Minako Kurisu

Japan Agency for Marine-Earth Science Technology | JAMSTEC · Research Institute for Marine Resources Utilization

Whether Inner Mongolia OIB-like basalts originate from the modern upper mantle [e.g. depleted MORB mantle (DMM)] with recycled oceanic crust in the form of pyroxenite or ancient primordial mantle (lower mantle) dominated by peridotite remains unclear. This study presents high-precision W-Fe isotopic data for Late Cenozoic Chifeng basalts (CBs) in I...

The host phase of iodine (I) in biogenic iron oxyhydroxides (BIOS) was determined using X-ray absorption near-edge structure (XANES). I K-edge and LIII-edge XANES analyses of BIOS collected from deep-sea hydrothermal environments revealed that the primary form of I in the BIOS is an organic species. Furthermore, LIII-edge XANES fitting implied the...

A key driver to develop stable tungsten (W) isotope geochemistry is its unique relationship with molybdenum (Mo). Here, we establish a combined double-spike (DS) methods for W (180W-184W spike) and...

The atmospheric deposition of iron (Fe) promotes primary production in the surface ocean, which results in the enhanced uptake of carbon dioxide into surface seawater. Given that microorganisms in seawater utilize dissolved Fe (d-Fe) as a nutrient, the bioavailability of Fe in aerosol particles depends on its solubility. However, the factors contro...

Internal radiation exposure from neutron-induced radioisotopes environmentally activated following atomic bombing or nuclear accidents should be considered for a complete picture of pathologic effects on survivors. Acute and localized high dose radiation exposure from hot particles taken into the body must induce cell death and severe damage to tis...

Atmospheric deposition of iron (Fe) in aerosol particles is enhanced primary production on the ocean surface, resulting in promoting the uptake of carbon dioxide into the surface seawater. Atmospheric deposition of iron (Fe) promotes primary production in the surface ocean, resulting in enhanced uptake of carbon dioxide into surface seawater. Since...

Zinc (Zn) in aerosols plays important roles for biological activity and attracts public attention from the perspective of environmental measures. Because of its high volatility and water solubility, Zn is readily released into the atmosphere by human activities and supplied to natural water. To explore the origin and formation process of Zn in atmo...

Atmospheric deposition is one of the main sources of dissolved iron (Fe) in the ocean surfaces. Atmospheric processes are recognized as controlling fractional Fe solubility (Fesol%) in marine aerosol particles. However, the impact of these processes on Fesol% remains unclear. One of the reasons for this is the lack of field observations focusing on...

Hydrothermal groundwater may have played many roles in hydrogeochemical cycles on early Mars, including being a source of cations and reductants, a sink of CO₂, and a causative fluid of post-depositional diagenesis. However, few laboratory experiments have been investigated hydrothermal reactions within the Martian crust. Here we describe hydrother...

In this study, we compared the high-energy resolution X-ray fluorescence X-ray absorption near-edge structure (HERFD-XANES) and normal XANES spectra of various iron (Fe) species and Fe in atmospheric aerosol samples to explore the advantages of Fe K-edge HERFD-XANES for Fe speciation in aerosols using the linear combination fitting (LCF) of XANES s...

Atmospheric deposition is one of the dominant sources of dissolved Fe on the ocean surface. Atmospheric processes are recognized as controlling fractional Fe solubility (Fesol%) in marine aerosol particles, but the impact of these processes on Fesol% remains unclear. One of the reasons for this is the lack of field observations focusing on the rela...

The source apportionment of aerosol iron (Fe), including natural and combustion Fe, is an important issue because aerosol Fe can enhance oceanic primary production in the surface ocean. Based on our previous finding that combustion Fe emitted by evaporation processes has Fe isotope ratios (δ56Fe) that are approximately 4 ‰ lower than those of natur...

The source apportionment of aerosol iron (Fe), including natural and combustion Fe, is an important issue because aerosol Fe can enhance oceanic primary production in the surface ocean. Based on our previous finding that combustion Fe emitted by evaporation processes has Fe isotope ratios (δ56Fe) that are approximately 4 ‰ lower than those of natur...

We have succeeded in operating a transition-edge sensor (TES) spectrometer and evaluating its performance at the SPring-8 synchrotron x-ray light source. The TES spectrometer consists of a 240 pixel National Institute of Standards and Technology (NIST) TES system, and 220 pixels are operated simultaneously with an energy resolution of 4 eV at 6 keV...

Internal radiation exposure from neutron-induced radioisotopes environmentally activated following atomic bombing or nuclear accidents should be considered for a complete picture of pathologic effects on survivors. Inhaled hot particles expose neighboring tissues to locally ultra-high doses of β-rays and can cause pathologic damage. 55MnO2 powder w...

Plain Language Summary Early Mars is believed to have possessed an abundance of liquid water on its surface. The Mars rover Curiosity has found both complex organic matter and bio‐essential elements within the lake deposits at Gale crater. To further understand habitability on early Mars, knowledge of the redox states of the aqueous environments is...

Combustion iron (Fe) in aerosols is one of the sources of dissolved Fe in the surface ocean. Iron isotope ratio (δ⁵⁶Fe) is an important tool for source apportionment of Fe, because combustion Fe emitted by evaporation possibly yields lower δ⁵⁶Fe values than natural materials. However, there are insufficient data of δ⁵⁶Fe for the combustion Fe. Henc...

Biomass burning is an important source of soluble Fe transported to the open ocean; however, its exact contribution remains unclear. Iron isotope ratios can be used as a tracer because Fe emitted by combustion can yield very low Fe isotope ratios due to isotope fractionation during evaporation processes. However, data on Fe isotope ratios of aeroso...

Marine ferromanganese oxides contain a large amount of trace elements such as arsenic (As) and molybdenum (Mo). However, the host phases of tetrahedral AsO43- and MoO42- oxyanions therein have not been clearly identified so far. In this work, we explored the mineralogical components of hydrogenetic (HG) ferromanganese nodules and compared the distr...

Atmospheric deposition of marine aerosols is one of the important sources of dissolved trace metals in the ocean. Analyses of trace metals and stable isotope ratios in size-fractionated aerosol particles using extraction experiments are useful to understand the dissolution behavior and biogeochemical cycles of trace metals in the marine environment...

Fe-kaolinite has been detected in granite saprolite beneath sedimentary kaolin deposits in the Seto district of central Japan. Granite saprolite, which was found underneath sedimentary kaolin deposits formed in fluvial and lacustrine environments, had been subjected to kaolinization. The clay fractions of granite saprolite consist mostly of kaolini...

Light-absorbing iron oxide (FeOx) aerosols such as magnetite contribute to shortwave atmospheric heating and possibly affect the biogeochemical cycle. However, their atmospheric abundance and emission sources are poorly understood. In this study, we quantified the abundance and mixing states of FeOx at two urban sites in Tokyo and Chiba, Japan, usi...

Seven size-fractionated aerosol samples were collected from Hiroshima, Japan, and were analyzed in terms of chemical composition, soluble fraction of iron (Fe), Fe species, and Fe isotope ratios. The results suggested that Fe in fine particles contained a larger fraction of anthropogenic aerosols than coarse particles did. Iron in the fine particle...

Particle surfaces of mineral aerosols are important reaction sites in the atmosphere. A previous study suggested that calcite in aerosols emitted during dust periods neutralizes sulfuric acid. In this study, depth-dependent X-ray absorption fine structure spectroscopy for individual particle was employed to determine calcium (Ca) species at particl...

Iron isotope ratios (δ56/54Fe) of various anthropogenic materials produced by combustion processes were analyzed. It was revealed that particles emitted through combustion processes, such as fine aerosols collected from a tunnel or fly ash (extracted by 1 M HCl solution), yielded much lower isotope ratios than other materials on the earth’s surface...