Article
Geology
Deyong Li, Xiting Liu, Honggang Cheng, Jie Liang, Shujuan Xu, Gang Dong, Chaoyang Li, Xiaodian Jiang
Summary: This study provides a detailed analysis of the geomorphological and erosional-depositional features of submarine canyons in the Okinawa Trough. It reveals that the canyons mainly developed during the last glacial maximum and were influenced by slope failure induced by gas hydrate dissociation and methane seepage. The study confirms the complex relationship between submarine canyons and methane seepage associated with gas hydrate through seismic expressions and geological features.
ORE GEOLOGY REVIEWS
(2022)
Article
Engineering, Marine
Xiaolin Ou, Junjiang Zhu, Sanzhong Li, Yonggang Jia, Zhongjia Jia, Shengsheng Zhang, Shaoyu Zhang, Ruixue Chen, Xingquan Chen, Dong Ding, Huilin Xing, Yanhui Suo, Pengcheng Wang, Yongjiang Liu
Summary: This study processed raw multi-beam bathymetry data from the central and northeastern South China Sea to construct a high resolution bathymetric map and identify various seafloor geomorphological features. The formation of Shenhu canyon, submarine dunes, and seamounts is attributed to turbidity currents, dominant currents, tidal currents, and regional tectonic activities.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
M. Wolfson-Schwehr, C. K. Paull, D. W. Caress, R. Gwiazda, N. M. Nieminski, P. J. Talling, C. Carvajal, S. Simmons, G. Troni
Summary: This study demonstrates how ultra-high resolution seabed mapping using new technology can help understand the processes shaping submarine canyons. The study conducted time-lapse surveys of the Monterey Canyon axis, revealing centimeter-scale seabed textures and the effects of turbidity currents and internal tides. The results suggest that the scale gap between modern seafloor surveys and the ancient rock record may eventually be bridged with new mapping technology.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Oceanography
Taira Nagai, Toshiyuki Hibiya
Summary: Coastal submarine canyons are potential areas for fishing due to enhanced turbulent mixing, and recent studies have suggested that diurnal coastal trapped waves (CTWs) play a role in inducing turbulent mixing in these canyons. However, the detailed processes of CTWs generation and dissipation in submarine canyons have not been well investigated. In this study, numerical experiments in Suruga Bay, Japan, show that diurnal tidal currents generate cyclonic CTWs along the coast, and interactions between these CTWs and the seafloor topography lead to intensified flow and mixing in the middle of the bay.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Review
Geosciences, Multidisciplinary
Cheng-Shing Chiang, Ho-Shing Yu, Atsushi Noda, Taqumi TuZino
Summary: By examining bathymetric and seismic reflection data, the morphology of the Huapinghsu Channel/Mienhua Canyon System was refined. The channel functions as a sediment conduit, transporting sediments from western Taiwan rivers to the Southern Okinawa Trough. Suspended particles in the Mienhua Canyon are transported along the canyon course and eventually into the Southern Okinawa Trough, even during sea-level highstand. The control factors of the channel/canyon system include sea level changes, sediment input, tectonics, and climate.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Hongxiang Guan, Lei Liu, Yu Hu, Sanzhong Li, Niu Li, Zhilei Sun, Nengyou Wu, Ian Somerville
Summary: This study investigates the mechanisms and parameters of past and current methane releases in the Okinawa Trough through comprehensive analysis of a piston core. The research also provides evidence for the response of gas hydrates in the trough to environmental changes.
Article
Geology
E. M. Mahon, M. W. Wallace
Summary: The Latrobe Group in the Gippsland Basin consists of well-developed, stacked shoreface and coastal plain deposits, cut by large, incised channel systems. However, a re-evaluation of these channels using seismic, well log, and core data suggests that they are actually submarine canyons rather than channels of fluvial origin. This study has significant implications for tectonic and eustatic histories globally.
SEDIMENTARY GEOLOGY
(2022)
Article
Geology
Song Zhu, Xuejie Li, Huodai Zhang, Zhibin Sha, Zhen Sun
Summary: The characteristics, distribution, and genesis of pockmarks in the South China Sea are explored based on high-resolution multibeam bathymetric data and multichannel seismic profiles. Pockmarks in the area vary in shape, size, and depth, likely originating from methane seepages or pore fluids migrating vertically along geological structures. Bottom currents also play a role in shaping pockmark morphologies.
INTERNATIONAL GEOLOGY REVIEW
(2021)
Article
Geosciences, Multidisciplinary
Di Luo, Feng Cai, Qing Li, Guijing Yan, Yunbao Sun, Ang Li, Gang Dong
Summary: Applying geophysical data can help us understand the detailed characteristics of methane seepages, including seismic chimneys, pockmarks, submarine domes, and so on, which may represent different stages of methane seepage.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Environmental Sciences
Xiaodong Zhang, Zhifei Liu, Yulong Zhao, Pengfei Ma, Christophe Colin, Andrew Tien-Shun Lin
Summary: This study collected surface sediments from typical geomorphological units in the northern South China Sea to investigate the composition, distribution, and controlling factors of deep-sea microplastics. The results showed that the abundance and polymer type of microplastics are influenced by sedimentary dynamic conditions.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Ellie S. Jones, Steve W. Ross, Craig M. Robertson, Craig M. Young
Summary: Anthropogenic debris has been found in all studied marine environments, even in the deepest parts of the sea. This study examined sediment cores and ROV video to analyze the density and distribution of debris, including micro-and macroplastics, in Norfolk and Baltimore canyons. The findings show that canyons serve as important repositories and conduits for debris to the deep sea, impacting benthic invertebrate communities.
MARINE POLLUTION BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
Taoyu Xu, Yazhi Bai, Gang Yang, Xisheng Fang, Yanguang Liu, Changfei Tao, Xuefa Shi
Summary: This study investigates the seismic reflection characteristics and controlling factors of gas within the East China Sea clinoform. The seismic profiles reveal distinct gas-related seismic reflection characteristics along the coast, and the analysis suggests that the seismic reflection is influenced by factors such as anaerobic oxidation of methane, seabed erosion, clinoform stratification, and hydrostatic pressure.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Dehui Qiao, Yasong Wang, Jianchun Yu, Bilin Liu, Jianqiang Wu, Huangmin Ge, Yuli Wei, Yunping Xu
Summary: Cross-shelf transport plays a significant role in marine carbon cycles. This study examined the concentration and optical composition of dissolved organic matter (DOM) in surface water samples collected from the East China Sea to the Okinawa Trough. The study found that compared to the Okinawa Trough, the East China Sea had higher concentrations of dissolved organic carbon and different optical parameters. The distribution of fluorescence components varied with the regions. Additionally, it was observed that DOM is well mixed in the East China Sea shelf but has limited transport across the Okinawa Trough.
JOURNAL OF MARINE SYSTEMS
(2023)
Article
Multidisciplinary Sciences
Hiroki Kise, Akira Iguchi, Takuji Ikegami, Yosuke Onishi, Koichi Goto, Yuichiro Tanaka, Travis W. W. Washburn, Miyuki Nishijima, Taiga Kunishima, Nobuyuki Okamoto, Atsushi Suzuki
Summary: The aim of this study was to clarify the population structures of dominant benthic megafaunal species near hydrothermal vent fields in the Okinawa Trough using a population genetics approach. The results showed strong genetic connectivity and/or large population sizes for the studied species.
SCIENTIFIC REPORTS
(2023)
Article
Geochemistry & Geophysics
H. Grob, M. Riedel, M. J. Duchesne, S. Krastel, J. Bustamante, G. Fabien-Ouellet, Y. K. Jin, J. K. Hong
Summary: The Canadian Arctic Southern Beaufort Sea has significant relict submarine permafrost and gas hydrate occurrences formed during previous glaciations. The degradation of submarine permafrost releases greenhouse gases, contributing to climate change. This study investigates the presence of submarine permafrost and gas hydrates on the outer continental shelf using seismic reflection indicators. The findings confirm the distribution of present submarine permafrost along the southern Canadian Beaufort Sea region and extend it to the outer continental shelf.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Geosciences, Multidisciplinary
Kentaro Izumi, Yuki Haneda, Yusuke Suganuma, Makoto Okada, Yoshimi Kubota, Naohisa Nishida, Moto Kawamata, Takuya Matsuzaki
Summary: This study investigated the Chiba composite section in central Japan through multiple sedimentological and geochemical analyses to establish high-resolution chemostratigraphy and reconstruct the paleoenvironments in detail. The results showed changes in organic matter sources and mixing ratios of marine vs. terrestrial organic matter at different Marine Isotope Stages, indicating variability in environmental conditions over time.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2021)
Article
Ecology
Takeshige Ishiwa, Yuki Tokuda, Takuya Itaki, Satoshi Sasaki, Yusuke Suganuma, Shintaro Yamasaki
Summary: The sediments around Antarctica provide valuable records of sea-level changes, but accessing field-based evidence of ice-sheet and sea-level change is challenging. Researchers used a portable sonar system to collect baseline data in East Antarctica for reconstructing sea-level and ice-sheet changes.
Article
Geosciences, Multidisciplinary
Kento Motomura, Shoichi Kiyokawa, Minoru Ikehara, Takashi Sano, Wouter Bleeker, Kentaro Tanaka, Tsubasa Miki, Yuji Sano
Summary: This study reports the record of major oxygenation events in shale samples from the Nuvilik Group in Cape Smith belt, Canada, providing key information about environmental transitions during the period of 2.0-1.8 billion years ago. The presence of quartz, white mica, pyrite, and pyrrhotite in the shale samples is noted as major components.
PRECAMBRIAN RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
T. Tonegawa, E. Araki, H. Matsumoto, T. Kimura, K. Obana, G. Fujie, R. Arai, K. Shiraishi, M. Nakano, Y. Nakamura, T. Yokobiki, S. Kodaira
Summary: Seismic wave extractions were performed using ambient noise records observed by distributed acoustic sensing (DAS) technology. It was shown that microseisms can be investigated at a local scale using DAS records observed in the ocean. P and Scholte wave extractions were successfully performed from ambient seafloor noise observed by DAS, indicating that the waves are originated from the pressure field at the sea surface.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geosciences, Multidisciplinary
Y. Nakamura, K. Shiraishi, G. Fujie, S. Kodaira, G. Kimura, Y. Kaiho, T. No, S. Miura
Summary: This article investigates the structural characteristics associated with variations in slip behavior on the plate boundary in the Nankai subduction zone. It reports the presence of a structurally anomalous region in the overriding plate, potentially with low velocity, at the boundary between the zone of large coseismic slip and the area producing slow earthquakes. This anomaly appears to be related to depth-dependent variations in plate boundary slip style and plate coupling in the central-western Nankai Trough.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
G. Kimura, Y. Nakamura, K. Shiraishi, G. Fujie, S. Kodaira, T. Tsuji, R. Fukuchi, A. Yamaguchi
Summary: This study examines the geologic structure of the boundary region between the Kumano and Muroto domains off the Kii Peninsula and finds that upper plate composition plays a key role in controlling segmentation.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Shoichi Kiyokawa, Masaru Yasunaga, Takanori Hasegawa, Ayako Yamamoto, Daisaku Kaneko, Yuta Ikebata, Noriko Hasebe, Yukiyasu Tsutsumi, Mami Takehara, Kenji Horie
Summary: The Goto Islands, located at the westernmost tip of the Japan archipelago, preserve a lower-middle Miocene sedimentary sequence deposited during rifting of the continental margin and opening of the Sea of Japan.
Article
Geochemistry & Geophysics
Yanfang Qin, Yasuyuki Nakamura, Shuichi Kodaira, Gou Fujie
Summary: This study collected seismic data from different regions along the Japan trench during the 2011 Tohoku earthquake to investigate the impact of along-trench structures on seismic activities. The study found variations in geological structures, such as differences in sediment thickness and the presence of fold-and-thrust belts in the south. These structural variations influence shallow megathrust slip and tsunami generation.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Kento Motomura, Kenji Horie, Minoru Ikehara, Takashi Sano, Mami Takehara, Shoichi Kiyokawa
Summary: After the Great Oxidation Event, Earth's atmosphere and surface ocean were oxygenated, resulting in significant changes in the environment and biology. Positive nitrogen isotopic compositions in marine deposits from the Paleoproterozoic era indicate aerobic nitrogen cycling and the availability of bioavailable nitrate, but the nitrogen cycling in freshwater environments remains unclear. Through analysis of black shales in the late Paleoproterozoic Embury Lake Formation, it was found that the formation accumulated in a sulfate-poor freshwater basin and had depleted nitrogen conditions. The nitrogen isotopic compositions suggest a nitrate-limited environment, which is different from coeval marine deposits. Nitrate depletion in the freshwater basin is proposed, while nitrate was available for nitrate-assimilating organisms in the ocean during the late Paleoproterozoic.
Article
Geosciences, Multidisciplinary
Satoru Baba, Eiichiro Araki, Yojiro Yamamoto, Takane Hori, Gou Fujie, Yasuyuki Nakamura, Takashi Yokobiki, Hiroyuki Matsumoto
Summary: Off Cape Muroto area in southwest Japan, which is located along the Nankai Trough, is a typical area with both slow and megathrust earthquakes. To better understand the tectonic conditions, high-resolution monitoring of slow earthquakes is necessary. In this study, distributed acoustic sensing (DAS) measurement was conducted using offshore fiber-optic cable to observe shallow tremors, a type of slow earthquakes, for the first time. The tremor signals recorded by DAS had longer durations and consisted of several phases with apparent velocities coherent only in tens of meters, providing information about the spatial relationship between slow earthquakes and structural characteristics.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Mutsumi Iizuka, Osamu Seki, David J. Wilson, Yusuke Suganuma, Keiji Horikawa, Tina van de Flierdt, Minoru Ikehara, Takuya Itaki, Tomohisa Irino, Masanobu Yamamoto, Motohiro Hirabayashi, Hiroyuki Matsuzaki, Saiko Sugisaki
Summary: Sedimentary records from offshore of the East Antarctic Ice Sheet provide evidence for two ice loss events during the Last Interglacial period, leading to elevated sea levels similar to the present day. Understanding Antarctic ice-sheet dynamics during this period can provide valuable insights for predicting future sea-level change. A high-resolution record from the Wilkes Subglacial Basin reveals fluctuations of the ice sheet, with thinning, melting, and potentially retreat during both early and late stages of the Last Interglacial.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Ryuta Arai, Seiichi Miura, Yasuyuki Nakamura, Gou Fujie, Shuichi Kodaira, Yuka Kaiho, Kimihiro Mochizuki, Rie Nakata, Masataka Kinoshita, Yoshitaka Hashimoto, Yohei Hamada, Kyoko Okino
Summary: Geological research in the Hyuga-nada area of Japan reveals the importance of vertical fluid pathways within the overriding plate for slip behaviors and the formation of mud volcanoes.
NATURE COMMUNICATIONS
(2023)
Article
Geosciences, Multidisciplinary
Yasuyuki Nakamura, Shuichi Kodaira, Gou Fujie, Mikiya Yamashita, Koichiro Obana, Seiichi Miura
Summary: By collecting seismic profiles along the Japan Trench, this study examined the structural characteristics of the incoming Pacific plate. It found that the thickness of the incoming sediments decreased closer to the earthquake occurrence zone, with a minimum thickness near the 2011 Tohoku earthquake location. The distribution and dip direction of normal faults also varied along the trench, potentially corresponding to different slip styles along the plate boundary.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2023)
Article
Environmental Sciences
Yusuke Suganuma, Heitaro Kaneda, Martim Mas E. Braga, Takeshige Ishiwa, Takushi Koyama, Jennifer C. Newall, Jun'ichi Okuno, Takashi Obase, Fuyuki Saito, Irina Rogozhina, Jane Lund Andersen, Moto Kawamata, Motohiro Hirabayashi, Nathaniel A. Lifton, Ola Fredin, Jonathan M. Harbor, Arjen P. Stroeven, Ayako Abe-Ouchi
Summary: This study suggests that a regional sea-level highstand triggered rapid thinning of the East Antarctic Ice Sheet during the Holocene. The findings provide important geological records for ice sheet changes and sea-level rise, and contribute to model validation.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Shoichi Kiyokawa, Takashi Kuratomi, Tatsuhiko Hoshino, Shusaku Goto, Minoru Ikehara
Summary: Hydrothermal iron-oxyhydroxide chimney mounds have been discovered in a fishing port in Nagahama Bay, Japan. These mounds accumulate rapidly through biogenic activity, with bacterial stalks containing FeOH colloidal matter. This challenges previous theories on the formation of iron mounds and provides valuable insights into ancient iron formations.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2021)
