Submarine Groundwater Discharge at a Mega‐Tidal Beach DOI Creative Commons

Raymond D. Craddock,

Aaron A. Mohammed, Joseph Tamborski

et al.

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(11)

Published: Nov. 1, 2024

ABSTRACT Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh and circulating seawater, manifesting as submarine discharge (SGD). Water circulation induced by tidal pumping enhances the exchange chemicals between aquifers waters thereby influences biogeochemistry zones. Here, we report results an SGD field study conducted at a steep, mega‐tidal sand gravel beach along Canadian coast Bay Fundy, region with world's highest tides (semi‐diurnal ranges exceeding 10 m). Several physical geochemical measurement techniques were employed to document spatiotemporal variability. was directly sampled from seepage meters installed over multiple cycles two summer campaigns. rates estimated tracer mass balances for radon (August 2020) radium isotopes (July 2021) cycles. averaged estimates ranged 12 87 cm d −1 , average 42 while tracing yielded tidally rate 86 . 23 43 shoreline 6 71 offshore, depending on residence times. Radionuclide analyses meter suggest that time seawater through aquifer is less than 1 day. measurements settings are rare, combination steep slopes, highly permeable sediments high range drive very diffusive SGD. Salinity gradients intertidal zone demonstrate primarily comprised circulated negligible groundwater. Although freshwater proportion relatively low, large volumetric total can still contribute amounts terrestrially derived remineralized nutrients waters.

Language: Английский

Submarine Groundwater Discharge at a Mega‐Tidal Beach DOI Creative Commons

Raymond D. Craddock,

Aaron A. Mohammed, Joseph Tamborski

et al.

Hydrological Processes, Journal Year: 2024, Volume and Issue: 38(11)

Published: Nov. 1, 2024

ABSTRACT Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh and circulating seawater, manifesting as submarine discharge (SGD). Water circulation induced by tidal pumping enhances the exchange chemicals between aquifers waters thereby influences biogeochemistry zones. Here, we report results an SGD field study conducted at a steep, mega‐tidal sand gravel beach along Canadian coast Bay Fundy, region with world's highest tides (semi‐diurnal ranges exceeding 10 m). Several physical geochemical measurement techniques were employed to document spatiotemporal variability. was directly sampled from seepage meters installed over multiple cycles two summer campaigns. rates estimated tracer mass balances for radon (August 2020) radium isotopes (July 2021) cycles. averaged estimates ranged 12 87 cm d −1 , average 42 while tracing yielded tidally rate 86 . 23 43 shoreline 6 71 offshore, depending on residence times. Radionuclide analyses meter suggest that time seawater through aquifer is less than 1 day. measurements settings are rare, combination steep slopes, highly permeable sediments high range drive very diffusive SGD. Salinity gradients intertidal zone demonstrate primarily comprised circulated negligible groundwater. Although freshwater proportion relatively low, large volumetric total can still contribute amounts terrestrially derived remineralized nutrients waters.

Language: Английский

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