High-flux gaseous hydrogen emissions in a back-arc basin: Qianyuan vents

<br>Data S1. Raman spectra of Qianyuan vents fluids and mixed gas hydrates collected in the gas collection tank.<br>Movie S1.<i> </i><i>In situ</i> detection of gas components at the Qianyuan vents using in situ Raman spectroscopy.Movie S2. Collection of gases from the Qianyuan vents using a gas collection tank and evaluation of the hydrogen flux at the Qianyuan vents based on this.Movie S3.<i> </i><i>In situ</i> Raman spectra collection from gases in the gas collection tank by inserting the Raman spectroscopy probe, detecting the formation of mixed gas hydrates.