@article {2854,
	title = {Sea Level Rise Explains Changing Carbon Accumulation Rates in a Salt Marsh Over the Past Two Millennia},
	journal = {Journal of Geophysical Research: Biogeosciences},
	volume = {124},
	year = {2019},
	month = {Sep-10-2019},
	pages = {2945 - 2957},
	abstract = {High rates of carbon burial observed in wetland sediments have garnered attention as a potential {\textquotedblleft}natural fix{\textquotedblright} to reduce the concentration of carbon dioxide (CO2) in Earth{\textquoteright}s atmosphere. A carbon accumulation rate (CAR) can be determined through various methods that integrate a carbon stock over different time periods, ranging from decades to millennia. Our goal was to assess how CAR changed over the lifespan of a salt marsh. We applied a geochronology to a series of salt marsh cores using both 14C and 210Pb markers to calculate CARs that were integrated between 35 and 2,460 years before present. CAR was 39 g C{\textperiodcentered}m-2{\textperiodcentered}year-1 when integrated over millennia but was upward of 148 g C{\textperiodcentered}m-2{\textperiodcentered}year-1 for the past century. We present additional evidence to account for this variability by linking it to changes in relative sea level rise (RSLR), where higher rates of RSLR were associated with higher CARs. Thus, the CAR calculated for a wetland should integrate timescales that capture the influence of contemporary RSLR. Therefore, caution should be exercised not to utilize a CAR calculated over inappropriately short or long timescales as a current assessment or forecasting tool for the climate change mitigation potential of a wetland.},
	keywords = {Carbon storage, Geochronology, Salt marsh, sea-level rise},
	issn = {2169-8953},
	doi = {10.1029/2019JG005207},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005207},
	author = {McTigue, Nathan and Davis, Jenny and Rodriguez, Antonio B. and McKee, Brent and Atencio, Anna and Currin, Carolyn}
}
@article {2874,
	title = {Salt Marsh and Fringing Oyster Reef Transgression in a Shallow Temperate Estuary: Implications for Restoration, Conservation and Blue Carbon},
	journal = {Estuaries and Coasts},
	volume = {40},
	year = {2017},
	month = {Jan-07-2017},
	pages = {1013 - 1027},
	abstract = {The importance of intertidal estuarine habitats, like salt marsh and oyster reef, has been well established, as has their ubiquitous loss along our coasts with resultant forfeiture of the ecosystem services they provide. Furthering our understanding of how these habitats are evolving in the face of anthropogenic and climate driven changes will help improve management strategies. Previous work has shown that the growth and productivity of both oyster reefs and salt marshes are strongly linked to elevation in the intertidal zone (duration of aerial exposure). We build on that research by examining the growth of marsh-fringing oyster reefs at yearly to decadal time scales and examine movement of the boundary between oyster reef and salt marsh at decadal to centennial time scales. We show that the growth of marsh-fringing reefs is strongly associated to the duration of aerial exposure, with little growth occurring below mean low water and above mean sea level. Marsh-shoreline movement, in the presence or absence of fringing oyster reefs, was reconstructed using transects of sediment cores. Carbonaceous marsh sediments sampled below the modern fringing oyster reefs indicate that marsh shorelines within Back Sound, North Carolina are predominantly in a state of transgression (landward retreat), and modern oyster-reef locations were previously occupied by salt marsh within the past two centuries. Cores fronting transgressive marsh shorelines absent fringing reefs sampled thinner and less extensive carbonaceous marsh sediment than at sites with fringing reefs. This indicates that fringing reefs are preserving carbonaceous marsh sediment from total erosion as they transgress and colonize the exposed marsh shoreline making marsh sediments more resistant to erosion. The amount of marsh sediment preservation underneath the reef scales with the reef{\textquoteright}s relief, as reefs with the greatest relief were level with the marsh platform, preserving a maximum amount of carbonaceous sediments during transgression by buffering the marsh from erosional processes. Thus, fringing oyster reefs not only have the capacity to shelter shorelines but, if located at the ideal tidal elevation, they also keep up with accelerating sea-level rise and cap carbonaceous sediments, protecting them from erosion, as reefs develop along the marsh.},
	issn = {1559-2723},
	doi = {10.1007/s12237-016-0196-8},
	url = {http://link.springer.com/10.1007/s12237-016-0196-8},
	author = {Ridge, Justin T. and Rodriguez, Antonio B. and Fodrie, F. Joel}
}
@article {526,
	title = {Catastrophic hurricane history revealed by organic geochemical proxies in coastal lake sediments: a case study of Lake Shelby, Alabama (USA)},
	journal = {Journal of Paleolimnology},
	volume = {39},
	year = {2008},
	note = {id: 2037; PT: J; UT: WOS:000251730600010},
	pages = {117-131},
	abstract = {We developed a new method for reconstructing millennia-long hurricane records from coastal environments that uses Organic Geochemical Proxies (OGPs) of organic carbon and nitrogen concentrations and their delta C-13 and delta N-15 compositions. The new method is independent of presence/absence of sand layers and improves significantly the severe-storm history resolution. The subject of this investigation is a 1.5 m long sediment core raised at 2.8 m water depth from the center of Lake Shelby, Alabama, a freshwater lake located approximately 250 m from the Gulf of Mexico, from which an overwash sand-layer based record was previously derived. The core contains two distinct sediment units; an upper 62 cm thick, fine-grained, organic-rich lacustrine sapropel (gyttja) that shows no visible structures except one sand lamina at 23.7 cm depth, and an underlying 90 cm thick, organic-poor lagoon/estuary clay unit. The sapropel unit was deposited over a 682 +/- 30 cal year time interval (1320-2002 A.D.) with a mean sedimentation rate of 0.79 +/- 0.04 mm/year. Lake Shelby{\textquoteright}s water column exhibits two contrasting states based on water chemistry surveys (i) an "isolated", stratified, mode under calm weather conditions with a relatively low trophic state, and (ii) a "flooded" mode occurring during storm surges when nutrient-rich seawater floods the lake. Statistically significant delta C-13 and delta N-15 positive excursions in organic matter, up to maximum values of -25 (parts per thousand PDB) and 4 (parts per thousand Air N-2), respectively, are interpreted as geochemical responses to the marine intrusions that fertilize the lake, increase light availability, and cause eutrophication spikes. Detailed OGPs analyses crossing a sand layer that offers visual evidence of a catastrophic hurricane overwash event at 1717 A.D. exhibit large delta C-13 and delta N-15 positive shifts bounded by rapid returns to base values, thus confirming the validity of the hurricane identification by the OGPs model. Our data indicate that 11 catastrophic hurricanes hit the Alabama coast over the past 682 years with a rough recurrence interval of one in 62 years.},
	issn = {0921-2728},
	doi = {10.1007/s10933-007-9101-6},
	author = {Lambert, W. Joe and Aharon, Paul and Rodriguez, Antonio B.}
}
@article {438,
	title = {Sea-level history of the Gulf of Mexico since the Last Glacial Maximum with implications for the melting history of the Laurentide Ice Sheet},
	journal = {Quaternary Science Reviews},
	volume = {26},
	year = {2007},
	note = {id: 2038; PT: J; UT: WOS:000248732200007},
	pages = {920-940},
	abstract = {Sea-level records from the Gulf of Mexico at the Last Glacial Maximum, 20 ka, are up to 35 m higher than time-equivalent sea-level records from equatorial regions. The most popular hypothesis for explaining this disparity has been uplift due to the forebulge created by loading from Mississippi River sediments. Using over 50 new radiocarbon dates as well as existing published data obtained from shallowmarine deposits within the northern Gulf of Mexico and numerical models simulating the impact of loading due to the Mississippi Fan and glacio-hydro-isostasy, we test several possible explanations for this sea-level disparity.. We find that neither a large radiocarbon reservoir, sedimentary loading due to the Mississippi Fan, nor large-scale regional uplift can explain this disparity. We do find that with an appropriate model for the Laurentide Ice Sheet, the observations from the Gulf of Mexico can be explained by the process of glaciohydro-isostasy. Our analysis suggests that in order to explain this disparity one must consider a Laurentide Ice Sheet reconstruction with less ice from 15 ka to its disappearance 6 ka and more ice from the Last Glacial Maximum to 15 ka than some earlier models have suggested. This supports a Laurentide contribution to meltwater pulse 1-A, which could not have come entirely from its southern sector. (c) 2007 Elsevier Ltd. All rights reserved.},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2007.01.001},
	author = {Simms, Alexander R. and Lambeck, Kurt and Purcell, Anthony and Anderson, John B. and Rodriguez, Antonio B.}
}
@article {285,
	title = {Seaward-branching coastal-plain and Piedmont incised-valley systems through multiple sea-level cycles: Late Quaternary examples from Mobile Bay and Mississippi Sound, USA},
	journal = {Journal of Sedimentary Research},
	volume = {77},
	year = {2007},
	note = {id: 2039; PT: J; UT: WOS:000246987600011},
	pages = {139-158},
	abstract = {Most incised valleys become more organized seaward through tributaries merging with the main trunk valley. Late Quaternary incised valleys on the Mississippi and Alabama inner continental shelf branch seaward, although they do coalesce towards the shelf break where they feed shelf-edge deltas. To link fluvial systems with their associated previously mapped incised valleys on the shelf, and evaluate the contribution of small coastal-plain valley systems to the lowstand systems tract, high-resolution seismic data and cores were collected from Mobile Bay, eastern Mississippi Sound, and the Mobile bay-head delta. These data show four unconformity-bounded stacked units, and this study focuses on the upper two regionally mappable units. The upper two unconformities were sampled in core as exposure surfaces, and, on the basis of stratigraphic position, depth of incision, and C-14 dates, are interpreted as sequence boundaries. The shallowest sequence boundary (A) formed in response to the Oxygen Isotope Stage 2 sea-level lowstand, while the underlying sequence boundary (B) formed in response to an earlier lowstand (Stage 6?). A map of Sequence Boundary B shows a network of seaward-branching valleys, 20-35 m deep and 0.6-7.7 km wide, that extend across Mobile Bay and Mississippi Sound. These valleys, which are bounded by well-developed terraces, are extensions of the piedmont Mobile fluvial system and the coastal-plain Fowl and La Batre fluvial systems. A map of the Stage 2 Sequence Boundary shows that all systems generally reoccupied their previous valley positions and are separated by interfluve plateaus. Valley fill between Sequence Boundary B and the Stage 2 Sequence Boundary is generally composed of a basal unit of alluvial sediments overlain by bay-head delta deposits; however, Stage 2 to 1 valley fill is composed entirely (if central-basin sediments. The presence of bay-head delta deposits on the inner shelf indicates this depositional environment backstepped across the estuaries to modern positions. Backstepping likely occurred as the low-gradient paleovalleys were inundated, resulting in rapid rates of transgression. Fluvial gradients measured on Sequence Boundary B and the Stage 2 Sequence Boundary, below the modern Mobile bay-head delta plain and the estuaries, are very low (1.3-0.3 m/km). The Mobile bay-head delta and upper Mobile Bay are confined by steep topography, which opens basinward into the low-gradient shorelines surrounding lower Mobile Bay and Mississippi Sound. During falling sea level, channel branching likely occurred as the low-gradient fluvial systems extended basinward beyond the confined topography. These channels incised as sea level fell below the steeper shelf break during the lowstand. Stage 2 valley morphology is partially influenced by the position of the underlying Stage 6 valleys. Both coastal-plain and piedmont valley systems exhibit compound fill, indicating that differentiation between these types of incised valleys cannot be based on valley-fill architecture alone.},
	issn = {1527-1404},
	doi = {10.2110/jsr.2007.016},
	author = {Greene, D. Lawrence, Jr. and Rodriguez, Antonio B. and Anderson, John B.}
}
@article {938,
	title = {An assessment of the Late Holocene record of severe storm impacts from Lake Shelby, Alabama},
	journal = {Gulf Coast Association of Geological Societies Transactions},
	volume = {53},
	year = {2003},
	note = {id: 1111},
	pages = {443-452},
	abstract = {The historical record of severe storms on the Gulf Coast extends back only about 100 years. To better predict how the Gulf Coast will be impacted by future climate change and associated changes in storm frequency it is necessary to extend the severe storm record back to the time when global climate was different than today. A 3200-year record of severe storm impacts was reported from Lake Shelby, AL, using sand layers as proxies of storm intensity and frequency (Liu and Fearn, 1993). To enhance the understanding of the Lake Shelby environment and changes that may occur during severe storms seismic data, water chemistry profiles, sediment cores, radiocarbon dates, and geochemical measurements were obtained. The results indicate that Lake Shelby is a stratified lake in terms of salinity and dissolved oxygen. The lake floor is composed of two general lithologies, gyttja located below about 2 m water depth, and sand located along the entire perimeter of the lake. Radiocarbon dates and stable isotope data indicate that the lake was a brackish water lagoon prior to 80014C yrs BP when it became isolated and transformed into a lacustrine environment. Interpretation of sand layers recognized in sediment cores from Lake Shelby as indicators of severe storms may be ambiguous. New data suggest that severe-storm records based on geochemical stratigraphy may provide higher resolution and confidence than conventional overwash techniques.},
	author = {Lambert, W. Joe and Aharon, Paul and Rodriguez, Antonio B.}
}
