Temperature and salinity effects in modeling the trajectory of the 2011 Penglai 19-3 oil spill     

Yebao Wang  Xiangyang Zheng  Xiang Yu 《Marine Georesources & Geotechnology》2017,35(7):946-953

In this paper, two hydrodynamic models were developed using Delft3D and were then applied to the 2011 Penglai 19-3 accident in the Chinese Bohai Sea. One model includes constant temperature and salinity, while the other model utilizes variable temperature and salinity. The two models both simulate currents fields in the Bohai Sea and utilize wind data from the National Meteorological Service of Germany (DWD) to calculate the drift of spilled oil. The hydrodynamic simulation results are consistent with the results of previous studies. We subsequently predict the surface oil trajectories of the Penglai 19-3 oil spill based on the two models, respectively. Comparing the oil-spill simulation results with remote sensing information, we show that the model with variable temperature and salinity exhibits a better fit with the actual observations. Temperature and salinity were two important factors that influenced the movement of spilled oil on the sea surface. According to the result of the variable thermohaline model, most of the oil particles spread northwest and a small portion spreads southeast to the Chinese Bohai Strait. We conclude that density currents should be considered in future oil-spill studies to generate more realistic results.  相似文献   

Characterization of the cyp19a1a gene froma BAC sequence in half-smooth tongue sole (Cynoglossus semilaevis) and analysis of its conservation among teleosts     

SHAO Changwei  LIU Geng  LIU Shanshan  LIU Changlin  CHEN Songlin 《海洋学报(英文版)》2013,32(8):35-43

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烃源岩中C19~C29甾烷系列和25 降藿烷系列的检出及其地质意义   总被引：1，自引：1，他引：0  

王作栋  孟仟祥  陶明信  王晓锋  李中平  徐永昌 《沉积学报》2009,27(1):180-185

沉积有机质中通常可检测到C21（孕甾烷）、C22（升孕甾烷）和C27~C29甾烷,但C19、C20和C23~C26甾烷并不常见。在三塘湖盆地芦草沟组黑色页岩中检出了完整的C19~C29甾烷系列和25 降藿烷系列。如此完整且丰度较高的此类化合物,尚无文献报道。这一新的资料可能蕴含着丰富的油气地球化学信息。初步认为这2个系列的化合物指示:其古环境为干旱和咸化水体环境;有机质以藻类和浮游生物等低等水生生物来源为主,在沉积初期遭受强烈的生物降解作用;原始有机质与细菌降解的产物共存,成为生烃先质。  相似文献   

小质量AGB星热脉冲阶段氟的核合成     

刘永新  张波  彭秋和 《中国天文和天体物理学报》1996,(1)

本文计算并讨论了当13C以渐进注入方式进入氦燃烧壳层时，19F在小质量AGB星热脉冲中的核合成问题．采用小质量AGB星热脉冲的氢氦混合燃烧模型，中子源为13C（a,n）16O，质子则是脉冲开始时从氢燃烧壳层卷入的．对丰度的数值计算结果表明，在小质量AGB星的热脉冲中，19F是能够有效合成的，有效合成的温度T的范围为1．8≤D＜2．8（T8=T/108K）．采用小质量AGB星的挖掘模型，计算了AGB星大气中氟、氧等元素丰度的变化，较好地拟会了观测结果．对中子源的双脉冲机制，本文亦做了初步探讨．  相似文献   

Vereisung und Meeresspiegel     

E. Seibold  I. Seibold 《International Journal of Earth Sciences》1996,85(3):403-408

GLACIATION AND SEALEVEL — EARLY RESEARCH: Changes of sealevel positions depend on vertical crustal movements, different distributions of oceanic water masses and variations of ocean water volume. In spite of the fact that C. Maclaren explained the relations between the fluctuations of continental ice masses and ocean water volumes correctly in 1842, only two years after the classical paper of L. Agassiz, it took half a century to reach global agreement on the matter. Some examples of the different ways of research may illustrate the complex treatment of the problem, the fact that correct approaches were forgotten but wrong ideas were discussed for decades and the influence of geological authorities. However, some problems remain open even now, such as the exact dating of Pleistocene and Holocene sealevel fluctuations in different geological settings, or the influence of a changing geoid.

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How do people perceive the disclosure risk of maps? Examining the perceived disclosure risk of maps and its implications for geoprivacy protection     

Junghwan Kim  Margaret C. Levenstein  Douglas B. Richardson 《制图学和地理信息科学》2021,48(1):2-20

ABSTRACT

This research examines how people subjectively perceive the disclosure risk of a map using original data collected in an online survey with 856 participants. The results indicate that perceived disclosure risk increases as the amount of locational information displayed on a map increases. Compared to point-based maps, perceived disclosure risk is significantly lower for kernel density maps, convex hull maps, and standard deviational ellipse maps. The results also revealed that perceived disclosure risk is affected by map scale and the presence of information of other people on a map. For geomasking methods, perceived disclosure risk decreases as aggregation level increases and as relocation distance increases. However, aggregation methods (point to polygon) are more effective in preventing the re-identification of individuals when compared to relocation methods (point to point). Lastly, the perceived disclosure risk of a map that displays socially-vulnerable people is significantly higher than that of a map that displays non-vulnerable groups. Specifically, a map displaying the private locations of elementary school students has the highest perceived disclosure risk. Based on the results, a set of geoprivacy protection guidelines for mapping people’s private locations to minimize people’s perceived disclosure risk is proposed. Implications for mapping infectious diseases like the COVID-19 are also discussed.  相似文献   

Aerosol transmission of human pathogens: From miasmata to modern viral pandemics and their preservation potential in the Anthropocene record     

《地学前缘(英文版)》2022,13(6):101282

Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter (“miasmata”). Notable Roman and medieval scholars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century microbiology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious historical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid-20th century work of Wells, Riley and Mills who proved how expiratory aerosols (their “droplet nuclei”) could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th century “Great Acceleration” of an increasingly hypermobile human population repeatedly infected by different strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chemistry are accelerating human awareness of current environmental challenges. As such, the “anthropause” lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be preserved in the Anthropocene stratal record.  相似文献   

Distribution and impacts on the geological environment of antiviral drugs in major waters of Wuhan,China     

《China Geology》2022,5(3):402-410

This study investigated water samples collected from the surface water and groundwater in Wuhan City, Hubei Province, China in different stages of the outbreak of the coronavirus disease 2019 (hereinafter referred to as COVID-19) in the city, aiming to determine the distribution characteristics of antiviral drugs in the city’s waters. The results are as follows. The main hydrochemical type of surface water and groundwater in Wuhan was Ca-HCO₃. The major chemical components in the groundwater had higher concentrations and spatial variability than those in the surface water. Two antiviral drugs and two glucocorticoids were detected in the surface water, groundwater, and sewage during the COVID-19 outbreak. Among them, chloroquine phosphate and cortisone had higher detection rates of 32.26% and 25.80%, respectively in all samples. The concentrations of residual drugs in East Lake were higher than those in other waters. The main drug detected in the waters in the later stage of the COVID-19 outbreak in Wuhan was chloroquine phosphate, whose detection rates in the surface water and the groundwater were 53.85% and 28.57%, respectively. Moreover, the detection rate and concentration of chloroquine phosphate were higher in East Lake than in Huangjia Lake. The groundwater containing chloroquine phosphate was mainly distributed along the river areas where the groundwater was highly vulnerable. The residual drugs in the surface water and the groundwater had lower concentrations in the late stage of the COVID-19 outbreak than in the middle of the outbreak, and they have not yet caused any negative impacts on the ecological environment.©2022 China Geology Editorial Office.  相似文献   

The distribution and ecological risks of antibiotics in surface water in key cities along the lower reaches of the Yellow River: A case study of Kaifeng City,China     

《China Geology》2022,5(3):411-420

A large number of antibiotics have been discharged into rivers by human activities, posing a threat to aquatic ecosystems. The surface water of the Yellow River Basin also suffers antibiotic pollution, which hinders the improvement in the aquatic ecological environment. This study investigated and analyzed the characteristics and assessed the ecological risks of antibiotic pollution in surface water bodies such as canals, rivers and fish ponds in Kaifeng, Henan Province, which is a key city along the lower reaches of the Yellow River. The test results are as follows. A total of 15 types of antibiotics were detected in the surface water. They had a total antibiotic concentration of 12.2–249.9 μg/L, of which tetracyclines (TCs) and quinolones accounted for the highest percentages. Six types of quinolones had detection rates of up to 100%, and doxycycline (DC) and oxytetracycline (OTC) had average concentrations of 29.52 μg/L¹ and 13.71 μg/L, respectively. The major canals with water diverted from the Yellow River had total concentrations of quinolones and TCs of 22. 0 μg/L and 14.9 μg/L, respectively, which were higher than those in previous studies. This phenomenon may be related to the decrease in the water flow of the Yellow River during the dry season and the increase in the antibiotic consumption of residents in the context of the Covid-19 outbreak. The upper reaches of the Huiji River in the Xiangfu District had higher antibiotic content than other districts in Kaifeng. Specifically, TCs accounted for 72.38%–91.84% of all antibiotics, and the DC and OTC concentrations were significantly higher than other antibiotics in the upper reaches. As indicated by the ecological risk assessment results, TCs had the highest ecological risks to green algae. Among them, DC had medium-high risks; TC, OTC, and chlortetracycline (CTC) had medium-high risks; trimethoprim (TMP) and lomefloxacin (LOM) had low risks; other TC antibiotics had no risk. Compared with green algae, most antibiotics showed higher ecological risks to daphnia and lower ecological risks to fish. DC and OTC dominate antibiotic pollutants in the surface water in Kaifeng City, and especially in Xiangfu District, where DC and OTC have medium-high risks. The TCs in the major Yellow River showed medium risks to both green algae and daphnia. It can be speculated that the antibiotic pollution in the Yellow River might pose a certain threat to the ecological security of water in Kaifeng City.©2022 China Geology Editorial Office.  相似文献   

1840年以来长江大洪水演变与气候变化关系初探   总被引：25，自引：3，他引：22  

施雅风  姜彤  苏布达  陈家其  秦年秀 《湖泊科学》2004,16(4):289-297

长江洪水灾害是我国频率高、为患严重的自然灾害之一.本文依据可靠资料,选择1840年至2000年间32次大洪水记录,探讨其演变与气候变化的关系.认知1910s前的19世纪冷期出现大洪水13次(包括1870年的极值大洪水事件)频率为1.9次／10a.1921-2000年间出现了大洪水19次,频率为2.4次／10a.20世纪暖期又分出两个变暖时段,前一变暖时段的峰值期1920s-1940s出现大洪水9次,包含1931年全流域大洪水.后一变暖时段,即1980s与1990s出现大洪水8次.实测记录到的最大洪水1954年位于前一变暖时段结束阶段.1990s是全球,也是我国近百年中最暖年代,受东南季风影响大的中下游地区夏季降水量是近百年最多的,大暴雨频率也是有较多记录的40年来最高的.以此出现了10年5次大洪水高频率现象,包含1998年全流域型大洪水,表明了全球变暖的显著影响.也指示30-40年问周期性振荡中多雨年代.如此可预期21世纪初期降水会有小幅度下降与大洪水频率在短期内降低的可能性.长江上游受西南季风影响较大,19世纪下半期与20世纪上半期为多降水期,大洪水频率较高.20世纪下半期为少降水期,大洪水频率较低.关于气候变化研究有待深入,前景不易预估.  相似文献