Holocene Relative Sea Level Rise and Subsidence in Northern Gulf of Mexico: ABSTRACT

AAPG Bulletin ◽  
1988 ◽  
Vol 72 ◽  
Author(s):  
Shea Penland, John R. Suter, Karen
2020 ◽  
Vol 644 ◽  
pp. 33-45
Author(s):  
JM Hill ◽  
PS Petraitis ◽  
KL Heck

Salt marshes face chronic anthropogenic impacts such as relative sea level rise and eutrophication, as well as acute disturbances from tropical storms that can affect the productivity of these important communities. However, it is not well understood how marshes already subjected to eutrophication and sea level rise will respond to added effects of episodic storms such as hurricanes. We examined the interactive effects of nutrient addition, sea level rise, and a hurricane on the growth, biomass accumulation, and resilience of the saltmarsh cordgrass Spartina alterniflora in the Gulf of Mexico. In a microtidal marsh, we manipulated nutrient levels and submergence using marsh organs in which cordgrasses were planted at differing intertidal elevations and measured the impacts of Hurricane Isaac, which occurred during the experiment. Prior to the hurricane, grasses at intermediate and high elevations increased in abundance. After the hurricane, all treatments lost approximately 50% of their shoots, demonstrating that added nutrients and elevation did not provide resistance to hurricane disturbance. At the end of the experiment, only the highest elevations had been resilient to the hurricane, with increased above- and belowground growth. Added nutrients provided a modest increase in above- and belowground growth, but only at the highest elevations, suggesting that only elevation will enhance resilience to hurricane disturbance. These results empirically demonstrate that S. alterniflora in microtidal locations already subjected to submergence stress is less able to recover from storm disturbance and suggests we may be underestimating the loss of northern Gulf Coast marshes due to relative sea level rise.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Liu ◽  
Jiang Li ◽  
John Fasullo ◽  
Devin L. Galloway

Abstract Relative sea level rise at tide gauge Galveston Pier 21, Texas, is the combination of absolute sea level rise and land subsidence. We estimate subsidence rates of 3.53 mm/a during 1909–1937, 6.08 mm/a during 1937–1983, and 3.51 mm/a since 1983. Subsidence attributed to aquifer-system compaction accompanying groundwater extraction contributed as much as 85% of the 0.7 m relative sea level rise since 1909, and an additional 1.9 m is projected by 2100, with contributions from land subsidence declining from 30 to 10% over the projection interval. We estimate a uniform absolute sea level rise rate of 1.10 mm ± 0.19/a in the Gulf of Mexico during 1909–1992 and its acceleration of 0.270 mm/a2 at Galveston Pier 21 since 1992. This acceleration is 87% of the value for the highest scenario of global mean sea level rise. Results indicate that evaluating this extreme scenario would be valid for resource-management and flood-hazard-mitigation strategies for coastal communities in the Gulf of Mexico, especially those affected by subsidence.


Terra Nova ◽  
1992 ◽  
Vol 4 (3) ◽  
pp. 293-304 ◽  
Author(s):  
J.C. Varekamp ◽  
E. Thomas ◽  
O. Plassche

2021 ◽  
Author(s):  
Frances E. Dunn ◽  
Philip S. J. Minderhoud

<p>As one of the largest deltas in the world, the Mekong delta is home to over 17 million people and supports internationally important agriculture. Recently deposited sediment compacts and causes subsidence in deltas, so they require regular sediment input to maintain elevation relative to sea level. These processes are complicated by human activities, which prevent sediment deposition indirectly through reducing fluvial sediment supply and directly through the construction of flood defence infrastructure on deltas, impeding floods which deliver sediment to the land. Additionally, anthropogenic activities increase the rate of subsidence through the extraction of groundwater and other land-use practices.</p><p>This research shows the potential for fluvial sediment delivery to compensate for sea-level rise and subsidence in the Mekong delta over the 21st century. We use detailed elevation data and subsidence scenarios in combination with regional sea-level rise and fluvial sediment flux projections to quantify the potential for maintaining elevation relative to sea level in the Mekong delta. We present four examples of localised sedimentation scenarios in specific areas, for which we quantified the potential effectiveness of fluvial sediment deposition for offsetting relative sea-level rise. The presented sediment-based adaptation strategies are complicated by existing land use, therefore a change in water and sediment management is required to effectively use natural resources and employ these adaptation methods. The presented approach could be an exemplar to assess sedimentation strategy feasibility in other delta systems worldwide that are under threat from sea-level rise.</p>


The Holocene ◽  
2017 ◽  
Vol 28 (3) ◽  
pp. 354-362 ◽  
Author(s):  
Lan Li ◽  
Cheng Zhu ◽  
Zhen Qin ◽  
Michael J Storozum ◽  
Tristram R Kidder

2018 ◽  
Author(s):  
David Patrick Gold ◽  
James P. G. Fenton ◽  
Manuel Casas-Gallego ◽  
Vibor Novak ◽  
Irene Pérez-Rodríguez ◽  
...  

The island of Jamaica forms the northern extent of the Nicaraguan Rise, an elongate linear tectonic feature stretching as far as Honduras and Nicaragua to the south. Uplift and subaerial exposure of Jamaica during the Neogene has made the island rare within the Caribbean region, as it is the only area where rocks of the Nicaraguan Rise are exposed on land. Biostratigraphic dating and palaeoenvironmental interpretations using larger benthic foraminifera, supplemented by planktonic foraminifera, nannopalaeontology and palynology of outcrop, well and corehole samples has enabled the creation of a regional relative sea-level curve through identification of several depositional sequences. This study recognises ten unconformity-bounded transgressive-regressive sequences which record a complete cycle of relative sea level rise and fall. Sequences are recognised in the Early to ‘Middle’ Cretaceous (EKTR1), Coniacian-Santonian (STR1), Campanian (CTR1), Maastrichtian (MTR1-2), Paleocene-Early Eocene (PETR1), Eocene (YTR1-3) and Late Eocene-Oligocene (WTR1). These transgressive-regressive cycles represent second to fourth order sequences, although most tie with globally recognised third order sequences. Comparisons of the Jamaican relative sea-level curve with other published global mean sea-level curves show that local tectonics exerts a strong control on the deposition of sedimentary sequences in Jamaica. Large unconformities (duration >1 Ma) are related to significant regional tectonic events, with minor overprint of a global eustatic signal, while smaller unconformities (duration <1 Ma) are produced by global eustatic trends. The relatively low rates of relative sea-level rise calculated from the regional relative sea-level curve indicate that carbonate production rates were able to keep pace with the rate of relative sea-level rise accounting for the thick successions of Maastrichtian carbonates and those of the Yellow and White Limestone Groups. Carbonate platform drowning within the White Limestone Group during the Oligocene to Miocene is attributed to environmental deterioration given the low rates of relative sea-level rise.


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