An integrated geophysics cruise to map the northern edge in the Chukchi Borderland and the adjacent Canada Basin - constraints on basin history and crustal structure

绘制楚科奇边境和邻近加拿大盆地北部边缘地图的综合地球物理巡航——对盆地历史和地壳结构的限制

• 批准号: 1916575
• 负责人: Bernard Coakley
• 金额: $ 123.71万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916575&HistoricalAwards=false
• 关键词: integrated; geophysics; cruise; map; northern

Over the last fifty years, we have learned the ocean basins are relatively young. Knowing their history is necessary to understand the ancient, adjacent continents. The Amerasia Basin of the Arctic Ocean is a mystery. While it is an ocean basin, the familiar patterns created by seafloor spreading are not obvious. As a result, it has not been possible to understand the basin history. This project will study the history of three adjacent features in the Amerasia Basin: the Chukchi Borderland, the Alpha Ridge and the Canada Basin This project plan to use the Geological Survey of Denmark and Greenland (GEUS) portable, flexible multi-channel seismic reflection (MCS) system on a research vessel. This system, which has been successfully operated in thick pack ice, will collect MCS data, for stratigraphic and structural interpretation, and provide sufficient source strength for full crustal refraction work. Stronger constraint on the deep crustal structure will be obtained in two locations in the Canada Basin with ocean bottom seismometers (OBS). Refraction data will also be acquired with sonobuoys during MCS profiling and will be used to model upper crustal structure. The collection and analysis of the data will provide new knowledge about the formation of the Amerasia Basin and improve our understanding of the history of northeast Eurasia and northwest North America. This project will also help educate a new generation of Arctic marine geoscientists, support scientific ocean drilling to sample the sediments below the seafloor and help define the extent of US territory in the Arctic Ocean. For the most part, current understanding of the Amerasia Basin is based on observations made on the adjacent continents and an assumption about the tectonic displacements that formed the basin. A new approach based on establishing critical relationships between adjacent features will make it possible to recreate the tectonic history of the ocean by scaling up from local relationships. The Chukchi Borderland is a block of extended continental crust embedded in the deep water Amerasia Basin. To understand the basin opening, it is necessary to restore the Borderland to its pre-opening position. The choice of this position distinguishes tectonic models of the basin which are not well constrained by observations. In previous work, a 2- MCS survey across the transition from the Chukchi Shelf to Borderland established that there have been only slight displacements across this boundary since Early Cretaceous. Understanding the structure and history of the northern edge of the Borderland, known primarily from bathymetric data, is the next step. In this area, three of the major structures of the Amerasia Basin intersect: the Borderland, Alpha Ridge and the Canada Basin. A dedicated MCS survey in this area will improve our understanding of these structures and their termination or continuation below the sediment cover to the north and east. In this project, MCS and refraction surveys will elucidate the relations between the overtly continental, high-standing block and the surrounding crust, which may be, in part, of continental composition as well. Observing the northern edge of the Chukchi Borderland and adjacent deeper water areas will, by distinguishing crustal types, provide new constraints on the history of the Amerasia Basin.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.

在过去的五十年中，我们了解到海盆相对年轻。知道他们的历史对于了解古老的邻近大陆是必要的。北极海洋盆地是一个谜。虽然它是一个海盆，但海底蔓延创造的熟悉模式并不明显。结果，不可能了解盆地历史。该项目将研究美洲盆地盆地三个相邻特征的历史：Chukchi Borderland，Alpha Ridge和加拿大盆地该项目计划使用丹麦和格陵兰（GEUS）便携式（GEUS）便携式，灵活的多渠道地震反射（ MCS）在研究船上的系统。该系统已在厚包冰中成功运行，将收集MC数据，用于地层和结构解释，并为完全的地壳折射工作提供足够的源强度。在加拿大盆地的两个位置将获得具有海底地震仪的两个位置的深层地壳结构的限制（obs）。在MCS分析期间，还将使用Sonobuoy获取折射数据，并将用于建模上皮结构。数据的收集和分析将提供有关阿米亚盆地盆地形成的新知识，并提高我们对欧亚大陆东北部和西北北美历史的理解。该项目还将有助于教育新一代的北极海洋地球科学家，支持科学海洋钻探，以对海底下方的沉积物进行采样，并有助于定义北极海上美国领土的程度。在大多数情况下，当前对阿米他亚洲盆地的理解是基于对相邻大陆的观察结果以及对形成盆地的构造位移的假设。一种基于建立相邻特征之间关键关系的新方法将使通过从当地关系扩展来重现海洋的构造历史。 Chukchi Borderland是嵌入深水Amerasia盆地的大陆壳的一个块。要了解盆地开口，有必要将边境恢复到其开幕前的位置。该位置的选择区分了盆地的构造模型，这些模型不受观察的良好约束。在先前的工作中，从Chukchi货架到Borderland的过渡过程中，一项2个MCS调查确定，自白垩纪早期以来，该边界上只有微小的位移。下一步是理解边境北边缘的结构和历史，主要是从测深数据中得知的。在这个地区，阿美裔盆地的三个主要结构相交：边境地区，阿尔法山脊和加拿大盆地。该领域的一项专门的MCS调查将提高我们对这些结构的理解及其在北部和东部沉积物覆盖以下的终止或延续。在该项目中，MC和折射调查将阐明公开的大陆，高位块与周围地壳之间的关系，这可能部分是大陆构成。观察Chukchi Borderland的北部边缘和邻近的深水区将通过区分地壳类型，对Amerasia盆地的历史提供新的限制。该奖项反映了NSF的法定任务，并被认为是通过使用该基金会的智力来评估的值得支持的。优点和更广泛的影响审查标准。

项目成果

PERI-GLACIAL FEATURES MAPPED IN THE CHUKCHI BORDERLAND; CONSTRAINTS ON GLACIAL EXTENT AND MOTION

楚科奇边境地区的冰周特征；

• DOI: 10.1130/abs/2022cd-373936
• 发表时间: 2022
• 期刊: Geological Society of America Abstracts with Programs
• 作者: Keith, Bradley;Anfinson, Owen A.;Coakley, Bernard J.
• 通讯作者: Coakley, Bernard J.

Seismic Imaging across the Northern Chukchi Borderland: Implications of the Canada Basin Opening

楚科奇北部边境地区的地震成像：加拿大盆地开放的影响

• 发表时间: 2022
• 期刊: Transactions American Geophysical Union
• 作者: Priyanto, Wisnu;Coakley, Bernard
• 通讯作者: Coakley, Bernard

Crustal Images of the Canada Basin and Its Relationship with the Extinct Mid Oceanic Ridge

加拿大盆地的地壳图像及其与灭绝洋中脊的关系

• 发表时间: 2023
• 期刊: Transactions of the American Geophysical Union
• 作者: Priyanto, W.S.;Coakley B.J.
• 通讯作者: Coakley B.J.