Article
Geochemistry & Geophysics
Rebekka Steffen, Holger Steffen
Summary: Deformation caused by ice loads leads to displacement and stress changes, resulting in glacially induced faults. However, not all faults are optimally orientated for reactivation within their regional stress regime. This study analyzes the potential for non-optimally orientated faults to be reactivated within glacially induced stress fields, depending on their location and orientation within the regional stress field.
Review
Geosciences, Multidisciplinary
Vincent Roche, Giovanni Camanni, Conrad Childs, Tom Manzocchi, John Walsh, John Conneally, Muhammad Mudasar Saqab, Efstratios Delogkos
Summary: Normal faults typically consist of multiple sub-parallel segments separated by intact or breached relay zones, which can be classified based on their orientations and connections in 3D space. A large database of fault surfaces generated from 3D seismic reflection surveys highlights the diversity in fault geometry and demonstrates that geological controls play a significant role in the observed fault geometries. The presence of a variety of relay zone geometries on a single fault suggests that individual faults can contain both bifurcating and unconnected segments in three dimensions.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geochemistry & Geophysics
Bailey A. Lathrop, Christopher A. -L. Jackson, Rebecca E. Bell, Atle Rotevatn
Summary: Understanding how normal faults grow is crucial for determining the tectono-stratigraphic evolution of rifts. Recent studies suggest that normal faults develop in two distinct stages: a lengthening stage and a throw/displacement accumulation stage. This study in particular reveals that normal faults experience changes in length and throw accumulation as they progress through different stages of their lifespan, with a decrease in surface trace length as the faults become inactive.
Article
Geosciences, Multidisciplinary
Oyewande O. Ojo, Leonard O. Ohenhen, Folarin Kolawole, Steven G. Johnson, Patrick R. Chindandali, Estella A. Atekwana, Daniel A. Lao-Davila
Summary: This study investigates the segmentation and strain accommodation along the Bilila-Mtakataka Fault (BMF) system in the Southern Malawi Rift. By integrating surface and subsurface data, the researchers reveal the discrepancy between the surface segmentation, fault offset, and long-term throw of the BMF. They also observe different geological characteristics in different segments of the fault. The study suggests that the BMF may continue to accumulate strain and pose a significant seismic hazard in the region.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Revathy M. Parameswaran, Ingi Th. Bjarnason, Bergthora S. Thorbjarnardottir
Summary: This study analyzes the stress state and faulting mechanisms in the Hjalli-Olfus region of Iceland between July 1991 and December 1999. It finds that the region experiences left-lateral strike-slip events with nodal planes oriented in an ENE or WSW direction, possibly influenced by the Hengill volcanic system and the central SISZ.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
A. Testa, P. Boncio, S. Baize, F. Mirabella, S. Pucci, B. Pace, M. Riesner, C. Pauselli, M. Ercoli, L. Benedetti, A. Di Chiara, R. Civico
Summary: The study reveals that the Anghiari fault has experienced seven paleo-earthquakes in the past, with a slip rate of over 0.2 mm/yr averaged over the last 25,000 years and a recurrence interval of about 2,500-3,200 years. Furthermore, paleoseismological analysis indicates the presence of an extensional stress field throughout the sedimentation of the faulted strata.
Article
Geosciences, Multidisciplinary
Luca Smeraglia, Marco Mercuri, Stefano Tavani, Antonio Pignalosa, Michael Kettermann, Andrea Billi, Eugenio Carminati
Summary: The study combined field-collected structural data and a virtual outcrop model constructed from drone imagery to characterize the fracture distribution within the damage zone of a low-displacement carbonate-hosted fault in Italy. Results showed that fractures in the damage zone exhibit varying degrees of maturity and permeabilities, with the potential for the damage zone to serve as fracture corridors for fluid flow in subsurface reservoirs. This suggests that changes in subsurface permeabilities in carbonate fractured reservoirs may be associated with high permeability fracture zones developed within the damage zones of low-displacement faults.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Chemistry, Analytical
Chunyang Wei, Chengzhuang Yu, Shanshan Li, Feng Pan, Tiejun Li, Zichao Wang, Junwei Li
Summary: The droplet rotation-based microfluidic mixer utilizes PDMS deformation to construct subsidence and induce rapid and homogenous fluid mixing by causing droplets to rotate. This method demonstrates high mixing efficiency and offers advantages of low-cost, ease of operation, and high efficiency, with wide applications in pharmaceutics, chemical synthesis, and biologics.
Article
Geosciences, Multidisciplinary
Xiaoyu Zou, Yuri Fialko, Andrew Dennehy, Alexander Cloninger, Shabnam J. Semnani
Summary: The orientations of active antithetic faults can provide valuable information about the strength of the seismogenic crust. The observed fault orientations deviate from the expected optimal orientations and can be explained by fault rotation due to cumulative tectonic strain. By identifying small-scale strike-slip faults, we gain insights into the in situ strength of the seismogenic crust.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Computer Science, Interdisciplinary Applications
Leila Ashouri Nalkiashari, Seyedeh Hanieh Firouzeh, Meghdad Payan, Reza Jamshidi Chenari, Ali Shafiee
Summary: In this study, the interaction between normal fault and shallow surface/embedded strip foundations is examined using an upper bound limit analysis formulation in conjunction with finite element discretization and linear programming technique. Rigid mitigating barrier walls are proposed as an efficient retrofitting strategy to protect shallow foundations against fault rupture. The results show that applying a rigid concrete wall with suitable dimensions can significantly reduce the destructive effects of fault rupture on the surface footing rotation.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Geosciences, Multidisciplinary
Giovanni Camanni, Giovanni Freda, Efstratios Delogkos, Andrew Nicol, Conrad Childs
Summary: This study investigates the vertical and horizontal displacement transfer mechanisms across a relay zone adjacent to the Moab Fault. Photogrammetry and 3D modeling techniques were used to analyze the relay-bounding faults and subordinate faults within the relay zone. It was found that horizontal displacement transfer occurs through a shallow dipping relay ramp, while vertical displacement transfer is facilitated by antithetic faults within the relay ramp.
JOURNAL OF STRUCTURAL GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Manon Carpenter, Jack N. Williams, Ake Fagereng, Luke N. J. Wedmore, Juliet Biggs, Felix Mphepo, Hassan Mdala, Zuze Dulanya, Blackwell Manda
Summary: The early stages of normal fault growth in the Zomba Graben have been investigated through field observations. The study provides insights into the displacement of active border and intrarift faults, as well as the extent of fault damage and mineralisation associated with their surface exposures. The results suggest that the Zomba border fault has a wider fault zone compared to the intrarift faults, with greater fault damage and mineral alteration. The research findings also highlight the rapid lengthening of normal faults in the area, despite their low displacement.
JOURNAL OF STRUCTURAL GEOLOGY
(2022)
Article
Energy & Fuels
Xudong Zhang, Xiaoming Liu, Xiaoqin Zheng
Summary: This paper proposes an improved axis rotation method for fault diagnosis and tolerant control of multi-phase PMSM drives. The method can effectively diagnose and distinguish faults without selecting a threshold value, and the degree of fault can be further estimated.
Article
Engineering, Electrical & Electronic
Hong Guo, Si Guo, Jinquan Xu, Xinlei Tian
Summary: This study proposed a new power switch open-circuit fault diagnosis approach for the six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) system, which can detect and locate the fault using average current Parks vector. The method can effectively detect power switch open-circuit fault online with a simple structure and low computation burden.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Energy & Fuels
Jie Ji, Kongyou Wu, Yangwen Pei, Wenjian Guo, Yin Liu, Tianran Li
Summary: This study focuses on evaluating the sealing capacity of strike-slip faults by utilizing the displacement pressure difference, considering the impacts of gravity and horizontal stress on fault rocks. The quantitative relationship between the displacement pressure of rocks, burial depth, and clay content is revealed, highlighting the importance of normal stress magnitude, stress regime, and clay content in controlling the sealing capacity of strike-slip faults.
Article
Geology
Clement de Sagazan, Jean-Arthur Olive
Summary: The study suggests that intense sedimentation can prolong the existence of normal faults bounding the Andaman Sea spreading center, and simulations show that increasing sedimentation rate can increase fault lifespan by around 50%. Sedimentation helps focus tectonic strain onto longer-lived faults, especially those with slower throw rates favored by a greater magmatic input.
Article
Geochemistry & Geophysics
Xubo Zhang, Jian Lin, Mark D. Behn
Summary: The study investigates mantle heterogeneity and basin evolution in the South China Sea by simulating mantle flow, thermal structure, and melting processes beneath the ridge axis. The results suggest that crustal thickness, mantle potential temperature, source composition, and melt migration patterns all contribute to the variability in mantle composition within the basin. Additionally, the eastern and southwest subbasins exhibit different mantle sources, with the eastern basin showing contamination by lower continental crust.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
H. F. Mark, J. A. Collins, D. Lizarralde, G. Hirth, J. B. Gaherty, R. L. Evans, M. D. Behn
Summary: This study presents new insights into seismic discontinuity and shear by investigating the upper mantle discontinuity structure at the NoMelt site in the central Pacific.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Multidisciplinary Sciences
Ching-Yao Lai, Laura A. Stevens, Danielle L. Chase, Timothy T. Creyts, Mark D. Behn, Sarah B. Das, Howard A. Stone
Summary: Research on the Greenland Ice Sheet shows that the basal hydrology undergoes significant changes beneath glacier lakes as the melt season progresses. By studying surface uplift relaxation following rapid lake drainage events, researchers have discovered a universal relaxation law that indicates a two-order-of-magnitude increase in subglacial transmissivity. This suggests that seasonal meltwater input drives substantial changes in basal hydrology beneath lakes.
NATURE COMMUNICATIONS
(2021)
Article
Geochemistry & Geophysics
Benjamin Z. Klein, Mark D. Behn
Summary: In subduction zones, material from the Earth's surface is recycled to the interior, but its fate is uncertain. The behavior of recycled material is influenced by sediment thickness and composition, as well as the thermal state of the subduction zone. Modern subduction zones exhibit a variety of processes, including relamination of ascending diapirs.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Javier Escartin, Barbara John, Mathilde Cannat, Jean-Arthur Olive, Michael Cheadle, Gretchen Frueh-Green, Carol Cotterill
Summary: The new high-resolution bathymetric data provides insights into volcanic extension and tectonic processes on the Atlantis Massif and surrounding seafloor. This study reveals the occurrence of localized volcanic activity and shifts in axial valley location related to detachment faults on the slow-spreading Mid-Atlantic Ridge.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geosciences, Multidisciplinary
B. M. Urann, V. Le Roux, O. Jagoutz, O. Muntener, M. D. Behn, E. J. Chin
Summary: According to geochemical analyses, the water content of arc magmas can reach up to 20 wt% in the lower crust, highlighting the importance of water in the formation of porphyry deposits. By measuring volatile abundances in lower-crustal cumulate minerals, researchers have found that pyroxenes retain the water content of the magmas and record a range of water contents in primitive melts. Subsequent crystal fractionation results in the formation of super-hydrous melts with a water content of approximately 12-20 wt%, which have been rarely observed in previous studies.
Article
Multidisciplinary Sciences
Jean-Arthur Olive, Luca C. Malatesta, Mark D. Behn, W. Roger Buck
Summary: Erosion and sedimentation play a crucial role in shaping the topography and redistributing stress in the Earth's crust. Surface processes can focus deformation onto fewer and longer-lasting faults at tectonic plate boundaries. However, the sensitivity of tectonic deformation to erosional efficiency remains unknown due to the lack of calibrated parameters and difficulties in inferring fault activity from the geological record.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geochemistry & Geophysics
Jie Chen, Jean-Arthur Olive, Mathilde Cannat
Summary: Melt supply at slow-ultraslow spreading ridges is reduced and variable. 2-D numerical models reveal that melt injection frequency and temperature of host rocks influence the thermal regime, and periodic magma supply induces oscillatory thermal regimes.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
William J. Shinevar, Oliver Jagoutz, Mark D. Behn
Summary: In this study, a tool called WISTFUL is introduced to help researchers analyze seismic datasets by quantitatively converting upper mantle seismic wave speeds into temperature, density, composition, and related parameters. The tool utilizes a large database, MATLAB functions, scripts, and user interfaces to provide features such as plotting relationships, calculating seismic wave speeds, and inverting temperature. The accuracy and sources of error in the methodology are evaluated through comparison of observed and calculated data.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geochemistry & Geophysics
William J. Shinevar, Eva M. Golos, Oliver Jagoutz, Mark D. Behn, Robert D. van der Hilst
Summary: The continental lithospheric mantle beneath the United States exhibits lateral variations in temperature, with a range of 800-900 degrees C at depths of 60, 80, and 100 km. The eastern region is generally cooler (350-850 degrees C at 60 km), while the western region is hotter (typically >1000 degrees C at 60 km, >1200 degrees C at 80-100 km). The chemical depletion predicted by WISTFUL does not fully compensate for the density difference caused by temperature. Oscillatory convection may be occurring in the lithosphere below the United States, with alternating cycles of cooling, densification, and sinking, followed by reheating and rising.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Emmanuel A. Codillo, Veronique Le Roux, Benjamin Klein, Mark D. Behn, Horst R. Marschall, Gray E. Bebout
Summary: Mélange rocks, which are mixtures of subducted materials and serpentinized mantle rocks, may ascend from the slab-top into the overlying mantle and influence the compositional characteristics of arc magmas. This study performed experiments on natural mélange rocks to investigate their melting behavior and buoyancy. The results show that melting of mélange rocks is unlikely to occur along the slab-top, and diapirism into the hotter mantle wedge is required for melting to initiate. The study also evaluates the accuracy of thermodynamic modeling in reproducing the phase equilibria and density evolution of mélange compositions, highlighting the need for an improved thermodynamic database. This research provides experimental constraints on mélange buoyancy and has implications for understanding subduction zone processes.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Multidisciplinary Sciences
David Bekaert, Esteban Gazel, Stephen Turner, Mark D. Behn, J. Marten de Moor, Sabin Zahirovic, Vlad C. Manea, Kaj Hoernle, Tobias P. Fischer, Alexander Hammerstrom, Alan M. Seltzer, Justin T. Kulongoski, Bina S. Patel, Matthew O. Schrenk, Saemundur A. Halldorsson, Mayuko Nakagawa, Carlos J. Ramirez, John A. Krantz, Mustafa Yucel, Christopher J. Ballentine, Donato Giovannelli, Karen G. Lloyd, Peter H. Barry
Summary: Mantle plumes are known conduits for upwelling enriched material, but the extent of lateral flow processes dispersing mantle material far from vertical conduits remains unclear. Data from hydrothermal fluids in Central America show high He-3/He-4 values in Panama, likely derived from a Galapagos plume-like mantle infiltrating through a slab window. These findings suggest the potential for lateral mantle flow to transport geochemical heterogeneities over long distances.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geography, Physical
Mark D. Behn, David L. Goldsby, Greg Hirth
Summary: Viscous flow in ice is often described by the Glen flow law, but experimental studies show that deformation in ice can be strongly dependent on grain size. The variation in grain size with deformation conditions results in an effective stress exponent intermediate between grain boundary sliding and dislocation creep, consistent with a value of n = 3 +/- 0.5 over the range of strain rates found in most natural systems.