Helium degassing related to the Kobe earthquake

Geochemistry of dissolved gases from the Eastern Carpathians - Transylvanian Basin boundary

“…Recent studies show the role of dissolved gases in active tectonic settings, volcanic and non-volcanic areas (Sano et al, 1998(Sano et al, , 2004Hilton et al, 2002;Shaw et al, 2003;Chiodini et al 2004Chiodini et al , 2011Yang et al, 2005;De Leeuw et al, 2007;Italiano et al 2009Italiano et al , 2014Ray et al, 2009;Ohba et al, 2010;Pinti et al, 2011;Barry et al, 2013;Sano and Fischer, 2013;Marrero-Diaz et al 2015;Inguaggiato et al 2016;Benavente et al 2016;Birke et al, 2016;). Venting of highly mineralized (TDS>1000 mg/L) sparkling groundwater is a common feature along the Eastern Carpathians making the area an important water resource for Romania.…”

Construction of a Newly Designed Small-Size Mass Spectrometer for Helium Isotope Analysis: Toward the Continuous Monitoring Of 3He/4He Ratios In Natural Fluids

“…Helium in several geochemical reservoirs of the Earth has characteristic isotopic ratios, i.e., 3 He/ 4 He= 1.4×10 −6 in air, 1.1×10 −5 in the upper mantle, and <10 −7 in the crust, resulting in a wide range of 3 He/ 4 He ratios of more than three orders of magnitude in geochemical/geological samples. 1,2) e di usivity of helium is very high compared to other geochemical tracers because of its low molecular weight and chemical inertness.…”

“…Moreover He can escape from the Earth's atmosphere to outer space because of its high velocity in the upper atmosphere, resulting in low concentrations of He in the atmosphere (5.2 ppm). ese features make the 3 He/ 4 He ratio a very sensitive tracer for the transportation of volatiles and identi cation of their source reservoirs. erefore, if we continuously monitor the isotopic ratio of He in uids derived from the interior of the Earth, it would be possible to detect a change of 3 He/ 4 He ratio resulting from He release with various 3 He/ 4 He ratios from di erent reservoirs as the result of seismic or volcanic activities occurring in the crust and/or mantle.…”

“…ese features make the 3 He/ 4 He ratio a very sensitive tracer for the transportation of volatiles and identi cation of their source reservoirs. erefore, if we continuously monitor the isotopic ratio of He in uids derived from the interior of the Earth, it would be possible to detect a change of 3 He/ 4 He ratio resulting from He release with various 3 He/ 4 He ratios from di erent reservoirs as the result of seismic or volcanic activities occurring in the crust and/or mantle. For example, variations in 3 He/ 4 He ratios in groundwater samples have been observed a er earthquakes, which were considered to be the result of changes in groundwater ow systems due to the destruction of brittle, crustal rocks associated with earthquakes.…”

“…erefore, if we continuously monitor the isotopic ratio of He in uids derived from the interior of the Earth, it would be possible to detect a change of 3 He/ 4 He ratio resulting from He release with various 3 He/ 4 He ratios from di erent reservoirs as the result of seismic or volcanic activities occurring in the crust and/or mantle. For example, variations in 3 He/ 4 He ratios in groundwater samples have been observed a er earthquakes, which were considered to be the result of changes in groundwater ow systems due to the destruction of brittle, crustal rocks associated with earthquakes. [3][4][5] Sano et al 6) reported post-eruptive increase in 3 He/ 4 He ratios in steam wells from volcanic islands, possibly resulting from additional magmatic He discharges from activated magmas.…”