CAREER: A Model-Based Rosetta Stone to Decipher the Stratigraphic Expression of Glacial Isostasy

海平面上升将是气候变暖对社会最严重的影响之一。为了评估极地冰盖和海平面变化对温度升高的敏感性，这个CAREER奖研究了在浅海底积累的沉积物如何记录海平面变化。当冰盖融化时，地球表面的弯曲是可以预见的，这是对冰盖重量减少和海洋沃茨淹没大陆边缘的反应。这种弯曲导致当地海平面的变化不同于如果融化的水均匀地充满世界海洋，就像浴缸一样预测的上升。冰盖融化引起的海平面上升在地球仪上各不相同，一些沉积物档案保存了比其他档案更准确的海平面变化测量值。这项研究将使用计算机模型绘制全球地图，显示过去两个地质时期海平面变化的差异，温度高于21世纪的预测。这些地图将澄清地质学家可以利用来自地球仪的沉积物档案的明显不同的海平面变化幅度的情况，以提供对过去冰盖融化位置和规模的更准确的重建。该项目通过创建“罗塞塔石碑”来解码过去温暖时期沿海地质中保留的古代海平面变化幅度，从而改进未来海平面预测，从而促进了对气候的了解。综合教育计划将编制关于海平面变化的科学和道德的新课程，以激励大学生参与日益增加的解决海平面预测和减缓问题的工作队伍。该教育计划将让非STEM专业的本科生创作和传播艺术推广产品，向公众解释海平面变化的地理差异。固体地球化学家和第四纪地层学家的合作表明，冰川均衡调整（GIA）同时产生和破坏可容纳空间，因此冰川-间冰期循环的地层记录应该在不同地方出现不同;反过来，从地层档案中推断出的同时期当地海平面的空间差异，应该可以提供对冰川消退的规模和融化来源的深入了解。该建议进行数值GIA模拟，以“指纹”的空间偏差glacioeucorphism的文献提出的幅度和融化源上新世中期温暖期和渐新世开始的南极冰盖。然后，这些空间变化的海平面记录将作为一个软件的输入，该软件模拟沉积和沉降如何调节GIA在地层学中的表现。研究结果将用于解码冰河时代地层学中保留的海平面空间模式，适用于整个地质时间尺度。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Rising sea levels will be among the most severe impacts of a warming climate on society. To assess the sensitivity of polar ice caps and sea-level change to increase in temperatures, this CAREER award examines how sediments accumulating on the shallow seafloor archive sea-level change. As ice sheets melt, the earth’s surface bends predictably in response to the shrinking weight of the ice sheets and ocean waters flooding continent edges. This bending causes local sea-level change to differ from the rise predicted if melt water evenly filled the world’s oceans, like a bathtub. The sea-level rise in response to a melting ice sheet will differ across the globe, with some sediment archives retaining a more accurate measure of sea-level change than others. This research will use computer models to make global maps of differences in sea-level change for two past geological epochs with temperatures higher than 21st century projections. Such maps will clarify the circumstances for which geologists can leverage the apparently different magnitudes of sea-level change from sediment archives around the globe to provide more accurate reconstructions of past ice sheet melt location and scale. This project advances climate understanding by creating a ‘Rosetta Stone’ to decode the magnitude of ancient sea-level change retained in coastal geology of past warm periods so as to refine future sea level projections. The integrated education plan will generate novel curriculum on the science and ethics of sea-level change to inspire university students to participate in a growing workforce addressing sea level projection and mitigation. The education plan will engage non-STEM undergraduates to create and disseminate artistic outreach products explaining geographic differences in sea-level change to the public.Collaboration between solid earth geophysicists and Quaternary stratigraphers has revealed that glacial isostatic adjustment (GIA) concurrently creates and destroys accommodation, such that the stratigraphic record of glacial–interglacial cycles should appear different from place to place; in turn spatial differences in contemporaneous local sea level deduced from the stratigraphic archive should provide insight into the magnitude and melt source of a deglaciation. This proposal undertakes numerical GIA simulations to ‘fingerprint’ spatial deviations from glacioeustasy for literature-proposed magnitudes and melt sources for the mid-Pliocene warm period and the Oligocene inception of the Antarctic ice sheet. These spatially variable sea-level records will then serve as inputs into a software that models how sedimentation and subsidence modulate how GIA manifests in stratigraphy. The results will serve to decode spatial patterns in sea level retained in ice-age stratigraphy applicable across the geological timescale.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.