摘要
冲绳海槽作为西太平洋活跃的弧后盆地,蕴藏大量天然气水合物资源,其分解驱动的甲烷泄漏对全球碳循环具有重要影响。本研究构建末次冰期至2100 AD冲绳海槽冷泉区底水温度时间序列,结合数值模型(水合物相态模型、稳定带分布模型、资源量经验模型),定量评估了底水温度上升与海平面变化对冲绳海槽冷泉区水合物稳定性的多尺度效应。结果表明:末次冰期(1.94±0.8℃)水合物稳定带深82.7±14.8 m,资源量0.17±0.03 Gt。末次冰期后,尽管海平面上升150 m产生的静压力补偿了约60%的底水温度上升对水合物稳定性的影响,但底水温度上升2.1±0.4℃,引发了水合物分解,水合物资源量降至0.14±0.02 Gt(1985年)。近几十年来,随着全球变暖趋势的加剧,冲绳海槽冷泉区底水温度从3.5±1.09℃升至4.5±0.82℃,水合物稳定带深度缩减约3.3 m,水合物资源量衰减21%。结合全球气候模型,发现当前阶段至2100 AD研究区内底水温度将进一步提升到6.6±0.93℃,稳定带深度缩减至61.6±4.8 m,资源量降至0.05±0.01 Gt。本研究揭示气候变暖下冲绳海槽水合物分解的响应机制,强调其作为区域碳源对全球收支的潜在贡献,为气候模型优化与生态风险评估提供关键约束。
The Okinawa Trough,an active back-arc basin in the western Pacific,hosts vast natural-gas-hydrate reserves whose dissociationdriven methane seepage exerts a non-negligible influence on the global carbon cycle.We constructed a bottom-water temperature(BWT)time series from the Last Glacial Maximum(LGM)to 2100 AD,and combined it with numerical modules(hydrate phase-equilibrium,stability-zone distribution,and resource empirical models)to quantify the multi-scale impacts of BWT rise and sea-level change on hydrate stability.Results show that in the LGM(1.94±0.8℃),the gas hydrate stability zone(GHSZ)extended to 82.7±14.8 m below seafloor and the hydrate inventory totaled to 0.17±0.03 Gt.After LGM,although a 150-m sea-level rise supplied hydrostatic compensation that offset~60%of the warming effect on hydrate stability,a BWT increase of 2.1±0.4℃ triggered dissociation,reducing the inventory to 0.14±0.02 Gt by 1985.In recent decades,accelerating global warming has raised BWT from 3.5±1.09℃ to 4.5±0.82℃,shoaling the GHSZ by~3.3 m and eroding the hydrate mass by 21%.Coupled with CMIP6 climate projections,we estimated that BWT would reach 6.6±0.93℃ by 2100 AD,thinning the GHSZ to 61.6±4.8 m and shrinking the resource to 0.05±0.01 Gt.This study unveils the response mechanism of Okinawa Trough hydrates to climatic warming and highlights their potential contribution as a regional carbon source to the global budget,providing critical constraints on climate-model refinement and ecological-risk assessment.
作者
徐思南
李世兴
张喜林
耿威
曹红
翟滨
张栋
陈烨
徐翠玲
吕泰衡
周渝程
侯晓帆
吴自军
辛梅
孙治雷
XU Sinan;LI Shixing;ZHANG Xilin;GENG Wei;CAO Hong;ZHAI Bin;ZHANG Dong;CHEN Ye;XU Cuiling;LV Taiheng;ZHOU Yucheng;HOU Xiaofan;WU Zijun;XIN Mei;SUN Zhilei(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266237,China;Laboratory for Marine Mineral Resources,Qingdao Marine Science and Technology Center,Qingdao 266237,China;State Key Laboratory of Marine Geology,School of Ocean and Earth Science,Tongji University,Shanghai 200092,China;Qingdao Marine Management and Assurance Center,Qingdao 266000,China)
出处
《海洋地质与第四纪地质》
北大核心
2025年第6期93-102,共10页
Marine Geology & Quaternary Geology
基金
山东省重点研发计划(重大科技创新工程)(2023CXGC010401)
山东省博士后创新项目(SDCX-ZG-202302026)
国家自然科学基金(42406046,42476082,42176057,92358301)
中国博士后科学基金项目(2023M741869)
同济大学海洋地质国家重点实验室开放课题(MGK202418)。
关键词
碳循环
冷泉甲烷泄漏
水合物稳定带
气候变暖
冲绳海槽
carbon cycle
cold seep methane leakage
hydrate stability zone
global warming
Okinawa Trough
