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A. W. Rempel
University of Oregon

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Preprint content
Published: 07 July 2021
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The importance of glacier sliding has motivated a rich literature describing the thermomechanical interactions between ice, liquid water, and bed materials. Early recognition of the gradient in melting temperature across small bed obstacles led to focussed studies of regelation. An appreciation for the limits on ice deformation rates downstream of larger obstacles highlighted a role for cavitation, which has subsequently gained prominence in descriptions of subglacial drainage. Here, we show that the changes in melting temperature that accompany changes in normal stress along a sliding ice interface near cavities and other macroscopic drainage elements cause appreciable supercooling and basal mass exchange. This provides the basis of a novel formation mechanism for widely observed laminated debris-rich basal ice layers.

ACS Style

Alan Rempel; Colin R. Meyer; Kiya Riverman. Melting temperature changes during slip across subglacial cavities drive basal mass exchange. 2021, 1 .

AMA Style

Alan Rempel, Colin R. Meyer, Kiya Riverman. Melting temperature changes during slip across subglacial cavities drive basal mass exchange. . 2021; ():1.

Chicago/Turabian Style

Alan Rempel; Colin R. Meyer; Kiya Riverman. 2021. "Melting temperature changes during slip across subglacial cavities drive basal mass exchange." , no. : 1.

Article
Published: 15 June 2021
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Flow through partially frozen pores in granular media containing ice or gas hydrate plays an essential role in diverse phenomena including methane migration and frost heave. As freezing progresses, the frozen phase grows in the pore space and constricts flow paths so that the permeability decreases. Previous works have measured the relationship between permeability and volumetric fraction of the frozen phase, and various correlations have been proposed to predict permeability change in hydrology and the oil industry. However, predictions from different formulae can differ by orders of magnitude, causing great uncertainty in modeling results. We present a floating random walk method to approximate the porous flow field and estimate the effective permeability in isotropic granular media, without solving for the entire flow field in the pore space. In packed spherical particles, the method compares favorably with the Kozeny-Carman formula. We further extend this method with a probabilistic interpretation of the volumetric fraction of the frozen phase, simulate the effect of freezing in irregular pores, and predict the evolution of permeability. Our results can provide insight into the coupling between phase transitions and permeability change, which plays important roles in hydrate formation and dissociation, as well as in the thawing and freezing of permafrost and ice--bed coupling beneath glaciers.

ACS Style

Jiangzhi CheniD; Shenghua MeiiD; Alan W RempeliD. Estimating permeability of partially frozen soil using floating random walks. 2021, 1 .

AMA Style

Jiangzhi CheniD, Shenghua MeiiD, Alan W RempeliD. Estimating permeability of partially frozen soil using floating random walks. . 2021; ():1.

Chicago/Turabian Style

Jiangzhi CheniD; Shenghua MeiiD; Alan W RempeliD. 2021. "Estimating permeability of partially frozen soil using floating random walks." , no. : 1.

Research letter
Published: 16 March 2021 in Geophysical Research Letters
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In unglaciated terrain, the imprint of past glacial periods is difficult to discern. The topographic signature of periglacial processes, such as solifluction lobes, may be erased or hidden by time and vegetation, and thus their import diminished. Belowground, periglacial weathering, particularly frost cracking, may have imparted a profound influence on weathering and erosion rates during past climate regimes. By combining a mechanical frost‐weathering model with the full suite of Last Glacial Maximum climate simulations, we elucidate the meters‐deep magnitude and continent‐spanning expanse of frost weathering across unglaciated North America at ∼ 21 ka. The surprising extent of modeled frost weathering suggests, by proxy, the broad legacy of diverse periglacial processes. Complementing previous studies that championed the role of precipitation‐driven changes in Critical Zone evolution, our results imply an additional strong temperature control on surficial process efficacy across much of modern North America, both during glacial periods and modern climes.

ACS Style

J. A. Marshall; J. J. Roering; A. W. Rempel; S. L. Shafer; P. J. Bartlein. Extensive Frost Weathering Across Unglaciated North America During the Last Glacial Maximum. Geophysical Research Letters 2021, 48, 1 .

AMA Style

J. A. Marshall, J. J. Roering, A. W. Rempel, S. L. Shafer, P. J. Bartlein. Extensive Frost Weathering Across Unglaciated North America During the Last Glacial Maximum. Geophysical Research Letters. 2021; 48 (5):1.

Chicago/Turabian Style

J. A. Marshall; J. J. Roering; A. W. Rempel; S. L. Shafer; P. J. Bartlein. 2021. "Extensive Frost Weathering Across Unglaciated North America During the Last Glacial Maximum." Geophysical Research Letters 48, no. 5: 1.

Article
Published: 01 February 2021 in Journal of Glaciology
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Ice stream discharge responds to a balance between gravity, basal friction and lateral drag. Appreciable viscous heating occurs in shear margins between ice streams and adjacent slow-moving ice ridges, altering the temperature-dependent viscosity distribution that connects lateral drag to marginal strain rates and ice stream velocity. Warmer ice deforms more easily and accommodates faster flow, whereas cold ice supplied from ice ridges drives advective cooling that counteracts viscous heating. Here, we present a two-dimensional (three velocity component), steady-state model designed to explore the thermal controls on ice stream shear margins. We validate our treatment through comparison with observed velocities for Bindschadler Ice Stream and verify that calculated temperatures are consistent with results from previous studies. Sweeping through a parameter range that encompasses conditions representative of ice streams in Antarctica, we show that modeled steady-state velocity has a modest response to different choices in forcing up until temperate zones develop in the shear margins. When temperate zones are present, velocity is much more sensitive to changes in forcing. We identify key scalings for the emergence of temperate conditions in our idealized treatment that can be used to identify where thermo-mechanical feedbacks influence the evolution of the ice sheet.

ACS Style

Pierce Hunter; Colin Meyer; Brent Minchew; Marianne Haseloff; Alan Rempel. Thermal controls on ice stream shear margins. Journal of Glaciology 2021, 67, 435 -449.

AMA Style

Pierce Hunter, Colin Meyer, Brent Minchew, Marianne Haseloff, Alan Rempel. Thermal controls on ice stream shear margins. Journal of Glaciology. 2021; 67 (263):435-449.

Chicago/Turabian Style

Pierce Hunter; Colin Meyer; Brent Minchew; Marianne Haseloff; Alan Rempel. 2021. "Thermal controls on ice stream shear margins." Journal of Glaciology 67, no. 263: 435-449.

Journal article
Published: 23 October 2020 in Journal of Advances in Modeling Earth Systems
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Freezing in porous media is associated with a host of dynamic phenomena that stem from the presence and mobility of premelted liquid at subzero temperatures. Accurate assessments of the progressive liquid‐‐‐ice phase transition is required for predictive models of frost damage, glacier‐‐‐till coupling, and many other cold regions processes, as well as for evaluating the capacity for water storage in near‐surface extraterrestrial environments. We use a Monte Carlo approach to sample the pore space in a synthetic 3D packing of poly‐dispersed spherical particles, and evaluate local geometrical constraints that allow us to assess changes in the relative proportions of pore fluid and ice. By approximating the phase boundary geometry in fine‐grained pores while considering both the curvature of the liquid‐‐‐ice interface and wetting interactions with matrix particles, our model predicts changes in phase equilibrium in granular media over a broad temperature range, where present accounting for the colligative effects of chloride and perchlorate solutes. In addition to formulating the constitutive behavior needed to better understand properties and processes in frozen soils, our results also provide insight into other aspects of phase equilibria in porous media, including the formation of methane hydrates in permafrost and marine sediments, and the partitioning between liquid water and vapor in the vadose zone.

ACS Style

Jiangzhi Chen; Shenghua Mei; Julia T. Irizarry; Alan W. Rempel. A Monte Carlo Approach to Approximating the Effects of Pore Geometry on the Phase Behavior of Soil Freezing. Journal of Advances in Modeling Earth Systems 2020, 12, 1 .

AMA Style

Jiangzhi Chen, Shenghua Mei, Julia T. Irizarry, Alan W. Rempel. A Monte Carlo Approach to Approximating the Effects of Pore Geometry on the Phase Behavior of Soil Freezing. Journal of Advances in Modeling Earth Systems. 2020; 12 (10):1.

Chicago/Turabian Style

Jiangzhi Chen; Shenghua Mei; Julia T. Irizarry; Alan W. Rempel. 2020. "A Monte Carlo Approach to Approximating the Effects of Pore Geometry on the Phase Behavior of Soil Freezing." Journal of Advances in Modeling Earth Systems 12, no. 10: 1.

Article
Published: 10 August 2020
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At thermodynamic equilibrium, gas hydrates are arranged in the pore space of host sediments to minimize free energy, including the energy of interfaces. Through an analogy with frozen soil, we show that free energy minimization in hydrate-bearing sediments requires the presence of a water film of finite thickness separating hydrate from the sediment grains. The thickness of this premelted layer may be predicted from a balance of intermolecular forces acting across the film. Temperature and porewater salinity are the strongest determiners of premelted layer thickness. We show that, at temperatures and salinities typical of the subsurface or commonly used in laboratory investigations of hydrate-bearing porous media, the premelted layer varies in thickness from microns to sub-nanometer, with thicker layers corresponding to lower salinities and/or higher temperatures. Balance of intermolecular forces predicts that hydrate will be completely nonwetting on hydrophilic surfaces, including silica. We also show that flow through premelted layers may be a significant component of the permeability of hydrate-bearing sediments, particularly at moderate to high hydrate saturation (>60%); and that the electrical conductivity of the premelted layer at needs to be accounted for in assessments of hydrate abundance from subsurface resistivity logs. This work highlights the importance of considering premelted layers when predicting the effects of hydrate on sediment properties.

ACS Style

Hugh DaigleiD; Alan W Rempel. Water films in hydrate-bearing sediments. 2020, 1 .

AMA Style

Hugh DaigleiD, Alan W Rempel. Water films in hydrate-bearing sediments. . 2020; ():1.

Chicago/Turabian Style

Hugh DaigleiD; Alan W Rempel. 2020. "Water films in hydrate-bearing sediments." , no. : 1.

Article
Published: 12 March 2020
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Freezing in porous media is associated with a host of dynamic phenomena that stem from the presence and mobility of premelted liquid at subzero temperatures. Accurate assessments of the progressive liquid---ice phase transition is required for predictive models of frost damage, glacier---till coupling, and many other cold regions processes, as well as for evaluating the capacity for water storage in near-surface extraterrestrial environments. We use a Monte Carlo approach to sample the pore space in a synthetic 3D packing of poly-dispersed spherical particles, and evaluate local geometrical constraints that allow us to assess changes in the relative proportions of pore fluid and ice. By approximating the phase boundary geometry in fine-grained pores while considering both the curvature of the liquid---ice interface and wetting interactions with matrix particles, our model predicts changes in phase equilibrium in granular media over a broad temperature range, where present accounting for the colligative effects of chloride and perchlorate solutes. In addition to formulating the constitutive behavior needed to better understand properties and processes in frozen soils, our results also provide insight into other aspects of phase equilibria in porous media, including the formation of methane hydrates in permafrost and marine sediments, and the partitioning between liquid water and vapor in the vadose zone.

ACS Style

Jiangzhi Chen; Shenghua Mei; Julia T Irizarry; Alan W Rempel. A Monte Carlo approach to approximating the effects of pore geometry on the phase behavior of soil freezing. 2020, 1 .

AMA Style

Jiangzhi Chen, Shenghua Mei, Julia T Irizarry, Alan W Rempel. A Monte Carlo approach to approximating the effects of pore geometry on the phase behavior of soil freezing. . 2020; ():1.

Chicago/Turabian Style

Jiangzhi Chen; Shenghua Mei; Julia T Irizarry; Alan W Rempel. 2020. "A Monte Carlo approach to approximating the effects of pore geometry on the phase behavior of soil freezing." , no. : 1.

Journal article
Published: 01 October 2019 in Earth and Planetary Science Letters
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ACS Style

Colin R. Meyer; Alexander A. Robel; Alan Rempel. Frozen fringe explains sediment freeze-on during Heinrich events. Earth and Planetary Science Letters 2019, 524, 1 .

AMA Style

Colin R. Meyer, Alexander A. Robel, Alan Rempel. Frozen fringe explains sediment freeze-on during Heinrich events. Earth and Planetary Science Letters. 2019; 524 ():1.

Chicago/Turabian Style

Colin R. Meyer; Alexander A. Robel; Alan Rempel. 2019. "Frozen fringe explains sediment freeze-on during Heinrich events." Earth and Planetary Science Letters 524, no. : 1.

Preprint content
Published: 16 August 2019
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ACS Style

Colin Meyer; Alexander Robel; Alan Rempel. Frozen fringe explains sediment freeze-on during Heinrich events. 2019, 1 .

AMA Style

Colin Meyer, Alexander Robel, Alan Rempel. Frozen fringe explains sediment freeze-on during Heinrich events. . 2019; ():1.

Chicago/Turabian Style

Colin Meyer; Alexander Robel; Alan Rempel. 2019. "Frozen fringe explains sediment freeze-on during Heinrich events." , no. : 1.

Journal article
Published: 26 July 2019 in Geosciences
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Earth-based building materials are increasingly valued in green design for their low embodied energy, humidity-buffering ability, and thermal stability. These materials perform well in warm dry climates, but greater understanding of long-term durability is needed for successful adoption in colder and/or wetter climates. The presence of stabilizers dramatically improves resistance to surface erosion from wind and rain, compared to unstabilized adobe and cob counterparts, and the influences of soil composition, fiber type, and diverse binders, on rain and wind surface erosion have been investigated in detail. Frost and freeze-thaw resistance, however, have been less well-studied, despite strong interest in stabilized earth materials in northern North America, Europe, and Asia. In particular, recent studies have relied on a widespread misunderstanding of the mechanism by which frost damage occurs in porous materials that will impede efforts to create valid models for material design and improvement. In addition, the influence of radiative thermal stresses on wall surfaces has been overlooked in favor of focus on ambient air temperatures. Here, we apply contemporary understanding of cracking by segregated ice growth to develop a macroscopic damage index that enables comparison between performance of different materials subject to different weather patterns. An examination of predicted damage patterns for two stabilized earth building materials and two conventional materials in twelve cities over two time periods reveals the dominant factors that govern frost vulnerability. We find that the frost resilience of earth building materials is comparable to that of the conventional materials we examined, and that assessments that neglect expected variations in water content by assuming full saturation are likely to yield misleading results. Over recent years, increased winter temperatures in several cities we examined predict reduced material vulnerability to frost damage, but we also find that accompanying increases in humidity levels have made some cities much more vulnerable.

ACS Style

Alan W. Rempel; Alexandra R. Rempel. Frost Resilience of Stabilized Earth Building Materials. Geosciences 2019, 9, 328 .

AMA Style

Alan W. Rempel, Alexandra R. Rempel. Frost Resilience of Stabilized Earth Building Materials. Geosciences. 2019; 9 (8):328.

Chicago/Turabian Style

Alan W. Rempel; Alexandra R. Rempel. 2019. "Frost Resilience of Stabilized Earth Building Materials." Geosciences 9, no. 8: 328.

Journal article
Published: 23 May 2019 in Journal of Glaciology
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Glacier sliding over small obstacles relies on melting on their upstream sides and refreezing downstream. Previous treatments have appealed to ‘pressure melting’ as the cause of the spatial variations in melting temperature that drive thisregelationprocess. However, we show that typical liquid pressure variations across small obstacles are negligible and therefore variations in ice pressure closely approximate variations in effective stress. For a given change in effective stress, the equilibrium melting temperature changes by an order of magnitude more than when the pressure of ice and liquid both change by an equal amount. In consequence, the temperature gradients that drive heat flow across small obstacles are larger than previously recognized and the rate of regelation is faster. Under typical conditions, the transition wavelength at which ice deformation and regelation contribute equally is of m-scale, several times longer than previous predictions, which have been reported to underestimate field inferences.

ACS Style

Alan W. Rempel; Colin R. Meyer. Premelting increases the rate of regelation by an order of magnitude. Journal of Glaciology 2019, 65, 518 -521.

AMA Style

Alan W. Rempel, Colin R. Meyer. Premelting increases the rate of regelation by an order of magnitude. Journal of Glaciology. 2019; 65 (251):518-521.

Chicago/Turabian Style

Alan W. Rempel; Colin R. Meyer. 2019. "Premelting increases the rate of regelation by an order of magnitude." Journal of Glaciology 65, no. 251: 518-521.

Journal article
Published: 11 April 2019 in Journal of Volcanology and Geothermal Research
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Large-scale silicic volcanism has occurred frequently in regions mantled by thin to very thick glacial ice cover, with several notable examples during the Pleistocene (Yellowstone, Long Valley, Iceland), including high altitude activity during the most recent glacial (e.g. Cascades, Kamchatka, Andes). More ancient caldera-forming events must have occurred during episodes of long-lasting (ca. 10–50 Ma) snowball Earth glaciation in the Neo- and Paleo-proterozoic, and many extraterrestrial eruptions on other ice-covered planets and moons are also of this general form. Recent work suggests that the process of caldera collapse typically lasts hours to weeks, during which the caldera floor drops by several hundreds to thousands of meters and is covered by hot tephra. With this scenario in mind, we investigate glaciovolcanic interactions immediately following the deposition of thick, hot ash layers on ice and consider the destiny of buried tephra and melting ice inside calderas. Our focus is drawn in particular to the post-emplacement hydration of volcanic glasses, with the goal of assessing whether the δ18O, δ17O and δD signatures in ancient deposits might be used to infer the syn-eruptive climate state. Scaling arguments, augmented by an idealized 1D model, suggest that ice should often survive for several decades or centuries as an active meltwater source to the overlying cooling intracaldera tuff. As liberated glacial water (both liquid and vapor) infiltrates and interacts with the tephra layer, volcanic glasses can become fully hydrated to water saturations of several wt.%. Our theoretical treatment is motivated in part by our recent measurements of lower than modern δD values in products of several Pleistocene eruptions in the western U.S. occupying regions that were likely glaciated immediately prior to the emplacement of volcanic products. We discuss how δ18O–δD and δ18O–Δ17O systematics can be used to recognize syn-glacially hydrated intracaldera tephra, potentially including samples that have been buried, altered and subsequently exposed either by fault uplift and erosional exposure or by drilling operations, such as those being performed currently in the Central Snake River Plain near Yellowstone.

ACS Style

Alan W. Rempel; Ilya N. Bindeman. A model for the development of stable isotopic water signatures of tephra deposited on ice following subglacial caldera collapse. Journal of Volcanology and Geothermal Research 2019, 377, 131 -145.

AMA Style

Alan W. Rempel, Ilya N. Bindeman. A model for the development of stable isotopic water signatures of tephra deposited on ice following subglacial caldera collapse. Journal of Volcanology and Geothermal Research. 2019; 377 ():131-145.

Chicago/Turabian Style

Alan W. Rempel; Ilya N. Bindeman. 2019. "A model for the development of stable isotopic water signatures of tephra deposited on ice following subglacial caldera collapse." Journal of Volcanology and Geothermal Research 377, no. : 131-145.

Comment
Published: 07 February 2019 in Science
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Stearns and van der Veen (Reports, 20 July 2018, p. 273) conclude that fast glacier sliding is independent of basal drag (friction), even where drag balances most of the driving stress. This conclusion raises fundamental physical issues, the most striking of which is that sliding velocity would be independent of stresses imparted through the ice column, including gravitational driving stress.

ACS Style

Brent M. Minchew; Colin R. Meyer; Samuel S. Pegler; Bradley P. Lipovsky; Alan W. Rempel; G. Hilmar Gudmundsson; Neal R. Iverson. Comment on “Friction at the bed does not control fast glacier flow”. Science 2019, 363, eaau6055 .

AMA Style

Brent M. Minchew, Colin R. Meyer, Samuel S. Pegler, Bradley P. Lipovsky, Alan W. Rempel, G. Hilmar Gudmundsson, Neal R. Iverson. Comment on “Friction at the bed does not control fast glacier flow”. Science. 2019; 363 (6427):eaau6055.

Chicago/Turabian Style

Brent M. Minchew; Colin R. Meyer; Samuel S. Pegler; Bradley P. Lipovsky; Alan W. Rempel; G. Hilmar Gudmundsson; Neal R. Iverson. 2019. "Comment on “Friction at the bed does not control fast glacier flow”." Science 363, no. 6427: eaau6055.

Journal article
Published: 07 July 2018 in Journal of Geophysical Research: Solid Earth
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The occurrence of methane hydrate in marine reservoirs often correlates with the physical properties of the host sediments. High hydrate saturations (> 60% of the pore volume) found in association with coarser‐grained strata have been attributed to both enhanced advective transport through more permeable sediment layers and to perturbations in phase equilibrium related to pore‐space geometry that results in increased diffusive transport. To assess the relative importance of these mechanism in controlling hydrate occurrence, we develop a 1D model for hydrate growth along dipping, coarse‐grained layers embedded in a fine‐grained sediment package. We explicitly account for pore‐size effects on methane solubility and permeability‐driven variations in fluid flux. We show how the vertical distribution of hydrate varies in response to changes in grain size and rates of fluid advection, sedimentation, and in situ methane production. We then use our model to simulate centimeter‐scale variations in hydrate saturation observed at Walker Ridge Block 313, Hole H in the Gulf of Mexico. We find that the largest concentrations of hydrate are controlled by diffusion while increased advective methane supply favors more distributed growth throughout high‐permeability regions. Our results hold promise for using well‐log derived estimates of hydrate saturation to infer sediment properties and the sources and rates of methane supply during reservoir emplacement.

ACS Style

Brandon P. VanderBeek; Alan W. Rempel. On the Importance of Advective Versus Diffusive Transport in Controlling the Distribution of Methane Hydrate in Heterogeneous Marine Sediments. Journal of Geophysical Research: Solid Earth 2018, 123, 5394 -5411.

AMA Style

Brandon P. VanderBeek, Alan W. Rempel. On the Importance of Advective Versus Diffusive Transport in Controlling the Distribution of Methane Hydrate in Heterogeneous Marine Sediments. Journal of Geophysical Research: Solid Earth. 2018; 123 (7):5394-5411.

Chicago/Turabian Style

Brandon P. VanderBeek; Alan W. Rempel. 2018. "On the Importance of Advective Versus Diffusive Transport in Controlling the Distribution of Methane Hydrate in Heterogeneous Marine Sediments." Journal of Geophysical Research: Solid Earth 123, no. 7: 5394-5411.

Article
Published: 18 November 2017 in Geophysical Research Letters
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Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.

ACS Style

Quentin Bletery; Amanda M. Thomas; Alan W. Rempel; Jeanne L. Hardebeck. Imaging Shear Strength Along Subduction Faults. Geophysical Research Letters 2017, 44, 1 .

AMA Style

Quentin Bletery, Amanda M. Thomas, Alan W. Rempel, Jeanne L. Hardebeck. Imaging Shear Strength Along Subduction Faults. Geophysical Research Letters. 2017; 44 (22):1.

Chicago/Turabian Style

Quentin Bletery; Amanda M. Thomas; Alan W. Rempel; Jeanne L. Hardebeck. 2017. "Imaging Shear Strength Along Subduction Faults." Geophysical Research Letters 44, no. 22: 1.

Journal article
Published: 31 August 2016 in Geosciences
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The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties) on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding challenges the perception of limited evaporative cooling resources in arid climates and greatly expands the applicability of evaporative cooling in contemporary buildings to water-stressed regions.

ACS Style

Alexandra R. Rempel; Alan W. Rempel. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials. Geosciences 2016, 6, 38 .

AMA Style

Alexandra R. Rempel, Alan W. Rempel. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials. Geosciences. 2016; 6 (3):38.

Chicago/Turabian Style

Alexandra R. Rempel; Alan W. Rempel. 2016. "Intrinsic Evaporative Cooling by Hygroscopic Earth Materials." Geosciences 6, no. 3: 38.

Research article
Published: 27 November 2015 in Science Advances
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Understanding climatic influences on the rates and mechanisms of landscape erosion is an unresolved problem in Earth science that is important for quantifying soil formation rates, sediment and solute fluxes to oceans, and atmospheric CO2regulation by silicate weathering. Glaciated landscapes record the erosional legacy of glacial intervals through moraine deposits and U-shaped valleys, whereas more widespread unglaciated hillslopes and rivers lack obvious climate signatures, hampering mechanistic theory for how climate sets fluxes and form. Today, periglacial processes in high-elevation settings promote vigorous bedrock-to-regolith conversion and regolith transport, but the extent to which frost processes shaped vast swaths of low- to moderate-elevation terrain during past climate regimes is not well established. By combining a mechanistic frost weathering model with a regional Last Glacial Maximum (LGM) climate reconstruction derived from a paleo-Earth System Model, paleovegetation data, and a paleoerosion archive, we propose that frost-driven sediment production was pervasive during the LGM in our unglaciated Pacific Northwest study site, coincident with a 2.5 times increase in erosion relative to modern rates. Our findings provide a novel framework to quantify how climate modulates sediment production over glacial-interglacial cycles in mid-latitude unglaciated terrain.

ACS Style

Jill A. Marshall; Joshua J. Roering; Patrick J. Bartlein; Daniel G. Gavin; Darryl E. Granger; Alan W. Rempel; Sarah J. Praskievicz; Tristram C. Hales. Frost for the trees: Did climate increase erosion in unglaciated landscapes during the late Pleistocene? Science Advances 2015, 1, e1500715 .

AMA Style

Jill A. Marshall, Joshua J. Roering, Patrick J. Bartlein, Daniel G. Gavin, Darryl E. Granger, Alan W. Rempel, Sarah J. Praskievicz, Tristram C. Hales. Frost for the trees: Did climate increase erosion in unglaciated landscapes during the late Pleistocene? Science Advances. 2015; 1 (10):e1500715.

Chicago/Turabian Style

Jill A. Marshall; Joshua J. Roering; Patrick J. Bartlein; Daniel G. Gavin; Darryl E. Granger; Alan W. Rempel; Sarah J. Praskievicz; Tristram C. Hales. 2015. "Frost for the trees: Did climate increase erosion in unglaciated landscapes during the late Pleistocene?" Science Advances 1, no. 10: e1500715.

Journal article
Published: 28 April 2015 in Pure and Applied Geophysics
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ACS Style

Alan W. Rempel. Book Review. Pure and Applied Geophysics 2015, 172, 2937 -2938.

AMA Style

Alan W. Rempel. Book Review. Pure and Applied Geophysics. 2015; 172 (10):2937-2938.

Chicago/Turabian Style

Alan W. Rempel. 2015. "Book Review." Pure and Applied Geophysics 172, no. 10: 2937-2938.

Conference paper
Published: 18 June 2013 in Poromechanics V
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Deformation that results from crystallization in material pores commonly requires the supply of constituents through a fluid phase. With frost damage, the gradients in chemical potential necessary to drive transport are often caused by gradients in temperature. For submarine hydrates, compositional diffusion of methane is typically aligned with solubility gradients produced by the background temperature and pressure fields. Here, we show that under nearly isothermal and isobaric conditions, changes in the distribution of pore sizes can instead be the dominant cause of the potential gradients responsible for constituent supply. We illustrate the consequences and character of isothermal frost damage using the results from simple laboratory experiments. Field observations of hydrate anomalies in a submarine sand layer motivate comparison with a model for the diffusive growth of such deposits. These simple examples motivate further examination of the role of pore space heterogeneities in the development of other mineral systems.

ACS Style

Alan W. Rempel; Laura J. Van Alst. Potential Gradients Produced by Pore-Space Heterogeneities: Application to Isothermal Frost Damage and Submarine Hydrate Anomalies. Poromechanics V 2013, 1 .

AMA Style

Alan W. Rempel, Laura J. Van Alst. Potential Gradients Produced by Pore-Space Heterogeneities: Application to Isothermal Frost Damage and Submarine Hydrate Anomalies. Poromechanics V. 2013; ():1.

Chicago/Turabian Style

Alan W. Rempel; Laura J. Van Alst. 2013. "Potential Gradients Produced by Pore-Space Heterogeneities: Application to Isothermal Frost Damage and Submarine Hydrate Anomalies." Poromechanics V , no. : 1.

Proceedings article
Published: 18 June 2013 in Poromechanics V
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Slow slip and tremor in subduction zones take place where there is abundant evidence for elevated, near lithostatic pore pressures along the plate interface. In Japan and Cascadia, these depths (~30-45 km) are such that the main source of fluids must be attributed to chemical dehydration reactions. Here, we model the condsolidation of low porosity (~5%) oceanic crust subducting through the slow slip and tremor zone in the presence of pressure and temperature-dependent dehydration reactions. We use parameters consistent with the geometry of the Cascadia subduction margin and bulk rock permeabilities in the range 10-25 ≤ k0 ≤ 10-21 m2. The generation of pore pressures in excess of lithostatic values, and hence negative effective stresses, is a robust feature of our simulations. These results indicate that hydraulic fracturing likely occurs at relevant depths, and have implications for the generation mechanism of non-volcanic tremor in subduction zones.

ACS Style

Robert M. Skarbek; Alan W. Rempel. Thermal Consolidation with Chemical Dehydration Reactions: Pore Pressure Generation in the Slow Slip Region of Subduction Zones. Poromechanics V 2013, 1 .

AMA Style

Robert M. Skarbek, Alan W. Rempel. Thermal Consolidation with Chemical Dehydration Reactions: Pore Pressure Generation in the Slow Slip Region of Subduction Zones. Poromechanics V. 2013; ():1.

Chicago/Turabian Style

Robert M. Skarbek; Alan W. Rempel. 2013. "Thermal Consolidation with Chemical Dehydration Reactions: Pore Pressure Generation in the Slow Slip Region of Subduction Zones." Poromechanics V , no. : 1.