The impacts of the great Mississippi/Atchafalaya River flood on the oceanography of the Atchafalaya Shelf

Kolker, Alexander S.; Li, Chunyan; Walker, Nan D.; Pilley, Chet; Ameen, Alexander D.; Boxer, Georgia; Ramatchandirane, Cyndhia; Ullah, Mohammad Shahid; Williams, Kelly A.

doi:10.1016/j.csr.2014.04.023

Cited by 23 publications

(19 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A striking example is given by the wind at Amerada Pass, which is nearly 50% lower than the wind in the nearby open water (station North of Eugene Island, Figure ). Also, in this case, it appears that studies that used the data from Amerada Pass (Hiatt & Passalacqua, ; Kolker et al, ) underestimated wind‐induced sediment resuspension and transport in the Mississippi Delta.…”

Section: Discussionmentioning

confidence: 87%

Biased Wind Measurements in Estuarine Waters

et al. 2018

View full text Add to dashboard Cite

Near surface wind—conventionally measured 10 m above the ground, U10—is a fundamental variable for many processes acting in bays and estuaries. For practical reasons, wind in bays and estuaries is often measured at the land‐water interface, e.g., on docks, piers, and jetties. By analyzing time series of U10 from 15 stations in the Mississippi Delta, Louisiana, we show that wind measurements at the land‐water interface are biased and not representative of the wind over estuarine waters. Specifically, measurements at the land‐water interface underestimate the speed of winds blowing from land, because even short (<1 km) stretches of land with large bed roughness can significantly reduce U10. Wind measured next to large channels is biased not only in speed but also in direction, which tends to align with the channel axis. We suggest that very local (<1 km) variability in the boundary layer properties contributes to the large spatial variability of the measured estuarine wind field. Simple anisotropic corrections based on bed roughness should be applied to measurements made at the land‐water interface to estimate wind over adjacent estuarine waters. Alternatively, wind measured at offshore stations—even if located hundreds of km away—provide reliable estimates of estuarine wind. A more systematic use of wind measurements would likely increase the accuracy of estuarine numerical models and allow for more direct comparison between different estuarine systems.

show abstract

Section: Discussionmentioning

confidence: 87%

Biased Wind Measurements in Estuarine Waters

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The terrestrial climate reconstructions of Knox (2003), coupled with interpretations of the isotope record from the Gulf of Mexico slope and basin, suggest century-scale variations in the delivery of hemipelagic sediments by massive river plumes during the late Holocene (Montero-Serrano et al, 2010;Tripsanas et al, 2013). For comparison, the initial deposit of the 2011 flood was largely confined to the shallow shelf (Kolker et al, 2014;Xu et al, 2014).…”

Section: Autogenic Versus Allogenic: Climatic Influence On Holocene Dmentioning

confidence: 99%

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

Bentley

Blum

Maloney

et al. 2016

Earth-Science Reviews

148

View full text Add to dashboard Cite

The Mississippi River fluvial-marine sediment-dispersal system (MRS) has become the focus of renewed research during the past decade, driven by the recognition that the channel, alluvial valley, delta, and offshore regions are critical components of North American economic and ecological networks. This renaissance follows and builds on over a century of intense engineering and geological study, and was sparked by the catastrophic Gulf of Mexico 2005 hurricane season, the 2010 Deep Water Horizon oil spill, and the newly recognized utility of source-to-sink concepts in hydrocarbon exploration and production. With this paper, we consider influences on the MRS over Neogene timescales, integrate fluvial and marine processes with the valley to shelf to deepwater regions, discuss MRS evolution through the late Pleistocene and Holocene, and conclude with an evaluation of Anthropocene MRS morphodynamics and source-to-sink connectivity in a time of profound human alteration of the system. In doing so, we evaluate the effects of tectonic, climatic, and anthropogenic influences on the MRS over multiple timescales. The Holocene MRS exhibits autogenic process-response at multiple spatial and temporal scales, from terrestrial catchment to marine basin. There is also ample evidence for allogenic influence, if not outright control, on these same morphodynamic phenomena that are often considered hallmarks of autogenesis in sedimentary systems. Prime examples include episodes of enhanced Holocene flooding that likely triggered avulsion, crevassing, and lobe-switching events at subdelta to delta scales. The modern locus of the Mississippi fluvial axis and shelf-slope-fan complex was established by Neogene crustal dynamics that steered sediment supply. Dominant Miocene sediment supply shifted west to east, due to regional subsidence in the Rockies. Then, drier 3 conditions inhibited sediment delivery from the Rocky Mountains, and Appalachian epeirogenic uplift combined with wetter conditions to enhance sediment delivery from the Appalachians. Climatic influences came to the forefront during Pleistocene glacial-interglacial cycles. The fluvial system rapidly responded to sea-level rises and falls with rapid and extensive floodplain aggradation and fluvial knickpoint migration, respectively. More dramatically, meltwater flood episodes spanning decades to centuries were powerful agents of geomorphic sculpting and source-to-sink connectivity from the ice edge to the deepest marine basin. Differential sediment loading from alluvial valley to slope extending from Cretaceous to present time drove salttectonic motions, which provided additional morphodynamic complexity, steered deep-sea sediment delivery, diverted and closed canyons, and contributed to modern slope geometry. Despite the best efforts from generations of engineers, the leveed, gated, and dammed Mississippi still demonstrates the same tendency for self-regulation that confronted 19 th century engineers. This is most apparent in the bed-level aggradation and scour associated wit...

show abstract

“…Given the region's mostly shallow bathymetry, estuaries and many nearshore coastal environments are often well-mixed. However, intense stratification occurs around the Mississippi River plume, where a lens of fresh water several meters thick can develop (Walker, 1996;Kolker et al, 2014). The Loop Current, a geostrophic current that originates in the southern Gulf and can extend northward, is a dominant feature of the pelagic region and can transport heat and moisture northwards to the coast (NASEM, 2018).…”

Section: Physical Processesmentioning

confidence: 99%

Understanding the Long-Term Evolution of the Coupled Natural-Human Coastal System: The Future of the U.S. Gulf Coast

Glickson¹,

Özkan-Haller²,

Carter³

et al. 2018

Geological Society of America Abstracts With Programs

View full text Add to dashboard Cite

Division), and Eric White (The Water Institute of the Gulf). The committee would also like to thank Brad Murray of Duke University, who provided information to the committee via a webinar. This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We thank the following individuals for their review of this report:

show abstract

The impacts of the great Mississippi/Atchafalaya River flood on the oceanography of the Atchafalaya Shelf

Cited by 23 publications

References 45 publications

Biased Wind Measurements in Estuarine Waters

Biased Wind Measurements in Estuarine Waters

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

Understanding the Long-Term Evolution of the Coupled Natural-Human Coastal System: The Future of the U.S. Gulf Coast

Contact Info

Product

Resources

About