The Failure Forecast Method (FFM) was introduced as an empirical model for forecasting catastrophic material failures related to natural hazards, such as landslides and volcanic eruptions, with mixed success. During the 2018 eruption of Kilauea volcano, Hawaii, the draining of the summit magma reservoir into the Lower East Rift Zone resulted in the formation of a new caldera at the summit. I tested

Clumped isotopes thermometry (Δ47) and U-Pb dating of carbonates have been used to elucidate the temperature-time conditions of 10 tectonic calcite veins in the hanging wall of the South Pyrenean Frontal Thrust (Spain), the youngest thrust unit in the south-central Pyrenees. The Δ47 values indicate precipitation temperatures below ∼90 °C, in agreement with fluid inclusion analyses. 6 veins have been

Cataclasis is a first-order mechanism shaping fault-rock development in the brittle crust. The most accepted model for cataclasis is “constrained comminution” which predicts a power-law distribution of particle size described by the fractal dimension, D. In this paper, we statistically test for the presence of power-law scaling in 61 naturally and experimentally deformed fault rocks, thereby assessing

Continental weathering is a fundamental process in releasing magnesium (Mg) from crystalline rocks to the hydrosphere and biosphere. Mg isotopes can be substantially mobilized, re-distributed, and fractionated during weathering, and therefore can be used as a powerful tool to trace the biogeochemical cycle of Mg. Causes of significant Mg isotopic fractionation and behaviors during silicate weathering

The advection of seawater into the sediments deposited on the margins of Great Bahama Bank has been demonstrated to play in important role in ventilating the uppermost sediments, as well as supplying elements for diagenetic reactions deeper within the platform. Here, we implement a numerical model to calculate the rate of fluid advection at ODP Site 1003, using calcium isotopes as a tracer for fluid

Thermal and compositional convection in Earth's core are thought to be the main power sources driving geodynamo. The viability and strength of thermally and compositionally-driven convection over Earth's history depend on the adiabatic heat flow across the core-mantle boundary (CMB) which is governed by the thermal conductivity of a constituent Fe-Ni-light element alloy at the pressure-temperature

Variations in elastic wave velocity and amplitude prior to failure have been documented in laboratory experiments as well as in a limited number of crustal earthquakes. These variations have generally been attributed to fault zone healing, changes in crack density, or pore fluid effects modulated dilatation or fault slip. However, the relationships between amplitude and velocity variations during the

Nitrogen is a major and essential component of Earth's atmosphere, yet relative to other volatile elements, there are relatively few experimental constraints on the pathways by which nitrogen cycles between Earth's interior and exterior. We report mineral-melt and mineral-fluid partitioning experiments to constrain the behavior of nitrogen during slab dehydration and sediment melting processes. Experiments

The Bear Valley Intrusive Suite (BVIS) in the Southernmost Sierra Nevada exposes a trans-crustal magmatic system that spans emplacement pressures from 3-10 kbars, and was emplaced at all crustal levels between 100.1-101.5 Ma. As such, it represents an unparalleled snapshot of magmatic processes within continental arc crust. In this study we present new field observations combined with whole rock geochemistry

Megathrust ruptures and the ensuing postseismic deformation cause stress changes that may induce seismicity on upper plate crustal faults far from the coseismic rupture area. In this study, we analyze seismic swarms that occurred in the north Ecuador area of Esmeraldas, beginning two months after the 2016 Mw 7.8 Pedernales, Ecuador megathrust earthquake. The Esmeraldas region is 70 km from the Pedernales

We report results from multi-anvil (MA) and laser-heated diamond anvil cell (LH-DAC) experiments that synthesize high-pressure phases, including bridgmanite, ferropericlase, stishovite, and ultramafic liquid, in the presence of an argon-rich fluid. The goal of the experiments is to constrain the equilibrium distribution of argon in magma ocean environments. Argon concentrations in LH-DAC experiments

Basalts from the East Pacific Rise (EPR), Siqueiros transform zone and Mid-Atlantic Ridge (MAR) area have been analyzed for the platinum-group elements (PGE) and a wide range of incompatible elements. The low PGE content of the most primitive mid-ocean ridge basalts (MORB) suggests that they leave the mantle sulfide-saturated but become sulfide under-saturated, as a consequence of decompression, during

A number of possible hypotheses have been proposed to explain the origin of mid-lithospheric discontinuities (MLDs), typically characterized by ∼2-6% reductions in seismic shear wave velocity (VS) at depths of 60 km to ∼150 km in the cratonic sub-continental lithospheric mantle (SCLM). One such hypothesis is the presence of low-shear wave velocity, hydrous and carbonate mineral phases. Although, the

The measurement of methane clumped isotopologues (Δ13CH3D and Δ12CH2D2) allows exploring isotope bond ordering within methane molecules, and may reveal equilibrium temperatures. Whether such temperature reflects the formation or re-equilibration temperature of the methane is not well understood, but would have critical implications for the use of methane clumped isotopologues as geo-thermometers. Here

The α↔β phase transition in quartz is accompanied by relatively large, anisotropic changes in cell volume and elastic stiffness properties. Because quartz is among the most abundant minerals in Earth's continental crust, these changes have the potential to profoundly influence the state of stress, mechanical properties, metamorphism, and rheology of crustal rocks. Laboratory experiments confirm strongly

Carbonate zinc (Zn) isotopes have increasingly been used to track changes in seawater Zn isotopic composition. A large body of recent work, in particular studies conducted under the GEOTRACES program, have added significantly to our knowledge of how Zn behaves in the water column. However, our understanding of how water-column Zn isotopic signals become incorporated into carbonate sediments is at a

Caldera footprints and erupted magma volumes provide a unique constraint on vertical dimensions of upper crustal magma reservoirs that feed explosive silicic eruptions. Here we define a Vertical Separation (VS) ratio in which we compare the geometric vertical extent with the range of depths indicated petrologically by melt inclusion water and CO2 saturation pressures for fifteen caldera-forming eruptions

Numerical modeling coupling erosion with crustal deformation predicts that development of an orographic rain shadow may explain the asymmetric exhumation of convergent plate boundary orogens. This prediction is consistent with observations from the Southern Alps of New Zealand, where bedrock thermochronology indicates crustal exhumation has been concentrated along the wet, windward side of the mountains

Subduction of oceanic lithosphere is now occurring beneath the Aegean and central Caspian Seas, and beneath the Indo-Burman Ranges in NE India, generating zones of earthquakes that reach depths of more than 150 km. Their existence is surprising. In general, where the temperature of the mantle part of the oceanic lithosphere can be estimated, earthquakes are confined to material whose temperature is

Non-volcanic tremor (NVT) and episodic slow slip events (SSEs) have been observed below the seismogenic zone of relatively warm subduction zones for the past 20 years. Geophysical and geologic observations show that this portion of the subduction interface is fluid-rich, and many models for these slip behaviors necessitate high pore fluid pressures. However, whether these fluids are sourced from local

The dihedral angle (θ) between olivine and aqueous fluid is a critical parameter in identifying the grain-scale fluid connectivity which controls the distribution and migration of aqueous fluids in subduction zones besides physical properties of mantle wedges. Recent magnetotelluric observations have suggested the occurrence of significant fluid circulation in deep fore-arc regions, which can be explained

Deccan Traps (DT) volcanism and the Chicxulub bolide impact have been suggested as potential triggers of the Cretaceous–Paleogene boundary (KPB) mass extinction. Recently published geochronology has established a timeline for the main basaltic sequence of the DT, showing that the majority of eruptions occurred within 700–800 kyr spanning the KPB. Silicic to alkaline magmatism linked to the DT, spatially

We investigate seismic discontinuities in the mantle transition zone (MTZ) by analyzing SS precursors recorded at global seismic stations. Our observations confirm the global existence of the 520-km discontinuity. Although substantial regional depth variations in the 520-km discontinuity are generally correlated with temperature in the mid-MTZ, they cannot be fully explained by the Clapeyron slope

The process of meteorological lightning-induced modification of coherent volcanic rocks is examined by geochemical, textural, and experimental analysis of fulgurites from South Sister volcano, Oregon Cascades, USA. Lightning's effects on volcanic target rocks was simulated with an arc-welding device in order to reproduce the geochemical and textural features of natural fulgurites and to constrain temperatures

The source region of basalts in the mantle is chemically and lithologically heterogeneous. During decompression melting of a spatially distributed and lithologically heterogeneous mantle, mineral modes of distinct mantle sources vary continuously, resulting in spatial and temporal variations in the bulk partition coefficient of a trace element in different lithologies in the melting column, which in

Crystallization timescales in subvolcanic systems and the consequences of interaction between ascending magmas and gases remain largely unconstrained, as do links between these processes and monitoring signals at restless volcanoes. We apply diffusion chronometry to radially-oriented plagioclase and associated olivine in a glomerocryst from Tolbachik volcano (Kamchatka, Russia) to elucidate such processes

The two branches of the East African Rift System (EARS) are believed to have initiated diachronously. However, a growing body of work continues to suggest the onset of rifting in the Western Branch occurred in the Paleogene, coeval to the Eastern Branch. Due to a lack of pre-Miocene stratigraphy, attempts to resolve the geological history of the Western Branch must study the uplift and erosional histories

Determining the source of planetary water from the hydrogen isotope compositions of crustal samples is complicated by the overprinting of isotopically diverse source material by geologic and atmospheric processes. As Mars has no plate tectonics, crustal material, which may have isotopically exchanged with the martian atmosphere, is not recycled into the mantle keeping the water reservoirs in the mantle

The latest Proterozoic tectonic evolution of Avalonia, one of the largest peri-Gondwanan terranes, bears on the issue of Gondwana amalgamation during the transition from Rodinia to Pangea. New paleomagnetic results from mid–late Ediacaran strata in the Newfoundland sector of Avalonia confirm substantial apparent motion of that terrane between ca. 590 and 560 Ma, consistent with a true polar wander

Detrital apatite deposited before, during and after Grampian-Taconic arc accretion in western Ireland reveals dramatic changes in source provenance and provides a detailed detrital petrochronological record of a Wilson Cycle sited on the Laurentian margin. These determinations are made possible by recent improvements in source rock type diagnosis by apatite trace element analysis. In addition, by interrogating

Porphyry copper deposits are formed by fluids released from felsic magmatic intrusions of batholithic dimensions, which are inferred to have been incrementally built up by a series of sill injections. The growth of the magma chamber is primarily controlled by the volumetric injection rate from deeper-seated magma reservoirs, but can further be influenced by hydrothermal convection and fluid release

Oxidative weathering of continental rocks is the major source of redox-sensitive elements to the ocean. The timing for the initiation of oxidative weathering remains strongly debated. Here we report new δ238U data for the authigenic component of well-preserved ca. 3.07–2.90 Ga marine and lacustrine shales from the Mozaan and Dominion groups of the Kaapvaal Craton, South Africa. The δ238Uauth values

The diffusion of hydrogen in natural hydrothermal quartz crystals was studied between 657–956 °C at atmospheric pressure and various oxygen fugacity (fO2) conditions. Single crystals of OH-bearing quartz were dehydrated in the presence of Li or Na-enriched powders to induce Li-H or Na-H exchange, with the resulting diffusion profiles measured by both Fourier transform infrared (FTIR) spectroscopy and

Lava dome formation is a common process at stratovolcanoes involving the shallow intrusion or extrusion of viscous lava and may lead to the rise of spines. Spines are protrusions observed to extrude episodically during lava dome growth, yet the structural and mechanical factors controlling their formation are only partially understood. Here, we provide new, detailed insight into lava dome growth and

We explore the capability of interconnected sills to transport magma in the shallow crust, as well as the effect of simultaneous and temporally separated multiple magma emplacement on deformation pattern. We analyze this process through analogue models run with synchronous or diachronous magma injection from different, aligned inlets. Experimental results show that the position and activation in time

Modern style plate tectonics is characterized by one-sided subduction and continental margin basalt-andesite-dacite-rhyolite (BADR) magmatism, whereas continental magmatic rocks in the Archaean record had tonalite-trondjhemite-granodiorite (TTG) composition. Their main difference is the absence (in the modern style) and the presence (in the ancient style) of abundant juvenile, basalt-derived felsic

The crustal structure of the overriding plate in a subduction zone can have significant effects on subduction processes and therefore hazard along the margin. To investigate the controls of the overriding North American crust on the Cascadia Subduction Zone, a dense, trench perpendicular line of nodal seismometers was deployed in the Central Oregon forearc. The location of this deployment was chosen

An important measure of the strength of a mantle plume is its buoyancy flux B, defined as the integral over a horizontal plane of the product of the vertical velocity and the density deficit within the plume. In the case of the Iceland plume, which currently rises directly beneath the mid-Atlantic ridge, published estimates of B cover a range of a factor of 37. To reconcile these diverse estimates

The initial cooling stage and crystallization of a magma ocean were significantly affected by the thermodynamics and viscosity of iron silicate liquid. Here, we use first-principles molecular dynamics based on density functional theory plus the Hubbard U method to study the structures, thermodynamics and viscosities of Fe2SiO4 liquid at 3000–6000 K under pressure conditions spanning the entire mantle

Understanding the evolution of ocean basins is critical for studies in global plate tectonics, mantle dynamics, and sea-level through time, and relies on identifiable tectonic plate boundaries. The evolution of the 2.5 million km2 Amerasia Basin in the Arctic Ocean remains largely unsettled due to widespread overprint by the Cretaceous High-Arctic Large Igneous Province. Traces of an extinct, but deeply

In their Comment to Resentini et al. (2020), Mesalles et al. pointed out supposed fundamental inaccuracies concerning analytical aspects and the tectonic interpretation of fission-track data. This would invalidate the main conclusions of our study. Here we demonstrate that their criticism is ill-founded.

Understanding how tectonics, climate and lithology interact to control fluvial erosion is complicated because these factors are spatially-variable and they may not be well-represented by mean values. We address these complications using eight new and 54 published 10Be catchment-wide fluvial erosion rates from the south-central Andes. We assess how tectonics, climate, lithology, and topography control

Variations in the abundances of moderately volatile elements (MVE) are one of the most fundamental geochemical differences between the terrestrial planets. Whether these variations are the consequence of nebular processes, planetary volatilization, differentiation or late accretion is still unresolved. The element mercury is the most volatile of the MVE and is a strongly chalcophile element. It is

We investigate lunar troctolite petrogenesis with a series of forward models. We simulate the cumulate mantle overturn hypothesis by modeling the adiabatic ascent and decompression melting of primary mantle cumulates produced during differentiation of a lunar magma ocean (LMO). Combined equilibrium and fractional crystallization of candidate liquids generated by the melting model can reproduce the

We systematically investigate the spatiotemporal water storage changes in Taiwan using geodetic (GNSS and GRACE) and hydrological (precipitation, GLDAS and LSDM assimilation models, and in-situ groundwater level) datasets. We use GNSS-observed vertical deformation to estimate water storage changes based on elastic loading theory and weighted least-squares inversion, correcting for contributions from

Exposure of rocks and regolith to solar (SCR) and galactic cosmic rays (GCR) at the Moon's surface results in the production of ‘cosmogenic’ deuterium and noble gas nuclides at a rate that depends on a complex set of parameters, such as the energy spectrum and intensity of the cosmic ray flux, the chemical composition, size, and shape of the target as well as the shielding depth. As the effects of

Meteoric cosmogenic 10Be is a powerful tracer to quantify dates and rates of Earth surface processes over timescales of 103-105 yrs. A prerequisite for its applications is knowledge of the flux at which 10Be, produced in the atmosphere, is delivered to the Earth surface. Four entirely independent approaches are available to quantify this flux: 1) General Circulation Models (GCM) combined with 10Be

Quantifying the contribution of poleward oceanic heat transport to the Arctic Ocean is important for making future sea ice and climate predictions. To highlight its potential importance in a warmer world, we present a new record of water-mass exchange between the Atlantic and the Arctic Oceans using the authigenic neodymium isotopic composition of marine sediments from the Fram Strait during the past

Documenting accurately amplitude and rhythms of geomagnetic variations is a prerequisite to understand the mechanisms triggering geomagnetic excursions and reversals. We present new authigenic 10Be/9Be ratio (Be ratio) results covering the 60–20 ka time interval from equatorial core MD05-2920. The most significant Be ratio peak is located 18 cm above the main relative paleointensity (RPI) minimum recorded

Cratonic lithosphere is believed to have been chemically buoyant and mechanically resistant to destruction over billions of years. Yet the absence of cratonic roots at some Archean terrains casts doubt on the craton stability and longevity on a global scale. As unique mantle-derived melts at ancient continents, silica-poor, kimberlitic melts are ideal tools to constrain the temporal variation of lithosphere

Across the Archaean to Proterozoic transition, the composition of newly-formed felsic continental crust changed from tonalite–trondhjemite–granodiorite (TTG) to calc-alkaline granitoid, possibly coinciding with the emergence of plate tectonics. Nevertheless, TTG suites were sporadically produced in Proterozoic and Phanerozoic orogenic belts, and such occurrences may provide petrological and tectonic

Hydrogen in rocky planet atmospheres has been invoked in arguments for extending the habitable zone via N2-H2 and CO2-H2 greenhouse warming, and providing atmospheric conditions suitable for efficient production of prebiotic molecules. On Earth and Super-Earth-sized bodies, where hydrogen-rich primordial envelopes are quickly lost to space, volcanic outgassing can act as a hydrogen source, provided

Chemical zoning in igneous minerals is a potential record of the time, processes, and thermal evolution during the lifetime of a given magma reservoir. Abundances of volatiles (OH, Cl and F) in apatite from terrestrial and extraterrestrial plutonic and volcanic rocks have been used to study volatile behavior in magmas, however, volatile diffusivities in apatite are poorly constrained. Here we report

The amount of hydrogen stored in the Earth's interior is important for a range of issues, including the volatile incorporation during the Earth formation and the co-evolution of the atmosphere, the hydrosphere, and the interior. Recent experiments found titanium bearing ε-FeOOH in a hydrous basaltic system at 12–19 GPa and 1300 K. Pyrite-type FeOOH was found to be stable at pressures higher than 80

While the northward convex Pamir salient has been interpreted to be a Cenozoic feature, resulting from terranes of the Pamir experiencing ∼300 km of northward translation relative to Tibet and Afghanistan during the India-Asia collision, structural evidence for large magnitudes of translation is generally lacking. We focus on the geology of the Northern Pamir, which forms the outer margin of the salient

Thwaites Glacier (TG), West Antarctica, is losing mass in response to oceanic forcing. Future evolution could lead to deglaciation of the marine basins of the West Antarctic Ice Sheet, depending on ongoing and future climate forcings, but also on basal topography/bathymetry, basal properties, and physical processes operating within the grounding zone. Hence, it is important to know the distribution

The late heavy bombardment (LHB) hypothesis, wherein the terrestrial planets are thought to have suffered intense collisions ca. 3.9 billion years ago, is under debate. Coupled with new dynamical calculations, re-examination of geochronological data seem to support an earlier solar system instability and a smooth monotonic decline in impacts, as opposed to a “cataclysm.” To better understand this collisional

The interpretation of modern river apatite fission track (AFT) data of Taiwan by Resentini et al. (2020) presents some fundamental inaccuracies that call in question the main conclusions of the paper. The study aims at approximating source rock cooling histories by analysing erosional products, but ignores existing bedrock data in their maps and discussions. The allegedly “new” southern extension of

Magmatic reservoirs located in the upper crust have been shown to result from the repeated intrusions of new magmas, and spend much of the time as a crystal-rich mush. The geometry of the intrusion of new magmas may greatly affect the thermal and compositional evolution of the reservoir. Despite advances in our understanding of the physical processes that may occur in a magmatic reservoir, the resulting