In November 2016, we revisited the sites near the epicenter of the 2011 Tohoku-Oki earthquake to collect seawater and sediment samples. Sediment pore water results show that detectable mantle-derived He provided by high-pressure fluids during the 2011 Tohoku-oki earthquake may not exist any more in the area.

Validation by certified reference material (CRM) is important for guarantees of sample analysis. CRM of airborne particles and source materials can be used for validation of PM2.5 samples. Manual for PM2.5 chemical analysis (Ministry of environment, 2013) shows 30 elements as subjects. However, any CRM aren’t certified for all subject elements. 54 elements of airborne particles source CRMs were quantified to compare among researchers. These CRM’s lead isotope ratios which is a useful tracer of airborne particles were analyzed, too. Finally, airborne particles source CRMs were characterized by element composition and lead isotope ratio.

In this study, we aim to investigate the relation with fault and hot spring aquifer by measuring the amount of carbon dioxide released from the ground surface in the Beppu area. Active faults are concentrated in the Beppu area and active volcanoes such as Tsurumidake, Gaien Dake, Yufu-dake are located there. Allis & Yusa (1989) estimated the geothermal distribution at 100 m underground in the Beppu area. According to it, there are high temperature parts in the two parts of the Beppu area in the north and the south.It is located along the fault. In this study, the amount of carbon dioxide released from the soil was measured in the surrounding area of ​​the Horita fault and the Asamigawa fault in the southern part. As a result, the released amount of carbon dioxide shows high values ​​in areas along the Horita fault and the Asakigawa fault and in areas deviated from the faults to the north.It is suggested that the carbon dioxide released from the deep hot spring aquifer rises inside crust and it is measured as a high value at the surface.

Satsuma-Iwojima is a volcanic island belongs to Kikai Caldera. Along and beneath the shoreline, there are several hot springs. We collected and analyzed hot spring waters emanated from the seafloor in Nagahama Bay located in southwestern part of the island. The results are interpreted by a model that single source of Fe-rich hot spring is emanated from the seafloor and mixed with seawater. The seafloor hot spring is considered as one of Fe-rich hot springs that distribute around Inamura dake composed of basaltic rocks.

To estimate the origin of methane at ancient methane seeps, this study attempted to extract and analyze residual gases within a Miocene methane-seep carbonate collected at Joetsu, central Japan. Methane was liberated by acid digestion of powdered carbonates. The stable carbon isotopic composition of the methane indicated both biogenic and thermogenic origins. A weak positive correlation between carbon isotopic compositions of the methane and the carbonate suggests that the methane contained in the Miocene seep fluid was preserved within the host carbonate cements. Smaller amounts of methane were also liberated by heating and crushing carbonate chips, showing isotopic compositions similar to those liberated by the acid digestion. Methane could be adsorbed to surfaces of the carbonate crystals or entrapped within intercrystalline pore spaces or crystal inclusions. However, it cannot be ruled out that thermogenic gases were secondary entrapped within the carbonate during its burial.

The climate of Venus is governed by fast atmospheric circulation and sulfuric acid clouds. The Venus explorer Akatsuki monitors the variability of the three-dimensional structure of the atmosphere by using multiple wavelength imaging and radio wave sounding. In this talk the changing views of Venus' atmospheric circulation and cloud system are introduced.

Zao volcano is one of representative active stratovolcanoes in NE Japan, and has ca. 1 m.y. eruption history. From 2013, many precursory phenomena, such as volcanic tremors and slight uplift of summit area, have been detected. Noble gas data are very important to evaluate the volcanic activity, thus we performed noble gas analysis on the lake water and hot spring waters of Zao volcano. As a result, the helium isotope ratio is similar to the atmospheric, but slightly higher than the atmospheric ratio. Thus, a contribution from the mantle component is suggested by our mixing analysis, which may derive from the magmatic gas, possibly altered by some crustal processes. Further, we tried to find the contribution from magmatic composition using He isotopic ratio. Here we discuss such a contribution for magmatic noble gas and the magma plumbing system in the newest volcanism of Zao volcano.

Using the existing technology on CO2-EOR and underground gas storage, we need the leakage monitoring and remediation techniques for the successful implementation of CO2 underground storage within sedimentary basins. Modelling of CO2 upward migration behavior is analogous to accumulation mechanisms of shallow methane gas hydrate, where the difference of solubilities and the other properties between CH4 and CO2 is taken into account.

From 16th November to 15th December 2016, hydrothermal field was drilled at Izena Hole in Okinawa Trough using D/V Chikyu. Five sites were drilled along the transect line from the top of the northern mound of the HAKUREI site to the east side, and 1 site about 500 m northwest of the mound as the reference site. From the collected cores, samples for headspace gas measurement and interstitial water extraction were taken on the ship. Regarding the interstitial water extracted from the sample, pH, alkalinity, nutrients and hydrogen sulfide concentration on ship, and main elements concentration and boron isotopic ratio were measured on land. For samples for gas measurement, hydrocarbon and hydrogen concentrations were measured on ship and carbon isotopic ratios of methane on land.