High-Resolution Gravity, Tomography, and Seafloor Roughness

高分辨率重力、断层扫描和海底粗糙度

• 批准号: 0825045
• 负责人: David Sandwell
• 金额: $ 16.65万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0825045&HistoricalAwards=false
• 关键词: Resolution; Gravity; Tomography; Seafloor; Roughness

Intellectual Merit: Over the past 5 years an improved global marine gravity and bathymetry grids has been constructed with 1-minute resolution. Raw satellite altimeter waveforms from 1 year of ERS-1 and 1.5 years of Geosat were re-tracked, which has resulted in a 40% improvement in the accuracy of the global marine gravity field, enabling new scientific investigations of transform faults, seamounts, seafloor fabric, and ocean mixing. The improved gravity, combined with a new assembly of global depth soundings, is resulting in a new global bathymetry grid at 1 minute resolution. The present project involves merging the 1-minute resolution marine gravity model with a soon-to-be-published global gravity model (EGM08) complete to spherical harmonic degree 2160 (5 minute resolution), resultig in a seamless gravity field across the shorelines. A grid of uncertainty in the marine gravity will be constructed, based on altimeter data density, altimeter noise, and comparisons with shipboard gravity. A matching bathymetry/topography grid will be generated, with a focus on shallow ocean (1000 m) areas where new soundings are rapidly becoming available. A 1-minute data source grid will be developed that provides the link to the original sounding data. Web access will be provided to all of these data products including: grids, cleaned soundings, and images/maps. These new data resources will be used to investigate the effects of spreading rate on ridge segmentation, lithospheric strength, and crustal structure. These improvements to the global marine gravity and bathymetry grids will benefit scientific and petroleum exploration studies of continental margins. These data are foundational to many scientific studies supported by NSF and benefit a wide range of ocean science investigations. This project will ensure the data are freely available to everyone.Broader Impacts: Global bathymetric charts are used in many areas outside of the scientific community including: K-12 teaching of earth science and seafloor geography; undergraduate-level earth science and plate tectonics; law of the sea; mineral exploration; planning of fiber-optic cable routing and general interest by the public. This information is available on our web site http://topex.ucsd.edu in a variety of formats for expert, intermediate, and novice users.

智力优势：在过去5年中，建立了分辨率为1分钟的改进的全球海洋重力和水深网格。重新跟踪了ERS-1一年和Geosat 1.5年的原始卫星高度计波形，使全球海洋重力场的精度提高了40%，使对转换断层、海山、海底组构和海洋混合的新的科学调查成为可能。改进的重力，结合新的全球深度测深组合，正在产生一个新的1分钟分辨率的全球测深网格。本项目涉及将1分钟分辨率的海洋重力模型与即将出版的全球重力模型(EGM08)合并，使其达到球面调和度数2160(5分钟分辨率)，从而在海岸线上形成一个无缝重力场。根据高度计数据密度、高度计噪声以及与船上重力的比较，将构建海洋重力的不确定性网格。将生成一个匹配的水深/地形网格，重点放在浅海(1000米)地区，那里正在迅速获得新的探测数据。将开发一个1分钟的数据源网格，提供到原始探测数据的链接。将提供对所有这些数据产品的网络访问，包括：网格、清洁的水深和图像/地图。这些新的数据资源将被用来研究扩展速度对海脊分段、岩石圈强度和地壳结构的影响。全球海洋重力和水深网格的这些改进将有助于大陆边缘的科学和石油勘探研究。这些数据是国家科学基金会支持的许多科学研究的基础，有利于广泛的海洋科学调查。该项目将确保每个人都能免费获得数据。广泛影响：全球水深图被用于科学界以外的许多领域，包括：地球科学和海底地理的K-12教学；本科生水平的地球科学和板块构造学；海洋法；矿产勘探；光缆布线规划和公众的普遍兴趣。这些信息在我们的网站http://topex.ucsd.edu上以各种格式提供，供专家、中级和新手用户使用。