Shorebased Analysis of Alvin and Sentry High-resolution Sidescan, Multibeam and Imagery Data from the 8 degree, 20&#39; N latitude Seamounts

GSTDTAP

项目编号	1736544
	Shorebased Analysis of Alvin and Sentry High-resolution Sidescan, Multibeam and Imagery Data from the 8 degree, 20' N latitude Seamounts
	Daniel Fornari
主持机构	Woods Hole Oceanographic Institution
项目开始年	2017
	2017-07-15
项目结束日期	2019-06-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	45683(USD)
国家	美国
语种	英语
英文摘要	The ocean basins are underlain by mafic volcanic rocks that are erupted on the seafloor and originate at mid-ocean ridge spreading centers where upwelling of mantle material forms ocean crust and volcanic islands and seamounts. Presently, it is not known how much seafloor lava is erupted from fissures or other places in the ocean crust that are away from the spreading centers. In 2016, a major oceanographic expedition was sent out to an enigmatic seamount chain that extends to the west from the East Pacific Rise at 8° 20'N latitude in the eastern Pacific Ocean. To enhance the output of this expedition, two deep submergence platforms, the ALVIN, a human-occupied deep submergence vehicle, and SENTRY, an autonomous, robotic vehicle that is able to map deep ocean landscapes and operate independently from the ship and its operators, were added to the cruise and deployed. SENTRY provided high resolution mapping of the seafloor and the ALVIN allowed sampling of specific locations within the maps. This allowed targeted sample collection and selection of the most appropriate sites. It also provided important geologic context to where samples were taken. These two platforms returned a large volume (~20 terabytes) of near-bottom ALVIN and SENTRY data that now require processing. The dataset includes visual observations and high-resolution digital still and video imagery acquired using ALVIN, and near-bottom sonar data from SENTRY that provides ~1 m resolution of the volcanic terrain exposed on the seamount flanks and summits. This research involves the processing and partial analysis of this unique, high-resolution dataset in terms of extensive observational, sample and map coverage on volcanic seafloor away from the axis of a fast-spreading mid-ocean ridge out to seafloor ages of nearly 2 million years. The results of the processing and analysis is critical for enhancing the information collected on the expedition and its interpretation, especially with regard to evaluating relative age(s) of lava emplacement, quantitative measurement of seafloor topographic features, and illuminating the nature of seafloor volcanism along the seamount chain. Findings have important implications for our understanding of magmatic processes that occur significant distances (20-200 km) from a mid-ocean ridge spreading center axis where it is believe that most magmatism in the ocean occurs. Results of this work will also be key for constraining input parameters to geodynamic models that seek to describe melting processes in the upper mantle at fast-spreading ocean ridges. Broader impacts include providing important and complementary data for an major oceanographic expedition that will significantly enhance the research output, training of an early career scientist, processing a key dataset for understanding seafloor volcanic processes, and generating maps that could have importance for military submarine navigation. This research will process and provide preliminary analysis of the ALVIN and SENTRY data collected on the 2016, a major oceanographic expedition that explored the seamount chain that extends to the west of the East Pacific Rise at 8° 20'N latitude in the eastern Pacific Ocean. Data compilations and analyses that will be done include: georeferencing ~90,000 digital images acquired during 15 ALVIN dives and conducting quantitative analysis of the still- and video-imagery to help generate volcanic facies maps for each of the seamounts. These will be overlain on SENTRY multibeam and sidescan maps to produce geological maps of the surveyed areas and provide slope and seafloor textural analysis of SENTRY near-bottom sonar data. These will be correlated to volcanic feature morphology and sediment distribution that will be derived from digital still imagery analysis. The work will provide a morphological and slope analysis of EM122 multibeam data over the entire span of the 8° 20'N seamount area (~7000 km2) which will permit quantitative measurements of seamount basal diameters, height, morphology, presence of craters/calderas (and sizes), and seamount plan-view edifice shape characterization and aspect ratio. All of this will be done as a function of distance from the East Pacific Rise as well as the distance from each major edifice center and distance from adjacent abyssal hill faults. From this analysis, an estimation of the relative ages of features throughout the 8° 20'N seamount chain will be done, based on contact relationships with adjacent cones/edifices and faults at both regional and local scales. All processed data will be provided to a public data archive with all relevant metadata within two years. Publications from this work will be linked to data in the relevant data centers and archives.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71277
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Daniel Fornari.Shorebased Analysis of Alvin and Sentry High-resolution Sidescan, Multibeam and Imagery Data from the 8 degree, 20' N latitude Seamounts.2017.