四川鲜水河-安宁河断裂带温泉氢氧稳定同位素特征   总被引：1，自引：0，他引：1  

张磊  郭丽爽  刘树文  杨耀  施得旸 《岩石学报》2021,37(2):589-598

温泉地下水同位素特征对确定断裂带地下水来源、循环过程和断裂带活动性至关重要。为了确定青藏高原东缘温泉的地下水同位素特征和流体来源本研究采集了鲜水河-安宁河断裂带上温泉水、冷泉水、河流和积雪融水等样品,进行了氢氧稳定同位素和水化学组分测定,并进行了同位素特征的对比研究。分析结果表明,温泉水体δ¹⁸O变化范围为-19.04%~-12.71‰,平均值为-16.42‰;δ²H变化范围为-144.07‰~-88.63‰,平均值为-122.37‰。河水的δ¹⁸O变化范围为-15.90‰~-10.85‰,平均值为-13.86‰;δ²H变化范围为-118.21‰~-71.12‰,平均值为-98.99‰。康定冷泉δ¹⁸O和δ²H分别为-13.66‰和-106.74‰。道孚积雪融水的δ¹⁸O和δ²H分别为-10.27‰和-65.41‰。不同类型水体样品氢氧稳定同位素组成主要分布在全球和区域大气降水线上表明了大气降水成因,缺少明显的氧同位素漂移特征。不同类型水体同位素值差异较大显示出温泉与河水、积雪融水之间补给来源的不一致性。温泉同位素值具有明显的同位素高程效应,鲜水河-安宁河断裂带上氧同位素高程效应为-0.23‰/100m,氢同位素高程效应为-1.95‰/100m。温泉氧同位素漂移与相关离子比值、Na-K-Mg三角图、Li和Sr元素等指标表明研究区域大部分温泉的水岩作用强度弱。氢氧稳定同位素特征、水岩作用特征和循环深度揭示出温泉的成因为远距离大气降水运移补给地下水,地下水在地下热储层加热后通过断裂上升到地表形成温泉,这为认识青藏高原东缘地热水循环、断裂带活动性与演化特征提供了依据。  相似文献   

Geographical patterns of tree-limits of Norway spruce and Scots pine in the southern Swedish Scandes     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):237-245

The tree-limit altitudes of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) from 180 sites (within an area of 95?km?×?165?km) in the southern Scandes were correlated with the geographical variables latitude, longitude and distance to the sea. The results were compared with a similar investigation of the tree-limit of mountain birch (Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman) in the same area. The three tree-limit altitudes showed good negative correlation with latitude, poor correlation with longitude and good positive correlation with the distance to the sea, suggesting that on a regional scale the altitudes are controlled by macroclimate. At some sites, local topoclimatic features, some of which were partially aspect-dependent, may cause deviations in the regional pattern of tree-limit altitude that is set primarily by summer temperature. Tree-limit responses to potential future climate warming will probably differ substantially in magnitude from site to site in relation to local topography and associated ecological constraints.  相似文献   

G-856质子旋进式磁力仪-PC-1500计算机野外数据处理系统     

范晓日 《铀矿地质》1993,(4)

本文介绍了G-856质子旋进式磁力仪-PC-1500计算机野外数据处理系统的通讯接口硬件设计原理,数据采集和数据处理方法。本系统是野外数据处理的综合软件,解决了当前野外磁法测量中大量的数据处理问题。  相似文献   

浅析山西临汾中心地震台定点水准测段高差的变化特征     

张仰辉 《山西地震》2004,(3):22-24

叙述了山西临汾中心地震台定点水准观测场地及所跨断层的简况，利用1987年至2000年的观测资料对跨断层的2个测段高差变化进行了分析，结果表明，BM4-BM1测段能反映所监测断层的变化。  相似文献   

植物营养元素的含量和δ~(13)C值随海拔而变化的特征及营养元素相互作用对碳同位素分馏作用的影响   总被引：7，自引：0，他引：7  

朴河春  朱建明  朱书法  余登利  冉景丞 《地球科学进展》2004,(Z1)

为了研究植物营养元素的含量和δ~(13)C值随海拔而变化的相关关系,沿着海拔450 m的贵州茂兰至海拔1330 m的贵州安顺一线,采集和分析研究了C_3植物——小果蔷薇(R.cymosa Tratt)的叶片。分析结果表明,植物叶片中营养元素含量随着海拔的上升而产生的变化是:氮、磷和钾的含量会在增高,而钙和镁的含量却会降低。植物叶片的δ~(13)C值会增大,其变幅为 2.4‰/1000m。  相似文献   

山东临朐刘家庄水准高值异常分析   总被引：3，自引：0，他引：3  

李杰  范德海  张京华 《山西地震》2003,(1):24-26

综合分析了山东临朐刘家庄水准与降水、地下水位、测点标志的地质条件之间的关系，得出山东刘家庄水准高差异是由于地下水位下降导致两端点变化引起的，属非构造活动的结论。  相似文献   

Tree population dynamics of three altitudinal vegetation communities on Mount Cameroon (1989�C2004)     

Philip F.FORBOSEH  Terry C.H.SUNDERLAND  James A.COMISKEY  Michael BALINGA 《山地科学学报》2011,8(4):495-504

Changes in permanent sample plots in the lowland,submontane and montane forests on Mount Cameroon(4,095 m above sea level),an active volcano,are described for 15 years from 1989 to 2004.Throughout the study period,the stocking level of trees with a diameter at breast height(DBH) ≥ 10 cm in the three forests were lower than in pan-tropical stands suggesting a significant impact of volcanic and human-related activities on the vegetation communities on the mountain.Annual mortality rates in the submontane and montane forests were consistent with those reported for comparable altitudinal ranges in the Blue Mountains of Jamaica.The annual mortality rate was higher in the lowland forest than other lowland sites included.Divergence between recruitment and mortality rates was large suggesting that the three vegetation communities have not reached their climax.The seven-year difference in half-life of large trees(with a DBH ≥ 50 cm) in the submontane and montane forests suggests an altitudinal effect on turnover of larger trees that in turn contributes to the frequent small stature of high altitude forests.There was little evidence of an altitudinal effect on species turnover and growth rate.This finding supports generalizations about the zero effect of growth on the stature of high altitude trees.Understanding forest dynamics is crucially important in the management of tropical montane environmentsand in this instance particularly so given the recent creation of the Mount Cameroon National Park.  相似文献   

基于ECMWF再分析数据的大气波导分布规律研究   总被引：2，自引：0，他引：2  

王华  马贲  焦林  唐海川 《气象学报》2021,79(3):521-530

大气波导对电磁波传播有显著的影响,大气波导特征参量分布研究对于分析电磁波传播乃至雷达、通信等电子设备效能具有重要意义,利用ERA-Interim数据计算大气波导特征参量,并用海洋调查期间的低空探空火箭数据计算的大气波导进行了验证,在此基础上用2011—2016年ERA-Interim温度、湿度分层数据统计分析了全球大气波导的发生概率、强度、高度,得出的结论是:大洋东部、大陆西部的信风带是大气波导的高发区,大洋上大气波导的高发区（发生概率＞50%）主要有6个,分别是北太平洋海区、南太平洋海区、北大西洋海区、南大西洋海区、北印度洋海区、南印度洋澳大利亚西部海区;同时,存在3个大气波导低发区或无大气波导区（热带辐合带区、北半球中高纬度区、南半球中高纬度区）。这些大气波导高发和低发区的位置、范围、发生概率具有季节变化,北半球MAM季（3—5月）发生概率最高,出现的范围最大,SON季（9—11月）概率最低,出现的范围最小,DJF（12、1、2月）、JJA（6—8月）季节介于两者之间;南半球SON季发生概率最高,出现的范围最大,MAM季概率最低,出现的范围最小。北半球大气波导强度总体上强于南半球大气波导强度,北半球MAM季大气波导较强海域范围最大,强度最强,其次为JJA季,SON季大气波导较强海域范围最小,强度最弱;南太平洋大气波导强度季节变化不明显,强度与北太平洋比均较弱,南大西洋SON季大气波导较强海域范围最大,强度最强,DJF季大气波导较强海域范围最小,强度最弱;北印度洋MAM季大气波导强度强,是大洋上波导最强的海域,大气波导较强海域范围大,JJA季基本没有大气波导。大气波导高度在信风带靠近大陆西岸海域高度较低,随着向西离岸距离增大高度升高,大气波导高发区的波导高度季节变化特征是:北半球在SON、DJF季高度高,波导高度高的区域面积大,MAM、JJA季高度低,波导高度高的区域面积小;南半球在MAM、JJA季高度高,波导高度高的区域面积大,SON、DJF季高度低,波导高度高的区域面积小;其他中低纬度近岸海域大气波导高度较低,大陆包围的内海大气波导高度最低。   相似文献   

Altitude and adaptation: A study of geography and ethnic division     

《Applied geography (Sevenoaks, England)》2013

In this paper we investigate the influence of geography on ethnic division by drawing evidence from Tibetan ethnic regions in China. Using a novel township name index that identifies the ethnolinguistic origin of each township name, our empirical findings first show that regions with Han Chinese settlement in the past also witness higher concentration of Han population today. We also show that townships located at higher altitudes have less Han concentration. This altitude effect can be both indirect and direct; we find that the indirect effect through historical settlement is small compared to the direct physiological effect through altitude illness. The challenging environment of the plateau region acts as a physiological hindrance only for Han Chinese, and the natural separation continues to persist between the two groups.  相似文献   

Tree Population Dynamics of Three Altitudinal Vegetation Communities on Mount Cameroon(1989-2004)     

Philip F.FORBOSEH  Terry C.H.SUNDERLAND  James A.COMISKEY  Michael BALINGA 《山地科学学报》2011,(4)

Changes in permanent sample plots in the lowland,submontane and montane forests on Mount Cameroon(4,095 m above sea level),an active volcano,are described for 15 years from 1989 to 2004.Throughout the study period,the stocking level of trees with a diameter at breast height(DBH) ≥ 10 cm in the three forests were lower than in pan-tropical stands suggesting a significant impact of volcanic and human-related activities on the vegetation communities on the mountain.Annual mortality rates in the submontane and ...  相似文献