The Newmark seismic time‐history analysis method can take into account the effects of natural seismic peak ground acceleration (PGA), duration, and seismic frequency; seismic wave can be input into the method for simulation. This study calculates the dynamic response of the typical seabed slope of Caofeidian in the event of a similar Tangshan earthquake, and the displacement value can be used to quantitatively reflect the influence of the earthquake on the slope of the site. The allowable displacement value of the top of buildings or submarine slope can be used as a marker of security and stability analysis, which can further provide important reference for similar slope stability evaluation and offshore engineering construction.

The carbonate rock of the Qiulitage Formation is a significant stratum for oil and gas exploration in the Tarim Basin. To elucidate its environmental characteristics, we conducted tests and analyses of trace elements, carbon, and oxygen isotopes of the carbonate rocks of the Qiulitage Formation in the Kekeqigankake section of the Keping area. The results reveal that δ¹³C values range between −1.7‰ and 4.3‰, with an average value of 1.645‰. δ¹⁸O values fluctuate from −11.4‰ to −6‰, with an average value of −8.2475‰. Z values (paleosalinity) vary from 120.33 to 131.67, significantly exceeding 120 with an average value of 126.52, indicating a marine sedimentary environment. Paleotemperature values (T) range from 12.75 to 29.09 °C, with an average value of 21.36 °C, suggesting warm climate conditions. The Sr/Ba (3.42~24.39) and Sr/Cu (57.5~560) ratios are elevated, while Th/U (<1.32) and V/Cr (0.989~1.70) ratios are reduced, suggesting that the Qiulitage Formation was deposited in an oxygen-rich, warm marine sedimentary environment with relatively high salinity.

Due to the extremely complex geological conditions in the Bohai Strait, active faults is very developed and earthquake activity occurs frequently. It is of great importance to evaluate the regional crustal stability for the planning and construction of the Trans-straits Passage. In this study, the authors carry out the evaluation by means of buffer analysis, topology analysis and overlay analysis based on ArcGIS software. The evaluation mainly analyzed six assessment factors of Bohai Strait including neotectonic activity, active faults distribution, seismicity, tectonic stress fields, Bouguer gravity anomaly and geological disasters. In brief, the crustal stability of the eastern North Yellow Sea Basin is best, while that of the Bohai Basin and southwest Bohai Strait is poor. Meanwhile, small and frequent earthquakes in the southern Strait and geological disasters developed in the northern and central Strait such as tidal ridge and shallow gas which may adversely impact on the Trans-straits Passage construction.

China’s sinuous coastline is increasingly threatened by land subsidence driven by complex geological conditions and intensive human activity. Using year-round Sentinel-1A acquisitions for 2023 and SBAS-InSAR processing, we generated the first millimetre-resolution subsidence velocity field covering the 50 km coastal buffer of mainland China. We elucidated subsidence patterns and their drivers and quantified the associated socio-economic risks by integrating 1 km GDP and population data. Our analysis shows that ~55.77% of the coastal zone is subsiding, exposing 97.42 million residents and CNY 16.41 billion of GDP. Four hotspots—Laizhou Bay, northern Jiangsu, the Yangtze River Delta (YRD) and the Pearl River Delta (PRD)—exhibit the most pronounced deformation. Over-extraction of groundwater is identified as the primary driver. The 15 m resolution subsidence product provides an up-to-date, high-precision dataset that effectively supports sustainable development research in coastal hazard prevention, territorial spatial planning, and sea-level rise studies.

Introduction: Nutrients directly regulate the level of primary productivity, which is crucial for the stability of marine ecosystems. However, under the context of human activities leading to global warming, factors influencing alterations in coastal nutrient dynamics remain a mystery.Methods: A study was conducted to investigate the spatial distribution characteristics of nutrients and chlorophyll-a at 55 stations in the Bohai Bay region during the autumn of 2021.Results: The dominant factor influencing coastal zone ecology in the surveyed area was identified as temperature. Multiple factors (e.g., riverine input, sediment release, atmospheric deposition, and hydrodynamics) collectively impacted nutrient dynamics. The temperature along the north-south transect was consistent, with a distinct demarcation at 118.68°E (19°C), where the temperature gradient exhibited a pronounced east-high, west-low pattern. The temperature difference between the surface and bottom waters was minimal. In the high-temperature eastern region, the redox potential was high (above 100 mV), and very few locations had low dissolved oxygen levels, indicating active aerobic microbial activity. This led to the decomposition of substantial organic matter, resulting in elevated ammonia-nitrogen concentrations, and low pH levels. The presence of ammonia-nitrogen promoted the growth and reproduction of planktonic organisms.Discussion: Therefore, we are concerned that global climate warming may trigger changes, and even worsen, marine ecological environments in temperate coastal regions, necessitating heightened attention from researchers.