TAILIEUCHUNG - Geography and Oceanography - Chapter 8

Marine Sediments are:Particles of various sizes derived from a variety of sources that are deposited on the ocean vast “library” recording geologic, oceanographic and climatic conditions Remarkably complete compared to land Effects of water velocity on transport: rivers and nearshore vs open ocean. | Origin and Distribution of Marine Sediments What’s all that squishy muck at the bottom of the ocean? What can we learn from it? Marine Sediments are: Particles of various sizes derived from a variety of sources that are deposited on the ocean floor A vast “library” recording geologic, oceanographic and climatic conditions Remarkably complete compared to land Where do these come from? Inputs are: -- rivers -- atmosphere -- surface waters -- volcanoes (both on land and submarine) -- deep ocean water -- outer space Classifications By Size Clay -- Silt -- Sand -- Pebble -- Cobble mm 1 mm 100 mm Effects of water velocity on transport: rivers and near-shore vs open ocean Sediment Transport Fluid velocity determines the size of the particles that can be moved Size Sorting Classifications By Origin Terrigenous -- from land Biogenous -- from life in the oceans Hydrogenous -- precipitated from water Cosmogenous -- extraterrestrial Terrigenous sediments (from land) Rivers Winds (eolian) Glaciers (ice-rafted debris, IRD) Turbidites Sea level changes River sediment loads (units 106 tons/yr) Glacial (Ice-rafted debris) Turbidites Rapidly-accumulated terrestrial sediments Earthquake-triggered submarine avalanches High velocity (~50 mph!), erosive events Good examples preserved on Mary’s Peak Turbidites (submarine avalanches) Sea Level Changes Biogenous sediments (from living things) Calcareous (CaCO3) Foraminifera -- animals Coccolithophores -- plants Siliceous (SiO2) Radiolaria -- animals Diatoms -- plants mm = micron = millionth of a meter! mm = micron = millionth of a meter! mm = micron = millionth of a meter! mm = micron = millionth of a meter! Productivity = skeletons and soft tissue Accumulation depends on production and preservation SiO2 is preserved everywhere CaCO3 is variable, depending on P, T, pH Carbonate Compensation Depth South North Carbonate Compensation Depth The depth at which carbonate input from the surface waters is balanced by dissolution in corrosive deep waters In today’s ocean this depth (CCD) varies between 3 km (polar) and 5 km (tropical) Thus, accumulation rates vary a lot! Accumulation Rates for Oozes Productivity reproduction of planktonic organisms Preservation silica dissolves only very slowly calcium carbonate varies with depth Rates are variable: Coastal waters are often highly productive, with abundant planktonic organisms thriving in the surface waters. Why then are biogenous oozes rarely found nearshore?? the large input of terrigenous sediment to the continental margin overwhelms the biogenous component in the sediment. Hydrogenous (from sea water) Metalliferous sediments at spreading ridges -- “black smokers” Manganese nodules Evaporites -- Salt deposits baseball to bowling ball size! Cosmogenous (from outer space) Meteorites and comets Sediment Accumulation Sediment succession Distribution of Marine Sediments

• Địa Lý
• Sediment Transport
• Size Sorting
• River sediment loads
• sea water
• Marine Sediments
• oceanographic
• Journal of Science and Technology
• River hydrology and suspended sediment flux
• The red river system
• Assessing soil erosion
• Sediment transport deposition processes
• Vietnam Journal of Earth Sciences
• Surface sediment grain size distribution
• Sediment transport in the subaqueous Mekong Delta
• Grain size parameters
• The grain size distribution
• Dynamic Processes
• Transport Dynamics
• Suspended Particulate
• the Adjacent Continental
• Transport Patterns
• Soil erosion
• Sediment yield
• Transport capacity
• Gis based sediment yield model
• Vulnerability assessment of soil erosion
• Vietnam Journal of Mechanics
• Long shore sediment transport computation
• Hai Hau beach Nam Dinh province
• Hindcast waves to compute
• The complex topography
• Suspended sediment transport in coastal zone by tidal flow
• Comparison with the experiment
• Coastal zone by tidal flow
• The first order model
• Red River Basin
• MIKE 11 model
• Impact assessment of upstream
• Hai Phong City
• Summary of doctoral thesis
• Building numerical model
• Simulate the flow and sediment transport
• Small and medium watershed
• The technical limitation
• Hyperconcentrated Flows
• Boat Traffic
• Sediment Transport Processes
• Coastal Hydrodynamic
• Flux Modelling
• Shoreline Change
• Sediments Exchange
• Suspended Sediment
• Transport Determination
• Rainwater Tanks
• Filling Dynamics
• Morphological Modeling
• Dual Fluidized Beds
• Spray Model
• Innovative Nuclear Reactors
• Mass Forces
• Particle Hydrodynamics
• maximum dissemination
• Research Achievements
• General Gamma
• Thermo Hydrodynamics
• Analysis Techniques
• environmental emissions
• environmental specialist
• environmental consequences
• pollution prevention measures
• protection
• protection of the marine environment
• khí tượng thủy văn
• môi trường biển
• quản lý tài nguyên nước
• hải dương học
• tính toán thủy văn
• thuật ngữ môi trường
• khoa học môi trường
• xử lý chất thải
• quản lý môi trường
• ô nhiễm môi trường
• tài liệu báo cáo nghiên cứu khoa học
• cách trình bày báo cáo
• kiến thức toán học
• báo cáo toán học
• các báo cáo toán học hay
• Numerical simulation
• earth sciences
• Research
• scientific research
• scientific reports
• Numerical simulation on morphological process
• Thuan an coastal area
• The natural flow could change
• Sediment transport model
• Bed change
• Boundary condition
• Numerical model
• Using a numerical model
• Hydroelectricity production
• Numerical hydrodynamic
• Reach scale morphological
• River system managers
• trầm tích
• tài nguyên nước
• ô nhiễm nước mặt
• sức khỏe môi trường