Articles

Ionospheric responses to the 21 August 2017 solar eclipse by using data assimilation approach

Using the physics-based thermosphere-ionosphere model (NCAR-TIEGCM) with an ensemble Kalman filter, this study reports the first data assimilative analysis of the ionosphere responses to the solar eclipse on 2...

Authors: Chia-Hung Chen, Chien-Hung Charles Lin and Tomoko Matsuo

Simple evaluation of the degradation state of cultural heritage based on multi-view stereo

In this study, degradation of cultural heritage is discussed based on the comparison between the present shape of the Wareishi Rock Cliff Sculpture and its replica made 30 years ago through simple three-dimens...

Authors: Nobuaki Kuchitsu, Masayuki Morii, Shuji Sakai and Hiroki Unten

Day-to-day and short-term variabilities in the equatorial plasma bubble/spread F irregularity seeding and development

The background ionospheric conditions shaped by sunset electrodynamic processes are responsible for the development of equatorial plasma bubble (EPB)/equatorial spread F (ESF) irregularities of the post-sunset...

Authors: Mangalathayil Ali Abdu

Influence of microclimate on the directional dependence of sandstone pillar weathering in Angkor Wat temple, Cambodia

Angkor Wat temple, mainly composed of sandstone blocks, displays a type of religious architecture that signifies the worldviews of the Khmer and Hindu religions. The temple is a part of a UNESCO World Heritage...

Authors: Tetsuya Waragai and Yusuke Hiki

Using a climate-to-fishery model to simulate the influence of the 1976–1977 regime shift on anchovy and sardine in the California Current System

The influence of the well-known 1976–1977 regime shift on the Northern anchovy (Engraulis mordax) and the Pacific sardine (Sardinops caeruleus) populations in the California Current System (CCS) is investigated u...

Authors: Haruka Nishikawa, Enrique N. Curchitser, Jerome Fiechter, Kenneth A. Rose and Kate Hedstrom

Thermal maturity structures in an accretionary wedge by a numerical simulation

This study investigates the thermal maturity structure of the accretionary wedge along with the thermal history of sediments during wedge formation using a numerical simulation. The thermal maturity, which is ...

Authors: Ayumu Miyakawa, Masataka Kinoshita, Yohei Hamada and Makoto Otsubo

Geometrical dependence on the stress and slip tendency acting on the subduction megathrust of the Nankai seismogenic zone off Kumano

We assess the dependence of megathrust geometry near the updip edge of the Nankai seismogenic zone according to the slip tendency of the megathrust based on a reprocessed 3D PSDM seismic volume image and Inter...

Authors: Masataka Kinoshita, Kazuya Shiraishi, Evi Demetriou, Yoshitaka Hashimoto and Weiren Lin

Pliocene integrated chronostratigraphy from the Anno Formation, Awa Group, Boso Peninsula, central Japan, and its paleoceanographic implications

The Pliocene climate is one of the best analogs for the climate of a globally warmer future. Here, we present a new Pliocene integrated chronostratigraphy from the Anno Formation in the uppermost Awa Group, wh...

Authors: Yuki Haneda and Makoto Okada

Perspective on the response of marine calcifiers to global warming and ocean acidification—Behavior of corals and foraminifera in a high CO₂ world “hot house”

The CO₂ concentration of air has increased over the last two centuries and recently surpassed 400 ppm. Carbon cycle models project CO₂ concentrations of 720 to 1000 ppm for the IPCC intermediate scenario (RCP 6.0...

Authors: Hodaka Kawahata, Kazuhiko Fujita, Akira Iguchi, Mayuri Inoue, Shinya Iwasaki, Azumi Kuroyanagi, Ayumi Maeda, Takuya Manaka, Kazuyoshi Moriya, Haruka Takagi, Takashi Toyofuku, Toshihiro Yoshimura and Atsushi Suzuki

Estimate of the contraction rate of central Japan through the deformation of the Philippine Sea slab

The Philippine Sea (PHS) slab is severely deformed beneath central Japan, but it is subject to little deformation before the subduction along the Nankai Trough. Thus, it is considered that the currently observ...

Authors: Yukitoshi Fukahata

Paleo-stress orientations and magnitudes from triaxial testing and stress inversion analysis in Nankai accretionary prism sediments

Combined knowledge on the magnitude as well as the orientation of paleo-stress is usually not given. Based on drilling investigations and laboratory experiments, we are able to provide both, constraints on pal...

Authors: Yoshitaka Hashimoto, Michael Stipp, Jonathan C. Lewis and Frank Wuttke

Cyclostratigraphy of the Late Miocene to Pliocene sediments at IODP sites U1425 and U1430 in the Japan Sea and paleoceanographic implications

High-resolution studies of sedimentary sequences have reconstructed paleoceanographic changes in the Atlantic and southern and equatorial Pacific Oceans during the Late Miocene and Pliocene, but comparable ana...

Authors: Shunsuke Kurokawa, Ryuji Tada, Kenji M. Matsuzaki, Tomohisa Irino and Lofi Johanna

High-resolution Quaternary record of marine organic carbon content in the hemipelagic sediments of the Japan Sea from bromine counts measured by XRF core scanner

The marine organic carbon content in sediments is a useful tool for reconstructing past productivity in the ocean. Bromine has been proposed as a useful proxy for marine organic carbon, since bromine is more c...

Authors: Arisa Seki, Ryuji Tada, Shunsuke Kurokawa and Masafumi Murayama

Deep-float salinity data synthesis for deep ocean state estimation: method and impact

The importance of deep ocean observations has been recognized with regard to changes in the deep ocean such as global bottom-water warming. Therefore, sustainable deep ocean monitoring networks that use autono...

Authors: Shuhei Masuda, Satoshi Osafune and Tadashi Hemmi

Preface to the special issue “High-definition topographic and geophysical data in geosciences”

Authors: Yuichi S. Hayakawa, Thad A. Wasklewicz, Hiroyuki Obanawa and Shigekazu Kusumoto

Spatio-temporal changes in the seismic velocity induced by the 2011 Tohoku-Oki earthquake and slow slip event revealed from seismic interferometry, using ocean bottom seismometer’s records

Seismic interferometry is one of the most effective techniques for detecting temporal variations in seismic velocity caused by large earthquakes. Before the 2011 Tohoku-Oki earthquake (M_w9.0) near the Japan Trenc...

Authors: Miyuu Uemura, Yoshihiro Ito, Kazuaki Ohta, Ryota Hino and Masanao Shinohara

Deep learning approach for detecting tropical cyclones and their precursors in the simulation by a cloud-resolving global nonhydrostatic atmospheric model

We propose a deep learning approach for identifying tropical cyclones (TCs) and their precursors. Twenty year simulated outgoing longwave radiation (OLR) calculated using a cloud-resolving global atmospheric s...

Authors: Daisuke Matsuoka, Masuo Nakano, Daisuke Sugiyama and Seiichi Uchida

A two million year record of low-latitude aridity linked to continental weathering from the Maldives

Indian-Asian monsoon has oscillated between warm/wet interglacial periods and cool/dry glacial periods with periodicities closely linked to variations in Earth’s orbital parameters. However, processes that con...

Authors: Tereza Kunkelova, Simon J. A. Jung, Erica S. de Leau, Nick Odling, Alex L. Thomas, Christian Betzler, Gregor P. Eberli, Carlos A. Alvarez-Zarikian, Montserrat Alonso-García, Or M. Bialik, Clara L. Blättler, Junhua Adam Guo, Sébastien Haffen, Senay Horozal, Anna Ling Hui Mee, Mayuri Inoue…

FTIR microspectroscopy of carbonaceous matter in ~ 3.5 Ga seafloor hydrothermal deposits in the North Pole area, Western Australia

Carbonaceous matter in ~ 3.5 Ga hydrothermal vein deposits from the Dresser Formation, Western Australia, was analyzed using Fourier transform infrared (FTIR) microspectroscopy. Based on the spectroscopy, the ...

Authors: Motoko Igisu, Yuichiro Ueno and Ken Takai

A laboratory experiment on salt weathering by humidity change: salt damage induced by deliquescence and hydration

A laboratory experiment on salt weathering was carried out under changing humidity conditions. Three types of rock (tuff and dense and porous sandstone) with sodium chloride, sodium sulfate, or magnesium sulfa...

Authors: Masato Sato and Tsuyoshi Hattanji

Dynamic spectral characteristics of high-resolution simulated equatorial plasma bubbles

Manifestations of severe nighttime equatorial ionospheric disturbances have been observed for decades. It is generally accepted that the phenomena are caused by large depletions, referred to as equatorial plas...

Authors: Charles Rino, Tatsuhiro Yokoyama and Charles Carrano

Asteroid Ryugu before the Hayabusa2 encounter

Asteroid (162173) Ryugu is the target object of Hayabusa2, an asteroid exploration and sample return mission led by Japan Aerospace Exploration Agency (JAXA). Ground-based observations indicate that Ryugu is a...

Authors: Koji Wada, Matthias Grott, Patrick Michel, Kevin J. Walsh, Antonella M. Barucci, Jens Biele, Jürgen Blum, Carolyn M. Ernst, Jan Thimo Grundmann, Bastian Gundlach, Axel Hagermann, Maximilian Hamm, Martin Jutzi, Myung-Jin Kim, Ekkehard Kührt, Lucille Le Corre…

δ¹⁸O and SST signal decomposition and dynamic of the Pliocene-Pleistocene climate system: new insights on orbital nonlinear behavior vs. long-term trend

The global LR04 δ¹⁸O, the tropical ODP Site 846 sea surface temperature (SST), and the global ΔSST stack records were investigated using the advanced method for time-series decomposition singular spectrum analysi...

Authors: Paolo Viaggi

Mantle-derived fluids in the Nankai Trough Kumano forearc basin

Noble gas abundance and isotope data from 12 drilling mud gas samples obtained during IODP Expeditions 338 and 348 provide new insights on fluid origin and fluid migration in the inner accretionary prism below...

Authors: Thomas Wiersberg, Sebastian B. Hammerschmidt, Shigeshi Fuchida, Achim Kopf and Jörg Erzinger

Punctuated growth of an accretionary prism and the onset of a seismogenic megathrust in the Nankai Trough

Ocean drilling in the Nankai Trough forearc suggests a new scenario for the evolution of the Nankai subduction zone. Continuous subduction since the Late Cretaceous has been a common tectonic scenario, althoug...

Authors: Gaku Kimura, Hiroaki Koge and Takeshi Tsuji

Seasonal variation in isotopic composition and the origin of precipitation over Bangladesh

Water isotopic composition (δ¹⁸O and δD) in terrestrial proxies of past precipitation enable us to better understand and interpret variation in the Indian Summer Monsoon (ISM). Previous studies have suggested tha...

Authors: Masahiro Tanoue, Kimpei Ichiyanagi, Kei Yoshimura, Masashi Kiguchi, Toru Terao and Taiichi Hayashi

Water on Mars: Do submarine cyclic steps exist on the red planet?

Submarine cyclic steps have a significant impact on the evolution of the ocean floor on Earth. These upper-flow regime bedforms should be even more common in Martian reduced-gravity environments. We postulate ...

Authors: Svetlana Kostic and Isaac B. Smith

Influence of substrate and temperature on the crystallization of KNO₃ droplets studied by infrared thermography

Salt crystallization is a major agent of deterioration in buildings, especially important when belonging to a city’s cultural heritage. The study of this process is therefore essential to understand the decay ...

Authors: Patricia Vazquez, Lucas Sartor and Céline Thomachot-Schneider

Cool, alkaline serpentinite formation fluid regime with scarce microbial habitability and possible abiotic synthesis beneath the South Chamorro Seamount

South Chamorro Seamount (SCS) is a blueschist-bearing serpentinite mud volcano in the Mariana forearc. Previous scientific drilling conducted at SCS revealed highly alkaline, sulfate-rich formation fluids resu...

Authors: Shinsuke Kawagucci, Junichi Miyazaki, Yuki Morono, Jeff S. Seewald, C. Geoff Wheat and Ken Takai

Regolith behavior under asteroid-level gravity conditions: low-velocity impact experiments

The dusty regolith covering the surfaces of asteroids and planetary satellites differs in size, shape, and composition from terrestrial soil particles and is subject to environmental conditions very different ...

Authors: Julie Brisset, Joshua Colwell, Adrienne Dove, Sumayya Abukhalil, Christopher Cox and Nadia Mohammed

Role of the capillary fringe on the dilatation of a low porosity limestone submitted to unidirectional freezing

As a rule, usually only one face of the building stones of a monument is exposed to climatic variations. Penetration of temperature and humidity stress is unidirectional from the external surface while capilla...

Authors: Celine Thomachot-Schneider, Emilie Huby, Kevin Chalons, Xavier Drothière and Patricia Vazquez

Correction to: Laboratory experiments on agglomeration of particles in a granular stream

In the publication of this article (Nagaashi et al., 2018), there was an error in eqs. (7) and (10).

Authors: Yuuya Nagaashi, Tomomi Omura, Masato Kiuchi, Akiko M. Nakamura, Koji Wada and Sunao Hasegawa

In-situ mechanical weakness of subducting sediments beneath a plate boundary décollement in the Nankai Trough

The study investigates the in-situ strength of sediments across a plate boundary décollement using drilling parameters recorded when a 1180-m-deep borehole was established during International Ocean Discovery ...

Authors: Yohei Hamada, Takehiro Hirose, Akira Ijiri, Yasuhiro Yamada, Yoshinori Sanada, Saneatsu Saito, Noriaki Sakurai, Takamitsu Sugihara, Takahiro Yokoyama, Tomokazu Saruhashi, Tatsuhiko Hoshino, Nana Kamiya, Stephen Bowden, Margaret Cramm, Susann Henkel, Kira Homola…

Dynamic formation process of thick deformation zone on the shallow plate boundary fault of the Japan Trench: insight from analog experiments of half-graben subduction

The 2011 Tohoku-oki earthquake unexpectedly ruptured to the shallowest portion of the plate boundary fault and triggered a large tsunami. The shallow portion had generally been regarded as a seismically stable...

Authors: Hiroaki Koge, Yasuhiro Yamada, Akihiro Ohde, Arthur Bauville, Asuka Yamaguchi and Juichiro Ashi

Arsenic cycling in the Earth’s crust and hydrosphere: interaction between naturally occurring arsenic and human activities

Field-based research on naturally occurring arsenic contamination of surface waters and groundwaters and the mechanisms of contamination are reviewed. The distribution of arsenic is strongly related to areas o...

Authors: Harue Masuda

Toward reduction of the uncertainties in climate sensitivity due to cloud processes using a global non-hydrostatic atmospheric model

In estimates of climate sensitivity obtained from global models, the need to represent clouds introduces a great deal of uncertainty. To address this issue, approaches using a high-resolution global non-hydros...

Authors: Masaki Satoh, Akira T. Noda, Tatsuya Seiki, Ying-Wen Chen, Chihiro Kodama, Yohei Yamada, Naomi Kuba and Yousuke Sato

Observation of equatorial plasma bubbles by the airglow imager on ISS-IMAP

Using 630 nm airglow data observed by an airglow imager on the International Space Station (ISS), the occurrence of equatorial plasma bubbles (EPBs) is studied. In order to examine the physical mechanisms in t...

Authors: Hiroyuki Nakata, Akira Takahashi, Toshiaki Takano, Akinori Saito and Takeshi Sakanoi

Three-dimensional mapping and kinematic characterization of mass transport deposits along the outer Kumano Basin and Nankai accretionary wedge, southwest Japan

Three-dimensional (3D) seismic data from the southern Kumano Basin of southwest Japan image a nested series of moderately sized mass transport deposits (MTDs) that slid from a slope along the seaward side of t...

Authors: Jason Lackey, Gregory Moore and Michael Strasser

Diurnal cycle over a coastal area of the Maritime Continent as derived by special networked soundings over Jakarta during HARIMAU2010

This study investigates the nature and mechanisms of the diurnal precipitation system over a coastal area of the Maritime Continent (MC) by utilizing the data from a field campaign, HARIMAU2010. During the 1-m...

Authors: Masaki Katsumata, Shuichi Mori, Jun-Ichi Hamada, Miki Hattori, Fadli Syamsudin and Manabu D. Yamanaka

Earthquake early warning: what does “seconds before a strong hit” mean?

An earthquake early warning (EEW) system is designed to detect an event, determine its parameters (hypocenter, magnitude, and origin time), and issue an alert to sites/areas where necessary actions should be t...

Authors: Fumiko Tajima and Takumi Hayashida

Temporal change in seismic velocity associated with an offshore M_W 5.9 Off-Mie earthquake in the Nankai subduction zone from ambient noise cross-correlation

The Nankai subduction zone off the Kii Peninsula, Japan, has a large potential to generate megathrust earthquakes in the near future. To investigate the temporal variation of stress or strain in the Nankai sub...

Authors: Tatsunori Ikeda and Takeshi Tsuji

Surface deformation and source modeling of Ayaz-Akhtarma mud volcano, Azerbaijan, as detected by ALOS/ALOS-2 InSAR

Azerbaijan, located on the western edge of the Caspian Sea in Central Asia, has one of the highest populations of mud volcanoes in the world. We used satellite-based synthetic aperture radar (SAR) images deriv...

Authors: Kento Iio and Masato Furuya

Unseasonal development of post-sunset F-region irregularities over Southeast Asia on 28 July 2014: 2. Forcing from below?

An unseasonal development of Equatorial Plasma Bubble (EPB)/Equatorial Spread-F (ESF) activity in a wide longitudinal sector over India and Southeast Asia during the post-sunset hours of 28 July 2014 has been ...

Authors: K. K. Ajith, S. Tulasi Ram, B. A. Carter, S. Sathish Kumar, M. Yamamoto, T. Yokoyama, S. Gurubaran, S. Sripathi, K. Hozumi, K. Groves and R. G. Caton

Temporal changes in the internal stresses and pore pressures in a large-scale submarine mass transport deposit

We examined the temporal changes in the internal stresses and pore fluid pressures of a submarine mass transport deposit (MTD) in the Akkeshi Formation of the Upper Cretaceous–Paleocene Nemuro Group, eastern H...

Authors: Makoto Otsubo, Hajime Naruse and Ayumu Miyakawa

Geophysical constraints on microbial biomass in subseafloor sediments and coal seams down to 2.5 km off Shimokita Peninsula, Japan

To understand the ability of microbial life to inhabit a deep subseafloor coalbed sedimentary basin, the correlation between fluid transport properties and the abundance of microbial cells was investigated bas...

Authors: Wataru Tanikawa, Osamu Tadai, Yuki Morono, Kai-Uwe Hinrichs and Fumio Inagaki

Review of the generation mechanisms of post-midnight irregularities in the equatorial and low-latitude ionosphere

This paper provides a brief review of ionospheric irregularities that occur in magnetically equatorial and low-latitude regions post-midnight during low solar activity periods. Ionospheric irregularities can o...

Authors: Yuichi Otsuka

Revisiting ozone measurements as an indicator of tropical width

The total column ozone (TCO) amount varies with latitude, in part due to the difference in tropopause height between the tropics and midlatitudes. This dependency of TCO on latitude has been used to identify t...

Authors: Sean M. Davis, Birgit Hassler and Karen H. Rosenlof

Emissions of nitrous oxide (N₂O) from soil surfaces and their historical changes in East Asia: a model-based assessment

This study assessed historical changes in emissions of nitrous oxide (N₂O), a potent greenhouse gas and stratospheric ozone-depleting substance, from the soils of East Asia to the atmosphere. A process-based terr...

Authors: Akihiko Ito, Kazuya Nishina, Kentaro Ishijima, Shoji Hashimoto and Motoko Inatomi

Paleoceanographic history of the Japan Sea over the last 9.5 million years inferred from radiolarian assemblages (IODP Expedition 346 Sites U1425 and U1430)

Previous studies showed that the evolution of the Japan Sea paleoceanography since the Miocene has been influenced by the regional tectonism (e.g., opening/closing of the connecting seaways) and regional/globa...

Authors: Kenji M. Matsuzaki, Takuya Itaki, Ryuji Tada and Shin-ichi Kamikuri

Laboratory experiments on agglomeration of particles in a granular stream

Inelastic collisions occur among regolith particles, such as those in the ejecta curtain from a crater, and may cause clustering or agglomeration of particles and thus produce discrete patterns of ejecta depos...

Authors: Yuuya Nagaashi, Tomomi Omura, Masato Kiuchi, Akiko M. Nakamura, Koji Wada and Sunao Hasegawa