A surge of Skobreen, Svalbard     

Monica Sund 《Polar research》2006,25(2):115-122

Surging glaciers are common in Svalbard yet relatively few glaciers have been observed during a surge. This paper presents observations of the currently surging glacier Skobreen, in southern Spitsbergen. The study is based on examinations of new and archival photographs and maps. Skobreen, an 18 km² valley glacier terminating into the lower part of the glacier Paulabreen, has not been registered previously as a surging glacier. Skobreen experienced a build-up in its upper part, while there has been a lowering of the surface in the terminal region. Photographs from 1990 show incipient crevassing in the upper part. Photographs from 2003 show a slight advance of the terminus and marginal crevassing, indicating an initiation period of about 15 years for a surge of this glacier. In June 2005 transverse crevassing appeared in the upper part of the glacier, while the middle section moved as a block with strong shear margins and a pronounced drawdown of the ice surface. No traces of a surge front could be seen in the crevasse pattern. However, the crevasse pattern indicates an initiation area in the transition zone between the transverse crevassing in the upper part and the block of ice in the middle region.  相似文献   

Magma ascent and eruptive processes from textural and compositional features of Monte Nuovo pyroclastic products, Campi Flegrei, Italy     

Monica Piochi  Giuseppe Mastrolorenzo  Lucia Pappalardo 《Bulletin of Volcanology》2006,68(5):496-496

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1997年9月26日意大利中部Umbria-marche地震前的水文地质变化     

Monica Carro  Lucia Luzi  曹玲玲 《国际地震动态》2006,(7):71-85

分析了1997年9月26日意大利中部Umbria与marche交界地区的Umbria-marche地震序列引起的水文体系的变化。为了量化水文体系的变化,从地方当局和矿泉水公司收集了地下水位、泉水的流量以及河水流速等的资料,这些资料可以确定异常的影响面积,并且可以通过与从震前几年资料估算出的年平均体系的对比来量化异常的变化,试图对异常进行判定。分析结果表明,两个含水单元,即Umbria-marche山峰和Val-nerina单元,具有紧密的联系,它们都由于水文系统的改变而受到影响。地震前几个月两条河流测量站记录到了异常变化,认为是地震前兆异常。  相似文献   

Climatology of Northern Hemisphere blocking in the ECHAM model     

S. Tibaldi  F. D’Andrea  E. Tosi  E. Roeckner 《Climate Dynamics》1997,13(9):649-666

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Quartz deformation mechanisms in metasediments from Prins Karls Forland, Svalbard     

Daria Monica Walniuk  Alan Paul Morris 《Tectonophysics》1985,115(1-2)

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Preface     

Yin Hongfu  Tong Jinnan  Monica J.Campi 《中国地质大学学报(英文版)》2002,13(2)

ＴｈｅＩｎｔｅｒｎａｔｉｏｎａｌＳｙｍｐｏｓｉｕｍｏｎｔｈｅＧＳＳＰｏｆｔｈｅＰｅｒｍｉａｎ ＴｒｉａｓｓｉｃＢｏｕｎｄａｒｙａｎｄｔｈｅＰａｌｅｏｚｏｉｃ ＭｅｓｏｚｏｉｃＥｖｅｎｔｓｗａｓｈｅｌｄｉｎＣｈａｎｇｘｉｎｇＣｏｕｎｔｙ ,ＺｈｅｊｉａｎｇＰｒｏｖｉｎｃｅ,ＣｈｉｎａｏｎＡｕｇｕｓｔ 1 0 - 1 3,2 0 0 1 .Ｔｈｅｓｙｍｐｏｓｉｕｍｒｅｃｅｉｖｅｄａｎｄ ｐｒｉｎｔｅｄ 47ａｂｓｔｒａｃｔｓ.Ａｂｏｕｔ 60ｇｅｏｌｏｇｉｓｔｓｆｒｏｍ 1 3ｃｏｕｎｔｒｉｅｓａｔｔｅｎｄｅｄｔｈｅｓｃｉｅｎｔｉｆｉ…  相似文献   

Community Cohesion: Social and Economic Ties in the Personal Networks of Fisherfolk     

Fiona Nunan  Dražen Cepić  Bwambale Mbilingi  Konstantine Odongkara  Ernest Yongo  Monica Owili 《社会与自然资源》2018,31(3):306-319

Social ties influence access to knowledge and cooperation in natural resource management, with the sharing of certain characteristics thought to be positive for social cohesion and participatory forms of management. In this article, a holistic characterisation of fisherfolk personal networks is developed, disaggregating results by the main occupational groups within the fisheries studied, to provide a more nuanced understanding of the personal networks of types of fisherfolk. Links are then made between the characteristics of personal networks and evidence on how fisherfolk benefit from their networks, interpreted as contributing to social cohesion within the communities. The personal networks of fisherfolk (boat crew, boat owners and traders/processors) of Kenya, Tanzania and Uganda bordering Lake Victoria were investigated using personal network analysis, with fisherfolk asked who they discuss their fisheries activities with. The analysis found that networks based on the same occupation were more characteristic of fish traders/processors networks than those of boat crew and boat owners and that shared ethnicity, gender and location were characteristic of boat owner and boat crew networks, though shared ethnicity may reflect the composition of the communities rather than choice. Social and economic interactions within the networks were based on provision of credit, social support and advice, suggesting that these form the basis of social cohesion and should be taken into consideration in working with fishing communities in both development interventions and designing collaborative management approaches.  相似文献   

Estimation of the behavior factor of existing RC-MRF buildings     

Marco Vona  Monica Mastroberti 《地震工程与工程振动(英文版)》2018,17(1):191-204

In recent years, several research groups have studied a new generation of analysis methods for seismic response assessment of existing buildings. Nevertheless, many important developments are still needed in order to define more reliable and effective assessment procedures. Moreover, regarding existing buildings, it should be highlighted that due to the low knowledge level, the linear elastic analysis is the only analysis method allowed. The same codes (such as NTC2008, EC8) consider the linear dynamic analysis with behavior factor as the reference method for the evaluation of seismic demand. This type of analysis is based on a linear-elastic structural model subject to a design spectrum, obtained by reducing the elastic spectrum through a behavior factor. The behavior factor (reduction factor or q factor in some codes) is used to reduce the elastic spectrum ordinate or the forces obtained from a linear analysis in order to take into account the non-linear structural capacities. The behavior factors should be defined based on several parameters that influence the seismic nonlinear capacity, such as mechanical materials characteristics, structural system, irregularity and design procedures. In practical applications, there is still an evident lack of detailed rules and accurate behavior factor values adequate for existing buildings. In this work, some investigations of the seismic capacity of the main existing RC-MRF building types have been carried out. In order to make a correct evaluation of the seismic force demand, actual behavior factor values coherent with force based seismic safety assessment procedure have been proposed and compared with the values reported in the Italian seismic code, NTC08.  相似文献   

Illuminating Subsurface Microbial Water Quality Patterns Using Adenosine Triphosphate and Dynamic Time Warping Approaches     

Alex H. S. Chik  Monica B. Emelko  Alfred P. Blaschke  Jack F. Schijven 《Ground Water Monitoring & Remediation》2020,40(3):55-66

Aquifer microbial water quality evaluations are often performed by collecting groundwater samples from monitoring wells. While samples collected from continuously pumped sources are seldom disputed as representative of the aquifer, natural biofilm present in the vicinity of well screens may introduce unwanted microbial artefacts in monitoring wells that are only periodically sampled. The need for well water purging to obtain samples void of these artefacts has been widely recognized. However, purging methods are not standardized; many approaches presume that physico-chemical water quality stability achieved through the removal of 3 to 5 well volumes is indicative of the stability of target analytes. Using a data set collected from a shallow unconfined aquifer in Southern Ontario, Canada, the need for using dedicated approaches that account for the time-dependent nature of microbial water quality changes was demonstrated. Specifically, the utility of adenosine triphosphate (ATP) as a rapid, field-ready biochemical indicator of microbial water quality stability was investigated. This work shows that ATP concentrations reflect time-limited (bio)colloid transport processes that are consistent with other microbial water quality parameters monitored, but different from commonly measured physical and chemical water quality indicators of well purging adequacy. ATP concentrations occasionally fluctuated even after 3 or 4 h of purging, indicating that microbial artefacts attributable to biofilms in the vicinity of the well screen can still persist. The recurrence of characteristic ATP patterns in each well was systematically examined through the novel application of dynamic time warping (DTW), a nonparametric time series analysis approach. These patterns are believed to be linked with seasonal hydrogeological conditions, which warrant consideration in the design and interpretation of subsurface microbial water quality investigations.  相似文献   

Deep reflection seismic imaging of iron-oxide deposits in the Ludvika mining area of central Sweden     

Magdalena Markovic  Georgiana Maries  Alireza Malehmir  Julius von Ketelhodt  Emma Bäckström  Monica Schön  Paul Marsden 《Geophysical Prospecting》2020,68(1):7-23

Reflection seismic data were acquired within two field campaigns in the Blötberget, Ludvika mining area of central Sweden, for deep imaging of iron-oxide mineralization that were known to extend down to 800–850 m depth. The two surveys conducted in years 2015 and 2016, one employing a seismic landstreamer and geophones connected to wireless recorders, and another one using cabled geophones and wireless recorders, aimed to delineate the geometry and depth extent of the iron-oxide mineralization for when mining commences in the area. Even with minimal and conventional processing approaches, the merged datasets provide encouraging information about the depth continuation of the mineralized horizons and the geological setting of the study area. Multiple sets of strong reflections represent a possible continuation of the known deposits that extend approximately 300 m further down-dip than the known 850 m depth obtained from historical drilling. They show excellent correlation in shape and strength with those of the Blötberget deposits. Furthermore, several reflections in the footwall of the known mineralization can potentially be additional resources underlying the known ones. The results from these seismic surveys are encouraging for mineral exploration purposes given the good quality of the final section and fast seismic surveys employing a simple cost-effective and easily available impact-type seismic source.  相似文献