@article {2623,
	title = {A base-level stratigraphic approach to determining Holocene subsidence of the Ganges{\textendash}Meghna{\textendash}Brahmaputra Delta plain},
	journal = {Earth and Planetary Science Letters},
	volume = {499},
	year = {2018},
	month = {Jan-10-2018},
	pages = {23 - 36},
	abstract = {Relative sea level history, which is the result of the combined effects of land subsidence, sediment supply and absolute sea level history may be reconstructed from preserved sediment thicknesses. However, variations in the preserved sediment thicknesses between different sedimentary environments strongly limit the accuracy of this type of geological approach, particularly in fluvial channelized systems, such as delta plains. To address this, we apply three different and independent stratigraphic approaches to the case of the Ganges-Brahmaputra-Meghna Delta (GBMD). Our approach has been made possible by a broad dataset of geological archives we have collected, which includes more than 400 hand-drilled stratigraphic wells, 198 radiocarbon ages, and river seismic reflection data (255 km of high-resolution multichannel seismic images). The seaward gradient of accommodation and the limit of the subsiding delta plain are estimated, assuming that the delta is near or at the base-level, which is considered to be the relative sea-level. First, a statistical analysis of the variability of preserved sediment thicknesses is used to derive the average pattern of accommodation from the Holocene isopach. Secondly, the preserved sediment thicknesses are analyzed by geomorphotectonic domains to estimate an average pattern of accommodation. Thirdly, the burial history of the seismically imaged last glacial incision of the Brahmaputra River is reconstructed. Results suggest that the variability of preserved sediment thicknesses can be up to 35\% in a delta plain between river channel and flood plain deposits for the same relative sea-level history. Taking this variability into consideration, the Holocene relative sea-level history of the GBMD and the most likely pattern of subsidence are determined. Results provide evidence of moderate Holocene subsidence over the delta, gently increasing seaward from <0.2 mm/yr landward of the Hinge Zone, which can be considered as the northern limit of the subsiding delta plain, to 2 +/- 0.7 mm/yr in the middle fluvial delta to 4 +/- 1.4 mm/yr in the lower tidal delta. This enables us to construct the first millennial-scale map of subsidence pattern on the GBMD in which uncertainties on subsidence rates are provided. This map may aid in evaluating the negative impact that human modification may have on subsidence and relative sea level in the GBMD, and thereby help to determine better sustainable coastal management practices for the GBMD and other large delta plains. (C) 2018 The Authors. Published by Elsevier B.V.},
	keywords = {base level stratigraphic method, delta plain, Ganges-Brahmaputra-Meghna Delta, indicative meaning of sea level index, relative sea level, subsidence},
	issn = {0012821X},
	doi = {10.1016/j.epsl.2018.07.008},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X1830414X},
	author = {Grall, C. and Steckler, M.S. and Pickering, J.L. and Goodbred, S. and Sincavage, R. and Paola, C. and Akhter, S.H. and Spiess, V.}
}
@article {2624,
	title = {A base-level stratigraphic approach to determining Holocene subsidence of the Ganges-Meghna-Brahmaputra Delta plain},
	journal = {EARTH AND PLANETARY SCIENCE LETTERS},
	volume = {499},
	year = {2018},
	month = {10/01/2018},
	pages = {23-36},
	chapter = {23},
	abstract = {Relative sea level history, which is the result of the combined effects of land subsidence, sediment supply and absolute sea level history may be reconstructed from preserved sediment thicknesses. However, variations in the preserved sediment thicknesses between different sedimentary environments strongly limit the accuracy of this type of
geological approach, particularly in fluvial channelized systems, such as delta plains. To address this, we apply three different and independent stratigraphic approaches to the case of the Ganges-Brahmaputra-Meghna Delta (GBMD). Our approach has been made possible by a broad dataset of geological archives we have collected, which includes more than 400 hand-drilled stratigraphic wells, 198 radiocarbon ages, and river seismic reflection data (255 km of high-resolution multichannel seismic images). The seaward gradient of accommodation and the limit of the subsiding delta plain are estimated, assuming that the delta is near or at the base-level, which is considered to be the relative sea-level. First, a statistical analysis of the variability of preserved sediment thicknesses is used to derive the average pattern of accommodation from the Holocene isopach.
Secondly, the preserved sediment thicknesses are analyzed by geomorphotectonic domains to estimate an average pattern of accommodation. Thirdly, the burial history of the seismically imaged last glacial incision of the Brahmaputra River is reconstructed. Results suggest that the variability of preserved sediment thicknesses can be up to 35\% in a delta plain between river channel and flood plain deposits for the same relative sea-level history. Taking this variability into consideration, the Holocene relative sea-level history of the GBMD and the most likely pattern of subsidence are determined. Results provide evidence of moderate Holocene subsidence over the delta, gently increasing seaward from <0.2 mm/yr landward of the Hinge Zone, which can be considered as the northern limit of the subsiding delta plain, to 2 {\textpm} 0.7 mm/yr in the middle fluvial delta to 4 {\textpm} 1.4 mm/yr in the lower tidal delta. This enables us to construct the first millennial-scale map of subsidence pattern on the GBMD in which uncertainties on subsidence rates are provided. This map may aid in evaluating the negative impact that human modification may have on subsidence and relative sea level in the GBMD, and thereby help to determine better sustainable coastal management practices for the GBMD and other large delta plains.},
	keywords = {base level stratigraphic method, delta plain, Ganges{\textendash}Brahmaputra{\textendash}Meghna Delta, indicative meaning of sea level index, relative sea level, subsidence},
	issn = {0012-821X},
	author = {Grall, C and Steckler, MS and Pickering, JL and Goodbred, S}
}
@article { ISI:000262186900001,
	title = {Stratigraphy, pollen history and geochronology of tidal marshes in a Gulf of Maine estuarine system: Climatic and relative sea level impacts},
	journal = {MARINE GEOLOGY},
	volume = {256},
	number = {{1-4}},
	year = {2008},
	month = {DEC 20},
	pages = {1-17},
	type = {Review},
	abstract = {Sedimentologic and stratigraphic characteristics of five tidal marshes in Great Bay Estuary, New Hampshire, which is located on the western boundary of the Gulf of Maine, were assessed from 20 vibracores. detailed descriptions of surficial environments, pollen analyses, and radiocarbon dating. Modern marsh sequences in Great Bay Estuary initiated with a time-transgressive basal peat that formed at the upland-brackish marsh boundary. The oldest basal peat deposit sampled during this study was dated at similar to 4560 cal yr B.P (based on an age of 4060 +/- 40 C-14 yr B.P.). The original tidal marshes that formed in Great Bay Estuary apparently were unable to accrete at a high enough rate to allow seaward expansion, resulting in a transgressive sequence of low marsh or mudflat sediments overlying the basal peat. The transgressive tidal marsh sequence is capped by high marsh sediments that corresponded to a slowing of relative sea-level (RSL) rise in the region and regressive seaward expansion of the tidal marshes. However, significant variations from these transgressive-regressive sequences occur in the Great Bay tidal marshes as a result of more recent marsh expansion and tidal channel migrations. Detailed pollen analyses of a vibracore taken in a tidal marsh along Squamscott River with a sedimentary record spanning the last similar to 3900 cal yr B.P exhibit five well-documented marker horizons including: 1) an increase of Tsuga (hemlock); 2) the appearance of Picea (spruce); 3) Tsuga and Fagus (beech) declines; 4) an increase in Ambrosia (ragweed) coupled with a sudden decrease in Quercus (oak); and 5) the Castanea (chestnut) decline. Using published ages for these pollen horizons and a calibrated 14C age obtained during this study for a basal peat, accretion rates for this marsh system over five time intervals were calculated: 1) 0.4 to 0.5 mm yr(-1) from similar to 3900 to 2850 cal yr B.P.; 2) 0.6 mm yr(-1) from similar to 2850 to similar to 1960 cal yr B.P.; 3) 0.8 mm yr(-1) from similar to 1960 to similar to 580 cal yr B.P.; 4) 0.7 to 0.8 mm yr(-1) from similar to 580 to similar to 210 cal yr B.P.: and 5) 0.8 to 0.9 mm yr(-1) over the last 210 years. The long-term accretion rate for the entire sequence based on the calibrated C-14 age of the basal peat was 0.6 to 0.7 mm yr(-1). This result agrees with accretion rates determined from calibrated C-14 ages from two other tidal marsh systems in Great Bay Estuary with accretion rates between similar to 0.6 to similar to 0.8 mm yr(-1). Higher accretion rates were obtained at a nearby tidal marsh with 1.2 mm yr(-1) for just the marsh and 1.3 mm yr(-1) for the marsh and underlying subtidal sediment. The results of this study indicate that the sedimentology and stratigraphy of moderate-size tidal marshes in rocky, glaciated coasts are highly variable and are strongly influenced by complex interactions among RSL, climatic variations, and anthropogenic influences. For instance, the early development of many of the marshes in the Great Bay Estuary area were likely driven by changes in rates of RSL resulting in transgressive onlap boundaries, subsequently overlain by regressive intertidal marsh sequences. However, more recent changes in tidal marsh sediment composition deposited during a relatively slow, steady RSL rise likely result from other forcings. such as changes in minerogenic and orogenic sediment inputs due to anthropogenic effects, tidal channel migrations, major storms causing erosion of the marsh, or climatic changes causing shifts in sediment delivery or vegetation. (C) 2008 Elsevier B.V. All rights reserved.},
	keywords = {accretion, climate effects, pollen, relative sea level, salt marshes, sedimentology, stratigraphy},
	issn = {0025-3227},
	doi = {10.1016/j.margeo.2008.08.004},
	author = {Ward, Larry G. and Zaprowski, Brent J. and Trainer, Kevin D. and Davis, P. Thompson}
}
@article {2274,
	title = {Sea-level rise on eastern China{\textquoteright}s Yangtze delta},
	journal = {Journal of Coastal Research},
	volume = {14},
	year = {1998},
	note = {Yt592Times Cited:46
Cited References Count:27
},
	month = {Win},
	pages = {360-366},
	abstract = {The Yangtze delta is a densely populated, low-lying region highly vulnerable to flooding, high tides and typhoons. All previous studies indicated that relative sea level was higher from similar to 7500-4000 yrs. BP, then lowered and stabilized at about present msl during the past 3000 yrs. To the contrary, we find that sea level has been rising relative to the southern Yangtze delta plain based on new sea-level data derived from dated peats, reassessment of earlier sea-level curves and measurement of delta plain subsidence and analysis of prehistoric habitat bases from similar to 7000 to 3000 yrs. BP. Consequences of this relative rise include difficulty in expelling water from the low-lying delta plain to the coast and associated flood damage. Emplacement of the 3-Gorges Dam on the Yangtze will control flooding of the Yangtze river but decrease sediment accumulation on the delta plain that, in turn, is likely to accelerate saline inundation of this vital breadbasket.},
	keywords = {delta flooding, Holocene, neolithic sites, peat, radiocarbon dates, relative sea level, sea-level curve, subsidence, taihu lake, yangtze delta},
	isbn = {0749-0208},
	author = {Chen, Z. Y. and Stanley, D. J.}
}
