Seismic Stratigraphic Reconstruction of Cretaceous to Holocene Current Flow Through the Southeastern Gulf of Mexico

墨西哥湾东南部白垩纪至全新世洋流的地震地层重建

• 批准号: 1928888
• 负责人: Christopher Lowery
• 金额: $ 18.6万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1928888&HistoricalAwards=false
• 关键词: Seismic; Stratigraphic; Reconstruction; Cretaceous; Holocene

Ocean circulation in the Gulf of Mexico (GoM) is dominated by the Loop Current, which flows into the Gulf through the Yucatan Channel between Mexico and Cuba and then loops up and around the Gulf before entering the Florida Straits between Florida and Cuba, where it forms the Florida Current and feeds into the Gulf Stream. This system of connected ocean currents is one of the main mechanisms for transporting heat northward in the Atlantic Ocean and thus has a key influence on the climate of North America and Europe. Despite the importance of the Loop Current for regional and global climate, little is known about its long-term history, including when it was established and how it has varied through time. Understanding how the Loop Current has impacted the northward delivery of heat in response to changes in outside forcing, for example, is critical for reconstructing ocean/climate history and for predicting future changes. Fortunately, a unique record of past Loop Current behavior is preserved in sediment drift deposits preserved on the ocean floor. As currents flow across the seafloor, they move sediment around. Sediment is eroded from areas where currents are stronger and deposited where current velocity drops. Over time, these sediments can form thick accumulations known as drift deposits that represent archives of past current flow over millions of years. Recent echosounder surveys have identified sediment drifts on the shallow Campeche Bank in the GoM. In the adjacent deep waters, seismic surveys conducted in the 1980s revealed large features on the seafloor that also appear to be sediment drifts, though these older data do not have the resolution to see internal features that are key to interpreting changes in current strength and position. This project will conduct a high-resolution multichannel seismic (MCS) survey of the deposits in both regions to map and determine the nature of these deposits and use their 3-D seismic architecture to reconstruct the Gulf of Mexico's Loop Current over the past 90 million years. The seismic data obtained will also be used as a site survey for potential future scientific drilling in the region.This project is a multinational collaboration being conducted with scientists at the National Autonomous University of Mexico (UNAM) and from Germany and Cuba. The project team will deploy the University of Texas Institute for Geophysics' portable multichannel seismic system on board UNAM's R/V Justo Sierra to conduct a seismic survey along the Campeche Bank and adjacent deep-water environments to image the drift deposits there. The ages of the sedimentary units will be determined by tracing key horizons within them to cores previously collected within the study area by the Deep Sea Drilling Project. The combined data will be used to test the following hypotheses: 1) changes in the strength of currents entering the eastern GoM drove changes in the sedimentary architecture of both the shallow Campeche Bank and the adjacent deeper water; 2) progressive cooling throughout the Cenozoic has strengthened current flow in the eastern GoM, resulting in both increased scour in some areas and increased drift deposition in others; 3) drift deposits on shallow Campeche Bank extend back to the Late Cretaceous, indicating the presence of a proto-Loop Current entering the GoM for ~90 million years; and 4) significant drift deposits in the deeper basin between the Yucatan and Florida Straits date back to the Eocene/Oligocene Boundary and track the inflow of North Atlantic Deep Water into the GoM. By identifying and studying drift deposits in the eastern GoM, this project will pave the way for future scientific ocean drilling to core these drifts and study changes in Gulf of Mexico circulation and climate in much greater detail.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.

墨西哥湾的海洋环流以环流为主，环流通过墨西哥和古巴之间的尤卡坦海峡流入墨西哥湾，然后环流到墨西哥湾，然后进入佛罗里达海峡和古巴之间的佛罗里达海峡，在那里形成佛罗里达海流，进入墨西哥湾流。这种相互连接的洋流系统是大西洋向北输送热量的主要机制之一，因此对北美和欧洲的气候产生了关键影响。尽管环流对区域和全球气候很重要，但人们对其长期历史知之甚少，包括它是何时建立的，以及它如何随着时间的变化而变化。例如，了解环流如何影响热量向北输送，以响应外部强迫的变化，对于重建海洋/气候历史和预测未来变化至关重要。幸运的是，保存在海底的沉积物漂流沉积物中保存着过去环流行为的独特记录。当洋流流过海底时，它们会移动沉积物。泥沙从水流较强的地区被侵蚀，并沉积在流速下降的地方。随着时间的推移，这些沉积物可以形成被称为漂流沉积的厚重堆积，代表着数百万年来过去水流的档案。最近的回声探测仪调查发现了戈麦海浅滩坎佩切岸上的沉积物漂移。在邻近的深水水域，1980年代进行的地震调查揭示了海底的大特征，这些特征似乎也是沉积物漂移，尽管这些较旧的数据没有分辨率来看到对解释当前力量和位置变化至关重要的内部特征。该项目将对这两个地区的沉积物进行高分辨率多道地震(MCS)调查，以绘制和确定这些沉积物的性质，并使用它们的三维地震结构来重建过去9000万年来墨西哥湾的环流。获得的地震数据还将用于该地区未来潜在的科学钻探的现场勘测。该项目是与墨西哥国立自治大学(UNAM)以及来自德国和古巴的科学家进行的多国合作。项目团队将在UNAM的R/V Justo Sierra上部署德克萨斯大学地球物理研究所的便携式多道地震系统，沿坎佩切海岸和邻近的深水环境进行地震调查，以对那里的漂流沉积物进行成像。沉积单元的年龄将通过追踪其中的关键层位到以前深海钻探项目在研究区域内收集的岩心来确定。综合资料将被用来检验以下假设：1)进入戈壁东部的洋流强度的变化驱动了浅滩和邻近深水的沉积结构的变化；2)整个新生代的逐渐冷却加强了戈壁东部的水流，导致一些地区的冲刷增加，另一些地区的漂流沉积增加；3)浅滩的漂流沉积延伸到晚白垩世，表明进入戈马的原环流存在了大约9000万年；4)尤卡坦海峡和佛罗里达海峡之间的深部盆地中的重要漂移沉积可以追溯到始新世/渐新世边界，并追踪北大西洋深水流入GEM的过程。通过识别和研究GEM东部的漂流沉积物，该项目将为未来科学海洋钻探取心这些漂流铺平道路，并更详细地研究墨西哥湾环流和气候的变化。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Seismic Stratigraphy of Contourite Drift Deposits Associated With the Loop Current on the Eastern Campeche Bank, Gulf of Mexico

墨西哥湾东坎佩切浅滩与环流相关的等宽岩漂移沉积物的地震地层学

• DOI: 10.1029/2023pa004701
• 发表时间: 2024
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: Lowery, Christopher M.;Perez Cruz, Ligia;Urrutia Fucugauchi, Jaime;Wei, Jingxuan;Austin, Jr., James A.;Standring, Patricia
• 通讯作者: Standring, Patricia

Raw high-resolution multi-channel seismic reflection (MCS) field data from the JS2203 Gulf of Mexico Campeche Bank Seismic Survey (2022)

来自 JS2203 墨西哥湾坎佩切浅滩地震勘测的原始高分辨率多道地震反射 (MCS) 现场数据 (2022)

• DOI: 10.26022/ieda/331509
• 发表时间: 2024
• 期刊: Interdisciplinary Earth Data Alliance (IEDA
• 作者: Lowery, Christopher;Perez Cruz, Ligia;Urrutia-Fucugauchi, Jaime;Wei, Jingxuan;Austin, James;Standring, Patricia
• 通讯作者: Standring, Patricia