CAREER: Understanding the Solid Earth's Influence on Sea Level

海平面位于地球的固体、液体和气体成分的交汇处，因此形成了我们星球上影响生物学和地质学的基本边界。人类社会必须适应这一边界的变化，目前认为这一边界以每年2-3毫米的速度上升。虽然众所周知，诸如海水变暖和冰川融化等气候因素是海平面上升的主要原因，但固体地球的变形也以很少受到约束的方式影响海平面。该项目使用固体地球变形的数值模型来了解固体地球在几十年到数十亿年的时间尺度上影响海平面变化的机制。通过将海平面变化的预测模式与观测结果进行比较，我们将对固体地球对海平面的影响提出新的限制。这项工作的科学成果将直接转化为一项教育计划，旨在向本科生讲授固体地球与海平面之间的相互作用。本项目将重点研究与固体地球变形模式相关的三个时间尺度。在几十年到几百年的时间尺度上，我们将计算与地球对区域性冰川融化的弹性响应相关的海平面上升速率的空间变化。对于数千年或更长时间的时间尺度，我们将计算地球对冰川消融的随时间变化的粘性响应。对于数百万年或更长时间的时间尺度，我们将使用地幔对流的数值模型来确定海洋和地球内部之间的水交换如何通过改变海洋盆地特性（如洋中脊体积、海洋面积和平均海底深度）直接或间接地影响海平面。对于每个时间尺度，我们将校准海平面对特定强迫的响应。通过将这些海平面变化的预测模式与观测结果（来自卫星、验潮仪、沉积和地质约束）进行比较，我们将对海平面变化的历史和地质原因进行限制。这种理解将被整合到本科学生（首先在夏威夷大学，然后通过一个公开的网站）使用的教育模块中，以互动的方式探索固体地球和海平面之间的相互作用。这项研究将有助于量化海平面变化的原因及其在过去十年和一个世纪中的空间变化，从而有助于为未来海平面上升的沿海规划提供信息。它还将帮助我们了解固体地球对数千年和数百万年海平面变化的影响，这将有助于科学家了解海平面变化的地质记录及其与地球内部动力学的耦合。

Sea level lies at the intersection of Earth's solid, liquid, and gaseous components, and thus forms a fundamental boundary on our planet that affects both biology and geology. Human society must adjust to changes in this boundary, which is currently thought to be rising at 2-3 mm per year. Although it is known that climatological factors such as seawater warming and glacial melting are major contributors to sea level rise, deformation of the solid Earth also affects sea level in ways that are poorly constrained. This project uses numerical models of solid Earth deformation to understand the mechanisms by which the solid Earth influences sea level change over timescales ranging from decades to billions of years. By comparing predicted patterns of sea level change with observations, we will place new constraints on the solid Earth's effect on sea level. The scientific results from this effort will be translated directly into an educational program designed to teach undergraduate students about the interactions between the solid earth and sea level.This project will focus on three timescales relevant to modes of solid earth deformation. For timescales of decades to centuries, we will compute spatial variations in rates of sea level rise associated with Earth's elastic response to regional melting of glacial ice. For timescales of millennia and longer, we will compute the Earth's time-dependent viscous response to deglaciation. For timescales of millions of years and longer, we will use numerical models of mantle convection to determine how exchange of water between the oceans and Earth's interior affects sea level both directly and indirectly by changing ocean basin properties such as mid-ocean ridge volume, ocean area, and average seafloor depth. For each timescale, we will calibrate the sea level response to specific imposed forcing. By comparing these predicted patterns of sea level change with observations (obtained from satellite, tide gauge, sedimentary, and geologic constraints), we will place constraints on the historical and geologic causes of sea level change. This understanding will be incorporated into education modules that will be used by undergraduate students (first at the University of Hawaii and later everywhere via a publicly-available website) to probe the interaction between the solid earth and sea level in an interactive way. This research will help quantify the causes of sea level change and its spatial variations during the past decade and century, and thus will help inform coastal planning for future sea level rise. It will also help us understand the solid Earth's influence on sea level change over thousands and millions of years, which will help scientists understand the geologic record of sea level change and its coupling to the dynamics of Earth's interior.