Flow and nutrient dynamics in a subterranean estuary (Waquoit Bay, MA, USA): Field data and reactive transport modeling

Spiteri, Claudette
Slomp, Caroline P.
Charette, Matthew A.
Tuncay, Kağan
Meile, Christof
A two-dimensional (2D) reactive transport model is used to investigate the controls on nutrient (NO3-, NH4+, PO4) dynamics in a coastal aquifer. The model couples density-dependent flow to a reaction network which includes oxic degradation of organic matter, denitrification, iron oxide reduction, nitrification, Fe2+ oxidation and sorption of PO4 onto iron oxides. Porewater measurements from a well transect at Waquoit Bay, MA, USA indicate the presence of a reducing plume with high Fe2+, NH4+, DOC (dissolved organic carbon) and PO4 concentrations overlying a more oxidizing NO3- -rich plume. These two plumes travel nearly conservatively until they start to overlap in the intertidal coastal sediments prior to discharge into the bay. In this zone, the aeration of the surface beach sediments drives nitrification and allows the precipitation of iron oxide, which leads to the removal Of PO4 through sorption. Model simulations suggest that removal of NO3- through denitrification is inhibited by the limited overlap between the two freshwater plumes, as well as by the refractory nature of terrestrial DOC. Submarine groundwater discharge is a significant source of NO3- to the bay.


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Meile, C; Tuncay, Kağan; Van Cappellen, P (Elsevier BV, 2003-05-01)
Existing reactive transport models represent aquatic sediments as one-dimensional systems. These models account for the predominantly vertical chemical gradients recorded by traditional pore water and solid sediment sampling techniques (e.g., cores, dialysis samplers). However, advances in sampling techniques, including the rapid development of in situ microprofilers, are providing increasingly detailed data sets, which highlight the laterally heterogeneous nature of the water-sediment interface. In particu...
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Ozer, Ceren; Yalçıner, Ahmet Cevdet (Springer Science and Business Media LLC, 2011-11-01)
This paper describes the analysis of a parameter, "hydrodynamic demand,'' which can be used to represent the potential for tsunami drag force related damage to structures along coastlines. It is derived from the ratio of drag force to hydrostatic force caused by a tsunami on the structure. It varies according to the instantaneous values of the current velocities and flow depths during a tsunami inundation. To examine the effects of a tsunami in the present study, the analyses were performed using the tsunam...
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Tandon, K; Tuncay, Kağan; Hubbard, K; Comer, J; Ortoleva, P (Oxford University Press (OUP), 2004-01-01)
A data assimilation approach is demonstrated whereby seismic inversion is both automated and enhanced using a comprehensive numerical sedimentary basin simulator to study the physics and chemistry of sedimentary basin processes in response to geothermal gradient in much greater detail than previously attempted. The approach not only reduces costs by integrating the basin analysis and seismic inversion activities to understand the sedimentary basin evolution with respect to geodynamic parameters- but the tec...
Ground Motion Characterization for Vertical Ground Motions in Turkey—Part 1: V/H Ratio Ground Motion Models
Alipour, N.A.; SANDIKKAYA, MUSTAFA ABDULLAH; Gülerce, Zeynep (Springer Science and Business Media LLC, 2020-05-01)
Two approaches are used to develop the vertical design spectra in probabilistic seismic hazard assessment (PSHA): (i) performing PSHA for the vertical component using vertical ground motion models (GMMs), and (ii) utilizing the V/H ratio GMMs to scale the horizontal spectrum during or after the hazard calculations for the horizontal component. This study intends to develop a new framework for building a vertical ground motion logic tree that combines both vertical and V/H ratio GMMs in the PSHA analysis. Fo...
Hydrogeochemical outline of thermal waters and geothermometry applications in Anatolia (Turkey)
Mutlu, Halim; Güleç, Nilgün Türkan (Elsevier BV, 1998-10-01)
The chemical compositions of a total of 120 thermal water samples from four different tectonically distinct regions (Central, North, East and West Anatolia) of Turkey are presented and assessed in terms of geothermal energy potential of each region through the use of chemical geothermometers. Na-Ca-HCO3, type waters are the dominant water types in all the regions except that Na-Cl type waters are typical for the coastal areas of West Anatolia and for a few inland areas of West and Central Anatolia where dee...
Citation Formats
C. Spiteri, C. P. Slomp, M. A. Charette, K. Tuncay, and C. Meile, “Flow and nutrient dynamics in a subterranean estuary (Waquoit Bay, MA, USA): Field data and reactive transport modeling,” GEOCHIMICA ET COSMOCHIMICA ACTA, pp. 3398–3412, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38771.