water midterm 3

What is a coastal marine environment

Diverse ecosystem at land-ocean interface, from shoreline to outer continental shelf

what are the key features of a coastal marine environment

dynamic freshwater-saltwater interactions, variable salinity, sea-level rise and land subsidence, high biodiversity, exposure to waves/tide/storms, human impacts, and climate change effects

what is the coastal marine ecological classification standard (CMECS)

developed by NOAA; marine, coastal, and human modified settings

what is the coastal and marine ecosystem classification (CMEC)

used by EPA; estuarine, marine, coastal, and riverine

what is the international union for conservation of nature classification (IUCN)

marine (coral reefs), coastal (mangroves), and brackish (estuaries)

what is the united nations environment program classification (UNEP)

ecosystem types like coral reefs, mangroves, seagrasses, salt marshes, and rocky shores

what is the geomorphic classification

primary coasts (deltas, fjords, estuaries) and secondary coasts (beaches, dunes, and barrier islands)

what is a freshwater lens

forms due to density difference, freshwater floats above saltwater

what is submarine groundwater discharge (SGD)

created through freshwater-seawater interactions, also forms submarine springs

what is seawater intrusion

caused by over pumping/up coning, sea level rise, land subsidence, and surface water diversion

what is a geoidal eustasy

sea-level variation due to gravity changes from melting ice, elastic earth deformation (east coast sinking, alaska rising)

what are the impacts of coastal aquifers

promotes nitrogen and carbon release (eutrophication), upstream migration of tidal forests, soil degradation and coastal erosion. Sea water storage offsets sea-level rise by about 1mm/year

what is an estuary

sediment starved river meets ocean, high energy, tides dominate

what is a barrier island

sediment rich river meets ocean, high energy, longshore drift, waves

what is a delta

sediment rich river meets ocean, low energy, weak tides and waves

what is a coastal cliff

erosional, no river, high energy, wave erosion

how are estuaries formed

greater freshwater inflow than seawater influx, brackish water from mixing

what is the salinity gradient of an estuary

0-5 ppt near river, 5-25 ppt middle, >25 ppt at ocean

nutrient characteristics of estuaries

sediment settles in benthic zone, supporting high productivity and biodiversity

types of estuaries

lagoon (indian river), coastal plain (chesapeake bay), tectonic (san francisco bay), and fjord (norway)

landforms created by estuaries

salt marshes, swamps, mangrove swamps, tidal flats

how are deltas formed

sediment deposition at river mouth creates distributaries and wetlands

what are the types of deltas

arcuate (nile), birds foot (mississippi), cuspate (ganges), tectonic (mekong)

what type of water is found in a delta

fresh to brackish

what type of water is found in an estuary

brackish, salt gradient

what kind of wetlands are formed from deltas

larger, freshwater marshes

what kind of wetlands are formed from an estuary

smaller, salt marshes

what is the tidal influence on a delta

weak

what is the tidal influence on an estuary

strong

what are some functions of estuaries and deltas

habitats, nursery, fisheries, recreation, storm buffers, water purification, and flood control

what is the impact of rivers/runoff on marine environments

nutrients from weathering cause eutrophication

what is the impact of ocean currents on marine environments

upwelling brings deep nutrients to surface

what is the impact of marine sediments on marine environments

benthic storage and cycling

what is the impact of atmospheric deposition on marine environments

nitrogen inputs

what is the impact of SDG on marine environments

regional nutrient cycling

what is the impact of hydrothermal vents on marine environments

chemical-rich fluids

what is the impact of tides on marine environments

enhance mixing and redox reactions

human impacts on marine environments

eutrophication, pollution, climate change, altering ocean chemistry

ecological resources/services from marine environments

oxygen production, carbon dioxide absorption, nutrient cycling, and storm protection

economic resources/services from marine environments

food, pharmaceuticals, oil/gas, recreation

how are deep marine environment zones categorized

by depth and light, photic zone for productivity

features of deep marine environments

continental shelf, slope, abyss, trenches, hydrothermal vents

processes of deep marine environments

upwelling/downwelling circulates nutrients, forming organic-rich source rocks for fossil fuels over geologic time

significance of deep marine environments

high paleo-productivity leads to oil/gas reservoirs

what nutrient source has the largest impact on marine environments

rivers/runofff

what nutrient source has the least impact on marine environments

tides

what is hydraulic fracturing

high-pressure fluid injection to fracture low-permeability shale for oil/gas extraction

history of fracking

originated in 1940s, >275,000 US wells, global variations, banned in some countries

US energy is comprised of

about 80% fossil fuels, natural gas cleaner than coal, 50-60% less carbon dioxide

steps of fracking

horizontal drilling, casing, fluid injection (water, chemicals, proppants), fracturing, flowback, production

how is water used in fracking

acquisition, mixing, injection, wastewater handling (reuse, disposal)

fracking impacts on water

overdrafting, spills, contamination risks (from poor practices)

fracking impacts on induced seismieity

mainly from wastewater injection

fracking impacts on separation

fracturing depths far below aquifers

wastewater from fracking is composed of

brine, metals, and NORM

fracking wastewater management

injection into wells, treatment, reuse, land application, increasing reuse (roads)

natural gas compared to clean coal

less carbon dioxide, sulfur dioxide, and nitrogen oxide, but methane leaks

clean coal compared to natural gas

CCS possible but expensive