Representing and communicating deep uncertainty in climate-change assessments

IPCC reports provide a synthesis of the state of the science in order to inform the international policy process. This task is made difficult by the presence of deep uncertainty in the climate problem that results from long time scales and complexity. This paper focuses on how deep uncertainty can be effectively communicated. We argue that existing schemes do an inadequate job of communicating deep uncertainty and propose a simple approach that distinguishes between various levels of subjective understanding in a systematic manner. We illustrate our approach with two examples. To cite this article: M. Kandlikar et al., C. R. Geoscience 337 (2005).     

四川盆地东缘寒武系盐下油气勘探领域探讨

地球物理资料显示四川盆地东缘齐岳山附近寒武系高台组膏盐岩层下深部存在逆冲构造,其形成过程以及油气地质意义未见深入研究。笔者等综合四川盆地东部石柱地区线束三维和建南地区二维地震反射资料,并结合钻井资料以及区域地质研究成果,从构造继承性的角度探讨四川盆地震旦系灯影组台缘带类型,并分析了川东地区寒武系盐下油气圈闭特征。研究获得如下认识：①川东齐岳山北段构造变形强烈,普遍发育基底卷入构造,构造样式受青白口纪—南华纪裂谷与转换带构造位置的控制。②依据构造继承关系将盆内灯影组台缘带划分为德阳—安岳地区原生型台缘带、万源—达州地区继承型台缘带以及石柱地区继承—改造型台缘带。③依据青白口纪—南华纪裂谷的分布和后期构造作用影响大小,认为沿齐岳山向南至南川一带存在与石柱地区相似的灯影组继承—改造型台缘带,忠县、南川以西存在灯影组继承型台缘带。④研究区新元古界—下寒武统烃源岩、灯影组—龙王庙组滩相白云岩储层与寒武系膏盐岩层系构成完整的生储盖组合。⑤寒武系盐下基底逆冲可形成成排、成带的构造,与灯影组继承—改造型台缘带、龙王庙组滩相白云岩储层配置,形成断层相关的构造—岩性圈闭带,成为川东地区油气规模聚集有利区。研究认为四川盆地东部石柱地区震旦纪—早寒武世早期继承了青白口纪—南华纪裂谷构造特征,燕山期构造反转,高台组盐下形成基底卷入逆冲构造,具备生储盖等基本石油地质条件,具有重要的油气勘探现实意义。     

Effect of shipping activity on warming trends in the Canadian Arctic

This paper presents a detailed account of the effect of shipping activity on the increasing trends of air temperatures in the Canadian Arctic region for the period of 1980–2018. Increasing trend of temperature has gained significant attention with respect to shipping activities and sea ice area in the Canadian Arctic. Temperature, sea ice area and shipping traffic datasets were investigated, and simple linear regression analyses were conducted to predict the rate of change(per decade) of the average temperature, considering winter(January) and summer(July) seasons. The results indicate that temperature generally increased over the studied region. Significant warming trend was observed during July, with an increase of up to 1℃, for the Canadian Arctic region. Such increasing trend of temperature was observed during July from the lower to higher latitudes. The increase in temperature during July is speculated to increase the melting of ice. Results also show a decline in sea ice area has a significant positive effect on the shipping traffic, and the numbers of marine vessel continue to increase in the region. The increase in temperature causes the breaking of sea ice due to shipping activities over northern Arctic Canada.     

江西赣县大埠钨多金属矿田成岩成矿时空结构与找矿预测

大埠矿田位于南岭成矿带东段,是于都-赣县钨多金属矿集区重要组成,区内已发现钨多金属矿床（点）五十余处,矿床类型包括石英脉型、矽卡岩型、云英岩型和细脉浸染型等,各类矿化主要围绕大埠复式花岗岩体产出。然而,大埠矿田岩浆作用具有明显的多期次、多阶段的特点,各期次成岩成矿时代尚缺乏系统研究,各类岩浆岩与矿化关系争议较大。文章在岩体地质和矿床地质调查基础上,通过LA-(MC)-ICP-MS锆石U-Pb定年、锆石微量元素和Hf同位素分析,精确厘定了大埠花岗岩的成岩时代,探讨了多期次岩浆活动对区内成矿作用的贡献。锆石U-Pb定年结果分别为(429.1±4.7)Ma、(430.0±5.8) Ma、(431.8±4.7) Ma和(158.3±4.1) Ma,结合岩体地质填图信息,笔者认为大埠复式花岗岩基由加里东期和燕山期两部分组成。两期花岗岩均属于高钾钙碱性、过铝质S型花岗岩系列,两者均出现Eu负异常,燕山早期Eu负异常更明显。两期岩体锆石的ε_Hf(t)值分别为-6.3~-1.3与-11.4~-7.1,对应二阶段模式年龄为1.49~1.82 Ga与1.66~1.93 Ga,指示其母岩浆为中元古代的地壳部分熔融形成。锆石微量元素特征显示,两期花岗岩均为陆壳源区、具有相近的结晶温度,燕山早期花岗岩相对于加里东期有更高的结晶分异程度,有更高的氟含量,与钨成矿具有更强的相关性。大埠矿田钨多金属成矿时代集中在159~155 Ma,紧随燕山早期花岗质岩浆侵位而形成。基于大埠矿田成岩成矿时代格架研究,结合花岗岩成矿专属性和成矿地质条件分析,构建了区内钨多金属矿勘查模型,指明了大埠矿田细脉浸染型、云英岩型、内带石英脉型钨矿的找矿方向,预测大埠岩体东北部的燕山早期隐伏岩体具有寻找“合龙式”石英大脉型和细脉-云英岩型钨矿的潜力。     

福建行洛坑钨矿床白钨矿Sm-Nd等时线年龄及微量元素地球化学特征

行洛坑超大型钨矿床位于福建省宁化县东部,是武夷山成矿带内最大的钨矿床,具有储量大、品位低、黑钨矿与白钨矿资源量相近的特点。白钨矿作为含钨矿物,其形成年龄可以代表矿床的成矿时代,其地球化学特征反映了成矿作用环境和过程。文章在对行洛坑钨矿床钨矿脉特征、黑钨矿与白钨矿赋存状态开展调查的基础上,挑选白钨矿单矿物进行了Sm-Nd等时线测年和微量元素测试。研究结果显示,白钨矿结晶年龄为（142.6±2.8）Ma,略小于黑钨矿原位U-Pb年龄（150.5±8.1）Ma和石英流体包裹体Rb-Sr等时线年龄（147.5±2.9）Ma,与矿区隐伏岩体成岩年龄143.5~149.5 Ma在误差范围内完全吻合,也与矿物结晶世代关系吻合,都属于晚侏罗世的产物,说明钨成矿与隐伏岩体成岩近于同时或稍晚发生。白钨矿中微量及稀土元素特征显示第一世代成矿流体中Eu³⁺ < < Eu²⁺,指示成矿流体为还原性流体;第二世代成矿流体中Eu³⁺ > > Eu²⁺,指示成矿流体为氧化性流体。行洛坑钨矿成矿与华南中生代大规模成矿作用及其大地构造背景和动力学环境密切相关。     

葛洲坝至胭脂坝长江干流段江豚活动规律

长江江豚是我国一级保护野生动物,也是长江生态系统的指示性物种,其种群数量恢复情况及活动规律一直备受关注。本文选择长江宜昌段江豚活动频繁的葛洲坝下游至胭脂坝江段为研究区域,于2021年6月-2022年5月采用定点目测、水上流动监测与无人机监测相结合的方法分区监测长江江豚的游泳行为,分析长江江豚的活动规律,构建了长江江豚出水头次的零膨胀泊松回归模型,识别影响长江江豚出水头次的关键因素,建立长江江豚出水头次与各因素间的相关关系。结果表明:(1)葛洲坝至胭脂坝长江干流段监测到最大江豚出水头次为19头次,长江江豚集群规模以2~3头最为常见,占比达58.1%;长江江豚主要表现出4种行为特征,各行为占比从大到小依次为:玩耍＞休息＞摄食＞抚幼。(2)长江江豚在葛洲坝下游近坝区(A区,葛洲坝至至喜长江大桥)出水头次最多,且在秋冬季节累计出水头次多于春夏季节,冬季累计出水头次最高,达252头次。(3)长江江豚出水头次与电站下泄流量呈显著负相关;浊度增大,长江江豚出水的概率减小。本文研究结果对长江江豚生态保护策略及长江十年禁渔效果评估具有重要参考价值。     

Cloning and characterization of glyceraldehyde-3-phosphate dehydrogenase encoding gene inGracilaria/Gracilariopsis lemaneiformis

Glyceraldehyde-3-phosphate dehydrogenase （GAPDH） plays important roles in various cellular processes. A cytosolic GAPDH encoding gene （gpd） of Gracilaria/Gracilariopsis lemaneiformis was cloned and characterized. Deduced amino acid sequence of the enzyme of G. lemaneiformis had high homology with those of seven red algae. The 5＇-untranslated regions of the GAPDHs encoding genes of these red algae varied greatly. GAPDHs of these red algae shared the highly conserved glyceraldehyde 3-phosphate dehydrogenase active site ASCTTNCL. However, such active site of Cyanidium caldarium was different from those of the other six algae at the last two residues （CL to LF）, thus the spatial structure of its GAPDH active center may be different from those of the other six. Phylogenetic analysis indicated that GAPDH of G. lemaneiformis might have undergone an evolution similar to those of Porphyra yezoensis, Chondrus crispus, and Gracilaria verrucosa. C. caldarium had a closer evolutionary relationship with Cyanidioschyzon merolae than with Cyanidium sp. Virtual Northern blot analysis revealed that gpd of G. lemaneiformis expressed constitutively, which suggested that it might be house-keeping and could be adapted as an inner control in gene expression analysis of G. lemaneiformis.     

基于GIS的北京山区优势林分生态位分析

应用生态位理论,以北京山区森林资源为研究对象,分析优势林分的空间分布及其资源利用和环境适应能力的差异。基于GIS方法,建立优势林分空间分布数据库以及资源梯度信息数据库,分别采用Levins公式和Smith公式,在水分、热量、光照和土壤质量4维环境因子梯度上测定了研究区8个优势林分的生态位宽度,采用Pianka公式测定生态位重叠。结果表明:Smith公式考虑资源可利用性,得到的生态位宽度更能客观地反映优势林分资源空间利用程度;研究区各优势林分重叠度普遍较大,反映了对环境要求的相似性及资源共享的趋势性。     

Composition of plagioclases in volcanic rocks of King George Island, Antarctica with reference to the petrogenetic significance

Plagioclases occur mainly as phenocrysts in volcanic rocks of King George Island, South Shetland Islands, West Antarctica. In basaltic andesites and andesites of Keller Peninsula and Ullman Spur (Admiralty Bay), they are high structure state labradorite-andesines; and in high-A1 basalts and basaltic andesites of Barton and Weaver peninsulas (Maxwell Bay), they are high structure state bytownite-anorthites.∑REE, La/Yb ratios and δEu values of plagioclases from Admiralty Bay are higher than those from Maxwell Bay. All plagioclases have rather identical chondritenormalized transitional element distribution patterns, probably reflecting that crystal structure rather than composition of plagioclase controls their diversity. Compositions of plagioclases depend chiefly on those of their host rocks, compositional differences of plagioclases reveal that basaltic magmas in the Admiralty Bay area are more evolved than in the Maxwell Bay area.     

Softs of Fildes Peninsula, King George Island, the maritime Antarctic: Part I. Formation processes and pedogenetic particularities

Based on the data obtained from tens of the investigated soil profiles scattered over the Fildes Peninsula, King George Island, the maritime Antarctic, the soil-forming processes were discussed. It was concluded that on the weathering crusts resulted from various physical courses, the strong freeze-thaw action within regolith, significant organic matter accumulation, evident leaching and illuviation, as well as initial argillification dominated the formation and development of the soils on the Fildes Peninsula. Furthermore, this study indicated that the juvenility of genesis, poor profile-expression, variation in column thickness, etc. characterized the pedogenetic features of the soils of the Fildes Peninsula.