Browse Articles
Numerical Simulation of Cool Hydrothermal Processes in the Upper Volcanic Crust Beneath a Marine Sediment Pond: North Pond, North Atlantic Ocean
-  30 December 2021
Key Points
-
Patterns of fluid flow in the ocean crust beneath North Pond are complex and time varying, rather than single pass and unidirectional
-
Matching key surface and subsurface observations requires simulations with high aquifer permeability, kaq = 10−10–10−9 m2
-
North Pond hydrogeology differs considerably from isolated basement outcrops due to extensive seafloor connectivity to the overlying ocean
Subduction of an Oceanic Plateau Across Southcentral Alaska: Scattered‐Wave Imaging
-  28 December 2021
Key Points
-
Yakutat oceanic plateau is subducting beneath Wrangell Volcanic Field (WVF) to at least 110-km depth
-
A thin low-velocity layer delineates the megathrust atop the subducting Yakutat crust for over 450 km along-strike, at depths <35 km
-
A tear in the subducting Yakutat terrane lies 100–200 km west/northwest of the WVF
Synthetic Evaluation of Infrasonic Multipole Waveform Inversion
-  27 December 2021
Key Points
-
We investigate the ability to resolve multipole acoustic sources using infrasound waveform inversion methods for a variety of scenarios
-
A monopole inversion yields results that may be sufficient for practical purposes, even for multipole sources with a small dipole component
-
Synthetic inversion studies can increase understanding of the limitations of multipole infrasound inversions based on deployment scenarios
A New Tectonic Model Between the Madagascar Ridge and Del Cano Rise in the Indian Ocean
-  24 December 2021
Key Points
-
Revised seafloor ages up to Chron 31 in the Indian Ocean are obtained by new total and vector magnetic data
-
Our new tectonic scenario indicates that the Madagascar Plateau and Del Cano Rise once formed a single bathymetric high
-
The tectonics of oceanic plateaus in the Indian Ocean need to be reexamined, including continental fragment origin
A Reference Section Through Fast‐Spread Lower Oceanic Crust, Wadi Gideah, Samail Ophiolite (Sultanate of Oman): Petrography and Petrology
-  24 December 2021
Key Points
-
A reference profile through fast-spreading lower oceanic crust was established by outcrop sampling in the Wadi Gideah (Oman ophiolite)
-
The results imply a hybrid accretion, with in situ crystallization in the lower and subsiding crystal mushes in the upper gabbroic crust
-
Cooling of the deep crust was established by hydrothermal fault zones initially formed at very high temperatures in the magmatic regime
3‐D Crustal Azimuthal Anisotropy Reveals Multi‐Stage Deformation Processes of the Sichuan Basin and Its Adjacent Area, SW China
-  24 December 2021
Key Points
-
Ambient noise tomography reveals three different azimuthal anisotropy patterns and multi-stage deformation processes of the Sichuan Basin
-
The eastern margin of the Sichuan Basin shows a ring-shaped azimuthal anisotropy pattern due to compression and shear deformation
-
The bifurcated fast axis near the Longmenshan fault indicates the obstruction of the Sichuan Basin to the crustal low velocity materials
The Effect of Fault Architecture on Slip Behavior in Shale Revealed by Distributed Fiber Optic Strain Sensing
-  23 December 2021
Key Points
-
Slow slip in a fault zone in a clay caprock concentrates on two interfaces that sharply bound the fault zone material and the intact rock
-
Distributed strain sensing (DSS) shows equal measurand performance to potentiometers, better spatial resolution, and sensitivity to shear
-
Activated and unactivated fractures share similar orientations; activated fractures contain scaly clay
Go Extra Miles: An Additional Error Correction Procedure Aimed to Further Improve Phase Unwrapping Accuracy and Reduce Creep Model Uncertainty
-  23 December 2021
Key Points
-
We present a new method for automatically correcting unwrapping errors for InSAR time series
-
Integer Linear Programming from Compressed Sensing framework is used to calculate integer number of phase unwrapping error cycles
-
We reduce the creep model uncertainty of the San Andreas Fault creep section using the proposed phase unwrapping error correction
Mapping the Thermal Structure of the Amazon Craton to Constrain the Tectonic Domains
-  23 December 2021
Key Points
-
We used the depth to the bottom of the magnetic layer to predict the thermal structure
-
Our model suggests changes to the limits of Carajás and Bacajás domains as well as the Tapajós and Iriri Xingu domains
-
Serpentinized mantle portions correlate with world-class mineral deposits in the Carajás domain
Evidence for deeply‐subducted lower‐plate seamounts at the Hikurangi subduction margin: implications for seismic and aseismic behavior
-  7 January 2022
Key Points
-
We image velocity anomalies below the North Island, New Zealand, interpreted as deeply-subducted seamounts and fluid in the downgoing plate
-
Independent geological and geophysical observations corroborate our seamount interpretation
-
Inferred seamounts and intraslab fluid may partly explain enigmatic, along-strike plate-coupling transition at the Hikurangi margin
Are Creep Events Big? Estimations of Along‐strike Rupture Lengths
-  7 January 2022
Key Points
-
Identify 2120 creep events on the central San Andreas Fault and estimate their along-strike lengths
-
Creep event lengths range from sub-km to 10 km
-
Existence of large events makes it likely that slip is driven by large-scale frictional weakening
The rise, peak and decline of the seismic hazard related to hydraulic fracturing activities in the Duvernay play, Fox Creek area, Alberta
-  7 January 2022
Key Points
-
The annual likelihood of events in the Fox Creek area has consistently declined since 2015, in contrast with increasing activities
-
Induced seismicity is characterized by two regions with largely different -values and seismic hazard but similar earthquake numbers
-
The minimum injection volume to trigger seismicity increases over the years, indicating successful mitigation strategies
Crustal Structure Beneath the Northern Appalachians and the Eastern Grenville Province
-  7 January 2022
Key Points
-
Crustal thickness and velocities in eastern Canada are more variable in the Peri-Gondwanan than Peri-Laurentian domains
-
A step-like Moho feature in the northern Appalachians marks the boundary between the Peri-Gondwanan and Peri-Laurentian domains at depth
-
The lower crust in the Grenville Province is thicker and faster than that observed beneath the northern Appalachians
Strong upper‐plate heterogeneity at the Hikurangi subduction margin (North Island, New Zealand) imaged by adjoint tomography
-  6 January 2022
Key Points
-
We develop a high-resolution (4–30 s) 3D velocity model of the North Island of New Zealand with 28 adjoint tomography iterations
-
Distinct P- and S-wave velocity changes of up to ±30% are made to the existing model in the upper 30 km
-
The tomographic results provide improved images of tectonic and magmatic structures throughout the Hikurangi subduction margin
Pn anisotropic tomography of Northeast Asia: New insight into subduction dynamics and volcanism
-  6 January 2022
Key Points
-
Low-V zones with trench-parallel FPDs under the Japan Islands indicate compressed mantle flows
-
High-V zones with trench-normal FPDs under the Japan trench suggest simple shear deformation of the subducting Pacific plate
-
Low-V zones with zone-parallel FPDs connecting the volcanoes indicate channels for material and energy exchanges among the volcanoes
Which picker fits my data? A quantitative evaluation of deep learning based seismic pickers
-  6 January 2022
Key Points
-
We conducted a large scale benchmark of machine learning pickers using six models and eight datasets
-
Best overall performance is observed for EQTransformer, GPD and PhaseNet, with advantages for EQTransformer on teleseismic distances
-
Models transfer well between different regions with similar distances, but not between regional and teleseismic distances
Compositional variation of picrites in the Emeishan large igneous province modulated by water in the mantle plume
-  6 January 2022
Key Points
-
Both high-Ti and low-Ti picrites in the Emeishan large igneous province are hydrous
-
The major and trace element compositions of picrites are related to the water content in their mantle sources
-
Compositional variations in a large igneous provinces are affected by volatiles in mantle plumes
Three‐dimensional modeling of hysteresis in rocks
-  5 January 2022
Key Points
-
The limitations of one-dimensional hysteretic model are discussed
-
The hysteretic behaviors hysteretic mesoscopic elastic units are redefined
-
A three-dimensional model of hysteresis in rock is developed
Formation of Metamorphic Soles underlying Ophiolites during Subduction Initiation: A Systematic Numerical Study
-  5 January 2022
Key Points
-
Systematic numerical models are conducted to clarify the conditions of metamorphic sole generation in different tectonic settings
-
Subduction initiation at (back-arc) spreading center is a favorable setting for formation of metamorphic sole underlying ophiolite
-
P-T conditions of natural metamorphic soles may represent a high temperature regime facilitating their weakening and exhumation
Precise point positioning for the efficient and robust analysis of GPS data from large networks
- Journal of Geophysical Research: Solid Earth
-  5005-5017
-  10 March 1997
Calibration of the ruby pressure gauge to 800 kbar under quasi‐hydrostatic conditions
- Journal of Geophysical Research: Solid Earth
-  4673-4676
-  10 April 1986
A moment magnitude scale
- Journal of Geophysical Research: Solid Earth
-  2348-2350
-  10 May 1979
Determination of earthquake source parameters from waveform data for studies of global and regional seismicity
- Journal of Geophysical Research: Solid Earth
-  2825-2852
-  10 April 1981
The development and evaluation of the Earth Gravitational Model 2008 (EGM2008)
- Journal of Geophysical Research: Solid Earth
-  19 April 2012
Key Points
- Document the development of first ever gravity model to degree 2190
- Demonstrate EGM2008's performance
- Compare EGM2008 with other models
ITRF2014: A new release of the International Terrestrial Reference Frame modeling nonlinear station motions
- Journal of Geophysical Research: Solid Earth
-  6109-6131
-  18 July 2016
Key Points
- ITRF2014 benefits from accurate modeling of station annual and semiannual displacements
- ITRF2014 benefits from accurate modeling of postseismic deformations for sites affected by major earthquakes
- Leading to the determination of accurate and robust secular frame and site velocities
Seismic velocity structure and composition of the continental crust: A global view
- Journal of Geophysical Research: Solid Earth
-  9761-9788
-  10 June 1995
Slip instability and state variable friction laws
- Journal of Geophysical Research: Solid Earth
-  10359-10370
-  10 December 1983
Dynamic weakening of serpentinite gouges and bare surfaces at seismic slip rates
- Journal of Geophysical Research: Solid Earth
-  8107-8131
-  23 September 2014
Key Points
- Gouge friction approaches that of bare surfaces at high normal stress
- Dehydration reactions and bulk melting in serpentinite in < 1 m of slip
- Flash heating causes dynamic frictional weakening in gouge and bare surfaces
Mapping Deep Electrical Conductivity Structure in the Mount Isa region, Northern Australia: Implications for Mineral Prospectivity
- Journal of Geophysical Research: Solid Earth
-  10655-10671
-  25 October 2019
Key Points
- Magnetotelluric data reveal crustal architecture of the eastern margin of the Proterozoic Mount Isa Province
- Magnetotelluric models demonstrate spatial correlation between the crustal-scale Carpentaria conductivity anomaly and the Gidyea Suture zone
- Crustal-penetrating structures act as potential pathways for transporting metalliferous fluids to form mineral deposits in the upper crust
Aseismic continuation of the Lesser Antilles slab beneath continental South America
- Journal of Geophysical Research: Solid Earth
-  25 January 2003
The development and evaluation of the Earth Gravitational Model 2008 (EGM2008)
- Journal of Geophysical Research: Solid Earth
-  19 April 2012
Key Points
- Document the development of first ever gravity model to degree 2190
- Demonstrate EGM2008's performance
- Compare EGM2008 with other models
Tectonic evolution of the west Scotia Sea
- Journal of Geophysical Research: Solid Earth
-  2 February 2005
Philippine Sea and East Asian plate tectonics since 52 Ma constrained by new subducted slab reconstruction methods
- Journal of Geophysical Research: Solid Earth
-  4670-4741
-  13 May 2016
Key Points
- Twenty-eight East Asia subducted slabs mapped from tomography and unfolded to constrain plate reconstructions
- Slab evidence for a subducted 8000 × 2500 km “East Asian Sea” that existed between the Pacific and Indian Oceans in the early Cenozoic
- Miocene arc-arc collision between the northern Philippine Sea plate and the Ryukyu-SW Japan Eurasian margin ~15–20 Ma
Evidence for the Innermost Inner Core: Robust Parameter Search for Radially Varying Anisotropy Using the Neighborhood Algorithm
- Journal of Geophysical Research: Solid Earth
-  7 December 2020
Key Points
-
The “neighborhood algorithm” provides a robust methodology for testing layered anisotropy in the Earth's inner core
-
There is no significant change observed in the strength of anisotropy with depth in the inner core
-
The innermost inner core is defined as a gradual change in the slow propagation direction of anisotropy
Over a Century of Sinking in Mexico City: No Hope for Significant Elevation and Storage Capacity Recovery
- Journal of Geophysical Research: Solid Earth
-  30 March 2021
Key Points
-
Integration of 115 years of deformation data reveals subsidence up 50 cm/year in Mexico City
-
The majority of the subsidence is irreversible and its rates are linearly correlated to the thickness of the upper aquitard
-
Migration of low-quality water to the productive aquifer sets the stage for a water crisis, which influences the socioeconomic landscape
ITRF2014: A new release of the International Terrestrial Reference Frame modeling nonlinear station motions
- Journal of Geophysical Research: Solid Earth
-  6109-6131
-  18 July 2016
Key Points
- ITRF2014 benefits from accurate modeling of station annual and semiannual displacements
- ITRF2014 benefits from accurate modeling of postseismic deformations for sites affected by major earthquakes
- Leading to the determination of accurate and robust secular frame and site velocities