Papers by Randall Parkinson
Journal of Geophysical Research, 2021
Everglades, 1994
8 SEA LEVEL CONTROL on STABILITY of EVERGLADES WETLANDS Harold R. Wanless Randall W. Parkinson Le... more 8 SEA LEVEL CONTROL on STABILITY of EVERGLADES WETLANDS Harold R. Wanless Randall W. Parkinson Lenore P. Tedesco ABSTRACT The expansive coastal wetlands and freshwater marsh of south Florida are a result of the very slow relative rise of sea level during the ...
Marine Geology, 1991
... Earlier versions of the manuscript benefited from reviews by Richard Davis, Michael Field, Jo... more ... Earlier versions of the manuscript benefited from reviews by Richard Davis, Michael Field, John Meeder, Peter Roy and Frank Stapor. This document is contribution 147 of the Department of Oceanography and Ocean Engineering, Florida Institute of Tech-nology. ...
Diversity and Function in Mangrove Ecosystems, 1999
Environmental Geology, 1993
AAPG Bulletin, 1987
ABSTRACT Decelerating late Holocene sea level rise over the south Florida platform has been accom... more ABSTRACT Decelerating late Holocene sea level rise over the south Florida platform has been accompanied by changes in sediment composition which reflect a transition from physically emplaced (allochthonous) sediment to biologically emplaced (autochthonous) sediment. This interpretation is based on a south Florida submergence curve which suggests that the rate of sea level rise has decreased from 26 cm/100 years, prior to 3200 y.B.P., to 3.5 cm/100 years thereafter. These compositional changes are recognizable within both mixed siliciclastic/carbonate and pure carbonate depositional systems. For example, mangrove islands located in the Ten Thousand Islands area of southwest Florida are overlain by a Holocene sediment sequence which consists of (in ascending order) (1) thin basal mangrove peat, (2) thin oyster zone, (3) shelly quartz packstone, (4) oyster or vermetid packstone to boundstone, and (5) mangrove peat. The lower sequence (units 1 through 3) reflects an early deepening phase which accompanied a rapid rise in sea level. Biological sediment production was not rapid enough to keep up with rising sea level and, as such, the mangrove-fringed shoreline was overstepped. The overlying subtidal shelly quartz packstones reflect local reworking of Pleistocene quartz sands and, later, the introduction of quartz sand by suspension from offshore. As sea level rise slowed, biological sediment production and accumulation began to exceed rates of sea level rise and subsequently deposits built up to and kept pace with rising sea level (units 4 and 5). Carbon-14 dates confirm this interpretation as the thin basal peats date at 4000 y.B.P. (rapid rise) and oysters at the base of unit 4 date at 1000 y.B.P. (slow rise).
Journal of Coastal Research, 1994
Tidal wetlands provide numerous ecological functions and protect urban areas from saltwater intru... more Tidal wetlands provide numerous ecological functions and protect urban areas from saltwater intrusion and storm surge. Because these areas occur at the land-sea interface they are strongly influenced by changing sea-level elevation. Hence, it is of interest to quantify the effects of sea-level rise anticipated to accompany global climate change into the next century.
Revista De Biologia Tropical, 2017
Infomacion geomorfologica, sedimentologica y estratigrafica obtenida en la region norte de la co... more Infomacion geomorfologica, sedimentologica y estratigrafica obtenida en la region norte de la costa Caribe de Costa Rica sugiere que el delta del rio Colorado es dominado por olas fomado en una margen continental pasiva. Esta situacion costera es significativamente diferente del Caribe sur y Pacifico, donde los rasgos geomorfologicos y liticos son indicativos de una margen continental sismicamente activa. La distintiva historia asismica y la geomorfologicos de margen pasiva de las llanuras costeras del Caribe norte parecen estar controladas por la presencia de rasgos tectonicos (i.e., la Zona de Fractura de Nicoya Este) que desconecta la region de areas adyacentes tectonicamente activas. Aunque la informacion recabada durante este estudio piloto, incluye dos dataciones radiometricas con carbono de la base del mantillo del bosque anegado y sedimentos del pantano de palmas, no fueron suficientes para documentar el cambio relativo del mar, confirmando la situacion asismica de la...
Comments on previously published article
Journal of Coastal Research, 1994
This paper (1) reviews mangrove forest peat accretion data obtained from carbonate settings of th... more This paper (1) reviews mangrove forest peat accretion data obtained from carbonate settings of the Wider Caribbean Region and (2) evaluates the fate of these forests based upon current global eustatic sea-level rise projections. Historical peat accretion rates calculated using 137 Cs or 210 Pb average 3.7 mm yr -1 . Peat accretion rates calculated using 14 C average 1.0 mm yr -1 . The discrepancy between historical and geological accretion rates, also recognized in salt marsh settings, is attributed to organic decomposition and sediment compaction. Our conceptual model, which is based upon comparisons between projected rates of global eustatic sea level rise and peat accretion, predicts stable forest conditions only if historical accretion rates persist during a conservative (low) sea-level rise of ~1.3 mm yr 1 . Best guess (middle) and high estimates of a sea-level rise of as much as 8 mm yr 1 will likely submerge mangrove forests located within carbonate settings of the Wider Cari...
It is now widely accepted global sea level will rise a meter or more by the year 2100, yet prior ... more It is now widely accepted global sea level will rise a meter or more by the year 2100, yet prior to this investigation no local government along the east-central Florida coast had begun to seriously address the potential consequences of concomitant erosion and inundation. In the fall of 2009, the City of Satellite Beach (City), Florida, authorized a project designed to: (1) assess municipal vulnerability to rising sea level and (2) initiate the planning process to properly mitigate impacts. Results indicate about 5% of the City landscape will submerge during the initial +2 ft (0.6 m) rise, with inundation generally restricted to fringing wetlands and finger canal margins proximal to the Banana River. At +4 ft (1.2 m), 25% of the City is submerged including South Patrick Drive, one of two major transportation corridors through the City. Residential areas in the north- (c.f. Pelican Coast) and south-west corners of the City are subject to limited inundation. At an elevation of +6 ft (...
ABSTRACT The Ten Thousand Islands (TTI) are a myriad of low relief mangrove islands which lie alo... more ABSTRACT The Ten Thousand Islands (TTI) are a myriad of low relief mangrove islands which lie along the low energy, subtropical southwest Florida coast. The region has been subjected to a relative rise in Holocene sea level, which has continuously decelerated up to its present position.Data derived from surface and subsurface sampling indicate that the Holocene sediment package of the TTI area consists of two sediment sequences. The lower sediment sequence is transgressive and was generated as a mangrove fringed shoreline passively retreated landward under the influence of rising sea level and was replaced by a shallow subtidal coastal marine setting. The upper sediment sequence consists of (1) biogenic shallowing upwards sequences or (2) thickened mangrove peat layers, reflecting island emergence and shoreline stabilization, respectively. Island emergence compartmentalized the area, reducing wave and current energy and promoting the deposition of organic rich shelly mudstone and wackestone in protected inter-island bays.Based on coastal stratigraphy and Carbon-14 dates, these changes in coastal response are directly related to changing rates of Holocene sealevel rise. The initial rapid rise, which averaged about 26 cm/100 years (Neuman, 1976, unpublished; Wanless, 1982) prompted shoreline retreat and the development of a transgressive facies sequence. All deposits associated with the deepening phase dated at $>$3,500 ybp. As the rate of rise slowed to an average of $
Results of a vulnerability assessment of the Indian River Lagoon to climate change indicate futur... more Results of a vulnerability assessment of the Indian River Lagoon to climate change indicate future risks to water quality can be mitigated through adaptation actions targeting anticipated increases in pollutant loads from wastewater treatment plants, on site treatment and disposal systems, and surface water storage and conveyance infrastructure. Nine adaptation actions are recommended and if successfully implemented could reduce risks caused by climate change by fifty percent. The mitigating benefits of these actions are expected to cascade into other elements of the Lagoon, like living resources and habitats. The results and recommendations of this investigation are novel because they are based upon site-specific data and anticipated risks prioritized using a repeatable and defensible methodology. Furthermore, the focus and deliverables were informed by stakeholder involvement to facilitate utility to and implementation by resource practitioners. The next challenge is to implement,...
Holocene sea-level rise has been the most significant natural influence on the evolution of both ... more Holocene sea-level rise has been the most significant natural influence on the evolution of both physical and biological aspects of east Central Florida's continental margin. Under conditions of rising Holocene sea level the barrier island system has retreated landward through erosional shoreface retreat. This landward retreat of the barrier island system has lead to constantly changing conditions of water quality (e.g., salinity), substrate composition, circulation, and water depth within the Indian River Lagoon. These changes have taken place over a broad range of spatial (meters to 100s of kilometers) and temporal (hours to 1,000s of years) scales. Because each of these parameters influence coastal biodiversity, it can be assumed that at least some of the historical changes noted to have occurred within the Indian River Lagoon are a natural response to Holocene sea-level rise and the concomitant landward retreat of the barrier island system. Geologic data are useful in distin...
Uploads
Papers by Randall Parkinson