Seismic and Hydrostratigraphic Characterization of the Onshore-Offshore Freshwater Systems of Martha’s Vineyard and Nantucket, Massachusetts, USA

沿海水文系统为世界各地的沿海社区提供重要的淡水资源。这些资源是由地下水井开采的，这些水井从地下不到100米的含水层中产生。在全球范围内，由于过度使用、人口增长和气候变化，这些资源正在减少。为了改善水的供应和安全，需要采取新的方法来了解未充分利用和量化不足的淡水资源。其中一种资源是从陆上延伸到海上的淡水，在一些地区，如美国东北边缘，可能延伸到离岸100公里处。为了更好地了解这些陆上-海上水文系统的动态，我们需要专门的、协调的陆上和海上水文地质研究。本研究项目在玛莎葡萄园岛和楠塔基特岛，马萨诸塞州，美国将增加我们对沿海淡水资源的了解，通过地球物理调查表征沿海环境中的沉积分层。这项工作是综合、多管齐下（地球物理、钻井和采样、建模）研究的关键部分，这些研究需要了解陆上-海上系统的动态，并定义其作为资源的潜力。这项研究有可能建立研究全球陆上和近海淡水资源的议定书，增进对未开发的淡水资源的了解，并为今后关于这一资源的维持和可持续性的研究提供信息。在过去的15年里，对陆上-海上淡水系统的研究越来越多，包括地球物理调查和数值模型，这些研究都是由钻井数据驱动的，而不是为了解决淡水资源而收集的。然而，到目前为止，还没有专门的、综合的陆上-海上研究来研究这些近海淡水资源的动态、数量和产能。我们建议通过收集、处理和解释地震数据对美国马萨葡萄园岛和楠塔基特岛的水文地层学进行研究，这是第一个完整的陆上-海上表征的关键部分。从该合同中获得的数据将用于支持国际大陆科学钻探计划（ICDP）的提议，该计划将钻井量化该沿海含水层系统陆上部分的水文特性和地下水年龄。这是对国际海洋发现计划（IODP）的一项建议的补充，该计划通过钻井来量化这一陆上-海上含水层的海上组成部分的水文特性和地下水年龄。结合起来，这项研究将是第一个专门的、横跨海岸线的陆上和海上淡水的地质、地球物理和水文地质研究，解决了许多与全球存在的这些淡水系统的动态、可持续性和效用相关的问题。该奖项由地球科学水文科学项目共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Coastal hydrological systems provide significant freshwater resources to coastal communities around the world. These resources are exploited by groundwater wells that produce from aquifers at depths of less than 100 m. Globally, these resources are declining due to overuse, increasing population, and climate change. To improve water supplies and security, new approaches to understanding underused and poorly quantified freshwater resources are needed. One such resource is freshwater that extends from onshore to offshore, potentially extending up to 100km offshore in some regions, such as the northeastern margin of the United States. To better understand the dynamics of these onshore-offshore hydrologic systems, we need dedicated, coordinated onshore and offshore hydrogeological studies. This research project on Martha’s Vineyard and Nantucket, MA, USA will increase our understanding of the coastal freshwater resources by characterizing the sedimentary layering in the coastal environment through geophysical surveys. This work is a critical piece to the integrative, multi-pronged (geophysics, drilling and sampling, modeling) research that is required to understand the dynamics of the onshore-offshore systems and to define their potential as a resource. This study has the potential to establish the protocols for studying global onshore-offshore freshwater resources, to improve understanding of under-developed freshwater resources, and to inform future studies on the maintenance and sustainability of this resource.Over the last 15 years, there has been growing research on onshore-offshore freshwater systems including geophysical surveys and numerical models that have been motivated by drilling data that were not collected to address freshwater resources. To date, however, no dedicated and integrated onshore-offshore study has been completed to study the dynamics, volumes, and producibility of these offshore freshwater resources. Our proposed study of the hydrostratigraphy on Martha’s Vineyard and Nantucket Island, MA, USA through collection, processing, and interpretation of seismic data is a key portion to the first complete onshore-offshore characterization. The data obtained from this award will be used to support an International Continental Scientific Drilling Program (ICDP) proposal to drill wells to quantify the hydrologic properties and groundwater age for the onshore portion of this coastal aquifer system. This complements an International Ocean Discovery Program (IODP) proposal to drill wells to quantify hydrologic properties and groundwater age for the offshore component of this onshore-offshore aquifer. Combined, this research would be the first dedicated, shoreline-crossing geological, geophysical, and hydrogeological study of onshore-offshore freshwater addressing many questions related to the dynamics, sustainability, and utility of these freshwater systems that exist globally. This award was co-funded by the Earth Sciences Hydrologic Sciences Program.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.