The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
Guebuem Kim - One of the best experts on this subject based on the ideXlab platform.
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large Submarine groundwater Discharge and benthic eutrophication in bangdu bay on volcanic jeju island korea
Limnology and Oceanography, 2005Co-Authors: Dong-woon Hwang, Yongwoo Lee, Guebuem KimAbstract:We estimated the Submarine Discharge of groundwater (SGD) and associated nutrients into the semienclosed Bangdu Bay on a volcanic island, Jeju, Korea, by analyzing 222 Rn, Ra isotopes ( 224 Ra and 226 Ra), and nutrients in seawater, pore water, and coastal groundwater. The Submarine inputs of groundwater into Bangdu Bay of 120‐180 m 3 m 22 yr 21 (on the basis of 222 Rn, 224 Ra, 226 Ra, and Si mass balances) were much higher than those reported from typical continental margins. The nutrient fluxes from SGD were about 90%, 20%, and 80% of the total input (except from open ocean waters) for dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved inorganic silicate (DSi), respectively. These excess nutrient inputs from SGD are the major sources of ‘‘new nutrients’’ in this bay. On the basis of photosynthetic pigments and benthic algal distributions, we suggest that the large fluxes of excess nutrients from SGD can cause benthic eutrophication in a semienclosed bay on this highly permeable volcanic island.
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Submarine groundwater Discharge sgd into the yellow sea revealed by 228ra and 226ra isotopes implications for global silicate fluxes
Earth and Planetary Science Letters, 2005Co-Authors: Guebuem Kim, Jae Woong Ryu, Han Soeb Yang, Seong Taek YunAbstract:Abstract We estimated the magnitude of Submarine groundwater Discharge (SGD) into the Yellow Sea, which is one of the largest continental shelves in the world, using 226 Ra and 228 Ra isotopes. On the basis of 228 Ra and 226 Ra mass-balance models, we estimated the advective flux of 226 Ra through SGD to be ∼270 × 10 12 dpm yr − 1 in the Yellow Sea. Using this 226 Ra flux and the measured 226 Ra activity in coastal groundwater, the Submarine Discharge of groundwater (mostly brackish groundwater) was calculated to be at least 40% of the river-water input (∼2.3 × 10 11 m 3 yr − 1 ). Then, on the basis of the SGD and the concentration of Si in coastal groundwater, we estimated the flux of Si through SGD to be 20–100% of that associated with river Discharge (∼23 × 10 9 mol yr − 1 ). This large SGD is likely to be due to the high tidal range (up to 10 m) and the wide distribution of sandy sediments in the Yellow Sea, favorable for the recirculation of seawater through bottom sediments and rocks. This result from such a large area implies that the Si flux through SGD may be significant on a global scale.
Tengfong Wong - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an ultrasonic ground water seepage meter
Ground Water, 2001Co-Authors: Ronald J Paulsen, Christopher F Smith, Daniel Orourke, Tengfong WongAbstract:Submarine ground water Discharge can influence significantly the near-shore transport and flux of chemicals into the oceans. Quantification of the sources and rates of such Discharge requires a ground water seepage meter that provides continuous measurements at high resolution over an extended period of time. An ultrasonic flowmeter has been adapted for such measurements in the Submarine environment. Connected to a steel collection funnel, the meter houses two piezoelectric transducers mounted at opposite ends of a cylindrical flow tube. By monitoring the perturbations of fluid flow on the propagation of sound waves inside the flow tube, the ultrasonic meter can measure both forward and reverse fluid flows in real time. Laboratory and field calibrations show that the ultrasonic meter can resolve ground water Discharges on the order of 0.1 μm/sec, and it is sufficiently robust for deployment in the field for several days. Data from West Neck Bay, Shelter Island, New York, elucidate the temporal and spatial heterogeneity of Submarine ground water Discharge and its interplay with tidal loading. A negative correlation between the Discharge and tidal elevation was generally observed. A methodology was also developed whereby data for the sound velocity as a function of temperature can be used to infer the salinity and source of the Submarine Discharge. Independent measurements of electrical conductance were performed to validate this methodology.
Alexandria B Boehm - One of the best experts on this subject based on the ideXlab platform.
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Submarine Discharge of nutrient enriched fresh groundwater at stinson beach california is enhanced during neap tides
Limnology and Oceanography, 2008Co-Authors: Nicholas R De Sieyes, Kevan M Yamahara, Blythe A Layton, Elizabeth H Joyce, Alexandria B BoehmAbstract:The influence of fortnightly spring–neap tidal variability on Submarine Discharge of fresh and saline groundwater was examined at Stinson Beach, California. Stinson Beach is a residential community that utilizes on-site systems for wastewater disposal. Fresh, shallow groundwater at the site contains high concentrations of nutrients (dissolved inorganic nitrogen [DIN], soluble reactive phosphate [SRP], and silicate) and human fecal bacteria. A groundwater-derived freshening and nutrification of the surf zone during neap tides was observed, followed by a 4-d increase in chlorophyll a concentrations. Analytical models and a freshwater budget in the surf zone were used to estimate the saline and fresh Discharge of Submarine groundwater. We estimate fresh groundwater Discharge between 1.2 and 4.7 L min21 m21 shoreline during neap tides compared with 0.1 and 0.5 L min21 m21 during spring tides. This compares with 15.9 and 22.0 L min21 m21 saline groundwater Discharge (forced by waves and tides) during neap and spring tides, respectively. Despite the smaller total (fresh + saline) flux of groundwater during neap compared with spring tides, the larger fresh Discharge component during neap tides raises surf zone silicate, DIN, and SRP by 14% ,3 5 %, and 27%, respectively, relative to spring tides. This observed fortnightly pulsing of fresh groundwater-derived nutrients was consistent with seaward hydraulic gradients across the fresh part of the beach aquifer, which varied due to aquifer overheight near the beach face. Darcy–Dupuit estimates of seaward fresh groundwater flow in this area agreed well with the fresh Discharge results of the mass balance.
Seong Taek Yun - One of the best experts on this subject based on the ideXlab platform.
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Submarine groundwater Discharge sgd into the yellow sea revealed by 228ra and 226ra isotopes implications for global silicate fluxes
Earth and Planetary Science Letters, 2005Co-Authors: Guebuem Kim, Jae Woong Ryu, Han Soeb Yang, Seong Taek YunAbstract:Abstract We estimated the magnitude of Submarine groundwater Discharge (SGD) into the Yellow Sea, which is one of the largest continental shelves in the world, using 226 Ra and 228 Ra isotopes. On the basis of 228 Ra and 226 Ra mass-balance models, we estimated the advective flux of 226 Ra through SGD to be ∼270 × 10 12 dpm yr − 1 in the Yellow Sea. Using this 226 Ra flux and the measured 226 Ra activity in coastal groundwater, the Submarine Discharge of groundwater (mostly brackish groundwater) was calculated to be at least 40% of the river-water input (∼2.3 × 10 11 m 3 yr − 1 ). Then, on the basis of the SGD and the concentration of Si in coastal groundwater, we estimated the flux of Si through SGD to be 20–100% of that associated with river Discharge (∼23 × 10 9 mol yr − 1 ). This large SGD is likely to be due to the high tidal range (up to 10 m) and the wide distribution of sandy sediments in the Yellow Sea, favorable for the recirculation of seawater through bottom sediments and rocks. This result from such a large area implies that the Si flux through SGD may be significant on a global scale.
Ronald J Paulsen - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an ultrasonic ground water seepage meter
Ground Water, 2001Co-Authors: Ronald J Paulsen, Christopher F Smith, Daniel Orourke, Tengfong WongAbstract:Submarine ground water Discharge can influence significantly the near-shore transport and flux of chemicals into the oceans. Quantification of the sources and rates of such Discharge requires a ground water seepage meter that provides continuous measurements at high resolution over an extended period of time. An ultrasonic flowmeter has been adapted for such measurements in the Submarine environment. Connected to a steel collection funnel, the meter houses two piezoelectric transducers mounted at opposite ends of a cylindrical flow tube. By monitoring the perturbations of fluid flow on the propagation of sound waves inside the flow tube, the ultrasonic meter can measure both forward and reverse fluid flows in real time. Laboratory and field calibrations show that the ultrasonic meter can resolve ground water Discharges on the order of 0.1 μm/sec, and it is sufficiently robust for deployment in the field for several days. Data from West Neck Bay, Shelter Island, New York, elucidate the temporal and spatial heterogeneity of Submarine ground water Discharge and its interplay with tidal loading. A negative correlation between the Discharge and tidal elevation was generally observed. A methodology was also developed whereby data for the sound velocity as a function of temperature can be used to infer the salinity and source of the Submarine Discharge. Independent measurements of electrical conductance were performed to validate this methodology.
