Li Tanghua, García-Artola Ane, Shaw Timothy A, Peng Dongju, Walker Jennifer S, Cearreta Alejandro, Horton Benjamin P
Earth Observatory of Singapore, Nanyang Technological University, Singapore, 639798, Singapore.
Departamento de Geología, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, Leioa, Spain.
Sci Rep. 2024 Dec 28;14(1):31302. doi: 10.1038/s41598-024-82692-1.
Coastal populations are susceptible to relative sea-level (RSL) rise and accurate local projections are necessary for coastal adaptation. Local RSL rise may deviate from global mean sea-level rise because of processes such as geoid change, glacial isostatic adjustment (GIA), and vertical land motion (VLM). Amongst all factors, the VLM is often inadequately estimated. Here, we estimated the VLM for the Oka estuary, northern Spain and compared it to the VLM component of sea-level projections in the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) and the Spanish National Climate Change Adaptation Plan (NCCAP). To estimate VLM, we updated Holocene RSL data from the Atlantic coast of Europe and compared it with two 3D GIA models. Both models fit well with RSL data except in the Oka estuary. We derived a VLM rate of - 0.88 ± 0.03 mm/yr for the Oka estuary using the residuals of GIA misfits. Comparable VLM rates of - 0.85 ± 0.14 mm/yr and - 0.80 ± 0.32 mm/yr are estimated based on a nearby Global Navigation Satellite Systems station and differenced altimetry-tide gauge technique, respectively. Incorporating the updated late Holocene estimate of VLM in IPCC AR6 RSL projections under a moderate emissions scenario increased the rate of RSL rise by 15% by 2030, 11% by 2050, and 9% by 2150 compared to the original IPCC AR6 projections, and also increased the magnitude of RSL rise by over 40% by 2035 and 2090 compared with projections from the Spanish NCCAP. Our study demonstrates the importance of accurate VLM estimates for local sea-level projections.
沿海地区的人口容易受到相对海平面（RSL）上升的影响，准确的局部预测对于沿海地区的适应至关重要。由于大地水准面变化、冰川均衡调整（GIA）和垂直地面运动（VLM）等过程，局部RSL上升可能与全球平均海平面上升有所偏差。在所有因素中，VLM往往估计不足。在此，我们估算了西班牙北部奥卡河口的VLM，并将其与政府间气候变化专门委员会（IPCC）第六次评估报告（AR6）和西班牙国家气候变化适应计划（NCCAP）中海平面预测的VLM分量进行了比较。为了估算VLM，我们更新了欧洲大西洋沿岸全新世的RSL数据，并将其与两个三维GIA模型进行了比较。除了在奥卡河口外，两个模型都与RSL数据拟合良好。利用GIA拟合残差，我们得出奥卡河口的VLM速率为-0.88±0.03毫米/年。基于附近的全球导航卫星系统站和差分测高-验潮技术，分别估算出可比的VLM速率为-0.85±0.14毫米/年和-0.80±0.32毫米/年。在中等排放情景下，将更新后的全新世晚期VLM估计值纳入IPCC AR6 RSL预测中，与原始的IPCC AR6预测相比，到2030年RSL上升速率增加了15%，到2050年增加了11%，到2150年增加了9%，并且与西班牙NCCAP的预测相比，到2035年和2090年RSL上升幅度增加了40%以上。我们的研究证明了准确估算VLM对于局部海平面预测的重要性。
