Using the radium quartet for evaluating groundwater input and water exchange in salt marshes

RAMA, .; Moore, Willard S.

doi:10.1016/s0016-7037(96)00289-x

Cited by 207 publications

(145 citation statements)

References 9 publications

Supporting

Mentioning

139

Contrasting

Order By: Relevance

“…K d = Ra solid /Ra liquid Distribution coefficients are determined in a variety of ways, usually in laboratory experiments where Ra isotopes are spiked onto sediment/water slurries (Rama and Moore, 1996;Hancock et al, 2006) or in laboratory experiments where sediment and water are equilibrated (Webster et al, 1995 (Benes, 1990). It is also important to determine which fraction of the sedimentary Ra pool is being used to calculate K d .…”

Section: )mentioning

confidence: 99%

“…Ra release in surface estuaries has been mainly attributed to desorption of Ra from suspended and bottom sediments as salinity increases (Li and Chan, 1979;Elsinger and Moore, 1980). However, radium behavior within the STE has additional complexity including varying fractions of exchangeable sediment Ra (Porcelli and Swarzenski, 2003); grain size and porosity of sediments (Webster et al, 1995, Hancock et al, 2006; changes in ionic strength (salinity) (Elsinger and Moore, 1980;Webster et al, 1995); temperature effects (Rama and Moore, 1996); pH (Sanchez and Rodriguez-Alvarez, 1999;Lauria et al, 2004); and barite solubility (Ba and Ra are chemical analogs) (Langmuir and Riese, 1985;Grundl and Cape, 2006). Other controls have been suggested but not thoroughly examined including the redox state of groundwater (including Eh and pH) (Puigdomènech and Bergström, 1995;Porcelli and Swarzenski, 2003) and the presence Fe and, in particular, Mn (hydr)oxides, since Ra has a very high affinity for Mn and Fe (Bollinger and Moore, 1993;Sun and Torgersen, 2001;Charette and Sholkovitz, 2006).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New perspectives on radium behavior within a subterranean estuary

et al. 2008

View full text Add to dashboard Cite

Abstract:Over the past decade, radium isotopes have been frequently applied as tracers of submarine groundwater discharge (SGD). The unique radium signature of SGD is acquired within the subterranean estuary, a mixing zone between fresh groundwater and seawater in coastal aquifers, yet little is known about what controls Ra cycling in this system. The focus of this study was to examine controls on sediment and groundwater radium activities within permeable aquifer sands (Waquoit Bay, MA, USA) through a combination of field and laboratory studies. In the field, a series of sediment cores and corresponding groundwater profiles were collected for analysis of the four radium isotopes, as well as dissolved and sediment associated manganese, iron, and barium. We found that in addition to greater desorption at increasing salinity, radium was also closely tied to manganese and iron redox cycling within these sediments. A series of laboratory adsorption/desorption experiments helped elucidate the importance of 1) contact time between sediment and water, 2) salinity of water in contact with sediment, 3) redox conditions of water in contact with sediment, and 4) the chemical characteristics of sediment on radium adsorption/desorption. We found that these reactions are rapid (on the order of hours), desorption increases with increasing salinity and decreasing pH, and the presence of Fe and Mn (hydr)oxides on the sediment inhibit the release of radium.These sediments have a large capacity to sorb radium from fresh water. Combined with these experimental results, we present evidence from time series groundwater sampling 2 that within this subterranean estuary there are cyclic periods of Ra accumulation and release controlled by changing salinity and redox conditions.

show abstract

Section: )mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New perspectives on radium behavior within a subterranean estuary

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The sources of 226Ra, 228Ra, 223Ra, and 224Ra to coastal waters include desorption from sediments and discharge of salty groundwater [Moore, 1987[Moore, , 1996Rama and Moore 1996]. After release from sediments, the activity of 226Ra and 228Ra on particles is regenerated very slowly.…”

Section: Age Modelsmentioning

confidence: 99%

“…This paper is not concerned with the relative amounts of Ra supplied by sediment desorption and groundwater discharge, but these inputs (or the isotopic ratios of the inputs) must be stable over the time period of the experiment. Additional studies are required to quantify the relative source functions of these short-lived Ra tracers [Rama and Moore, 1996].…”

Section: Age Modelsmentioning

confidence: 99%

Ages of continental shelf waters determined from ²²³Ra and ²²⁴Ra

Moore¹

2000

J. Geophys. Res.

Self Cite

188

153

View full text Add to dashboard Cite

“…These naturally occurring isotopes are useful environmental tracers for measuring coastal ocean mixing rates (Moore, 1996(Moore, , 2000aCharrette et al, 2003Charrette et al, , 2007Charrette et al, , 2013Hancock et al, 2006), ages of river plumes (Moore and Krest, 2004;Gu et al, 2012), and estuarine residence times Rapaglia et al, 2010), and as indicators of SGD (Rama and Moore, 1996;Charrette et al, 2008). One must note that this research has to date primarily been conducted in the seas and estuaries of moderate, subtropical, and tropical climates, and only rarely in the Arctic seas.…”

Section: Introductionmentioning

confidence: 99%

Discovery and characterization of submarine groundwater discharge in the Siberian Arctic seas: a case study in the Buor-Khaya Gulf, Laptev Sea

et al. 2017

View full text Add to dashboard Cite

Abstract. It has been suggested that increasing terrestrial water discharge to the Arctic Ocean may partly occur as submarine groundwater discharge (SGD), yet there are no direct observations of this phenomenon in the Arctic shelf seas. This study tests the hypothesis that SGD does exist in the Siberian Arctic Shelf seas, but its dynamics may be largely controlled by complicated geocryological conditions such as permafrost. The field-observational approach in the southeastern Laptev Sea used a combination of hydrological (temperature, salinity), geological (bottom sediment drilling, geoelectric surveys), and geochemical ( 224 Ra, 223 Ra, 228 Ra, and 226 Ra) techniques. Active SGD was documented in the vicinity of the Lena River delta with two different operational modes. In the first system, groundwater discharges through tectonogenic permafrost talik zones was registered in both winter and summer. The second SGD mechanism was cryogenic squeezing out of brine and watersoluble salts detected on the periphery of ice hummocks in the winter. The proposed mechanisms of groundwater transport and discharge in the Arctic land-shelf system is elaborated. Through salinity vs. 224 Ra and 224 Ra/ 223 Ra diagrams, the three main SGD-influenced water masses were identified and their end-member composition was constrained. Based on simple mass-balance box models, discharge rates at sites in the submarine permafrost talik zone were 1.7×10 6 m 3 d −1 or 19.9 m 3 s −1 , which is much higher than the April discharge of the Yana River. Further studies should apply these techniques on a broader scale with the objective of elucidating the relative importance of the SGD transport vector relative to surface freshwater discharge for both water balance and aquatic components such as dissolved organic carbon, carbon dioxide, methane, and nutrients.

show abstract

Using the radium quartet for evaluating groundwater input and water exchange in salt marshes

Cited by 207 publications

References 9 publications

New perspectives on radium behavior within a subterranean estuary

New perspectives on radium behavior within a subterranean estuary

Ages of continental shelf waters determined from ²²³Ra and ²²⁴Ra

Discovery and characterization of submarine groundwater discharge in the Siberian Arctic seas: a case study in the Buor-Khaya Gulf, Laptev Sea

Contact Info

Product

Resources

About

Using the radium quartet for evaluating groundwater input and water exchange in salt marshes

Cited by 207 publications

References 9 publications

New perspectives on radium behavior within a subterranean estuary

New perspectives on radium behavior within a subterranean estuary

Ages of continental shelf waters determined from 223Ra and 224Ra

Discovery and characterization of submarine groundwater discharge in the Siberian Arctic seas: a case study in the Buor-Khaya Gulf, Laptev Sea

Contact Info

Product

Resources

About

Ages of continental shelf waters determined from ²²³Ra and ²²⁴Ra