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The construction of dams for intercepting and storing water has altered surface water distributions, land-sea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs (MLRs) in Chinese mainland during 1950–2016, and to investigate the gravity, displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during 1950–2016, particularly in the Yangtze River (Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output (e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under long-term reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes.

In this study, we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System (GNSS) receivers over French Polynesia during the period 2007–2020, and obtain, as ancillary results, estimates of the absolute changes in sea level at the same locations. To verify our processing approach to determining vertical motion, we first modeled vertical motion at the International GNSS Service (IGS) THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations, with a good agreement. We obtained the following estimates for the vertical land motions at the tide gauges: Tubuai island, Austral Archipelago −0.92 ± 0.17 mm/yr, Vairao village, Tahiti Iti: −0.49 ± 0.39 mm/yr, Rikitea, Gambier Archipelago −0.43 ± 0.17 mm/yr. The absolute variations of the sea level are: Tubuai island, Austral Archipelago 5.25 ± 0.60 mm/yr, Vairao village, Tahiti Iti: 3.62 ± 0.52 mm/yr, Rikitea, Gambier Archipelago 1.52 ± 0.23 mm/yr. We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia.

The morphological evolution of embayed beaches on a microtidal coast is assumed to largely respond to the degree of exposure to wave conditions, decreasing the mobility with increasing beach indentation (and vice versa). However, the number of sediment arrivals at the beach or the impact of extreme storms can modify this relationship. Here, we present an analysis of 10 embayed beaches along the Catalan coast with different morphometric and sedimentary characteristics to identify the most relevant parameters controlling the morphological evolution of these embayed beaches at the inter‐annual and decadal scales. The study was mostly based on LiDAR topographic data collected from 2012 to 2017, aerial photographs from 1945 to 2021, sediment sampling and a long‐term series analysis of the forcing parameters (waves, sea level, precipitation and land‐use changes). The results show a net loss of volume on all the studied beaches at an inter‐annual scale and a general shoreline retreat during the last few decades, suggesting the influence of common processes on the evolution of the studied beaches. Smaller pocket beaches with medium‐to‐high indentations are more sensitive to changes induced by local factors and show higher variability in the volume of the emerged beach and shoreline position than larger beaches. The most relevant factors influencing the evolution of the studied beaches on a decadal scale were identified as changes in sea level and the reduction in sediment inputs provided by streams due to land‐use changes in the drainage basin. At the inter‐annual scale, the impact of extreme events is the main factor controlling beach behaviour. These general trends can be opposite locally for beaches that receive large amounts of sediment via longshore transport from adjacent beaches. [ABSTRACT FROM AUTHOR]

Rakhi Nala (Gorge) section of Eastern Sulaiman Range, Pakistan hosts world-class geological sections from the Cretaceous to the Recent. Here, Late Eocene Kirthar Formation is having a conformable lower contact with the greenish grey massive shale of the Baska Member of the Ghazij Formation. The rusty beds of the Oligocene Chitarwatta Formation are overlying the Kirthar Formation. To understand the detailed microfacies and depositional setting, detailed fieldwork was carried out in the Kirthar Formation in the outer Sulaiman Foldbelt. The late Eocene Kirthar Formation includes Habib Rahi Limestone, Domanda Shale, Pirkoh Limestone, and Drazinda Shale. Domanda Shale Member was deposited in transgression before Habib Rahi Limestone Member was deposited. It was followed up by the deposition of the second member Pirkoh Limestone and Marl Member. Habib Rahi Limestone, Pirkoh Limestone, and Marl Member have catch-up-to-keep-up deposition with rise and fall of sea level. Some facies of Drazinda and Domanda Shales represent a restricted setting supported by the presence of gypsum, while deep sea facies were also identified. This study will provide a guide for evaluating sedimentological concepts and understanding complex facies in highly oil and gas-prone stratigraphic sequences especially in the Eastern Tethys Region. [ABSTRACT FROM AUTHOR]

The Gulf of Thailand is ideal for studying eustatic sea level fluctuations in Southeast Asia due to its shallow basin and tectonic stability. However, our understanding of how this region's relative sea level (RSL) has fluctuated over the Holocene epoch is far from complete. In this study, we used lithostratigraphy, loss on ignition, grain size, and pollen analyses to reconstruct the environmental changes in the Sam Roi Yot wetland, which was significantly influenced by seawater intrusion, driven by fluctuations in RSL in the Gulf of Thailand. Therefore, the analyzed pollen records of the sediment core from the wetland reflected variabilities in the RSL in the Gulf of Thailand. Subsequently, we found that after a sea level highstand prior to 4000 cal y BP, the RSL gradually fell with two significant regressions at c. 2950 and 1850–1450 cal y BP before rising at 1450–1050 cal y BP and declining after that. The inconsistency between RSL reconstruction based on our results and the global sea level changes simulated by the Glacial Isostatic Adjustment (GIA) model further suggests that long–term El Niño Southern Oscillations (ENSO) variabilities may have played a significant role in sea level changes in the Gulf of Thailand over the Late-Holocene period. Thus, during extended El Niño or La Niña conditions, the sea level would have been consistently lower or higher than expected from eustatic and isostatic processes alone. Overall, this study emphasizes the importance of considering regional factors such as ENSO to understand sea level changes in Southeast Asia. [ABSTRACT FROM AUTHOR]

The East China Sea (ECS), which is located in the transitional zone between land and ocean, is the main site for the burial of sedimentary organic carbon. Despite good constraints of the modern source to the sinking process of organic carbon, its fate in response to changes in climate and sea level since the last deglaciation remains poorly understood. We aim to fill this gap by presenting a high-resolution sedimentary record of core EC2005 to derive a better understanding of the evolution of the depositional environment and its control on the organic deposition since 17.3 kyr. Our results suggest that sedimentary organic carbon was deposited in a terrestrial environment before the seawater reached the study area around 13.1 kyr. This significant transition from a terrestrial environment to a marine environment is reflected by the decrease in TOC/TN and TOC/TS ratios, which is attributed to deglacial sea level rise. The sea level continued to rise until it reached its highstand at approximately 7.3 kyr when the mud depocenter was developed. Our results further indicate that the deposition of the sedimentary organic carbon could respond quickly to abrupt cold events, including the Heinrich stadial 1 and the Younger Dryas during the last deglaciation, as well as 'Bond events' during the Holocene. We propose that the rapid response of the organic deposition to those cold events in the northern hemisphere is linked to the East Asian winter monsoon. These new findings demonstrate that organic carbon deposition and burial on the inner shelf could effectively document sea level and climatic changes. [ABSTRACT FROM AUTHOR]

Secondary weathering of exposed continental shelf sediment at low-latitudes may play a significant role in atmospheric CO2 consumption during glacial periods, which is negative feedback for climate stability. However, more lines of evidences are required to verify the link of glacial weathering with climate. This study presents a comprehensive analysis of geochemical proxies that indicate the silicate weathering intensity in the northern South China Sea (SCS) over orbital timescales since ∼244 ka. Provenance discrimination results, based on the Sr-Nd isotopes values and the patterns of rare earth elements (REEs), suggest that the terrigenous sediment was primarily derived from Taiwan Island. The silicate weathering records revealed two different weathering regimes during glacial periods in the northern SCS, corresponding to changes in monsoon climate and sea-level. During the early period of Marine Isotope Stage 6 (MIS 6), the increase in weathering intensity was in response to climate variability, and the rapid delivery of terrigenous sediment through contour currents allowed for the preservation of climate signals in the continental margin. In contrast, the significant increase in weathering intensity during the glacial periods at late MIS 2 and late MIS 6, was a result of the sedimentary recycling process dominated by sea-level rises. In this case, the marginal sea weathering records did not truly reflect climate changes, due to secondary weathering processes on the exposed continental shelf. Our new geochemical results emphasize the dynamic coupling effects of climate and sea-level changes in transmitting and preserving silicate weathering signals at low-latitude during glacial periods. When using marginal sea sediments for paleoclimatic and paleo-weathering reconstruction, one should be cautious of the complex influence of sediment source-to-sink processes on sediment composition, and a holistic approach may provide more robust constraints.

This study presents new insights into the depositional environment and stratal sequences of Lower Cretaceous (LC) siliciclastic sediments in Northwest Libya. The LC rocks in the study area consist of cross-bedded sandstones with subordinate occurrences of mudstones and are exposed over > 300 km along the Nafusa escarpment. They are explored as reservoirs for hydrocarbons and groundwater and are known to contain dinosaur fossils and petrified wood. Due to these fossils and to their position between two marine carbonates, theses siliciclastics have been mistakenly interpreted as having a continental origin. Recent surveys of quarries and road cuts revealed new sedimentary information that have not been previously considered. The most important of these are the dominance of marine indicators over the continental ones, as well as the identification of paleosol intervals with contrasting degrees of maturity. The study thus concluded that the majority of these LC strata were deposited on a marine clastic shelf rather than in a fluvial environment. The spatial variations within these strata can be ascribed mainly to sea level fluctuations in the presence of local paleo highs, of which some were episodically subjected to pedogenesis. The study also revealed the occurrence of at least three episodes of sea level oscillations during the LC. [ABSTRACT FROM AUTHOR]

The sea surface is variable in time and space; therefore, many researchers are currently interested in searching for dependencies and connections with the elements influencing this diversity, e.g., with the seabed topography. An important problem is combining or comparing models obtained based on different data sets with different accuracies and spatial resolutions. These studies are designed to discover the relationship that may exist between observations of the shape of the seabed and changes in sea level. The aim of this study is to investigate the relationship by checking the correlation between the observations from the point recording of satellite altimetry measurements and the bathymetric data. The object of research is the capital city of Gabon—Libreville, located on the west coast of Africa and three point in Las Palmas. The results present sea level, salinity, and potential temperature variations in selected points. The highest trends of sea level changes occur, at one point, in the open ocean (P6) and at coastal points (Libreville, P3, Pointe Noire). The study indicates that, from 1993 to 2020, the temperature trend at the assessed points is on average 0.018  ±  0.012 °C·year−1, while the average salinity trend is 0.008  ±  0.005 1e−3 year−1. The correlation coefficients for the sea water temperature trend and the sea water salinity trend—determined at 0.20 and 0.08—present a weak linear relationship. Correlation takes slightly higher values for elevation, which is determined at 0.38. Research shows that there is a relationship between satellite and bathymetric observations on the east coast of Africa; however, the strength of the correlation depends on the location. [ABSTRACT FROM AUTHOR]

Brazilian continental islands represent a natural laboratory to study speciation driven by recent phenotypic and genotypic divergence. The Bothrops jararaca species group is distributed in the Brazilian Atlantic Forest and on most of the Brazilian continental islands. The group is currently composed of the mainland common lancehead (B. jararaca) and four insular species (B. alcatraz, B. insularis, B. otavioi, and B. sazimai). Here, we evaluate mitochondrial DNA and morphological diversity of the B. jararaca species group and aim to provide additional evidence to understand insularization processes on the Brazilian coast. Our results, interpreted together with a comprehensive review of geomorphological data, provide a new conceptual framework for understanding the colonization process of the Brazilian continental islands. This framework suggests a history of multiple rounds of periodic isolation and reconnection between insular populations and their mainland relatives throughout the last 420,000 years. Furthermore, although some insular populations may have speciated prior to the last glacial maximum, other species likely diverged within the last 11,000 years. Additionally, the repeated evolution of size and dietary shift in the B. jararaca species group suggests a remarkable case of convergent adaptation. Our study provides evidence that the Bothrops from Ilha da Moela (Brazilian state of São Paulo) represents an undescribed species, presenting a distinct phenotype, and an exclusive history of isolation and adaptation. We describe this unique lancehead as a new species and we suggest it should be listed as critically endangered based on its endemicity to a small island that is severely impacted by constant and longstanding human presence. [ABSTRACT FROM AUTHOR]

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The southern Red Sea is a key region for investigating the effect of climate forces on a semi-closed basin. Detailed micropaleontological (planktic foraminifera) and isotopic (δ18Ο, δ13C) analyses along with reconstructions of sea surface temperature and salinity on a sediment core from the Farasan banks revealed the imprints of sea level changes and the South Asian Monsoon on the area. Comparison with surrounding records provided insights on the Red Sea-Gulf of Aden (GoA)-Northwestern Arabian Sea (NWArS) water exchange pattern over the last 30 ka. During glacial sea-level lowstand, flow of water from the GoA prevented hypersalinity in the southern Red Sea. Deglacial sea level rise improved water mass exchange between the NWArS, GoA and the entire Red Sea, resulting in relatively similar surface water conditions during the early Holocene when sea-level rise slowed. Thus, sea level change is the major driver of Red Sea δ18O variability. Southwest Monsoon (SWM), which was dominant during the late glacial and Early-Middle Holocene, enhanced surface productivity in the southern Red Sea. Northeast Monsoon (NEM) dominated around Heinrich stadial 1, as indicated by a nearly aplanktonic zone that was probably caused by restricted GoA inflow and low productivity. [ABSTRACT FROM AUTHOR]

The Gulf of Mexico coastal plain contains one of the largest dune systems in Mexico. These dunes and particularly their paleosols contain valuable paleoenvironmental information, however this aspect has been poorly studied. Here, we present the preliminary results obtained from buried paleosols of coastal dune ridges in Veracruz with the aim to reconstruct the environmental conditions during their formation as well as the phases of stability (pedogenesis) and instability (sedimentation) of the landscape. Three profiles were studied in the areas of Punta Delgada, PD (in the north), Palma Sola, PS, and La Mancha, LM (in the south). The chronological frame was constructed by radiocarbon dating of paleosols organic matter and pedogenic carbonates, and by Optical Stimulated Luminiscence (OSL) dating for the dune sediments. For each section several paleosols levels were identified whose properties permitted the differentiation of pedogenetic trends as well as their periods of formation. Nevertheless, the three sections did not provide for a continuous record of pedogenesis and sedimentation, as most of the paleosols are truncated by erosion. PS is the most complete profile which is formed from Marine Isotope Stage (MIS) 5c to MIS 1, with especially well-developed Holocene paleosols. LM includes only paleosols developed during MIS 4 and MIS 3, and PD shows only one paleosol originated during MIS 2. Although, the chronology is not complete as it has been constructed with a few dates, we consider each section contains information from different chronological windows. The results demonstrate that the oldest paleosols formed under more humid conditions during MIS 5c to 5a and probably MIS 4. As the MIS 4 to MIS 2 paleosols contain pedogenic carbonates, we interpret drier climates or with higher evapotranspiration rates. Paleosols from the early Holocene exhibit vertic properties probably formed by seasonal climates. Soils from the Middle-Late Holocene are less developed, due to the activation of the dune sedimentation. The results found here are compared at a regional scale with the dune system in the northern Gulf of Mexico and Yucatan peninsula, revealing both synchronous and asynchronous systems of eolian dynamics. The major asynchrony relates to the Wisconsinian stage (MIS 4 to MIS 2) for which high intensity of dune development is documented in the Veracruz and northern coasts whereas no dunes of that age are found in the Yucatan peninsula. [ABSTRACT FROM AUTHOR]

The sea surface is variable in time and space; therefore, many researchers are currently interested in searching for dependencies and connections with the elements influencing this diversity, e.g., with the seabed topography. An important problem is combining or comparing models obtained based on different data sets with different accuracies and spatial resolutions. These studies are designed to discover the relationship that may exist between observations of the shape of the seabed and changes in sea level. The aim of this study is to investigate the relationship by checking the correlation between the observations from the point recording of satellite altimetry measurements and the bathymetric data. The object of research is the capital city of Gabon—Libreville, located on the west coast of Africa and three point in Las Palmas. The results present sea level, salinity, and potential temperature variations in selected points. The highest trends of sea level changes occur, at one point, in the open ocean (P6) and at coastal points (Libreville, P3, Pointe Noire). The study indicates that, from 1993 to 2020, the temperature trend at the assessed points is on average 0.018 ± 0.012 °C·year−1, while the average salinity trend is 0.008 ± 0.005 1e−3 year−1. The correlation coefficients for the sea water temperature trend and the sea water salinity trend—determined at 0.20 and 0.08—present a weak linear relationship. Correlation takes slightly higher values for elevation, which is determined at 0.38. Research shows that there is a relationship between satellite and bathymetric observations on the east coast of Africa; however, the strength of the correlation depends on the location.

The multidecadal fluctuations in sea level changes play an important role in the exact quantification of present‐day global mean sea level (GMSL) rise and its acceleration. Here, we use an array processing technique (optimal sequence estimation) to analyze 44 global tide gauge (TG) sea‐level records with identical January 1933–December 2019 data spans. The results reveal for the first time a common 64.0 ± 3 years periodic oscillation with a spherical harmonic Y21 spatial pattern. Based on the estimated equivalent "excitation" amplitude (A = 47.7 ± 2 mm) and phase (φ = −0.406 rad), we constructed a global model for this 64 years sea‐level fluctuation. The complex amplitudes of the extracted ∼64 years fluctuation from 94 TG records with different data spans, and of two GMSL time series are consistent with the corresponding results predicted by the constructed model using the stacking results using 44 TGs. We find that the 64 years oscillation has significant contributions on the estimate of reconstructed GMSL trend: it contributed about 24% to the sea‐level trend during 1993–2014 and cause a relative deceleration during 2024–2055; while it contributes slightly to the satellite‐based GMSL trend estimates during 1993–2020. We confirm that this 64 years signal is not originated from the Earth's polar motion; however, it has good consistency with the Earth's magnetic field dipole changes, and with the ∼65 years oscillation in the ΔLOD, which suggests that this 64 years signal could come from core motions. We believe our results unravel a new understanding of the mechanisms of GMSL's long‐term fluctuations within the Earth system. Plain Language Summary: The rate of GMSL rise since 1993 as measured by satellite altimetry is higher than that for the 20th century. Therefore, there is a debate about whether this rate change is accelerated or affected by multidecadal sea‐level fluctuations, which have been studied for decades. In this study, we find and model a global common 64 years multidecadal sea‐level oscillation base on tide gauge (TG) records. Although the amplitudes of this 64 years oscillation can reach 10–18 mm in some regional ocean basins, the average amplitude for the global ocean is only ∼1.12 mm. The 64 years oscillation has a limited effect on the rate of GMSL trend as estimated from satellite altimetry data (which cover almost the whole ocean); for studies on the regional shorter‐term sea level trend estimates and the time‐varying trend changes from longer GMSL time series, the 64 years fluctuation, if not properly accounted for, would have significant impacts. Our results also further prove that the satellite altimetry‐based GMSL trend estimate since 1993 is more reliable than that measured using TG data. Key Points: A common 64 ± 3 years oscillation with Y21 spatial pattern was unraveled, verified by tide gauge, and its mathematical model is presentedThe 64 years signal contributed ∼24% for the sea‐level trend estimate in the reconstructed GMSL, 1993–2014The 64 years signal is shown to be consistent with the Earth magnetic field dipole change, and hence its plausible origin may be core motions [ABSTRACT FROM AUTHOR]

The “Old Red Sand” (ORS) along the southeast coast of China is of significant paleoclimatic and paleoenvironmental significance. However, its provenance remains controversial. In this study, grain size characteristics and quartz grain surface microtextures were analyzed to study the origin and paleoenvironmental significance of the ORS, the results show that the grain size of the ORS show typical aeolian features, the quartz grain surface microtextures of the ORS show both aeolian features and subaqueous environments characteristics. Combined with the latest OSL dating data, we suggest that the ORS was coastal aeolian sand dunes developed since the last interglacial period. The formation of the ORS was restricted jointly by climate changes of the coastal area and the distance from the shoreline that resulted from sea level changes.

The southeastern segment of the Caspian Sea (CS) along the Iranian coast, which has a very gentle inner shelf slope, underwent rapid beach evolution in response to water level changes. Based on satellite altimetry data, the CS basin has experienced an accelerated water level fall drop in recent years, leading to an increase in the rate of shoreline changes. The shoreline dynamics and morphodynamics of the Amirabad coastal zone, Gorgan Bay, Miankaleh Spit, and Gomishan Lagoon are evaluated here to determine morphological changes of the study area. Landsat-TM/ETM+/OLI moderate spatial resolution products were acquired at unequal intervals between 1994 and 2015 to monitor the coastal changes using Geographic Information System (GIS) tools. The Digital Shoreline Analysis System (DSAS), a GIS software extension, has been used for estimation of the shoreline rate of change through several approaches, including End Point Rate (EPR), Linear Regression Rate (LRR), and Weighted Linear Regression (WLR). The results show that both Gorgan Bay and Gomishan Lagoon have significantly decreased in size during recent years, mainly due to the fall of the CS water level. Results also show that water level drop of the CS, along with net eastward littoral transport, resulted in the growing of the Miankaleh Spit. Further analysis based on the wave climate in the southeast CS and net estimated longshore sediment transport indicates that the littoral drift contributed to ~ 6% of the total annual elongation of the Miankaleh Spit during the study period. [ABSTRACT FROM AUTHOR]

Marine cycles driven by astronomical orbital periods, may reflect sea-level fluctuations, which considerably influence organic matter (OM) accumulation, redox conditions, and terrigenous input, and subsequently impact the heterogeneity of shale reservoirs. This study uses multivariate analysis to examine astronomical orbital cycles and sea-level fluctuations, and investigate coupling mechanism between seal level changes and pore heterogeneity in Lower Silurian Longmaxi marine shale reservoirs. We conducted a high-resolution cyclic stratigraphic study of the GR series and performed associated geochemical analyses. Milankovitch cycles were identified, including ∼1.2 Myr obliquity, ∼405 kyr long eccentricity, and ∼95 kyr short eccentricity cycles. Climate change driven by ∼1.2 Myr long obliquity cycles resulted in two climate fluctuations (hot-humid and dry-cold), causing eustatic changes with two transgression-regression cycles (2 transgressive system tracts (TST) and 2 regressive system tracts (RST) identified. The changes in sea level during these periods considerably influenced the heterogeneity of shale pores, leading to variations in pore types and characteristics in response to sea-level fluctuations. For instance, during TST1, deglaciation occurred, causing a rapid rise in sea level and the deposition of organic-rich shales in a deep-water anoxic environment with limited terrigenous influx. This environment, combined with abundant biogenic silica, contributed to the accumulation of OM and promoted porosity, making organic pores dominant during the TST1 to RST1 period. Subsequently, the Upper Yangtze area shifted to a semi-restricted dysoxic - oxic deep-water shelf with the fall in sea level. This change resulted in decreased paleoproductivity and increased terrigenous influx, directly leading to reduced pore development, with inorganic pores becoming the main pore type during the TST2 to RST2 period. • The 1.2Myr long obliquity cycles drive the eustatic changes in the Upper Yangtze area. • The heterogeneity of shale pores is the ultimate response to sea level fluctuations. • Paleoclimate and eustatic changes are the key for shale reservoir pore heterogeneity. [ABSTRACT FROM AUTHOR]

The Kerala coast displays a spectrum of varied geomorphic features that are evolved as a function of Late Quaternary land-sea interaction. The southern Kerala coast, south of Achankovil Shear Zone (ASZ) has been characterised by cliffed coast with entrenched estuarine basins, pocket beaches, promontories, older and younger strand plains, etc., that are evolved as a result of the transgressive-regressive phases to which the coast has been subjected during the late Quaternary Period. In spite of having varied geomorphic features, lacuna in comprehending the evolutionary phases of the coastal landform features is the primary impediment that bolstered us to unravel the Late Quaternary land-sea interactions and landform changes of the coast between Thottapally and Vizhinjam. Moreover, the last two centuries are known to have been witnessing many natural as well as human induced environmental perturbations in the area.The present study attempts to reconstruct t he late Quaternary landform dynamics based on the satellite data while the last century changes were extracted from the Digital Shoreline Analysis System (DSAS). The evidences based on geomorphic variations suggest that the present study area hosts two distinct paleo-coastlines – 1) coincides with the eastern boundary of the older strand plains (accreted during Late Pleistocene) and, 2) marks the boundary between older and younger strand plains (accreted during Early–Middle Holocene). A sector-wise analysis reveals that the northern half of the study area is characterised by many coast perpendicular estuarine basins with well-developed Bay Head Deltas in its fluvial end, and Flood Tide Islands near the estuarine mouth. On the contrary, the southern half is characterised by pocket beaches and coast parallel backwater bodies developed during the regressive phases of the sea. A high-resolution study of the shoreline changes during the period, 1920–2018 reveals that the younger strandlines are vulnerable to severe coastal erosion and shoreline retreat at many places compared to coastal accretion. The study stresses the imminent need for continuous monitoring and implementation of site-specific mitigation measures for the conservation and management of this coast known for its outstanding natural beauty and strategic beach placer deposits. [ABSTRACT FROM AUTHOR]

Abstract Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines. Specifically, we calculate the time‐averaged vertical motion rates required to explain the present‐day elevations of the dated sequence of paleoshorelines on Santiago volcanic island (Cape Verde). We thus obtain a vertical motion history consisting of time‐averaged vertical motion rates spanning the five intervening periods between paleoshoreline formation and the present day: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma, mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. We numerically tested top‐down (volcanic loading) and bottom‐up (lithosphere thinning, underplating, and mantle plume) mechanisms to explain the inferred vertical movements, and we conclude that volcanic loading and crustal underplating are capable of producing the observed subsidence and uplift, respectively.

The Mezino-Lapshinovka section is constituted by the Upper Cretaceous carbonate clayey siliceous succession. It has been studied by XRD, SEM, microprobe, and geochemical analyses in order to reconstruct the main geologic events that influenced the formation of gaizes in the NE Peri-Tethys. A new scenario for their formation proposes that open-ocean siliceous ooze might have been delivered to the active subduction zone of the African-Arabian plate and then deposited in the shallow basin of NE Peri-Tethys. The bentonite interbeds were probably formed due to diagenetic alteration of the volcanic ash. It has been suggested that the sea water during the Santonian- Campanian was characterized by the oxic conditions, while there were two short episodes of anoxia or so-called anoxic non-sulfidic conditions. The early Santonian anoxic episode can be linked to the global anoxic event OAE 3 in the NE Peri-Tethys. The Campanian Mn anomaly coupled with the simultaneous increase in δ13C is considered to be a manifestation the Campanian eustatic rise.

We present a diatom record from a well‐dated 15.25 m composite sedimentary core from Verlorenvlei, a shallow coastal lake on the west coast of South Africa. We show that fluctuations in the diatom record occur in response to changes in sea level, ocean–atmosphere interactions and latitudinal shifts in the wind belts. During the early to mid‐Holocene, the system primarily responds to sea level changes. A marine community that favours high nutrients is evident, particularly during 9200–8000, 7420–7000 and 6200–5600 cal a bp, corroborating periods of Benguela upwelling linked to fluctuations in the southeast trade winds. Increases in bioproductivity (%TOC, C/N) and fresher‐water diatoms are associated with wetter conditions over the region and the northward migration of the southern westerly wind belt, most notably between 8000 and 7500 cal a bp and over the last 700 years. The latter trends are concomitant with changes in the extent of Antarctic sea ice and availability of moisture in southern South America. During the late Holocene, as sea levels stabilised to modern levels, climate variability is more strongly evident. The body of evidence further reveals the sensitivity of the region to high‐latitude atmospheric mechanisms, but also showcases the significance of the southeast trade winds. [ABSTRACT FROM AUTHOR]

Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines. Specifically, we calculate the time‐averaged vertical motion rates required to explain the present‐day elevations of the dated sequence of paleoshorelines on Santiago volcanic island (Cape Verde). We thus obtain a vertical motion history consisting of time‐averaged vertical motion rates spanning the five intervening periods between paleoshoreline formation and the present day: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma, mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. We numerically tested top‐down (volcanic loading) and bottom‐up (lithosphere thinning, underplating, and mantle plume) mechanisms to explain the inferred vertical movements, and we conclude that volcanic loading and crustal underplating are capable of producing the observed subsidence and uplift, respectively. Plain Language Summary: Oceanic volcanic islands experience vertical movements during their lifetime, which can be the consequence of several mechanisms like bending of the lithosphere due to the island's weight (subsidence) or horizontal intrusion of magma below the volcanic edifice (uplift). In order to discriminate among the possible mechanisms, we must correctly estimate the successive vertical displacements and motion rates. We account for eustatic sea level change and use dated paleoshorelines, working progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines, to obtain a step‐by‐step vertical motion history: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period of time are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. From analytical and numerical modeling, we conclude that volcanic loading and crustal underplating are likely mechanisms to explain the observed vertical displacements. Key Points: We anchor well‐constrained positions to calculate vertical motion ratesWe found a complex evolution of uplift and subsidence in Santiago IslandThe vertical displacements can be explained by the response of topography to isostasy [ABSTRACT FROM AUTHOR]

A knowledge of gas hydrates is critical for understanding complex geological, geophysical, and biogeochemical processes and for explaining the proposed link between gas hydrate destabilization and global sea level changes. With the aim of discussing the geochemical characteristics and implications for gas hydrate accumulation, this study assesses the changes in a series of organic and inorganic geochemical gas hydrate-bearing sediments within a core section obtained at site SHC in the Shenhu Area of the northern South China Sea that range from the Late Miocene to the present. High S/C ratios (0.53–5.6) and low TOC contents (<0.5%) suggest that strong ancient anaerobic oxidation of methane (AOM) occurred in sediments between 96 mbsf and 182 mbsf at site SHC. Therefore, the high total inorganic carbon (TIC) content (with a peak value of 47%) in sediments close to the gas hydrates-bearing sediment zone (GHBSZ) can be partially attributed to the AOM, and this also provides a reasonable explanation for the high concentrations of captured acid-extraction CH 4 (58.38–576.1 μl/g) in the samples. The relatively lower 13C values (−4.10‰ to −1.69‰) in the carbonate indicate that the contribution of dissolve inorganic carbon is partially from methanogenesis gas within the GHBSZ. However, the relatively higher values of δ 18O, as well as the inverse correlation between values of the δ 18O and the δ 13C observed in the GHBSZ, likely suggest a dissociation event of gas hydrates. These features are effective for indicating the presence of AOM in ancient times and implicate the formation of authigenic carbonates in sediments. The high value of authigenic carbonates by the AOM overly the GHBSZ in sediments, which implies the authigenic carbonate may have played an important role in the accumulation and sealing of gas hydrates at the SHC site. The relatively high contents of branched glycerol dialkyl glycerol tetraethers (B-GDGTs) and the relatively high values of the BIT index in the GHBSZ at SHC site are consistent with an increase in terrestrial source inputs which are marked by fine sands and silty deposits. These features also coincide with the change trend in the TOC/TN ratio and δ 13C org value, which imply an increase in terrestrial organic mass. Such significant paleoenvironment change is consistent with the results of previous studies based on sediment cores and seismic reflection data. It is thus suggested that those proxies are related to a relative sea level fall caused by the global "Messina carbon shift" in the South China Sea. Such geochemical imprints not only reveal that the ancient AOM played an important role in the formation of the reservoir-cap assemblage, but also suggest that reservoir generation at SHC site is related to a relative sea level change. We propose that the formation of authigenic carbonates and their sealing effect should be considered when studying gas hydrate accumulation mechanisms. • The formation of authigenic carbonates in the sediments of GHBSZ dues to ancient AOM. • The authigenic carbonates might serve as an important factor shaping the hydrate reservoir cap system. • GDGTs distribution, BIT index, TOC/TN and δ13C org are consistent with the increase in terrestrial source inputs in GHBSZ. • The reservoir generation of SHC is related to relative sea level drop. [ABSTRACT FROM AUTHOR]

Understanding the processes that govern the transformation of the landscape through time is essential for exploring the evolution of a coastal area. Coastal landscapes are dynamic sites, with their evolution strongly linked with waves and sea level variations. Geomorphological features in the coastal area, such as beachrock formations and dune fields, can function as indicators of the coastal landscape evolution through time. However, our knowledge of the chronological framework of coastal deposits in the Aegean coasts is limited. Optically Stimulated Luminescence dating techniques are deemed to be very promising in direct dating of the coastal sediments, especially when they are linked with archaeological evidence. The dating of the sediments from different sediment core depths, determined by the method of luminosity, allowed us to calculate the rate of sediment deposition over time. More recent coastal evolution and stability were examined from 1945 to 2020 with the use of aerial photographs and satellite images. This paper presents the 6000 ka evolution of a coastal landscape based on geomorphological, archaeological, and radio-chronological data. Based on the results, the early stages of the Ammoudara beach dune field appears to have been formed ~9.0–9.6 ka BP, while the OSL ages from 6 m depth represented the timing of its stabilization (OSL ages ~5–6 ka). This indicates that the dune field appears to already have been formed long before the Bronze Age (5–10 ka BP). It became stabilized with only localized episodes of dune reactivation occurring. In contrast, while high coastal erosion rates were calculated for modern times.

Abstract The Holocene evolution of eight South African coastal lakes and lagoons is examined and related to changes in fish composition over that period. Historical and current connectivity with riverine and marine environments are the primary determinants of present‐day fish assemblages in these systems. A small and remarkably consistent group of relict estuarine species have persisted in these coastal lakes and lagoons. The loss or reduction of connectivity with the sea has impacted on the diversity of marine fishes in all eight study systems, with no marine fishes occurring in those water bodies where connectivity has been completely broken (e.g. Sibaya, Groenvlei). In systems that have retained tenuous linkages with the sea (e.g., Verlorenvlei, Wilderness lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a freshwater biogeography perspective, the inflowing rivers of the four temperate systems reviewed here contain three or fewer native freshwater fishes, while the subtropical lakes that are fed by river systems contain up to 40 freshwater fish species. Thus, the significantly higher fish species diversity in subtropical versus temperate coastal lakes and lagoons comes as no surprise. Fish species diversity has been increased further in some systems (e.g., Groenvlei) by alien fish introductions. However, the impacts of fish introductions and translocations have not been studied in the coastal lakes and lagoons of South Africa. In these closed systems, it is probable that predation impacts on small estuarine fishes are significant. The recent alien fish introductions is an example of the growing threats to these systems during the Anthropocene, a period when human activities have had significant negative impacts and show potential to match the changes recorded during the entire Holocene.

A 30m-long sediment core covering the Holocene period was taken from the area of Gombong in the southern part of Central Java. The sediments were deposited in a shallow marine to lagoonal environment that was confirmed by the dominance of Ammonia beccarii along the core intervals. In addition, the species Quinqueloculina poeyana, Miliolinella lakemacquariensis, and Miliolinella subrotunda were also found in the sediments that are typical of normal shallow marine conditions. The decrease and increase in the abundance of these species throughout the core is an expression of sea level change in the area, which results the environmental changes. Low sea level is expressed by the dominance of Ammonia beccarii, and the low abundances or absence of the other three species. In contrast, high sea level stands are reflected by the presence of all four species. The high sea level would imply favorable conditions for benthic foraminifera because it would result in normal shallow marine conditions in the area. Finally, from this benthic assemblages study, it can be assumed that the environmental transformation from the originally shallow marine environment into land was occurred at level 5.5m depths of the sediment core, when all benthic foraminifera were terminated, including Ammonia beccarii. These new results from the shallow marine deposits in the Gombong area are a new contribution to the understanding of paleoenvironmental change in the region, which in turn is important for understanding sea level change as well as climate change in the region.

Substantial amounts of archaeological material have been found intermixed with beach pebbles and cobbles on the Tapes beach ridge at Longva on the island Flemsøya/Skuløya in Western Norway. The artefacts show that the beach ridge was settled in the Late Mesolithic. The most significant remains are fireplaces, birch bark from the floor of a tent/hut, fish sinkers and middens containing numerous waste flakes and lithic tools. Radiocarbon dating, mainly of burnt hazelnut shells, shows two periods of occupation. The older and longer period is dated to between 7600 and 6800 cal yr BP, and the younger phase to between 6200 and 5900 cal yr BP. Pollen analysis revealed open vegetation at the beach ridge during the occupation periods. Based on the beach ridge deposits and radiocarbon dates, we reconstructed the Tapes transgression maximum high tide sea level to 8.2–9.0 m between 7600 and 5600 cal yr BP. We conclude that the late Mesolithic inhabitants at Longva occupied the beach ridge while it was growing. During the largest storm surges – most likely to have been in the winter months – the sea would have washed over their settlements and deposited pebbles and cobbles on top of their remains. We suggest that the inhabitants abandoned the settlement before each stormy season, but returned and restored the site the following spring or summer. • Archaeological material found within the Tapes beach ridge, Western Norway. • Cultural remains are fireplaces, birch bark from a hut, fish sinkers and lithic tools. • Radiocarbon ages show occupation between 7600 and 5900 cal yr BP. • Storms overtopped the beach ridge and deposited pebbles and cobbles on the settlement. • The inhabitants abandoned the site before the stormy season, but returned next summer. [ABSTRACT FROM AUTHOR]

The present-day sea-level rise is a major indicator of climate change. The sea level in European seas has risen at a rate of 2.5 to 4 millimeters per year (von Schuckmann et al., 2018). The aim of this paper is to present the sea level variability in the Baltic Sea, as based on satellite altimetry. For this purpose, the paper presents a methodology of the investigation of the Baltic Sea level changes based on the Optimum Dataset (OptD) method. The OptD method was used to identify characteristic points from the analyzed data set. For detailed theoretical and empirical tests, the sea level anomaly was used. The time series were created from the data set after introducing the OptD method, in the period from January 1993 to December 2017. The time series are then used to characterize sea level trends, and inter-annual and semi-annual variability in the Baltic Sea region. The results prove that the linear change is higher at points which are located in the northern part of the Baltic Sea, while it is lower at points located in the western part of the Baltic Sea. The average trend is 4.1±0.2 mm/yr. However, the annual cycles in the sea level variations measured by altimetry reach maximum values in approximately the same months (November/December) in the whole Baltic Sea area. We find that there occur substantial regional deviations in sea level depending on the latitude and longitude. Our results confirm the need for research into the sea level variability in the Baltic Sea region. [ABSTRACT FROM AUTHOR]

Abstract Archaeological remains are valuable relative sea-level (RSL) indicators in Israel, a tectonically stable coast with minor isostatic inputs. Previous research has used archaeological indicators to argue for centennial sea-level fluctuations. Here, we place archaeological indicators in a quality-controlled dataset where all indicators have consistently calculated vertical and chronological uncertainties, and we subject the data to statistical analysis. We combine the archaeological data with bio-construction data from Dendropoma petraeum colonial vermetids. The final dataset consists of 99 relative sea-level index points and 12 limiting points from the last 4000 a. The temporal distribution of the index points is uneven; Israel has only four index points before 2000 a BP. We apply an Errors-In-Variables Integrated Gaussian Process (EIV IGP) to the index points to model the evolution of RSL. Results show RSL in Israel rose from −0.8 ± 0.5 m at ∼2750 a BP (Iron Age) to 0.0 ± 0.1 m by ∼1850 a BP (Roman period) at 0.8 mm/a, and continued rising to 0.1 ± 0.1 m until ∼1600 a BP (Byzantine Period). RSL then fell to −0.3 ± 0.1 m by 0.5 mm/a until ∼650 a BP (Late Arab period), before returning to present levels at a rate of 0.4 mm/a. The re-assessed Israeli record supports centennial-scale RSL fluctuations during the last 3000 a BP, although the magnitude of the RSL fall during the last 2000 a BP is 50% less. The new Israel RSL record demonstrates correspondence with regional climate proxies. This quality-controlled Israeli RSL dataset can serve as a reference for comparisons with other sea-level records from the Eastern Mediterranean. Highlights • 112 Israeli sea-level indicators are presented with IGCP standard metadata. • Archaeological remains are valuable sea-level indicator in Israel. • A Bayesian model with errors-in-variables integrated Gaussian process is applied. • Sea-level records in Israel show centennial fluctuations during the last 2 ka. • The reassessed Israeli data can be a reference for other East Mediterranean studies. [ABSTRACT FROM AUTHOR]

This study examines the morphology, lithological characteristic and controlling factors of coastal sediments in the northeast Gökova Graben (southwest Turkey). The northeast Gökova Graben is located in a region with several human settlements and tourism activities, in the summer. The analysis used in the study is field observation, Digital Elevation Model (DEM) analysis, 18 sieve (including statistical evaluations) and 18 X-ray Fluorescence (XRF) analyses. Due to the boundary of normal faults, predominantly faulted-rocky coasts are expected. However, four different coast types were determined in the northeast Gökova Graben. Evolution of these coast types is dependent on orientation of the normal faults and also distribution of different coastal rocks and rivers. The predominant coast type, rocky coasts are formed by faulted, high-resistant Jurassic-limestone. Owing to reworking and short transportation via brooks and the force of gravity, narrow gravely shingle beaches are only observable in front of the Quaternary-conglomerate cliff. Perennial streams form two different coasts. Long stream formed the wide sandy beach in the eastern end of Gulf. While short streams, which obliquely cut the graben, formed the sandy-gravely beach at the western end of the study area. Recent beachrock, coastal rock staining and wave notches are indicators for a stable sea level in the study area. Past sea level indicators are the hanging beachrocks and wave notches located in the western part of the study area. Past activities of the interior faults within the graben are responsible for ancient sea level fluctuations. Moreover, global warming increases the risk of sea level rise. A possible rise in the future sea-level may destroy narrow-gravely beaches. This risk may also threaten the wide sandy beach as well as the settlement in the area. [ABSTRACT FROM AUTHOR]

Abstract Future sea level changes are a threat to coastal communities worldwide. Therefore, reliable methods for the reconstruction of past relative sea-level variations are essential to make predictions of future developments. Beachrocks are a widely distributed indicator of Quaternary paleo-coastlines, with a high potential for preservation. Nevertheless, their use as sea-level indicator faces challenges in the determination of the exact elevation of beachrock formation with respect to paleo sea level. This information is crucial to the establishment of a sea-level index point. Our study area on the northeastern coastline of Oman shows a set of twelve marine terraces that reach a height of 500 m above mean sea level. While the upper terraces are erosional, the lowest three are depositional. On the erosional terraces beachrocks are the only sediment-cover that withstood erosion. On the depositional terraces however, beachrocks occur alongside other sediments, which can be fluvial, alluvial, or marine in origin. The coastal development of the area is of high interest as uplift and tectonic activity are ongoing. Fieldwork and petrographic methods on eight outcrops on three terrace levels led to the identification of eight lithofacies in six facies associations. We used facies analysis to improve the information on paleo sea level as derived by the sole use of geomorphological indicators. Here, we demonstrate that facies analysis (so far applied exclusively on sandy deposits) is applicable also to gravel-dominated systems. The results contribute to knowledge on local changes in the depositional environment and help to reconstruct uplift rates. Highlights • Facies analysis can improve the accuracy of beachrocks as sea-level indicator. • Six distinct lithofacies were identified in sand- and gravel-dominated beachrocks. • The method requires a certain thickness and well preserved beachrocks. • Berm and breaking depth are not always adequate limits of beachrock-formation. [ABSTRACT FROM AUTHOR]

Abstract An integrative multi proxy approach based on lithology, microfacies, bulk rock composition, total organic carbon (TOC), and δ13C carb was used to estimate southeastern Tethys sea level fluctuations during the deposition of the Maastrichtian-Danian oil shales in Jordan. Clay mineral assemblages were used as proxies to determine climatic variation induced sediment supply during the Cretaceous/Paleogene boundary (K/Pg) interval. The results from two cores (OS-02, Jafr Basin, southeast Jordan; OS-28 Azraq-Hamza Basin, central-east Jordan) reveal four major intervals of distinctive bulk rock composition reflecting sea level changes. Interval I (earliest Maastrichtian) with a low sea level and the formation of dolomites and a high detrital quartz input predates the oil shales. Intervals II and III in core OS-02 and interval II in core OS-28 represent the highest relative sea level following the Early Maastrichtian sea level rise on the Arabian Platform. Intervals III (core OS-02) and II (core OS-28) coincide with the highest organic matter deposition. Interval IV (core OS-02) and intervals III and IV (core OS-28) relate to the sea level regression-transgression cycle in the latest Maastrichtian through Danian and are marked by a large drop in the TOC content. Increased terrestrial influx during sea level lows is evident from two peaks/intervals of major negative δ13C carb values in core OS-28. Based on clay mineralogy it can be differentiated between warm/humid, warm/cool seasonally alternating, and cool/arid climates. When bulk rock composition is used as a sea level proxy, clay mineral assemblages from both cores reveal the dominance of warm and humid climate or, alternatively, warm/cool seasonal alternations during high sea levels (II and III core OS-02; II and IV core OS-28), while periods of arid and cool climate correspond to lower sea levels. The sea level changes and climatic variations deduced from the Jordanian oil shale successions are in agreement with the long term variations from the Egyptian Western Desert sections (southeastern Tethys), and the Tunisian El-Kef section (southweastern Tethys). Moreover, the sea level changes identified relate to the regional changes on the Arabian platform during the Maastrichtian-Danian. Highlights • 3 major sea level changes on the SE Tethys shelf in the Maastrichtian-Paleocene. • Dominance of the warm or seasonally alternating climate during high sea levels. • Dominance of similar sea level and climate conditions across the SE Tethyan shelf. • Analogy among SE and WE Tethys sea level and climatic changes in the Maastrichtian. • Negative δ13C carb excursions reflect periods of organic matter oxidation. [ABSTRACT FROM AUTHOR]

With increasing collaboration between archeology and natural sciences, the interactions between paleocultures and paleoenvironment have received more attention in recent years. In this investigation, the authors used nine radiocarbon dates from five profiles to explore the environmental evolution of the south coast of Laizhou Bay, and investigated the spatial-temporal distributions of archeological sites in the Middle Holocene as well as discussed the relationships between human cultures and environmental changes. The results show that the Neolithic archeological sites were mainly distributed in the flat (slopes < 4°) marine plain and alluvial plains with elevations below 29 m, and the quantity and frequency of archeological sites exhibited an early ascending and later descending trend. Multiple data such as those of slope and extent close to the riverside were integrated to indicate that the ability of the ancients to adapt to the environment gradually increased. Further comparison revealed the correlation among Holocene climate change and environmental evolution and the Neolithic cultural development in the study area, which concerns the generally improved living conditions, the development of the primitive culture whereas degeneration coincided with the culture's transition or interruption. The results highlight the geographical factors in the development of prehistoric culture, especially the climatic factors. [ABSTRACT FROM AUTHOR]

Abstract Coastal salt marsh, one of the blue carbon ecosystems that can adapt and mitigate climate change influence, is drawing global attention due to its high carbon sequestration capability. In China, however, coastal salt marsh has suffered great losses. Nation-wide analysis of salt marsh trends and management is critical to ecosystem protection and restoration. Thus, by analyzing previous coastal salt marsh studies, we found that the extent of coastal salt marsh varied greatly among the Liao River Delta, the Yellow River Delta, the middle coast of Jiangsu Province, Chongming Dongtan and Jiuduansha in Shanghai, with a 59% overall loss of salt marsh extent from the 1980s to the 2010s. The rate of salt marsh loss slowed down after the year 2000. Coastal land-claim (reclamation) is the most dominant driver of salt marsh loss. Climate change and coastal erosion, invasive species, and vegetation dynamics driven by competition and succession have also led to various effects on salt marsh extent and the ecological services they provide. Sea level rise, reclamation pressure and environmental pollution are the main factors, as negative drivers, together with conservation and restoration policies, as positive ones, affecting future trends in salt marshes. China has implemented several measures to protect and restore salt marshes, such as setting up protected areas, drawing marine ecological redline, and making strict regulations on reclamation. However, stronger legal protection for wetlands, more effective enforcement, and participation by local communities can further enhance salt marsh restoration, conservation and management. Graphical abstract Image 1 Highlights • Great losses (59%) of salt marshes occurred in China from the 1980s to the 2010s due to a few main drivers. • Salt marshes in China face natural and anthropogenic threats. • China has taken even tougher measures to conserve and restore salt marshes. • Legal basis for wetland protection, more effective enforcement and public participation are needed. [ABSTRACT FROM AUTHOR]

Abstract About 60% of Svalbard is covered by glaciers today, but many of these glaciers were much reduced in size or gone in the Early Holocene. High resolution modeling of the glacial isostatic rebound reveals that the largest glaciers in Nordaustlandet and eastern Spitsbergen survived the Early Holocene warming, while the smaller, more peripheral glaciers, especially in the northwest, started to form about 5,500 years ago, and reached 3/4 of their current size about 600 years ago. Relative sea level has been rising during the last few millennia in the north and western parts of Spitsbergen, while land still emerges in the remaining part of Svalbard. Here we show that this sea level rise in the northwest is caused by the regrowth of glaciers in the Mid- to Late Holocene that slowed down, and even reversed, the post-glacial isostatic uplift and caused the crust to subside over large areas of Spitsbergen. Highlights • Largest ice caps on Svalbard survived the Early Holocene warming. • Many cirque and valley glaciers re-formed 5500 years ago. • Regrowth of glaciers caused transgression in NW Svalbard last 2000 years. • Best Earth model has a thin lithosphere and low-viscosity asthenosphere. [ABSTRACT FROM AUTHOR]

Abstract We present the first quality-controlled relative sea-level (RSL) database for the Russian Arctic coast from the Barents Sea in the west to Laptev Sea in the east (29–152oE and 63 to 81oN). The database consists of 385 sea-level index points and 249 limiting dates and spans 24 ka to present. Sea-level indicators are derived from multiple proxies, including isolation basins, raised beaches, glacial erratics, marine terraces, laidas (salt marshes), and deltaic salt marshes. Here, we calculate the indicative meanings for all indicators and evaluated possible elevation errors. We have estimated the ages and uncertainties of index points and limiting dates using the most recent calibration datasets. In the western Russian Arctic (Barents and White Seas), RSL was driven by glacial isostatic adjustment (GIA) due to deglaciation of the Eurasian ice sheet complex. For example, within the Baltic crystalline shield, RSL fell rapidly from 80 to 100 m at 11–12 ka to 15–25 m at ∼4–5 ka. In the Arctic Islands of Franz-Joseph Land and Novaya Zemlya, RSL gradually fell from 25 to 35 m at 9 ka to 5–10 m at 3 ka. The Timan coast and the Kara Sea shelf are characterized by constant RSL rise due to proglacial forebulge collapse; Yamal and the Gydan Peninsula and Novaya Zemlya are all marked by a high LGM position of RSL, followed by a lowstand and consequent rise to a late Holocene highstand of several meters. Data from the Laptev Sea coasts and shelf and the New Siberian Islands demonstrate post-LGM RSL rise with a Holocene highstand of up to 5–10 m, with scatter caused by differential tectonic movements along a diffuse lithospheric plate boundary. The collected database allowed to estimate and discuss the reasons of both spatial and temporal variability of RSL histories in different parts of the Russian Arctic. Highlights • A database of post-glacial relative sea-level in the Russian Arctic was collected. • For the first time, both spatial and temporal uncertainties of RSL histories were estimated. • The main drivers of RSL variability were GIA, deglaciation patterns and vertical tectonic land motion. [ABSTRACT FROM AUTHOR]

Cretaceous sequences of theCauvery Basin, South India, can serve as an analogue to understand the subsurface successions with proven potential for commercial hydrocarbon exploration. In this area, the distribution of hydrocarbon reservoir and source rock facies was profoundly influenced by relative sea level changes amplified by rifting and related tectonic activities. Of particular interest are the sedimentary strata exposed in mines, quarries and outcrops around the Ariyalur area of Tamil Nadu, that mirror subsurface strata. This study reviews and integrates the stratigraphic studies based on this area and published over the past three decades. In particular, we concentrate on lithological features, macrofossils, microfossils, ichnofossils, magnetic polarity and sequence stratigraphy to reveal the geologic history of the Cauvery Basin. Age control, paleoenvironmental interpretations, paleobathymetry, paleoecology and paleotemperature are based on ammonites, belemnites, brachiopods, mollusks, nannofossils, and foraminifera. Key results include an integrated stratigraphic framework, paleobathymetry and sea level history that shows seven second/third-order depositional sequences, and major sea level falls during the late Turonian and late Maastrichtian linked to the Marion and Reunion mantle plumes, respectively. [ABSTRACT FROM AUTHOR]

Climate association between Groundwater Storage (GWS) and sea level changes have been missing from the Intergovernmental Panel on Climate Change, demanding a requisite study of their linkage and responses. Variability in the Hydrologic Unit Code—03 region, i.e., one of the major U.S. watersheds in the southeast caused by Sea Surface Temperature (SST) variability in the Pacific and Atlantic Ocean, was identified. Furthermore, the SST regions were identified to assess its relationship with GWS, sea level, precipitation, and terrestrial water storage. Temporal and spatial variability were obtained utilizing the singular value decomposition statistical method. A gridded GWS anomaly from the Gravity Recovery and Climate Experiment (GRACE) was used to understand the relationship with sea level and SST. The negative pockets of SST were negatively linked with GWS. The identification of teleconnections with groundwater may substantiate temporal patterns of groundwater variability. The results confirmed that the SST regions exhibited El Niño Southern Oscillation patterns, resulting in GWS changes. Moreover, a positive correlation between GWS and sea level was observed on the east coast in contrast to the southwestern United States. The findings highlight the importance of climate-driven changes in groundwater attributing changes in sea level. Therefore, SST could be a good predictor, possibly utilized for prior assessment of variabilities plus groundwater forecasting.