Article
Geochemistry & Geophysics
C. Peirce, M. J. Funnell, T. J. Reston, C. J. MacLeod
Summary: This study models the structure of multiple OCCs on the Mid-Atlantic Ridge using seismic tomography. The results suggest that the formation of OCCs may be influenced by the presence of magma and the characteristics of the crust. The study also investigates the drivers of hydrothermal circulation in different vent fields, revealing varying mechanisms in different regions.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Alessio Sanfilippo, Vincent J. M. Salters, Sergey Y. Sokolov, Alexander A. Peyve, Andreas Stracke
Summary: The upper mantle is a mixture of refractory and recycled crustal domains, with the recycled portions dominating the composition of surface basalts. Hf isotope ratios may provide hints for melting of refractory source materials in basalts, allowing the identification of depleted mantle materials. Basalts from the Arctic Atlantic show high Hf isotope ratios, suggesting a highly depleted asthenospheric mantle source beneath this region.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Engineering, Marine
Tianxiao Ji, Zhigang Zeng
Summary: This paper presents new data on the major elements, trace elements, and Nd-Hf isotopes of south mid-Atlantic ridge (SMAR) MORBs. The geochemical characteristics, including enrichment of fluid-mobile elements and anomalous trace element ratios, suggest that these MORBs have been modified by subduction.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Yinuo Zhang, Fan Zhang, Xubo Zhang, Tao Zhang, Jian Lin, Zhiyuan Zhou, Jiangyang Zhang
Summary: The mantle plumes modify geophysical and geochemical features along mid-ocean ridges. This study focuses on the interaction between the Jan Mayen Hotspot and the Mohns Ridge in the Arctic Ocean. By analyzing geophysical observations and using modeling results, the properties of the Jan Mayen plume were estimated, and the influence of the transform fault on plume dispersion was evaluated.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Pengyuan Guo, Yaoling Niu, Pu Sun, Junjie Zhang, Shuo Chen, Meng Duan, Hongmei Gong, Xiaohong Wang
Summary: The study provides new Sr-Nd-Hf isotopic data on mid-ocean ridge basalts from the Oceanographer and Hayes fracture zones at the Mid-Atlantic Ridge to constrain the nature and origin of upper mantle heterogeneity. The data illustrate that the mantle sources of these lavas comprise three components, including ADM, E-type I, and E-type II components, which explain the contrast in crustal thickness, ridge morphology, and mantle Bouguer anomalies between the two ridge segments.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Geochemistry & Geophysics
Kevin Growe, Ingo Grevemeyer, Satish C. Singh, Milena Marjanovic, Emma P. M. Gregory, Cord Papenberg, Venkata Vaddineni, Laura Gomez de la Pena, Zhikai Wang
Summary: Recent studies have challenged the idea that transform zone crust may be magmatically augmented instead of anomalous hydrated lithosphere. Research on the St. Paul fracture zone revealed that the crust along and away from the fracture zone showed almost uniform thickness of 5-6 km, resembling normal oceanic crust.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Fei Wu, Simon Turner, Kaj Hoernle, Folkmar Hauff, Bruce F. Schaefer, Thomas Kokfelt, Ilya Bindeman
Summary: Stable barium (Ba) isotopes are being used as tracers for the recycling of crustal material into the mantle. Small but significant Ba isotope variations have been found in global MORB, and this study provides new constraints on the Ba isotope composition of the depleted upper mantle and the origin of Ba isotope heterogeneity in MORB. The results indicate that recycled altered oceanic crust and crustal sedimentary materials play important roles in the chemical budget of the upper mantle.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geochemistry & Geophysics
Brian E. Tucholke, Ross Parnell-Turner, Deborah K. Smith
Summary: Magma supply plays a primary role in controlling seafloor morphology of oceanic crust. The study examines the global patterns of morphology on mid-ocean ridge flanks in relation to magma supply and spreading rate. The results demonstrate that morphology becomes more isotropic and irregular with decreasing magma supply. The study also reveals that seismically determined crustal thickness in certain regions includes significant non-magmatic components. The findings have implications for understanding the evolution of oceanic crust.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Haitao Zhang, Quanshu Yan, Chuanshun Li, Xuefa Shi, Yaomin Yang, Guozhi Wang, Qingfeng Hua, Zhiwei Zhu, Hui Zhang, Renjie Zhao
Summary: The study reveals that basalts from the South Mid-Atlantic Ridge contain chemical traces of the Saint Helena hotspot, with its influence extending from approximately 14.2 degrees S to 20.8 degrees S. Material flow from Cardno seamount toward the SMAR system may account for the stronger geochemical signals observed in certain segments along the ridge axes.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Chuanshun Li, Haitao Zhang, Yili Guan, Aimei Zhu, Xuefa Shi
Summary: This study presents new major and trace element as well as Sr-Nd-Pb isotope data for basalts from the South Mid-Atlantic Ridge. The results indicate the presence of Tristan mantle plume materials in the southern SMAR asthenosphere, which has influenced the geochemical compositions of the basalts in this region.
Article
Geochemistry & Geophysics
R. Parnell-Turner, D. K. Smith, R. P. Dziak
Summary: This article presents a catalog of T-phase events in the equatorial Atlantic ocean, including the Mid-Atlantic Ridge and transform faults. By studying seismic activity, insights can be gained into the processes of crustal accretion and transform fault slip. It was observed that areas with asymmetric spreading have higher seismicity rates and the majority of hydrothermal vents occur in these areas. Additionally, aseismic patches were found on almost all equatorial Atlantic transform faults.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Tran Danh Hung, Ting Yang, Ba Manh Le, Youqiang Yu, Mei Xue, Baohua Liu, Chenguang Liu, Jian Wang, Mohan Pan, Phan Thien Huong, Fang Liu, Jason P. Morgan
Summary: The study of crustal thickness and Vp/Vs ratios near an extinct mid-ocean ridge in the South China Sea reveals that as spreading ceased, the oceanic crust abruptly thinned and shifted to an ultraslow accretion style. Abnormally high Vp/Vs ratios indicate the presence of serpentine, suggesting the formation of normal faults and the enhancement of serpentinization along the ridge axis.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Oceanography
Xiongwei Niu, Pingchuan Tan, Weiwei Ding, Wei Wang, Yao Wei, Xiaodong Wei, Aiguo Ruan, Jie Zhang, Chunyang Wang, Yong Tang, Jiabiao Li
Summary: A new velocity model of the southern Kyushu-Palau Ridge (KPR) was derived from seismic data, revealing the structure of the KPR crust. The crust is divided into upper and lower layers, and the thickness decreases from the center to the sides. The velocity structure of the KPR is similar to nearby basins, indicating an oceanic crust.
ACTA OCEANOLOGICA SINICA
(2022)
Article
Geochemistry & Geophysics
Eduardo Contreras-Reyes, Sebastian Obando-Orrego, Ingo Grevemeyer
Summary: This study uses simultaneous P- and S-wave data to investigate the seismic structure of the oceanic crust. The results show different seismic properties at different locations, indicating hydrothermal alteration and compaction processes. The abrupt change in seismic properties at the layer 2/3 transition is attributed to epidotization and crack-change properties.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Soumen Mallick, Sophie E. Kuhl, Alberto E. Saal, Emily M. Klein, Wolfgang Bach, Brian D. Monteleone, Joseph S. Boesenberg
Summary: Several geochemical studies have confirmed the presence of compositional and lithological heterogeneities in mid-ocean ridge basalts. While the composition and age of these heterogeneities have been constrained, their origin remains highly debated.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Jannes Munchmeyer, Jack Woollam, Andreas Rietbrock, Frederik Tilmann, Dietrich Lange, Thomas Bornstein, Tobias Diehl, Carlo Giunchi, Florian Haslinger, Dario Jozinovic, Alberto Michelini, Joachim Saul, Hugo Soto
Summary: Deep learning models, such as EQTransformer, GPD, and PhaseNet, have shown the best performance in seismic event detection and phase picking. The study also reveals that models can be effectively transferred across regions with similar distances. The results and trained models are made accessible to end-users through the SeisBench framework for easy application.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
Youqiang Yu, Frederik Tilmann, Dapeng Zhao, Stephen S. Gao, Kelly H. Liu
Summary: This study reveals that the Woodlark rift follows a passive model and is mainly driven by slab pull.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Jack Woollam, Jannes Muenchmeyer, Frederik Tilmann, Andreas Rietbrock, Dietrich Lange, Thomas Bornstein, Tobias Diehl, Carlo Giunchi, Florian Haslinger, Dario Jozinovi, Alberto Michelini, Joachim Saul, Hugo Soto
Summary: Machine-learning methods have been widely used in seismology, but the current process of accessing benchmark datasets and models is time-consuming, which hinders the further development of machine learning techniques. To address this issue, we introduce SeisBench, an open-source framework that standardizes access to models and datasets and provides common processing and data augmentation operations. With SeisBench, seismologists can easily access various machine learning models and benchmark datasets.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Antje Schloemer, Joachim Wassermann, Wolfgang Friederich, Michael Korn, Thomas Meier, Georg Ruempker, Christine Thomas, Frederik Tilmann, Joachim Ritter
Summary: The German Seismological Broadband Array (DSEBRA) is a network of 100 mobile seismological stations that can operate independently or in conjunction with other stations. The network's first mission was part of the European AlpArray initiative, with the aim of studying seismic activity in the Alps??? Apennines???Carpathians???Dinarides orogenic system. The current deployment of DSEBRA stations covers the Alpine region of Germany, Austria, and Italy, as well as the Pannonian basins of Hungary. Equipped with state-of-the-art technology, these stations provide high-quality real-time seismic data.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Philippe Jousset, Gilda Currenti, Benjamin Schwarz, Athena Chalari, Frederik Tilmann, Thomas Reinsch, Luciano Zuccarello, Eugenio Privitera, Charlotte M. Krawczyk
Summary: Understanding physical processes prior to and during volcanic eruptions has improved significantly in recent years, but uncertainties about subsurface structures and undetected processes within the volcano prevent volcanologists from inferring subtle triggering mechanisms of volcanic phenomena. This article demonstrates that distributed acoustic sensing (DAS) with optical fibers allows for remote identification of volcanic events and imaging of hidden near-surface volcanic structural features, providing the basis for improved volcano monitoring and hazard assessment.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Shanshan Wu, Youqiang Yu, Ting Yang, Mei Xue, Frederik Tilmann, Haopeng Chen
Summary: This study uses seismic data and ambient noise tomography to construct a 3-D crustal shear-wave velocity (Vs) model beneath the Indochina Peninsula. The results show a low-Vs anomaly in the mid-lower crust of the Shan-Thai Block, which may be related to crustal flow from Southeast Tibet. The Khorat Plateau behaves as a rigid block but shows low-Vs anomalies in the lower crust and below the Moho, indicating partial modification by mantle-derived melts. The strike-slip shearing motions of the Red River Fault may dominate crustal deformation at its western flank, where a low-Vs anomaly is observed in the upper-middle crust.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Multidisciplinary Sciences
Bo Ma, Jacob Geersen, Dietrich Lange, Dirk Klaeschen, Ingo Grevemeyer, Eduardo Contreras-Reyes, Florian Petersen, Michael Riedel, Yueyang Xia, Anne M. Trehu, Heidrun Kopp
Summary: The updip limit of seismic rupture plays a major role in determining the size of a tsunami caused by a megathrust earthquake. Using seismic reflection data, researchers have found that the rupture area of the 2014 Iquique earthquake in offshore Northern Chile was characterized by low fluid pressure, while north and updip of the rupture area, there was excess fluid pressure. This knowledge can help assess the potential for future shallow rupture and improve understanding of the physical state of shallow plate boundaries.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Stefan Mroczek, Frederik Tilmann, Jan Pleuger, Xiaohui Yuan, Ben Heit
Summary: To better understand the tectonic structure of the Eastern Alps, a high resolution Moho map was created based on seismic analysis. The map revealed the underthrusting of European crust and a sharp transition to a flat and thinned crust associated with Pannonian extension tectonics. The Adriatic lithosphere also underthrusts northward and becomes steeper towards the Dinarides. The high velocity region in the mantle below the Eastern Alps is likely of European origin.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geology
Zhikui Guo, Sibiao Liu, Lars Ruepke, Ingo Grevemeyer, Jason P. Morgan, Dietrich Lange, Yu Ren, Chunhui Tao
Summary: Recent research shows that the crust in oceanic transform faults is thinner than in adjacent fracture zones, challenging the concept of transform faults as conservative plate boundaries. This study also reveals the addition of secondary magmatic material at the transition to passive fracture zones.
Article
Geochemistry & Geophysics
Eduardo Contreras-Reyes, Sebastian Obando-Orrego, Ingo Grevemeyer
Summary: This study uses simultaneous P- and S-wave data to investigate the seismic structure of the oceanic crust. The results show different seismic properties at different locations, indicating hydrothermal alteration and compaction processes. The abrupt change in seismic properties at the layer 2/3 transition is attributed to epidotization and crack-change properties.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Peter Makus, Christoph Sens-Schoenfelder, Luc Illien, Thomas R. Walter, Alexander Yates, Frederik Tilmann
Summary: This study analyzes seismic data from the Klyuchevskoy Volcanic Group in Russia to study signals related to volcanic activity. A new technique called time-segmented passive image interferometry is proposed to detect volcanic inflation and deflation. The results show that rainfall and snowfall have the strongest influence on the properties of rocks, and an eruption cycle in 2016 is associated with a significant increase in velocity.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Yu Ren, Dietrich Lange, Ingo Grevemeyer
Summary: The Blanco transform fault system (BTFS) off Oregon is highly segmented without prominent fracture zones longer than 100 km. The western part is focused at deep troughs, while the eastern part lacks a transform valley and instead developed the Blanco Ridge. The BTFS can be divided into an eastern mature transform system and a western immature transform system that is still evolving.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Environmental Sciences
Constanza Rodriguez Piceda, Ya-Jian Gao, Mauro Cacace, Magdalena Scheck-Wenderoth, Judith Bott, Manfred Strecker, Frederik Tilmann
Summary: Knowledge of the causative dynamics of earthquakes along subduction-zone interfaces and within oceanic slabs is important for seismic hazard assessments. This study combines seismic tomography, 3D structure analysis, and seismicity to investigate the factors controlling slab seismic activity beneath the southern Central Andes. The hydration state of the lithospheric mantle, oceanic slab, and plate interface can be evaluated using the Vp/Vs ratio. Regions of high Vp/Vs are caused by compaction effects and dehydration reactions, while areas of low Vp/Vs and inferred lower fluid content in the overriding plate are facilitated by enhanced flexural stresses.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Geosciences, Multidisciplinary
Diego Gonzalez-Vidal, Marcos Moreno, Christian Sippl, Juan Carlos Baez, Francisco Ortega-Culaciati, Dietrich Lange, Frederik Tilmann, Anne Socquet, Jan Bolte, Joaquin Hormazabal, Mickael Langlais, Catalina Morales-Yanez, Daniel Melnick, Roberto Benavente, Jannes Muenchmeyer, Rodolfo Araya, Benjamin Heit
Summary: We deployed a dense network in the seismic gap in Chile and obtained a microseismicity catalog of >30,000 events and time series from GNSS stations. We used Bayesian inversion to estimate interplate locking and found two highly locked regions of different sizes controlling seismicity patterns. The region with lower locking coincides with higher seismicity levels and events extending toward the trench.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Yuhan Li, Ingo Grevemeyer, Shuichi Kodaira, Gou Fujie
Summary: The seismic and velocity models of the Izu arc-backarc system reveal the processes of crustal formation and subduction zone recycling in the mantle. The study shows that basaltic volcanism plays a crucial role in the transformation process from arc to continental crust, while rhyolitic volcanism may relate to the juvenile stage of arc evolution or the remelting of middle crust. Additionally, mafic restite and cumulates have delaminated and formed extremely low mantle velocities, and the lack of high velocities in the lower crust of the Shikoku Basin rules out hydrous melts or anomalous mantle trapped during subduction zone reconfiguration.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)