Gold and other metals (Cu, Zn, Ag, etc.) are enriched in vent fluids, approximately 3–5 orders of magnitude higher than those in seawater, and this leads to the formation of sulfide enrichment in Cu, Zn, Au, and Ag deposited on the mid-ocean ridge and island arcs, as well as in back-arc basins. We developed a device that can extract the elements such as Cu, Zn, Au, and Ag from the vent fluids before the formation of the hydrothermal plume, sulfide deposit, and metalliferous sediment at the seafloor over a long period, which is beneficial to collecting hydrothermal resources effectively and avoiding the damage of ecological environments caused by mining the polymetallic sulfide resources. The application of this device will have significance for the development and utilization of seafloor hydrothermal resources, the sustainable development and implementation of the blue economy, and the construction of the marine ecological civilization in the future.

Fluorine and chlorine are important tracers for geochemical and environmental studies. In this study, a rapid alkaline digestion (NaOH) method for the simultaneous determination of fluorine and chlorine in marine and stream sediment reference samples using ion chromatography is developed. The proposed method suppresses the volatilization loss of fluorine and chlorine and decreases the matrix effects. The results are in good agreement with fluorine ~100%, chlorine ranging from 90 to 95% of the expected concentrations. The detection limits of this method were 0.05 μg/g for fluorine and 0.10 μg/g for chlorine. This method is simple, economical, precise and accurate, which shows great potential for the rapid simultaneous determination of fluorine and chlorine in large batches of geological and environmental samples commonly analyzed for environmental geochemistry studies.

Utilizing seawater samples collected during the summer of 2025 in the Dingzi Bay region, South Yellow Sea, this study conducted a comprehensive analysis of the contents and concentrations of dissolved gases (N₂, O₂, Ar, CO₂) and hydrocarbon gases (such as methane, ethane, and propane). The findings reveal that the dissolved gases in the study area are predominantly composed of N₂ and O₂, with average proportions of 77.8% and 21.6%, respectively. Notably, significant CO₂ anomalies were detected at certain stations, which may indicate intense organic matter degradation or the introduction of external fluids. Furthermore, wet gas constituents, including propane, butane, and isobutane, were identified in several samples, suggesting potential submarine oil and gas seepage or subsurface thermogenic gas input. Spatial analysis revealed that anomalous points were primarily concentrated at stations CJ01, CJ08, CJ10, and CQ01, with no significant correlation to water depth, suggesting that their distribution may be influenced by local geological structures or bottom currents. This study elucidates the complexity and heterogeneity of dissolved gas composition in the waters of Dingzi Bay, thereby providing a novel scientific foundation for regional carbon cycle research, seabed resource exploration, and marine environmental monitoring.

High-resolution marine sedimentary archives from active continental margins provide exceptional records of paleo-earthquake histories through the preservation of seismogenic turbidites. A 477cm long gravity core (HOBAB4-S2) retrieved from the southern Okinawa Trough (SOT) off eastern Taiwan at a water depth of 1505 m preserves a ~700-year record (1445–2003 AD) of alternating hemipelagic background sedimentation and rapid event deposits. Chronological control is established through accelerator mass spectrometry (AMS ¹⁴C) radiocarbon dating and excess ²¹⁰Pb profiling. Detailed sedimentological and geochemical analyses identify fifteen turbidite events (T1–T15), which are grouped into three lithofacies: TI (silt turbidites), TII (sandy silt turbidites), and TIII (silty sand turbidites). Temporal correlation demonstrates that the majority of these turbidite beds coincide with documented historical and instrumental earthquakes (M_w ≥ 6.6), confirming seismic shaking as the primary triggering mechanism. Notably, turbidite thickness, basal grain size and recurrence frequency increase during the Little Ice Age (LIA, ~1400–1850 AD), a pattern we attribute to enhanced terrestrial sediment supply driven by intensified typhoon activity, which preconditioned the slope system for seismically induced failure. These findings demonstrate that turbidite sequences in the SOT provide a reliable record of local paleo-earthquake activity, while establishing that their stratigraphic expression is modulated by climatically driven sedimentary preconditioning. This principle is critical to paleoseismic reconstruction in seismically active, storm-prone continental margins globally.