Littoral Mud Flats and Shorelines: Soil-Sea-Ice-Air and Benthic Life Interactions
Abstract
THIS ABSTRACT IS APPROVED FOR PUBLIC RELEASELittoral mud flats and shorelines: soil-sea-ice-air and benthic life interactions across different climate zonesMud flats and muddy shorelines represent 14% of the world#s coastlines in non-permafrost environments and most coastlines in permafrost environments. While muddy sediments are generally considered less erodible than their non-cohesive counterparts, some of the most dynamic coastlines worldwide are muddy. Geomechanical properties of tidal mud flats affect visibility andsensor performance, as well as trafficability and navigation; these properties can vary significantly in time and space and are currently mostly unpredictable. At best, the interactions between geomechanical properties (such as undrained shear strength, water content, and plasticity index) and hydrodynamic forcing as well as the cyclic exposure to air are poorly understood. Potential freezingand contact with ice, as well as the wide range of benthic lifeforms inhabiting mud flats, add complexity to answering even basic questions such as, what conditions will erode it, can I walk on it, or can I drive on it? This lack of accessibility, for both humans and standard geotechnical instrumentation, has greatly hampered our basic understanding of such environments, leading to a significant gap in knowledge and predictability of muddy shoreline evolution, navigation, and trafficability.Recent investigations have measured the geomechanical properties of tidal mud flats, proposing that tidal mud flat strength properties can vary considerably over short distances and speculating that variability is associated with mud composition and water content, but also with environmental conditions including the activity and abundance of benthic organisms, geochemistry, and freeze-thaw cycles where applicable. These knowledge gaps limit our ability to predict mud flat soil strength and the resulting trafficability and erosion thresholds. While physical access to mud flats is difficult, remote sensing from satellites can be globally applied across littoral regions. To the degreepossible, merging in situ measurements and understanding with remote sensing modalities will allow identification and comparison ofthe range of global mud flat types and of the processes governing the site-specific geomechanics. The proposed five-year study willaim to (1) determine what environmental processes and feedbacks control the geomechanics of littoral mud flats and shorelines; (2) measure these processes and feedbacks conjointly with geotechnical site characterization and satellite-based remote sensing; (3) assess if climatic regimes affect and possibly change which processes and feedbacks are dominant; (4) develop and validate a global mudflat classification framework; and (5) determine which satellite products would be most efficient for deriving the tidal flat geomechanical properties. This will be achieved through literature and data review, field and laboratory testing, cross-disciplinary fusion and data analysis.The proposed work is a collaborative effort led by PI Stark (University of Florida) and with PIs Jung (University of Florida), Paprocki (University of New Hampshire), Eidam (Oregon State University), Dorgan (University of Texas), and Yang (University of Alaska Anchorage).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 12, 2025
- Source ID
- N000142512180
Entities
People
- Nina Stark
Organizations
- Office of Naval Research
- United States Navy
- University of Florida