Sedimentary architecture of the Bohai Sea China over the last 1 Ma and implications for sea-level changes

Abstract. The ground vertical movement of the tide gauges around the Bohai sea was firstly analyzed by using the observation data from 2009 to 2017 of the nine co-located GNSS stations. It was found that the change rate of ground vertical motion of four stations was in the same order of magnitude as the sea level change. In particular, the land subsidence rate of BTGU station reaches 11.47&thinsp;mm/yr, which should be paid special attention to in the analysis of sea level change. Then combined with long-term tide gauges and the satellite altimetry results, the sea level changes in the Bohai sea and adjacent waters from 1993 to 2012 were analyzed. The relative and absolute sea level rise rates of the sea area are 3.81&thinsp;mm/yr and 3.61&thinsp;mm/yr, respectively, both are higher than the global average rate of change. At the same time, it is found that the vertical land motion of tide gauge stations is the main factor causing regional differences in relative sea level changes.

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The impact of rapid coastline changes and sea level rise on the tides in the Bohai Sea, China

Journal of Geophysical Research Oceans ◽

10.1002/jgrc.20258 ◽

2013 ◽

Vol 118 (7) ◽

pp. 3462-3472 ◽

Cited By ~ 53

Author(s):

H. E. Pelling ◽

K. Uehara ◽

J. A. M. Green

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Bohai Sea ◽

The Bohai Sea ◽

The Impact ◽

And Sea Level

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Regional sea level variability in the Bohai Sea, Yellow Sea, and East China Sea

Continental Shelf Research ◽

10.1016/j.csr.2015.11.005 ◽

2015 ◽

Vol 111 ◽

pp. 95-107 ◽

Cited By ~ 14

Author(s):

Yongcun Cheng ◽

Hans-Peter Plag ◽

Benjamin D. Hamlington ◽

Qing Xu ◽

Yijun He

Keyword(s):

Sea Level ◽

East China Sea ◽

Yellow Sea ◽

Bohai Sea ◽

East China ◽

Sea Level Variability ◽

The Bohai Sea ◽

China Sea ◽

Regional Sea Level

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Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2020.109736 ◽

2020 ◽

Vol 550 ◽

pp. 109736

Author(s):

Zhengquan Yao ◽

Xuefa Shi ◽

Yanguang Liu ◽

Selvaraj Kandasamy ◽

Shuqing Qiao ◽

...

Keyword(s):

Sea Level ◽

Continental Margin ◽

Bohai Sea ◽

The Bohai Sea

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INVESTIGATION OF THE INTERNAL STRUCTURE AND EVOLUTION OF THE HOLOCENE BARRIER OF MARICÁ (RIO DE JANEIRO, BRAZIL)

Brazilian Journal of Geophysics ◽

10.22564/rbgf.v33i3.948 ◽

2015 ◽

Vol 33 (3) ◽

pp. 461

Author(s):

Carolina Pereira Silvestre ◽

André Luiz Carvalho da Silva ◽

Maria Augusta Martins da Silva ◽

Amilsom Rangel Rodrigues

Keyword(s):

Internal Structure ◽

Sea Level ◽

Ground Penetrating Radar ◽

Rio De Janeiro ◽

Depositional Environments ◽

Sea Level Changes ◽

The Holocene ◽

Sea Level Fluctuations ◽

Sedimentary Architecture ◽

Ground Penetrating

ABSTRACT. The objective of this study is the identification of the internal structure of the Holocene barrier of the Maricá coastal plain (Rio de Janeiro, Brazil) for the understanding of the evolution of this coast. The regional geomorphology is characterized by the large Maricá lagoon and by two sandy barriers which confines a series of small near-dry lagoons. Geophysical data obtained from ground-penetrating radar (GPR) images, with 400 and 200 MHz shielded antennae and borehole samples, both reaching down to about 10 meters in depth, provided information about the sedimentary architecture and geological and oceanographical processes responsible for the evolution of this area in the Holocene. The results show that the barrier internal structure is formed by a set of strata presenting different geometries, dip directions and organization, relative to the following depositional environments: dunes, washover fans, beach and tidal channels. It was possible to determine the importance of the sea level changes, longshore currents and overwash processes for the barrier development. Strong reflectors representing eolian strata dipping towards the continent point out to a phase of barrier retrogradation; afterwards, a succession of very well preserved beach paleoscarps, located south of the previous barrier, shows a phase of barrier progradation. Such evidences indicate that the barrier evolved according to the Holocene sea level fluctuations recognized for the Brazilian coast.Keywords: ground-penetrating radar, barrier-lagoon system, Holocene, Maricá coast. RESUMO. O presente estudo objetivou identificar a estrutura interna da barreira holocênica buscando compreender a evolução da planície costeira de Maricá (Rio de Janeiro). A geomorfologia regional é caracterizada pela Lagoa de Maricá e duas barreiras arenosas, separadas por pequenas lagunas colmatadas. Dados geofísicos obtidos com um georadar, com antenas de 400 e 200 MHz, e amostras de sondagem geológica, ambos até a profundidade média de 10 metros, forneceram informações sobre a arquitetura sedimentar e os processos geológicos e oceanográficos responsáveis pela evolução desta área no Holoceno. Os resultados mostram que a estrutura interna da barreira é formada por um conjunto de estratos de diferentes geometrias, direções de mergulho e modos de organização relacionados aos seguintes ambientes deposicionais: dunas, leques de arrombamento, praias e canais de maré. Essas características permitiram o entendimento da dinâmica costeira responsável pelo desenvolvimento da barreira, com destaque para as variações do nível do mar, correntes de deriva litorânea e mecanismos de sobrelavagem. Refletores marcantes representando estratos eólicos inclinados para o continente indicam uma fase de retrogradação da barreira; a esse episódio se seguiu um período marcado por sucessivas paleoescarpas de tempestade, localizadas mais ao sul, indicando uma fase de progradação. Essas evidências mostram que a barreira evoluiu de acordo com as fases de transgressão e regressão marinha do Holoceno reconhecidas para o litoral brasileiro.Palavras-chave: georadar, sistema barreira-laguna, Holoceno, litoral de Maricá.

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Sea-level and climate signatures recorded in the 1 Myr continental margin deposits from the Bohai Sea

10.5194/egusphere-egu2020-9416 ◽

2020 ◽

Author(s):

Zhengquan Yao ◽

Xuefa Shi ◽

Yanguang Liu ◽

Shuqing Qiao

Keyword(s):

Grain Size ◽

Sea Level ◽

Continental Margin ◽

Principal Components ◽

Bohai Sea ◽

Sediment Accumulation ◽

Fine Fraction ◽

The Bohai Sea ◽

Floodplain Deposits ◽

And Sea Level

Sediment accumulation in the continental margin is largely influenced by both sea-level fluctuations and climate changes during the Quaternary Period. However, the response of sediment accumulation to these changes at orbital timescale, remains poorly understood, mainly due to (i) the scarce of sedimentary records with high-resolution chronology and (ii) the difficulty of distinguishing the role of sea-level from climate signals. Here we present sediment color reflectance (c*), grain size and total organic carbon (TOC) data of core BH08 (212.4 m; ~1 Myr) recovered from the Bohai Sea, China. The chronology of core BH08 was constrained at orbital timescale by using magnetostratigraphy and astronomical tuning methods. Sedimentary facies analysis suggests that the core sequence is dominated by alternations of deltaic system and floodplain deposits. Principal components analysis on grain size data reveals two principal components (PCs), including PC1 (31&#8211;500 &#181;m, coarse fraction) and PC2 (18&#8211;66 &#181;m, fine fraction). Comparison of PC1, PC2, c* and TOC with sedimentary environments, we found that PC1 and c* corresponds well with cycles of deltaic and floodplain deposits at ~100/40-kyr cycles, while PC2 and TOC display ~20-kyr cycle, in addition to the ~100/40-kyr cycles. We interpret that PC1 and c* are mainly sea-level dependent, whereas PC2 and TOC are controlled by a combination of monsoonal climate and sea level. We suggest that Milankovitch-scale monsoon climate controlled the sediments supply to the Bohai Sea during the last 1 Myr, while the redistribution of sediments by marine process (e.g. tidal currents) seem to have obscured the monsoonal signal in the grain size proxy (e.g. PC1) which is sensitive to sea-level change. Our results provide an example of climate and sea-level influenced sediment accumulation in the shallow continental margin influenced by monsoonal climate in an icehouse world.

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Analysis on the Extreme Sea Levels Changes along the Coastline of Bohai Sea, China

Atmosphere ◽

10.3390/atmos9080324 ◽

2018 ◽

Vol 9 (8) ◽

pp. 324 ◽

Cited By ~ 4

Author(s):

Jianlong Feng ◽

Delei Li ◽

Hui Wang ◽

Qiulin Liu ◽

Jianli Zhang ◽

...

Keyword(s):

Sea Level ◽

Bohai Sea ◽

High Tide ◽

Tide Gauges ◽

Mean Sea Level ◽

Sea Levels ◽

The Bohai Sea ◽

Extreme Sea Levels ◽

The Mean

Using hourly sea level data from four tide gauges, the changes of the extreme sea level in the Bohai Sea were analyzed in this work. Three components (i.e., mean sea level, tide and surge) as well as the tide–surge interaction were studied to find which component was important in the changes of extreme sea levels. Significant increasing trends exist in the mean sea level at four tide gauges from 1980 to 2016, and the increase rate ranges from 0.2 to 0.5 cm/year. The mean high tide levels show positive trends at four tide gauges, and the increasing rate (0.1 to 0.3 cm/year) is not small compared with the long-term trends of the mean sea levels. However, the mean tidal ranges show negative trends at Longkou, Qinhuangdao and Tanggu, with the rate from about −0.7 to −0.2 cm/year. At Qinhuangdao and Tanggu, the annual surge intensity shows explicit long-term decreasing trend. At all four tide gauges, the storm surge intensity shows distinct inter-annual variability and decadal variability. All four tide gauges show significant tide–surge interaction, the characteristics of the tide–surge interaction differ due to their locations, and no clear long-term change was found. Convincing evidence implies that the extreme sea levels increase during the past decades from 1980 to 2016 at all tide gauges, with the increasing rate differing at different percentile levels. The extreme sea level changes in the Bohai Sea are highly affected by the changes of mean sea level and high tide level, especially the latter. The surge variation contributes to the changes of extreme sea level at locations where the tide–surge interaction is relatively weak.

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An investigation of mass changes in the Bohai Sea observed by GRACE

Journal of Geodesy ◽

10.1007/s00190-020-01408-1 ◽

2020 ◽

Vol 94 (9) ◽

Author(s):

Dapeng Mu ◽

Tianhe Xu ◽

Guochang Xu

Keyword(s):

Sea Level ◽

Spatial Resolution ◽

Bohai Sea ◽

Water Mass ◽

Sea Level Change ◽

Groundwater Depletion ◽

Reconstruction Technique ◽

The Bohai Sea ◽

Level Change ◽

Mass Increase

Abstract The Gravity Recovery and Climate Experiment (GRACE) satellite mission has profoundly advanced our knowledge of contemporary sea level change. Owing to the coarse spatial resolution and leakage issue across the land–ocean boundary, it is challenging (even impossible) for GRACE to detect mass changes over a region smaller than its spatial resolution, especially a semi-enclosed basin (e.g., the Bohai Sea) that is adjacent to land with significant mass variation. In this contribution, the causes for the GRACE RL06 mass changes in the Bohai Sea are investigated using a reconstruction technique that is implemented with multisource data, including altimeter observations, steric estimates, and land mass changes from GRACE RL06 mascon solution. Our results by the reconstruction technique demonstrate that the GRACE annual cycles are primarily caused by water mass changes rather than sediment changes. On the other hand, the mass trends from both reconstructed signals and those observed by the GRACE RL06 spherical harmonic coefficients (SHCs) are small, ranging from − 0.38 mm/year to 0.51 mm/year (depending on different data sources). Given that our estimated accuracies are > 0.8 mm/year (the real accuracies should be larger), our reconstructed results cannot directly confirm the presence of sediment accumulation or water mass increase; however, analysis of only the altimetry data suggests the mass trends are due to water mass increase, which would amount to ~ 0.44 Gt/year. Further investigation suggests that the mass trends in the Bohai Sea suffer from a − 2.9 mm/year leakage-in effect from groundwater depletion in the North China and about 2.5 mm/year signal attenuation (resulting in a ~ 2.5 mm/year remaining trend that is roughly equivalent to the leakage-in trend, consequently leading to the small mass trend in the Bohai Sea). Our reconstruction results exemplify that elaborate data processing is necessary for specific cases. We also test whether the recently released RL06 mascon solutions that are resolved with constraints and require no further processing would improve the agreement with altimeter observations. We find that the seasonal cycles are improved relative to the RL06 SHCs; however, the rates derived from the mascon solutions cannot properly represent the altimeter-derived ocean mass estimates for the Bohai Sea, probably because the mascon solutions underestimate the rates or contain some processing artifacts. Nevertheless, the mascon solutions show enhanced signals, which offer new opportunities to investigate regional sea level change.

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Holocene coastal morphologies and shoreline reconstruction for the southwestern coast of the Bohai Sea, China

Quaternary Research ◽

10.1016/j.yqres.2016.06.002 ◽

2016 ◽

Vol 86 (2) ◽

pp. 144-161 ◽

Cited By ~ 6

Author(s):

Yanxia Liu ◽

Haijun Huang ◽

Yali Qi ◽

Xiao Liu ◽

Xiguang Yang

Keyword(s):

Sea Level ◽

Marine Sediments ◽

Bohai Sea ◽

Yellow River ◽

Water Levels ◽

The Holocene ◽

The Bohai Sea ◽

Digital Elevation ◽

Level Elevation ◽

Elevation Model

AbstractGround-penetrating radar (GPR) reflection profiles were interpreted and combined with sedimentological data to highlight the morpho-evolutionary history of the southwestern sector of the Bohai Sea. The internal structures in GPR images obtained near the Holocene maximum transgression boundary revealed concave-upward and onlap types of transgressive paleotopography. The relationship between historical courses of the Yellow River and the distribution of shell ridges at three periods (6 ka, 2 ka, and recent times) showed that the concave-upward types derived from the marine sediments overlap the fluvial sediments, and the onlap types from the marine sediments cover the coastal lagoon sediments. Based on the above paleogeographical setting, previous sea-level markers were corrected, taking into account uncertainties of their relationship to former water levels. The rates of vertical tectonic displacement, evaluated through comparison of the relative sea level (RSL) data from the GPR images and the Holocene predicted sea-level elevation, markedly affected RSL changes. The fitted RSL curves from the corrected sea-level indicators showed that the accuracy of former sea-level determinations can be improved by comparing with the maximum transgressive position of GPR detection. A topographic digital elevation model (DEM) for 6 ka is reconstructed based on the corrected data.

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