| 福建沿海全新世相对海平面变化:地质记录与“冰川?水均衡调整”模拟对比 |
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| 引用本文： | 王龙,王张华,李翠玉.福建沿海全新世相对海平面变化:地质记录与“冰川?水均衡调整”模拟对比[J].海洋学报,2022,44(9):109-123. |
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| 作者姓名： | 王龙 王张华 李翠玉 |
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| 作者单位： | 1.华东师范大学 河口海岸学国家重点实验室，上海 200241 |
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| 基金项目： | 国家留学基金委基金（201806140081） |
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| 摘 要： | 重建高质量的全新世相对海平面变化曲线，可为海岸带人类社会科学预测及应对未来海平面上升风险提供重要的地质历史依据和长时间尺度的数据参考。目前已发表了多条福建海岸带全新世相对海平面变化曲线，然而已有曲线反映的相对海平面变化历史存在较大差异，甚至是矛盾结果。同时，相对海平面长期变化机制及影响因素也不明确。本研究收集、整理了福建沿海已发表的全新世相对海平面数据，对已有数据的年代、高程、指示意义等属性信息进行重新检查和校正，根据国际方法体系，建立了该区域一个标准化的全新世“相对海平面数据库”，共包括海平面数据183个。在此基础上，采用“变量误差–综合高斯（EIV-IGP）”统计学模型，提出了一条新的福建沿海全新世相对海平面变化曲线。并应用“冰川–水均衡调整”（GIA）理论，开展了相对海平面变化GIA模拟。最后，综合相对海平面变化地质记录及GIA模拟结果，得出以下结论:（1）福建沿海距今11.28～7.08 cal ka，相对海平面由（–23.55±6.94）m快速连续上升至（–1.51±1.80）m；距今7.08～4.08 cal ka，相对海平面由（–1.51±1.80）m缓慢上升至约（1.09±1.38）m；距今3.48 cal ka前后，相对海平面高于现代海平面约（1.35±1.23）m；此后，波动下降并逐渐接近现代位置；（2）“冰川–水均衡调整”作用是福建全新世相对海平面变化的主要长期作用机制；距今11.28～7.00 cal ka，相对海平面变化主要受冰盖融水控制；距今7.00 cal ka以来，“水均衡调整”作用逐渐占据主导；（3）福建沿海中–晚全新世（距今6.75～0.16 cal ka）期间，存在高于现今海面位置的“高海平面”现象；不同于传统构造运动主导观点，研究认为GIA引起的“陆地掀斜”和“海洋虹吸”作用，可能是该区域“高海平面”现象产生的主要原因；（4）福建沿海全新世相对海平面变化，存在一定程度的空间差异。不同岸段之间的沉积物压实、差异性构造运动和潮差变化等非GIA因素，可能是这一现象产生的重要原因。
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| 关 键 词： | 海平面数据库 “变量误差–综合高斯”模型 陆地掀斜 海洋虹吸 高海平面 空间差异 |
| 收稿时间： | 2021-09-23 |
Holocene relative sea-level change of Fujian coast,southeastern China: Geological records and comparison with glacio-hydro isostatic adjustment modelling |
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| Institution: | 1.State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China2.Advanced Computing East China Sub-center, Suma Technology Co. Ltd., Kunshan 215300, China |
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| Abstract: | Reconstruction of high-quality Holocene relative sea levels (RSL) based on geological records can provide important past analogue and long-term reference for coastal societies to make better prediction and preparation for future sea-level rise. In the last decades, several Holocene RSL curves have already been published from Fujian coast, southeastern China. However, obvious differences and even contradictory results existed in these early-stage researches. At the same time, the mechanism and factors which control the long-term RSL change in this area are also unclear. In this study, new and published RSL data have been compiled from Fujian coast. Attribute information including location, age, elevation and indicative meaning of each data point has been re-examined and corrected. After that, a standardized Holocene relative sea level database which includes a total number of 183 data were established. On this basis, a new regional Holocene RSL curve was proposed by using the errors in variable-integrated gaussian process (EIV-IGP) statistical model. Finally, theoretical RSL change was predicted through solving the sea level equation (SLE). Combining the RSL geological records and GIA simulation results, conclusions are drawn as follow: (1) New Holocene RSL history of Fujian coast was reconstructed. 11.28–7.08 cal ka before present, RSL rose from (–23.55±6.94) m to (–1.51±1.80) m continuously; 7.08–4.08 cal ka before present, RSL rose slowly from (–1.51±1.80) m to (1.09 ±1.38) m; around 3.48 cal ka before present, RSL was about (1.35±1.23) m higher than modern sea level. Since then, the RSL has declined close to the modern position gradually. (2) In the Early Holocene (11.28–7.00 cal ka before present), the RSL change was mainly controlled by the meltwater from continental ice-sheet; and since 7.00 cal ka before present, hydro-isostatic process dominated the regional RSL change. (3) Holocene sea level highstand existed during 6.75–0.16 cal ka before present on Fujian coast. The highstand of sea level could be attributed to continental levering and ocean syphoning processes caused by GIA rather than tectonic movement. (4) Holocene RSL change showed spatial variability on the Fujian coast. Non-GIA factors including the compaction of unconsolidated strata, differential tectonic movements and tidal range changes, supposed to be related to this phenomenon. |
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