Holocene sea level changes in Southeast Asia

相对海平面（RSL）的变化是海平面上升、均衡、构造和其他局部因素（如沉积物压实引起的沉降）共同作用的结果。全新世海平面重建需要约束垂直陆地运动和冰川均衡调整（GIA）的地球物理模型，后者反过来用于校正由仪器测量（如潮汐计）获得的海平面测量结果。因此，按照标准化方案调查的区域全新世RSL数据集代表了评估过去一个世纪海平面变化以及评估21世纪局地和区域尺度海平面变化的长期基线。虽然某些地区有精确的全新世RSL数据集，但在东南亚等未来海平面上升高度脆弱的地区，RSL重建仍然有限，碎片化，并且在海平面指标及其与海平面的关系的正确解释以及年龄确定的质量方面仍然存在问题。该提案的首要问题是：我们如何提高对东南亚相对全新世海平面变化和相关过程的认识？我们将针对这个问题重新分析已发布的海平面数据集，这些数据集将按照标准化方法汇编在数据库中。然后，我们将扩展我们的初步数据集，调查Spermonde群岛的几个岛屿，这是一个对未来海平面上升高度敏感的地区。然后，我们将创建一套以东南亚为重点的大型地球模型，以便全面代表该地区可能的GIA影响，包括所选冰模型和地幔粘度剖面的不确定性，并使用我们的数据库和现场数据来改进模型范围，使其更接近地质数据。然后，我们将使用贝叶斯统计方法分析现场数据，以确定晚全新世海平面变化的模式。这些资料将与卫星图像的数据进行交叉分析，卫星图像将用于探测构成斯珀蒙德群岛的不同岛屿的人类占领水平和土地利用模式。该项目也得益于与海平面科学领域世界领先的国际伙伴的合作，将培养一名海平面研究各个方面的博士生，从实验室和实地技术到地球建模和数据分析。

Changes in relative sea level (RSL) are the net effect of contributions from eustatic, isostatic, tectonic and other local factors, such as subsidence due to sediment compaction. Holocene sea-level reconstructions are needed to constrain both vertical land movements and geophysical models of Glacial Isostatic Adjustment (GIA), that are in turn used to correct sea level measurements obtained with instrumental measures, such as tide gauges. Therefore, regional Holocene RSL datasets, surveyed following standardized protocols, represent a long-term baseline against which to assess changes in sea level during the past century and to evaluate sea-level changes in the 21st century at local and regional scale. While accurate Holocene RSL datasets are available for some areas, RSL reconstructions for a region highly vulnerable to future sea level rise such as Southeast Asia are still limited, fragmentary and there are still problems associated with the correct interpretation of sea-level indicators and their relationship to sea level, and with the quality of age determinations. The overarching question of this proposal is: how can we improve our knowledge of relative Holocene sea level changes and associated processes in Southeast Asia? We will target this question re-analyzing published sea level datasets, which will be compiled in a database following a standardized approach. We will then expand our preliminary dataset, investigating several islands of the Spermonde Archipelago, which is an area that is highly sensitive to future sea level rise. Then, we will create a large set of earth models focusing on Southeast Asia, in order to have a full representation of the possible GIA effects in this area, including uncertainties due to the selected ice model and mantle viscosity profile, and use both our database and field data to refine the range of models that matches more closely geologic data. Our field data will be then analyzed using a Bayesian statistical approach in order to identify patterns of Late Holocene sea level changes. This information will be cross-analyzed with data from satellite imagery, which will be used to detect the level of human occupation of the different islands composing the Spermonde Archipelago and the land use patterns. This project, also thanks to the cooperation with the international partners that are world leaders in sea level science, will train a PhD student in all the aspects of sea level research, from laboratory and field techniques to earth modelling and data analysis.