easily eroded Mesozoic mudstone bypassed the growth syncline during this stage. By the end of Lebo Shale deposition, an average of 12.1% of shortening and 6.46 km of uplift had occurred along the range margin. Continued growth syncline development was marked by the deposition of the Kingsbury Conglomerate. The Kingsbury Conglomerate was derived from resistant, middle and lower Paleozoic carbonate strata in the uplifted source terrane. Intraformational unconformities, recording as much as 55° of bed rotation, were developed within the Kingsbury Conglomerate as fold limb rotation occurred coeval with deposition. Cross sections indicate that during this early stage of fault-related folding, an average of 16.9% shortening and 8.12 km of uplift occurred along the eastern flank of the Bighorn Mountains (end of stage I). The intermediate stage (stage II) of footwall growth syncline development involved partial truncation of the growth syncline by the advancing thrust faults and deposition of the Moncrief Conglomerate. The lower portion of the Moncrief Conglomerate was rotated basinward in the developing growth syncline. The final stage of deformation (stage III) was dominated by the thrust faulting of middle and lower Paleozoic strata eastward over steeply dipping Mesozoic strata and rotated Eocene synorogenic conglomerate. During this stage of deformation, the Moncrief Conglomerate was deformed, as the initially blind thrusts propagated into the near-surface conglomerate deposits, truncated the entire footwall syncline, and overrode the synorogenic conglomerate package. Cross sections in areas where this final stage of deformation is well developed indicate that an average of 24.1% shortening and 9.7 km of uplift had occurred along the eastern margin of the Bighorn Mountains. The caliber of synorogenic deposition in the Powder River basin was linked directly to the lithologic composition of the Bighorn Mountains. Approximately half of the 3.6-km-thick source-stratigraphic section of the eastern Bighorn Mountains was eroded prior to accumulation of conglomerate. The majority of this eroded material was derived from Mesozoic mudstone and poorly indurated sandstone that were incapable of generating coarse detritus. The first Paleogene conglomerates deposited along the east-central Bighorn Mountains, therefore, do not represent the initiation of Laramide uplift, but instead represent the exposure of coarse-clast–forming rock types from the lower half of the hanging-wall stratigraphic section (i.e., the Mississippian Madison Limestone and Ordovician Bighorn Dolomite).

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Geological Society of America Bulletin

In this paper we present results of a global resource assessment for geothermal energy within deep aquifers for direct heat utilization. Greenhouse heating, spatial heating, and spatial cooling are considered in this assessment. We derive subsurface temperatures from geophysical data and apply a volumetric heat-in-place method to improve current global geothermal resource base estimates for direct heat applications. The amount of thermal energy stored within aquifers depends on the Earth's heat flow, aquifer volume, and thermal properties. We assess the thermal energy available by estimating subsurface temperatures up to a depth of three kilometer depending on aquifer thickness. The distribution of geothermal resources is displayed in a series of maps and the depth of the minimum production temperature is used as an indicator of performance and technical feasibility. Suitable aquifers underlay 16% of the Earth's land surface and store an estimated 4·105 to 5·106 EJ that could theoretically be used for direct heat applications. Even with a conservative recovery factor of 1% and an assumed lifetime of 30 years, the annual recoverable geothermal energy is in the same order as the world final energy consumption of 363.5 EJ yr−1. Although the amount of geothermal energy stored in aquifers is vast, geothermal direct heat applications are currently underdeveloped with less than one thousandth of their technical potential used.

Geothermal energy in deep aquifers: A global assessment of the resource base for direct heat utilization

World Stress Map Database Release 2016

Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: An example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran

Intelligent approaches for prediction of compressional, shear and Stoneley wave velocities from conventional well log data: A case study from the Sarvak carbonate reservoir in the Abadan Plain (Southwestern Iran)

Mojtaba Rajabi

Papers

The World Stress Map database release 2016 : Crustal stress pattern across scales

World Stress Map Database Release 2016

Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: An example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran

Intelligent approaches for prediction of compressional, shear and Stoneley wave velocities from conventional well log data: A case study from the Sarvak carbonate reservoir in the Abadan Plain (Southwestern Iran)

The present-day state of tectonic stress in the Darling Basin, Australia: Implications for exploration and production