Article
Geology
Muchen Sun, Youqiang Yu, Stephen S. Gao, Kelly H. Liu
Summary: A study has found a significant thinning of the mantle transition zone extending from central Honshu, Japan, to the Korean Peninsula, supporting the existence of a slab tear. The results also suggest that hot mantle material may flow through the tear and contribute to surface volcanism.
Article
Multidisciplinary Sciences
Nicola Alessandro Pino, Vincenzo Convertito, Cataldo Godano, Claudia Piromallo
Summary: Intermediate depth and deep earthquakes have always been puzzling and paradoxical. The proposed mechanisms to explain them rely on single parameters and fail to account for regional differences. However, a study of two subduction zones reveals that deep earthquakes are restricted to specific depths and affected by the presence of metastable olivine wedge.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
Jessica E. Pilarczyk, Yuki Sawai, Yuichi Namegaya, Toru Tamura, Koichiro Tanigawa, Dan Matsumoto, Tetsuya Shinozaki, Osamu Fujiwara, Masanobu Shishikura, Yumi Shimada, Tina Dura, Benjamin P. Horton, Andrew C. Parnell, Christopher H. Vane
Summary: The Philippine Sea/Pacific boundary megathrust is identified as another potential source of seismic hazard in the Tokyo Region and tsunamis in the Pacific, according to a study of 1,000 years of tsunami deposits along the Japanese coastline. The complex earthquake hazard assessments in the Tokyo Region are influenced by the trench-trench triple junction where multiple plates interact, raising the threat of great thrust earthquakes and tsunamis from different plate boundaries.
Article
Environmental Sciences
Jixin Qiao, Daniela Ransby, Peter Steier
Summary: This study presents the first high-resolution deposition records of anthropogenic uranium (U-236 and U-233) in a sediment core taken at the Philippine Sea continental slope off Mindanao Island in the equatorial northwest Pacific Ocean. The results show two notable peaks in U-236 and U-233 concentrations, with one peak corresponding to close-in Pacific Proving Grounds signal and the other peak corresponding to global fallout from nuclear weapons testing.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Jie Chen, Jianjun Zou, Aimei Zhu, Xuefa Shi, Dirk Nuernberg, Lester Lembke-Jene, Ralf Tiedemann, Kunshan Wang, Yonghua Wu, Zhi Dong, Jianxing Liu, Ruxi Dou
Summary: This study analyzed surface sediment samples from the Emperor Seamount Chain in the North Pacific and found that sediments can be divided into three zones with distinct features spatially. Each zone is characterized by different components, such as clayey silt, sand, and silty sand, indicating different sources and sedimentary processes in the study area.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Multidisciplinary Sciences
Thorne Lay, Stuart P. Nishenko
Summary: In the western South America, six very large-magnitude earthquakes have occurred so far in this century. The history of previous earthquakes in each source region has led to the identification of seismic gaps as potential hosts for future large earthquakes. The deployment of monitoring instruments has enhanced our understanding of the faulting processes and the accumulation of slip deficit on the megathrust fault. These findings provide valuable information for assessing the current earthquake hazard along the South American subduction zone.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Ehsan Jamali Hondori, Jin-Oh Park
Summary: This study used seismic data to obtain more detailed images and related information of the 2011 Tohoku-Oki earthquake, revealing that the pore-fluid pressure along the decollement and backstop interface is generally higher than the hydrostatic pressure, especially in the decollement. This high pressure leads to fault rupture and earthquake occurrence.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
Dapeng Zhao
Summary: Recent studies on seismic imaging of the Northwest Pacific and East Asian region have revealed significant lateral heterogeneities in the crust and upper mantle, shedding new light on various geological processes such as volcanism, earthquake mechanisms, and mantle dynamics. Significant advancements in seismic imaging techniques, particularly tomographic inversions for 3-D distribution of seismic anisotropy and attenuation, have provided important insights into lithospheric deformation, mantle convection, and the processes associated with plate subductions.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geochemistry & Geophysics
Jensen Jacob, Jerome Dyment, Dibakar Ghosal, Pawan Dewangan
Summary: By integrating fracture zones, magnetic isochrones, and focal mechanisms, this study provides a better understanding of the shallow strike-slip seismicity along the Sunda Trench. The research reveals a correlation between the shallow strike-slip seismicity and the contrasts of lithospheric thickness, density, and subductability. The importance of physical and mechanical properties of the subducting lithosphere in localizing seismicity at subduction zones is emphasized.
Article
Geography, Physical
Piotr Cienciala, Mishel Melendez Bernardo, Andrew D. Nelson, Andrew D. Haas
Summary: This study analyzed sediment yield estimates and sources in a forested mountain basin in the inland Pacific Northwest, generating three key conclusions. Firstly, the mean specific yield of clastic sediment was estimated to be 51 Mg km(-2) a(-1), among the highest for inland basins in northwestern North America. Secondly, the sediment source analysis suggested anthropogenic disturbances as an important factor influencing sediment yield. Lastly, the partitioning procedure revealed that bedload constituted approximately a third of the total clastic load exported from the basin.
Article
Geochemistry & Geophysics
Junichi Nakajima, Akira Hasegawa
Summary: Repeating earthquakes are interpreted as repeated ruptures of an isolated asperity patch surrounded by a stable sliding regime, and they have been observed in various tectonic settings. We investigated the occurrence of repeaters in the continental crust and subducting slabs beneath the Japanese Islands and found a prevalence of repeaters in both locations. The repeaters show similar seismicity rates and occur on well-defined fault planes coincidentally with non-repeating earthquakes, suggesting a common generation process independent of the tectonic regime.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Environmental Sciences
Hyung Jeek Kim, Dongseon Kim, Young-Gyu Park, Jong-Yeon Park, Ki-Young Choi, Joon Sang Park, Sung Min An, Kyungman Kwon, Jae Hoon Noh, Jeomshik Hwang
Summary: The impact of dust deposition on organic carbon export was assessed by examining the flux and composition of sinking particles in the northwest Pacific. The study found that dust deposition influenced the flux of sinking particles and that there were correlations between the flux peaks and the composition and rate of dust deposition.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geography, Physical
Romain Vaucher, Christian Zeeden, Amy I. Hsieh, Stefanie Kaboth-Bahr, Andrew T. Lin, Chorng-Shern Horng, Shahin E. Dashtgard
Summary: In this study, the hydroclimate variability of the northwest Pacific during the Pliocene-Pleistocene transition is assessed using gamma-ray log data from shallow-marine strata in the Western Foreland Basin, Taiwan. The comparison of the gamma-ray logs with sea-level and sea-surface temperature reconstructions reveals the influence of climate drivers on sedimentary cycles during this transition. The findings highlight the complex history of past hydroclimate dynamics in the northwest Pacific that can be recorded in shallow marine strata.
GLOBAL AND PLANETARY CHANGE
(2023)
Article
Chemistry, Physical
Jaewoo Jung, Kiseong Hyeong, Jae Hun Kim, Jonguk Kim, Youngtak Ko, Kiho Yang, Yongmoon Lee, Hyeonho An
Summary: This study investigates deep sea surface sediments from the equatorial Pacific Ocean and finds at least two sources of smectite, one from South America and the other from Asia and North America. The study also observes a positive correlation between the iron content of smectite and the ATP concentration in deep sea sediments, suggesting the importance of Fe-rich smectite as an iron source associated with microbial activity in deep sea environments.
APPLIED CLAY SCIENCE
(2022)
Article
Geochemistry & Geophysics
Zhanfei Li, Xiwei Xu, Paul Tapponnier, Guihua Chen, Junjie Ren, Kang Li, Jia Cheng, Wenjun Kang, Jiahong Luo
Summary: Using an Unmanned Aerial Vehicle survey, the surface trace of the Minle-Damaying Thrust (MDT) in NE Tibet's Qilian Shan's mountain front is accurately mapped, revealing its rupture behavior and geometry. The study shows that the eastern segment of the MDT regularly ruptures with an average vertical offset of around 2.9 meters, producing large earthquakes with magnitudes of 7.0-7.4.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Editorial Material
Geosciences, Multidisciplinary
Pratigya J. Polissar, Cassaundra Rose, Kevin T. Uno, Samuel R. Phelps, Peter deMenocal
Review
Astronomy & Astrophysics
Paul J. Wallace, Terry Plank, Robert J. Bodnar, Glenn A. Gaetani, Thomas Shea
Summary: Inclusions of silicate melt trapped inside crystals provide a detailed record of volcanic processes, but this record may be influenced by post-entrapment processes. They serve as a primary archive of dissolved gases in magma, which are crucial for causing volcanic eruptions.
ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 49, 2021
(2021)
Article
Geosciences, Multidisciplinary
Emma J. Liu, Kieran Wood, Alessandro Aiuppa, Gaetano Giudice, Marcello Bitetto, Tobias P. Fischer, Brendan T. McCormick Kilbride, Terry Plank, Tom Hart
Summary: The South Sandwich Volcanic Arc is a remote and enigmatic volcanic arc characterized by persistent gas emissions and frequent eruptive activity. Detailed measurements during an expedition in January 2020 revealed continuous gas emissions from Mt. Michael on Saunders Island, as well as low temperature fumaroles at active centers indicating interaction between magmatic fluids and hydrothermal systems. Carbon isotope measurements suggest a mantle-dominated carbon source along with a possible mixing of upper mantle and subduction components.
BULLETIN OF VOLCANOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Allison T. Karp, Jake W. Andrae, Francesca A. McInerney, Pratigya J. Polissar, Katherine H. Freeman
Summary: The establishment of C-4 grasslands in Australia was delayed compared to other continents, possibly due to the presence of fire-adapted C-3 woody vegetation and changes in rainfall affecting soil carbon transport. This ecosystem shift altered carbon storage and hydroclimate, leading to unique responses to climate change in Australian ecosystems.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Correction
Multidisciplinary Sciences
Terry Plank, Craig E. Manning
Summary: The paper has an updated version available for access.
Article
Multidisciplinary Sciences
Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Peter DeMenocal
Summary: Precise measurements of trace elements using LA-ICPMS reveal heterogeneities between different chambers of planktic foraminifer specimens. Comparing LA-ICPMS and ICP-OES data shows a strong correlation, suggesting that multi-chamber LA-ICPMS measurements can approximate the entire specimen Mg/Ca values. This correspondence links the two methods and demonstrates their suitability for individual foraminifera paleoceanographic reconstructions.
SCIENTIFIC REPORTS
(2021)
Review
Geochemistry & Geophysics
E. F. Rose-Koga, A. -S. Bouvier, G. A. Gaetani, P. J. Wallace, C. M. Allison, J. A. Andrys, C. A. Angeles de la Torre, A. Barth, R. J. Bodnar, A. J. J. Bracco Gartner, D. Butters, A. Castillejo, B. Chilson-Parks, B. R. Choudhary, N. Cluzel, M. Cole, E. Cottrell, A. Daly, L. V. Danyushevsky, C. L. DeVitre, M. J. Drignon, L. France, M. Gaborieau, M. O. Garcia, E. Gatti, F. S. Genske, M. E. Hartley, E. C. Hughes, A. A. Iveson, E. R. Johnson, M. Jones, T. Kagoshima, Y. Katzir, M. Kawaguchi, T. Kawamoto, K. A. Kelley, J. M. Koornneef, M. D. Kurz, M. Laubier, G. D. Layne, A. Lerner, K. -Y. Lin, P. -P. Liu, A. Lorenzo-Merino, N. Luciani, N. Magalhaes, H. R. Marschall, P. J. Michael, B. D. Monteleone, L. R. Moore, Y. Moussallam, M. Muth, M. L. Myers, D. F. Narvaez, O. Navon, M. E. Newcombe, A. R. L. Nichols, R. L. Nielsen, A. Pamukcu, T. Plank, D. J. Rasmussen, J. Roberge, F. Schiavi, D. Schwartz, K. Shimizu, J. B. Thomas, G. T. Thompson, J. M. Tucker, G. Ustunisik, C. Waelkens, Y. Zhang, T. Zhou
Summary: Mineral-hosted melt inclusions are crucial for understanding magmatic processes, necessitating guidelines for data collection and reporting to ensure quality and consistency. Erik Hauri made significant contributions to the study of melt inclusions and was honored posthumously at a workshop dedicated to his memory.
Article
Geosciences, Multidisciplinary
J. A. Power, D. C. Roman, J. J. Lyons, M. M. Haney, D. J. Rasmussen, T. Plank, K. P. Nicolaysen, P. Izbekov, C. Werner, A. M. Kaufman
Summary: The study focuses on the remote volcanoes Cleveland and Tana in the central Aleutian volcanic arc, discussing seismic activity, magma movement and eruption patterns in the region. The observations reveal a complex volcano-tectonic interaction zone between Cleveland and Tana, suggesting a larger volcanic system may influence magmatism in the area.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Pratigya J. Polissar, Kevin T. Uno, Samuel R. Phelps, Allison T. Karp, Katherine H. Freeman, Jennifer L. Pensky
Summary: The development of modern C-4 ecosystems on the Indian Subcontinent went through a series of ecosystem transformations driven by drying and fire feedbacks, possibly declining atmospheric pCO(2), beginning at 10.2 Myr and strengthening through the late Miocene.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Allison T. Karp, Kevin T. Uno, Pratigya J. Polissar, Katherine H. Freeman
Summary: The study examines the impact of fire dynamics on the expansion of C-4 grasslands in South Asia using molecular proxies and carbon isotope measurements from Bengal Fan sediments. The results suggest that fires facilitated the expansion and maintenance of C-4 grassland ecosystems in the region.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2021)
Article
Geochemistry & Geophysics
Samuel R. Phelps, Gwenn M. M. Hennon, Sonya T. Dyhrman, Maria D. Hernandez Limon, Olivia M. Williamson, Pratigya J. Polissar
Summary: The study investigates the response of Gephyrocapsa oceanica to varying CO2 levels and finds that epsilon(p) correlates with carbon demand relative to supply and is consistent with DIC manipulations. It also shows that the response of epsilon(p) depends on light conditions and the range of carbon demand relative to CO2 supply, which is incompatible with the traditional diffusive model.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Review
Geosciences, Multidisciplinary
Anna Barth, Terry Plank
Summary: This paper discusses the importance of water content in magmas beneath volcanoes for processes such as magma generation, viscosity, and buoyancy, as well as the methods and feasibility of recording water evolution in melt inclusions. It also proposes technical methods for identifying water loss and restoring the original water content.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Samuel R. Phelps, Heather M. Stoll, Clara T. Bolton, Luc Beaufort, Pratigya J. Polissar
Summary: This study examines the factors influencing epsilon(p37:2) in the ocean, finding irradiance to be a key determinant in modern oceans. The research suggests that future estimations of CO2 based on epsilon(p37:2) should incorporate empirical or mechanistic models to quantitatively account for variations in irradiance and cell size.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
E. M. Armstrong, A. K. Ault, K. K. Bradbury, H. M. Savage, P. J. Polissar, S. N. Thomson
Summary: During an earthquake, the energy generated by fault friction is dissipated as heat. The rise in temperature after an earthquake is important for determining the magnitude of past earthquakes, but it is difficult to accurately measure. Researchers compared two temperature-sensitive geochemical methods and found that they provided consistent estimates of the temperature rise after an earthquake.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Multidisciplinary Sciences
Nicholas A. O'Mara, Charlotte Skonieczny, David McGee, Gisela Winckler, Aloys J. -M. Bory, Louisa I. Bradtmiller, Bruno Malaize, Pratigya J. Polissar
Summary: This study uses plant-wax isotope and dust flux records to reveal that the long-term variability of the Northwest African monsoon is controlled by tropical solar radiation gradients. While increases in monsoon rainfall are associated with the expansion of grasslands into desert landscapes, the composition of the savanna ecosystems is predominantly driven by changes in pCO(2).
NATURE COMMUNICATIONS
(2022)