The surface of ice exhibits the swath phase-transition phenomena common to all materials and as such it acts an ideal test bed both theory experiment. It is readily available, transparent, optically birefringent, probing in laboratory does not require cryogenics or ultrahigh vacuum apparatus. Systematic study reveals range critical phenomena, equilibrium nonequilibrium phase-transitions, and, most relevant this review, premelting, that are traditionally studied more simply bound solids....

Frost heave is the process by which freezing of water-saturated soil causes deformation and upward thrust ground surface. We describe fundamental interactions between phase change fluid flow in partially frozen, saturated porous media (soils) that are responsible for frost heave. Water remains only frozen a medium at temperatures below C owing both to depression temperature curved boundaries interfacial premelting caused long-range intermolecular forces. show while former contributes...

Vast quantities of clathrate hydrate are found in the Arctic and marine sediments along continental margins. The structure traps enormous volumes methane gas, which is both a possible source global climate change potential energy resource. growth rate spatial distribution gas shallow influenced by variety interacting physical processes. In order to quantify these processes, we develop mathematical models for formation porous media. An analytical model derived idealized problem half‐space...

I examine the morphology of ice growth in porous media. Intermolecular forces cause premelted fluid to migrate and supply segregated (e.g., lenses) frost heave. account for net effect these microscopic interactions a homogenized model formulated terms fundamental physical properties characteristics medium that can be measured; no ad hoc parameterizations are required. Force equilibrium constraints yield rate migration toward lens boundary predict conditions under which new lenses initiated....

Slow slip and tectonic tremor in subduction zones take place at depths where there is abundant evidence for distributed shear over broad (∼10–10 3 m) composed of rocks with marked differences mechanical properties. Here we model quasi‐dynamic rupture along faults material mixtures characterized by different rate‐and‐state‐dependent frictional properties to determine the parameter regime capable producing slow an idealized zone setting. Keeping other parameters fixed, relative proportions...

The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes the factors controlling their global distribution: A fast convergence rate young buoyant lithosphere are not required to produce mega-earthquakes. We calculated curvature along major subduction zones world, showing that mega-earthquakes preferentially flat (low-curvature) interfaces. simplified analytic model demonstrates heterogeneity shear strength increases...

Frost processes more than doubled erosion rates in unglaciated terrain during the Last Glacial Maximum.

Significance A predictive understanding of landslide behavior remains elusive, to the extent that once motion is detected factors control whether will remain slow or accelerate catastrophic failure uncertain. Here, we adapt standard fault mechanics treatments present a single model captures both and motion. We test predictions using field, laboratory, remote sensing observations. The mode depends on material properties dimensions slip surface relative critical size. If exceeds this size has...

Frost heave occurs when the ground swells during freezing conditions due to growth of ice lenses in subsurface. The mechanics ice-infiltrated sediment, or frozen fringe, influences formation and evolution lenses. As fringe thickens freezing, progressive unloading can result dilation pore space new Compaction also occur as water is expelled from freezes onto We introduce a mathematical model for compaction within explore how internal variability fundamental characteristics frost cycles. At...

We examine how frictional heating drives the evolution of temperature, strength, and fracture energy during earthquake slip. For small slip distances, heat pore fluid are unable to escape shearing fault core, behavior is well approximated by simple analytical models that neglect any transport. Following large finite width shear zone compared thicknesses thermal hydrological boundary layers, approaches predicted for idealized case on a plane. To evaluate range in which predictions these two...

The ice‐till interface beneath soft‐bedded glaciers can be marked by an abrupt transition from ice layer above to unfrozen sediments below. Alternatively, the more gradual, with infiltrating underlying form a fringe that contains mixture of ice, liquid water, and sediment particles. thickness h is predicted commonly several decimeters meters in scale, implying significant transport occur when sliding occurs beneath. I adapt theories for thermodynamic mechanical balances control freezing...

The presence of a substrate can alter the equilibrium state another material near their common boundary. Examples include wetting and interfacial premelting. In latter case, temperature gradients induce spatial variations in thickness premelted film that reflect changes strength repulsion between solid. We show net thermomolecular force on macroscopic is equivalent to thermodynamic buoyancy force-proportional mass solid occupy volume enclosed by gradient.

Abstract The deformation of the ground surface that is produced by frost heave has motivated almost a century concerted laboratory, field and theoretical studies. Well before development equipment capable resolving microscopic films support liquid transport towards growing ice lenses, early investigators predicted their occurrence noted importance. Idealized experiments continue to prompt advances have been combined develop predictive models for macroscopic frost-heave characteristics are...

Abstract A fundamental goal of studying earth surface processes is to disentangle the complex web interactions among baselevel, tectonics, climate, and rock properties that generate characteristic landforms. Mechanistic geomorphic transport laws can quantitatively address this goal, but no widely accepted law for landslides exists. Here we propose a deep‐seated in weathered bedrock demonstrate its utility using two‐dimensional numerical landscape evolution model informed by study areas...

Abstract Episodic tremor and slip (ETS) along the subduction interface takes place where there is abundant evidence for elevated, near‐lithostatic pore pressures, at sufficiently great depths (30–45 km) that chemical dehydration reactions must act as their dominant source. We simulate fluid heat flow while tracking location of a vertically oriented, one‐dimensional column material it subducts through slow zone. The in transformed pressure‐dependent temperature‐dependent reaction we describe...

ABSTRACT The evolution of glaciers and ice sheets depends on processes in the subglacial environment. Shear seismicity along ice–bed interface provides a window into these processes. Such requires rapid loss strength that is typically ascribed to rate-weakening friction, i.e., decreasing friction with sliding or rate. Many experiments have investigated glacial materials at temperate conditions typical fast flowing glacier beds. To our knowledge, however, studies all found rate-strengthening...

Abstract In unglaciated terrain, the imprint of past glacial periods is difficult to discern. The topographic signature periglacial processes, such as solifluction lobes, may be erased or hidden by time and vegetation, thus their import diminished. Belowground, weathering, particularly frost cracking, have imparted a profound influence on weathering erosion rates during climate regimes. By combining mechanical frost‐weathering model with full suite Last Glacial Maximum simulations, we...

Abstract Ice stream discharge responds to a balance between gravity, basal friction and lateral drag. Appreciable viscous heating occurs in shear margins ice streams adjacent slow-moving ridges, altering the temperature-dependent viscosity distribution that connects drag marginal strain rates velocity. Warmer deforms more easily accommodates faster flow, whereas cold supplied from ridges drives advective cooling counteracts heating. Here, we present two-dimensional (three velocity...