Talc is expected to be an important water carrier in Earth's upper mantle, and understanding its electrical and seismic properties under high pressure and temperature conditions is required to detect possible talc-rich regions in subduction zones imaged using geophysical observations. We conducted acoustic and electrical experiments on natural talc aggregates at relevant pressure-temperature conditions

Faulting and folding of basement rocks together accommodate convergence within continental orogens, forming complex zones of intraplate deformation shaped by the fault interaction. Here we use the river terraces along the Dongda river to examine the tectonic deformation patterns of the hinterland and the foreland of the eastern North Qilian Shan, a zone of crustal shortening located at the northeast

Offset geomorphic markers are commonly used to interpret slip history of strike-slip faults and have played an important role in forming earthquake recurrence models. These data sets are typically analyzed using cumulative probability methods to interpret average amounts of slip in past earthquakes. However, interpretation of the geomorphic record to infer surface slip history is complicated by slip

In this paper, we present numerical modeling aimed to explain Deep Long Period (DLP) events occurring in middle-to-lower crust beneath volcanoes and often observed in association with volcanic eruptions or their precursors. We consider a DLP generating mechanism caused by the rapid growth of gas bubbles in response to the slow decompression of H2O–CO2 over-saturated basaltic magma. The nucleation and

Rare bedrock exposures of the eastern Denali fault zone in southwestern Yukon allow for the measurement, sampling, and analyses of brittle regime fault slip data and deformation mechanisms to explore relations to far field, oblique plate motions. Host rock lithologies and associated slip surfaces show episodic damage zone-related deformation and calcite ± hematite ± chlorite related hydrothermal fluid

We performed a series of hydraulic stimulations at 1.1 km depth in the Bedretto underground laboratory, Switzerland, as part of an overall research strategy attempting to understand induced seismicity on different scales. Using an ultra-high frequency seismic network we detect seismic events as small as Mw < −4, revealing intricate details of a complex fracture network extending over 100 m from the

In basaltic eruptions, bubbles move freely and collide within a volcanic conduit, leading to frequent bubble coalescence. Understanding the dynamics of buoyancy-driven coalescence of bubbles is crucial for predicting the explosivity of basaltic eruptions. We examine the evolution of the bubble volume distribution while considering buoyancy-driven coalescence and expansion due to decompression. We find

It remains controversial whether the interaction between a mantle plume and a craton destabilizes or reinforces the craton. The Tarim basin, with a craton core, a Permian Large Igneous Province, and internal deformation, is an ideal place to investigate this interaction. Here, we construct high-resolution S-wave velocity structures down to 15 km in depth using multi-frequency receiver functions from

Full waveform inversion (FWI) creates high resolution models of the Earth's subsurface structures from seismic waveform data. Due to the non-linearity and non-uniqueness of FWI problems, finding globally best-fitting model solutions is not necessarily desirable since they fit noise as well as the desired signal in data. Bayesian FWI calculates a so-called posterior probability distribution function

Distributed acoustic sensing (DAS) is an innovative technology with great potential for acquiring seismic data sets in urban areas. In this work, we check the suitability of a DAS data set acquired in Granada (Spain) for retrieving subsurface reflectivity from ambient noise. The fiber-optic is a pre-existing underground telecommunication cable that crosses the city from Northwest to Southeast. We use

In subduction zones, along-strike and downdip variations in megathrust slip behavior are linked to changes in properties of the subducting and overriding plates. Although marine geophysical methods provide insights into subduction zone structures, most surveys consist of sparse 2D profiles, limiting our understanding of first-order controls. Here, we use active-source seismic data to derive a 3D crustal-scale

The Lhasa terrane in southern Tibet occupies a central position in Asian tectonics, yet its pre-Mesozoic petrologic and tectonic evolution is poorly constrained, especially the Southern Lhasa subterrane (SLS). Here, new zircon U–Pb ages, zircon trace element and Hf isotopic compositions, and whole-rock geochemical data for mafic meta-igneous rocks from the SLS distinguish three tectono-thermal events

The region of northern Borneo in South East Asia sits within a post-subduction setting formed by the recent termination of two sequential but opposed subduction systems. In this study we use seismic data from a recent temporary array deployment to image the crustal velocity structure beneath northern Borneo using a two-stage Bayesian trans-dimensional tomography scheme, in which period dependent phase

Precambrian paleomagnetic studies are critical for testing paleogeographic reconstructions in deep time but rely on the fidelity of the assumption of the geocentric axial dipole (GAD) hypothesis. With high-reliability data from mafic dykes and volcanic rocks, the scatter of individual virtual geomagnetic poles (VGPs) can be used to test simple GAD models. In order to conduct such a test, the VGPs must

Understanding postseismic processes following the 2016 Mw 7.8 Kaikōura earthquake remains challenging due to the time-dependent afterslip over the complex forearc system including crustal faults and megathrust, and the viscoelastic relaxation of the upper mantle. How the 2016 Mw 7.8 Kaikōura crustal earthquake interacts with the megathrust has yet to be better understood. Here we have derived the first

We apply the Matrix Profile algorithm to 100 days of continuous data starting 10 days before the 2019 M 6.4 and M 7.1 Ridgecrest earthquakes from borehole seismic station B921 near the Ridgecrest aftershock sequence. We identify many examples of reversely polarized waveforms, but focus on one particularly striking earthquake pair with strongly negatively correlated P and S waveforms at B921 and several

Recently, a widespread and densely continuous-recording ocean-bottom seismograph network has been deployed in the Japan Trench subduction zone. Utilizing the offshore network data improves azimuthal station coverage for offshore earthquakes in the Japan Trench subduction zone. It has a potential to obtain centroid moment tensor (CMT) solutions more accurately than conventional analyses using onshore

The Dʺ layer, defined as 200–400 km in the lowermost mantle, is a thermal and chemical boundary layer between the solid silicate mantle and the liquid outer core. Deciphering the detailed structures of the Dʺ region is essential for unlocking the thermal and chemical states in the deep Earth. Here, we precisely measure the slowness and back-azimuth of the direct P-waves by beamforming based on the

In this study, we reveal the deformational structure of the crust of the northern part of the Ryukyu Arc and Okinawa Trough using ambient noise tomography. Compared with southern Ryukyu, the northern segment exhibits a wide and shallow basin, a crust without localized thinning, slow extension rates, and highly arc-oblique, right-lateral retreat of the Ryukyu Arc. We present both isotropic and azimuthally

We investigate the dynamic interactions between the Southern San Andreas Fault (SSAF) and a proximal normal fault (NF) beneath the Salton Sea in southern California. The NF, positioned near the SSAF terminus at Bombay Beach, exhibits 11–15 displacement events across 14 stratigraphic sequences, with a range of 0.2–1.4 m of vertical offset since ∼2–3 ka. Notably, four of these events may align temporally

Crustal perturbations related to seismic activity can generally be observed with the occurrence of a large magnitude event. For less energetic seismic sequences though, the associated transient crustal variations are questionably measurable, and their observation gets easily obscured by relatively stronger perturbations such as the ones related to hydrological processes. In this study we reveal the

The Mediterranean Hellenic Arc subduction zone (HASZ) has generated several MW≥${\mathrm{M}}_{W}\ge $8 earthquakes and tsunamis. Seismic-probabilistic tsunami hazard assessment typically utilizes uniform or stochastic earthquake models, which may not represent dynamic rupture and tsunami generation complexity. We present an ensemble of ten 3D dynamic rupture earthquake scenarios for the HASZ, utilizing

This study presents new seismic imaging of the Andean subduction zone through P-wave hybrid finite-frequency and ray-theoretical tomography. We measured both differential and absolute traveltimes using broadband seismic waveforms from stations in an array of ocean-bottom seismographs near the Chile Triple Junction (CTJ) and stations within 30° of the array. These data were combined with the global

While the electrical conductivity of smectite-rich rocks is high, previous studies have only partially revealed its dependence on temperature, salinity, and porosity. This knowledge gap mainly arises from challenges in controlling various experimental conditions when measuring the conductivity of real smectite-bearing rock samples and quantifying the smectite content. To mimic conductivity measurements

Fluid injection can induce seismicity by altering stresses on pre-existing faults. Here, we investigate minimizing induced earthquake potential by optimizing injection operations in a physics-based forecasting framework. We built a 3D finite element model of the poroelastic crust for the Raton Basin, Central US, and used it to estimate time dependent Coulomb stress changes due to ∼ ${\sim} $ 25 years

Antarctica is renowned for its ancient cratons, difficult-to-observe sutures and active continental rifts. Detailed lithospheric structure and strength estimates are crucial for understanding the potential distribution, long-term geological evolution, and deformation patterns of this continent. The lithospheric structure of the Antarctic continent is investigated based on joint modeling of elevation

The effect of light elements (LEs) such as sulfur on the physical properties of liquid iron-nickel alloy under the earth's outer core conditions is critical for understanding the core composition and dynamics. First-principles molecular dynamics simulations were employed to model Fe-Ni-S liquid with S concentrations in the range of (0–25) atomic percent (at%) at 4050 K and (0–33.33) at% at 5530 K and

No abstract is available for this article.

The geochemical alteration of host rocks might affect the productivity and the potential for induced seismicity of geothermal systems. In addition to natural alteration, following production and heat extraction, re-injected fluids at lower temperatures and different pressures may be in chemical disequilibrium with the rock, impacting mineral solubility and dissolution/precipitation processes. In this

Observations of seismic waves that have passed through the Earth's lowermost mantle provide insight into deep mantle structure and dynamics, often on relatively small spatial scales. Here we use SKS, S2KS, S3KS, and PKS signals recorded across a large region including the United States, Mexico, and Central America to study the deepest mantle beneath large swaths of North America and the northeastern

Earthquake interaction across multiple time scales can reveal complex stress evolution and rupture patterns. Here, we investigate the role of static stress change in the 2023 Mw 7.8 and 7.6 earthquake doublet along the East Anatolian Fault (EAF), using simulations of 19 historical earthquakes (M ≥ 6.1) and the 2023 earthquake doublet from 1822 to 2023. Focusing on six cascading sub-events during the

Interseismic coupling maps and, especially, estimates of the location of the fully coupled (locked) zone relative to the trench, coastline, and slow slip events are crucial for determining megathrust earthquake hazard at subduction zones. We present an interseismic coupling inversion that estimates the locations of the upper and lower boundaries of the locked zone, the lower boundary of the deep transition

Disposal of industrial wastewater and activities such as C⁢O2${\mathrm{C}\mathrm{O}}_{2}$ underground sequestration depend upon pressure conditions within deep geologic reservoirs. Sometimes, injection and storage are associated with induced seismicity, suggested to result from reservoir compartmentalization, leakage into faults, or other mechanisms in the subsurface. To understand subsurface pressure

Recent observations show that certain rupture phase can propagate backward relative to the earlier one during a single earthquake event. Such back-propagating rupture (BPR) was not well considered by the conventional earthquake source studies and remains a mystery to the seismological community. Here we present a comprehensive analysis of BPR, by combining theoretical considerations, numerical simulations

The elusive transition toward afterslip following an earthquake is challenging to capture with typical data resolution limits. A dense geodetic network recorded the Mw 7.1 Ridgecrest earthquake, including 16 Global Navigation Satellite System (GNSS) stations and 3 borehole strainmeters (BSM). The sub-nanostrain precision and sub-second sampling rate of BSMs bridges a gap between conventional seismologic

Settling-driven gravitational instabilities (SDGIs) can form at the base of buoyant particle-laden suspensions, modulating particle sedimentation in various settings such as meteorological and volcanic clouds, fluvial plumes, magma chambers, submarine hydrothermal plumes, or industrial emissions. These instabilities result in the formation of rapidly descending currents called ‘fingers’ within which

We have developed replicate paleomagnetic secular variation (PSV) records for MIS 6–7 (130–244 ka) from IODP Ex. 3 23 Sites 1,343, 1,344, and 1,345 (Bering Sea). We can correlate the PSV at all three sites and identify 90 inclination features and 64 declination features. We have developed relative paleointensity records for all three sites by normalizing the demagnetized natural remanence to magnetic

Due to relatively high terrain and negligible active tectonics, the southern Africa region boasts over 30 independent estimates of dynamic topography. These published estimates display a wide variance due to both the variety of methods used in computation and a lack of constraints on the regional mantle structure. Here we show that a focus on regional mantle structure is important to generate models

In slow spreading environments, oceanic crust is formed by a combination of magmatic and tectonic processes. Using full waveform inversion applied to active-source ocean bottom seismometer data, we reveal the presence of a strong lateral variability in the 40–48 Ma old oceanic crust formed at the slow-spreading Mid-Atlantic Ridge in the equatorial Atlantic Ocean. Over a 120 km-long section between

Continental rifting is one of the fundamental tectonics of the Earth evolution while our current understandings on the dynamic mechanism of the strike-slip ones are relatively limited. Here, we have utilized three kinds of core-refracted shear waves (including PKS, SKKS, and SKS) and employed the shear-wave splitting technique to systematically investigate the azimuthal anisotropy of the upper mantle

The physical properties of the Earth's inner core boundary (ICB) are crucial for understanding inner core growth and geodynamo generation. In this study, we analyze the differential travel time residuals (DTTRs) and waveform similarities of the core-reflected phases (PKiKP and PcP) to investigate fine-scale seismic structures of the ICB. To study the ICB beneath East Asia, we collect a total of 4,272

Biogenic magnetite crystals produced by magnetotactic bacteria (MTB) and associated magnetofossils in sediments are characterized by variable morphologies, grain sizes, and chain structures. Magnetofossils are widely used in paleomagnetic and paleoenvironmental studies, but the complex magnetofossil shapes and particle arrangements significantly affect magnetic properties, hampering their magnetic

The electrical conductivity of pure and Al/Fe-bearing phase E was measured up to 950 K at 15 GPa using a complex impedance spectroscopy. Pure phase E shows comparable conductivity to that of phase D, and a few orders of magnitude higher than that of phase A and super-hydrous phase B. Al-bearing phase E does not exhibit a conductivity difference, while a certain amount of incorporated Fe prominently

An unexpected major tsunami from the region near Sofu Seamount was observed on 8 October 2023. Sofu Seamount is located approximately 600 km from the coast of Japan. Due to far epicentral distances and the successive occurrence of seismic events, the conventional seismic analysis to reveal the accompanying seismic sequence cannot work well. We investigated high-frequency teleseismic P and regional

Mafic intrusions, lava flows, and felsic plutons in southwestern Laurentia have been hypothesized to be associated with the emplacement of a late Mesoproterozoic (Stenian Period) large igneous province. Improved geochronologic data resolve distinct episodes of mafic magmatism in the region. The ca. 1,098 Ma main pulse of southwestern Laurentia large igneous province (SWLLIP) magmatism is recorded by

Geophysical and geological studies provide evidence for cyclic changes in fault-zone pore fluid pressure that synchronize with or at least modulate slip events. A hypothesized explanation is fault valving arising from temporal changes in fault zone permeability. In our study, we investigate how the coupled dynamics of rate and state friction, along-fault fluid flow, and permeability evolution can produce

Surface morphology plays a crucial role in friction between two contacting geomaterial surfaces, yet many questions remain unanswered regarding how detailed frictional responses deviate from analytical solutions for smooth surfaces due to the presence of roughness. In this study, we revisit the Cattaneo-Mindlin problem for contacts between two fractally rough elastic or elasto-plastic spheres generated

The 2018 eruption of Sierra Negra volcano, Galápagos, Ecuador has provided new insights into the mechanisms of caldera resurgence, subsidence, and fissuring at basaltic shield volcanoes. Here, we integrate local (∼0.4 km) seismo-acoustic records and regional (∼85 km) infrasound array data to present new observations of the 2018 Sierra Negra eruption with improved time and spatial resolutions. These

Increasing deployment of dense arrays has facilitated detailed structure imaging for tectonic investigation, hazard assessment and resource exploration. Strong velocity heterogeneity and topographic changes have to be considered during passive source imaging. However, it is quite challenging for ray-based methods, such as Kirchhoff migration or the widely used teleseismic receiver function, to handle

Accommodation space governs the spatial and temporal distributions of sediments in continental margins. Mapping the sedimentation patterns, therefore, offers insights into the solid-Earth processes that shape accommodation space. We assembled an unprecedented amount of seismic and borehole data along the Eastern North American Margin and used it to divide the margin's sedimentary package into eight

Epidote is a potential water carrier in subducting oceanic crust, and it is involved in temperature records from blueschist and eclogite exhumed from subduction zones. Thermal conductivity (κ) and thermal diffusivity (D) of epidote were measured at 303–1,473 K and 0.5–3.0 GPa using the transient plane-source method. κ and D values decreased with temperature before dehydration, but increase anomalously

The Mongolia-Baikal region, located between the Siberia, North China, and Tarim cratons, exhibits the most pronounced lithospheric accretion and extension since the Phanerozoic. Despite its distance from plate boundaries, the region's notable tectonic activity underscores its importance for studying intraplate lithospheric deformation. However, its lithospheric thermal structure, particularly at high

Seismic anisotropy has been widely observed in the lower mantle transition zone and the uppermost lower mantle near several subducting slabs, which is typically attributed to the crystallographic preferred orientation (CPO) of constituent minerals. In this study, well-controlled uniaxial and simple shear deformation experiments were conducted on Mg-endmember phase D and Al-bearing phase D aggregates

Earthquake-triggered landslides are widely recognized. Despite extensive research on the seismic responses of landslides triggered by single earthquakes, there is a lack of understanding of the seismic responses of landslides due to earthquake sequences and multiple earthquakes, and the mechanisms of dynamic weakening under multiple earthquakes still lack support from experimental results. To explore

Glacial isostatic adjustment (GIA) describes the response of the solid Earth, oceans, and gravitational field to the spatio-temporal evolution of ice sheets during a glacial cycle. Present-day vertical displacements and sea-level changes vary throughout eastern North America in response to the melting of the Laurentide Ice Sheet following the Last Glacial Maximum. We use the open-source software SELEN4

Fluid overpressure from the water released by subducted sediments and oceanic crust is an important mechanism for generating earthquakes via brittle failure and frictional instability. If unstable, such fault materials may also host diverse fault reactivation mechanisms from slow slip events to moderate-sized earthquakes in cold subduction zones. We examine this hypothesis for glaucophane gouge - a

The horizontal propagation of slab detachment (slab tearing) is known to control lateral migration of the mountain uplift along the collisional belt. However, along-strike differential collision due to an oblique passive margin geometry can make the topography response more complex. In this study, we employ 3D thermomechanical modeling to distinguish between the lateral migration of the mountain topography

It remains uncertain whether a stagnant slab in the mantle transition zone can affect the asthenospheric mantle beyond its leading edge. To address this question, we investigated Cenozoic alkaline basalts from the Dariganga volcanic field (DVF) in southeastern Mongolia. The DVF is located west of North–South Gravity Lineament (NSGL) in Eastern China, which is spatially coincident with the seismically

Surface heat flow (SHF) serves as a vital parameter for assessing the heat transfer from deep Earth to the surface, which can provide crucial insights into internal geodynamic processes. As the “roof of the world,” the Tibetan Plateau and its tectonic evolution are highly important in terms of global climate change and geodynamic study. However, a comprehensive understanding of the SHF distribution

The Neoproterozoic carbonate rocks of the Araras Group (Amazon Craton) and the Sete-Lagoas and Salitre Formations (São Francisco Craton) share a statistically indistinguishable single-polarity (reversed) characteristic direction. This direction is associated with paleomagnetic poles that do not align with the expected directions for primary detrital remanence. We employ a combination of classical rock