Gas Emissions From Volcanoes of the Kuril Island Arc (NW Pacific): Geochemistry and Fluxes

Abstract

The Kuril Island arc extending for about 1,200 km from Kamchatka Peninsula to Hokkaido Island is a typical active subduction zone with ∼40 historically active subaerial volcanoes, some of which are persistently degassing. Seven Kurilian volcanoes (Ebeko, Sinarka, Kuntomintar, Chirinkotan, Pallas, Berg, and Kudryavy) on six islands (Paramushir, Shiashkotan, Chirinkotan, Ketoy, Urup, and Iturup) emit into the atmosphere > 90% of the total fumarolic gas of the arc. During the field campaigns in 2015–2017 direct sampling of fumaroles, MultiGas measurements of the fumarolic plumes and DOAS remote determinations of the SO2 flux were conducted on these volcanoes. Maximal temperatures of the fumaroles in 2015–2016 were 510°C (Ebeko), 440°C (Sinarka), 260°C (Kuntomintar), 720°C (Pallas), and 820°C (Kudryavy). The total SO2 flux (in metric tons per day) from fumarolic fields of the studied volcanoes was measured as ∼1,800 ± 300 t/d, and the CO2 flux is estimated as 1,250 ± 400 t/d. Geochemical characteristics of the sampled gases include δD and δ18O of fumarolic condensates, δ13C of CO2, δ34S of the total sulfur, ratios 3He/4He and 40Ar/36Ar, concentrations of the major gas species, and trace elements in the volcanic gas condensates. The mole ratios C/S are generally <1. All volcanoes of the arc, except the southernmost Mendeleev and Golovnin volcanoes on Kunashir Island, emit gases with 3He/4He values of >7RA (where RA is the atmospheric 3He/4He). The highest 3He/4He ratios of 8.3RA were measured in fumaroles of the Pallas volcano (Ketoy Island) in the middle of the arc.

Gas Emissions From the Western Aleutians Volcanic Arc

“…Trace gas N 2 , He, and Ar of Western Aleutian samples are shown in Figure 8 along with data from gas samples collected at other Alaska-Aleutian volcanoes (Evans et al, 2015;Symonds et al, 2003a) and from the geographically similar Kuril Island Arc (Taran et al, 2018). Our data display a range in compositions typical of arc gases world-wide (Giggenbach, 1996) with N 2 /He ratios generally >1,000 and He/Ar ratios affected by variable amounts of mixing with air or air-saturated water.…”

TROPOMI enables high resolution SO2 flux observations from Mt. Etna, Italy, and beyond

“…SO 2 is thus a precious and widely used proxy of volcanic activity and routinely measured with ground-based optical instruments 2,10–13 . While ground-based SO 2 measurements have allowed priceless insights into the inner workings of volcanoes and the effect of volcanic SO 2 degassing on the Earth system, most volcanoes still lack an observational database 14,15 , particularly in regions that have highly active but remote volcanic emitters such as Indonesia or the Kuril Islands and Kamchatka 16,17 .…”

Research agenda for the Russian Far East and utilization of multi-platform comprehensive environmental observations

“…The previous eruption data in Kamchatka and Kurile Islands indicate a significant contribution of volcanic activity to the atmospheric gas emissions (e.g. Carn et al 2017;Taran et al 2018). The effect has been registered over a major part of the northern hemisphere.…”

“…The relative hydrogen content in some cases reaches very high values, up to 39% in Cherny volcano in Chirpoi Island. Currently, there are no reliable estimates of the greenhouse gas emissions from the volcanoes of the Kuril Islands and Kamchatka (Taran et al 2018). It is necessary to carry out comprehensive studies using a suite of gas analyzers to monitor the ambient concentrations and quantify the greenhouse gas emissions from the volcanoes in the region.…”