@article {chu_earthquake-enhanced_2023,
	title = {Earthquake-enhanced dissolved carbon cycles in ultra-deep ocean sediments},
	journal = {Nature Communications},
	volume = {14},
	year = {2023},
	month = {09/2023},
	pages = {5427},
	abstract = {Hadal trenches are unique geological and ecological systems located along subduction zones. Earthquake-triggered turbidites act as efficient transport pathways of organic carbon (OC), yet remineralization and transformation of OC in these systems are not comprehensively understood. Here we measure concentrations and stable- and radiocarbon isotope signatures of dissolved organic and inorganic carbon (DOC, DIC) in the subsurface sediment interstitial water along the Japan Trench axis collected during the IODP Expedition 386. We find accumulation and aging of DOC and DIC in the subsurface sediments, which we interpret as enhanced production of labile dissolved carbon owing to earthquake-triggered turbidites, which supports intensive microbial methanogenesis in the trench sediments. The residual dissolved carbon accumulates in deep subsurface sediments and may continue to fuel the deep biosphere. Tectonic events can therefore enhance carbon accumulation and stimulate carbon transformation in plate convergent trench systems, which may accelerate carbon export into the subduction zones., Earthquakes enhance dissolved carbon production and fuel the microbial activities in hadal trench subsurface sediments, and ultimately strengthen carbon accumulation and transformation in the subduction zones.},
	issn = {2041-1723},
	doi = {10.1038/s41467-023-41116-w},
	url = {https://www.nature.com/articles/s41467-023-41116-w},
	author = {Chu, Mengfan and Bao, Rui and Strasser, Michael and Ikehara, Ken and Everest, Jez and Maeda, Lena and Hochmuth, Katharina and Xu, Li and McNichol, Ann and Bellanova, Piero and Rasbury, Troy and K{\"o}lling, Martin and Riedinger, Natascha and Johnson, Joel and Luo, Min and M{\"a}rz, Christian and Straub, Susanne and Jitsuno, Kana and Brunet, Morgane and Cai, Zhirong and Cattaneo, Antonio and Hsiung, Kanhsi and Ishizawa, Takashi and Itaki, Takuya and Kanamatsu, Toshiya and Keep, Myra and Kioka, Arata and McHugh, Cecilia and Micallef, Aaron and Pandey, Dhananjai and Proust, Jean No{\"e}l and Satoguchi, Yasufumi and Sawyer, Derek and Seibert, Chlo{\'e} and Silver, Maxwell and Virtasalo, Joonas and Wang, Yonghong and Wu, Ting-Wei and Zellers, Sarah}
}
@article {2813,
	title = {Millennial-scale fluctuations in water volume transported by the Tsushima Warm Current in the Japan Sea during the Holocene},
	journal = {Global and Planetary Change},
	volume = {183},
	year = {2019},
	month = {Jan-12-2019},
	pages = {103028},
	abstract = {Cyclic changes in volume transport of the Tsushima Warm Current (TWC) have been argued from diatom records in the southern Japan Sea off the Japanese islands during the Holocene. Although this phenomenon has not yet been confirmed by various proxy data, determining whether or not these oceanographic changes occurred is crucial for clarifying the nature of oceanographic changes in the southern Japan Sea. Here, we conducted a coupled analysis of Mg/Ca ratios and oxygen isotopes (δ18O) in shallow-dwelling Neogloboquadrina incompta from 13 core-top sediments in southern Japan, and developed a new equation for Mg/Ca temperature calibration (Mg/Ca = 0.311 {\texttimes} exp (0.07 {\texttimes} T)) as a proxy for spring sea surface temperature (SST). Using the newly developed, species-specific Mg/Ca-paleothermometry, we reconstructed SST variability for the past 6800 years from core YK10-7-PC09 in the southern Japan Sea. The Mg/Ca-derived SST record clearly represented five warmer periods at 6200{\textendash}6000, 4900{\textendash}4500, 4200{\textendash}3800, 2600{\textendash}2100, and 900{\textendash}400 cal. year BP, almost consistent with previously published diatom records. These warmer events also corresponded to the periods in which warm molluscan assemblages increased at the northern end of the TWC, suggesting that periods of higher SST can be seen as reflecting the increased volume transport of the TWC. We interpreted the results of a model study showing that higher solar irradiance provoked positive Arctic Oscillation (AO)-like spatial patterns and the negative phase of the Pacific Decadal Oscillation (PDO) to mean that increased (reduced) TWC volume transport on the multi-centennial to millennial time scales was caused by high (low) solar insolation via a potential link between AO and PDO. Given that larger and more frequent volcanic eruptions occurred in the mid Holocene than in the late Holocene, volcanic forcing on the TWC volume transport changes would have been more significant during the former, as seen in the highly variable SST from this period and distinct decreases in SST around ~5900 cal. year BP and ~6400 cal. year BP. The millennial-scale fluctuations seen in SSTs in the southern Japan Sea would have had a large impact on the evolution of vegetation and human adaptation in the northern Japanese islands, adjacent to the Japan Sea, over the last 6800 years.},
	keywords = {Holocene, Mg/Ca-derived, Neogloboquadrina incompta, sea-surface temperature, Solar forcing, The Japan Sea, Tsushima, Warm Current},
	issn = {09218181},
	doi = {10.1016/j.gloplacha.2019.103028},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0921818118306465},
	author = {Horikawa, Keiji and Kodaira, Tomohiro and Ikehara, Ken and Murayama, Masafumi and Zhang, Jing}
}
@article {97,
	title = {Stratigraphy and wiggle-matching-based age-depth model of late Holocene marine sediments in Beppu Bay, southwest Japan},
	journal = {New Global Perspectives on Paleontology, Stratigraphy, Paleoceanography, Paleoclimatology, and Tectonics in the East Asia and Western Pacific},
	volume = {69},
	year = {2013},
	note = {id: 2295},
	pages = {133-148},
	abstract = {We analyzed the lithology, magnetic susceptibility, bulk density, and X-ray radiographs of 14 sediment cores (1{\textendash}9 m long) from Beppu Bay in the western Seto Inland Sea, Japan, to establish the late Holocene stratigraphy in the deepest part of the bay and to develop an age{\textendash}depth model for the sediments there. The cores contained 18 thick (major event) high-density layers (16 turbidites and two volcanic ash; >1 cm thick), and both lithological observations and density variations in the hemipelagic mud that is dominant in the cores revealed a further 55 thin (minor event) high-density layers (},
	issn = {1367-9120},
	doi = {10.1016/j.jseaes.2012.07.002},
	url = {http://www.sciencedirect.com/science/article/pii/S1367912012002957},
	author = {Kuwae, Michinobu and Yamamoto, Masanobu and Ikehara, Ken and Irino, Tomohisa and Takemura, Keiji and Sagawa, Takuya and Sakamoto, Tatsuhiko and Ikehara, Minoru and Takeoka, Hidetaka}
}
