Atsushi Yasuda

Magma Plumbing System beneath Kirishima-Ohachi Volcano: Constraints from Olivine-hosted Melt Inclusions of the AD 1235 Takaharu Scoria Eruption

Hidemi Ishibashi, Yoshiharu Iwaki, Toru Ishikawa, Natsumi Hokanishi et autres

Major element composition analyses are conducted on melt inclusions (MIs) and their host olivine phenocrysts in Takaharu scoria, which erupted at AD 1235 from Ohachi volcano, Kirishima volcano group, SW Japan, to investigate the magma plumbing system beneath the volcano. Olivine-hosted MIs …

jp, ie, us (code pays fourni par la source)

Crystal clots record stable mush conditions and rapid pre-eruptive heating beneath Unzen volcano (1991–1995)

Kurumi Iwahashi, Atsushi Yasuda, Hidemi Ishibashi, Natsumi Hokanishi

The condition of a crystal-rich, mushy magma reservoir plays a crucial role in governing both the processes leading up to volcanic eruptions and the style of eruption that follows. However, constraining its pre-eruptive state remains a significant challenge. In this study, we …

jp, us (code pays fourni par la source)

Intraperitoneal immune microenvironment and efficacy of intraperitoneal chemotherapy in patients with gastric cancer and peritoneal metastasis

Tomoya Nakanishi, Motohiro Imano, Masashi Kohda, Hiroaki Kato et autres

We investigated the role of the intraperitoneal immune microenvironment in the therapeutic response of gastric cancer with peritoneal metastasis to intraperitoneal paclitaxel. Gastric cancer with peritoneal metastasis has a poor prognosis, even with systemic chemotherapy. Although intraperitoneal paclitaxel administration has demonstrated clinical …

jp (code pays fourni par la source)

Drone magnetic surveys for active volcanoes: a case study of Izu-Oshima volcano, Japan

Shigeo Okuma, Tadashi Nakatsuka, Ayumu Miyakawa, Masahiko Makino et autres

Aeromagnetic surveys using unmanned aerial vehicles (UAVs), or drones, are becoming popular as a useful subsurface survey method, especially in active volcanic regions. In this study, the results were compared for magnetic surveys using an unmanned autonomous helicopter (UAH) and a multicopter …

jp, us (code pays fourni par la source)

Principal Component Analysis of the Color of Bulk Ash Samples at Sakurajima Volcano, Southwest Japan

Taketo Shimano, Atsushi Yasuda, Masato Iguchi

We conducted principal component analysis on the colorimetric data of dried bulk ash samples collected daily between 2009 and 2015 at Sakurajima Volcano, southwest Japan. The CIE L*a*b* color system describes the colorimetric values. The analysis was performed for different sets of …

jp (code pays fourni par la source)

Transition from growth to collapse of the Plinian column during the 1783 eruption of Asama volcano, Japan, inferred from rock microtextures

Tatsuki Mizuno, Fukashi Maeno, Atsushi Yasuda

The 1783 eruption of Asama volcano was the most recent high-magnitude explosive eruption (VEI 4) in central Japan. During the climactic phase, the eruption transitioned from the formation of Plinian columns to the generation of pyroclastic density currents (PDCs). This study identified …

jp (code pays fourni par la source)

Characteristics of drifting pumice collected several weeks after the earthquakes in October 2023 near Izu-Torishima

Kurumi Iwahashi, Osamu Ishizuka, Masataka Kawaguchi, Teruki Oikawa et autres

Drifting pumices provide important clues for determining the activity of submarine volcanoes. On October 8, 2023, a tsunami hypothetically caused by a submarine eruption occurred near Izu-Torishima in the Izu-Bonin Arc. Later that month, two types of drifting pumice, white and gray, …

jp, us (code pays fourni par la source)

Petrological constraints on magma storage conditions during ongoing post-caldera volcanism at Ioto volcano, Ogasawara, Japan

Takahiro Miwa, Masashi Nagai, Tomofumi Kozono, Setsuya Nakada et autres

jp (code pays fourni par la source)

Changes in the magmatic plumbing system associated with the Gotemba sector collapse at Mount Fuji, Japan

Atsushi Yasuda, Yasuhisa Tajima

It is well known that magmatic plumbing systems change over time, but there is much debate as to why and how. We studied volcanic ejecta continuously deposited in an outcrop at Kagosaka Pass at the eastern base of Mount Fuji to investigate …

jp (code pays fourni par la source)

Improvement of the two-stage Stirling cooler below 20K

Atsushi Yasuda, Kiyomi Otsuka, Shoji Tsunematsu, Yoshikatsu HIRATSUKA et autres

Abstract Sumitomo Heavy Industries, Ltd. (SHI) supplies 4K-class and 1K-class cooler for space use. The 4K-class and 1K-class cooler consists of Joule-Thomson (JT) cooler and two-stage Stirling cooler as a pre-cooler. To improve the cooling capacity of 4K-class and 1K-class coolers, we …

jp (code pays fourni par la source)

Transition from Growth to Collapse of the Plinian Column During the 1783 Eruption, Asama Volcano, Japan, Inferred from Rock Microtextures and Physical Properties

Tatsuki Mizuno, Fukashi Maeno, Atsushi Yasuda

jp (code pays fourni par la source)

Temporal change in eruption style during the basaltic explosive An’ei eruption of the Izu-Oshima volcano, Japan: insights from stratigraphy and chemical composition analyses

Yuya Ikenaga, Fukashi Maeno, Atsushi Yasuda

Basaltic eruptions sometimes show an explosive and complex nature; thus, clarifying the sequence and controlling parameters is essential for understanding their causes. The An’ei eruption of the Izu-Oshima volcano during 1777–1792 was a complex basaltic eruption producing lava flows, pyroclastic falls, and …

jp (code pays fourni par la source)