Geostatistical Assessment of Ice Content Distribution Within the Glacier Bonnard

The Glacier Bonnard is a rock glacier located in the State of Valais, Switzerland. It overhangs a settlement and its slow downward constant creep constitutes an environmental hazard. It is therefore important to understand the glacier’s internal structure, particularly in terms of ice content, in order to evaluate its current global dynamic and future evolution. Following preliminary geophysical investigations, several boreholes have been drilled to measure the thickness of the glaciated mass and the vertical distribution of lithology and ice content. These new data are helpful in assessing the amount of ice within the Glacier Bonnard. Two geostatistical modeling approaches are considered: a direct modeling of ice content and an indirect approach linking together lithology and ice content by the use of the plurigaussian algorithm. Comparisons between these approaches are made in terms of ice content prediction and of global ice mass within the sampled area; they underline the benefit of the geostatistical modeling and particularly the advantages of the indirect approach.     

Effect of Baroclinicity on Vortex Axisymmetrization.Part Ⅰ：Barotropic Basic Vortex

The barotropic and baroclinic disturbances axisymmetrized by the barotropic basic vortex are examined in an idealized modeling framework consisting of two layers.Using a Wentzel-Kramers-Brillouin approach,the radial propagation of a baroclinic disturbance is shown to be slower than a barotropic disturbance,resulting in a slower linear axisymmetrization for baroclinic disturbances.The slower-propagating baroclinic waves also cause more baroclinic asymmetric kinetic energy to be transferred directly to the barotropic symmetric vortex than from barotropic disturbances,resulting in a faster axisymmetrization process in the nonlinear baroclinic wave case than in the nonlinear barotropic wave case.     

Developing and testing the Automated Post-Event Earthquake Loss Estimation and Visualisation (APE-ELEV) technique

An automated, real-time, multiple sensor data source relying and globally applicable earthquake loss model and visualiser is desirable for post-event earthquake analysis. To achieve this there is a need to support rapid data ingestion, loss estimation and integration of data from multiple data sources and rapid visualisation at multiple geographic levels. In this paper, the design and development of the Automated Post-Event Earthquake Loss Estimation and Visualisation (APE-ELEV) system for real-time estimation and visualisation of insured losses incurred due to earthquakes is presented. A model for estimating ground up and net of facultative losses due to earthquakes in near real-time is implemented. Since post-event data is often available immediately from multiple disparate sources, a geo-browser is employed to facilitate the visualisation and integration of earthquake hazard, exposure and loss data. The feasibility of APE-ELEV is demonstrated using a test case earthquake that occurred in Tohoku, Japan (2011). The APE-ELEV model is further validated for ten global earthquakes using industry loss data.     

A NOTE ON THE GEOGRAPHY OF SPORT

The recent phenomenon of relative metropolitan decline and non-metropolitan growth is set into two broader frameworks: first, decentralization is an expected consequence of earlier industrialization and metropolitanization; and, second, the change follows a parallel shift in power, industrialization, and urbanization from the core to the periphery of the country. Evidence is found for both. The older industrial states thus exhibit non-metropolitan growth, whereas many newly industrializing states continue to show vigorous metropolitanization.     

Empirical mass balance modelling of South American tropical glaciers: case study of Antisana volcano,Ecuador

Abstract

Most Latin American glaciers are located in the tropical Andes. The melting processes of Glacier “15” on Antisana volcano were studied to understand the relationship between glacier retreat and natural climate variability and global climate change. Glaciers on the Antisana volcano are crucial sources of water as they feed the headwater rivers that supply Quito with potable water. The aim of this study was to build empirical models based on multiple correlations to reconstruct the mass loss of glaciers over a period of 10 years at three scales: local (data recorded by meteorological stations located around the volcano), regional (data from stations located around the country) and global (re-analysis data). Data quality was checked using graphical and statistical methods. Several empirical models based on multiple correlations were created to generate longer time series (42 and 115 years) of the mass balance for the glacier ablation zone. The long mass balance series were compared with the temperature variation series of the Earth’s surface in the Southern Hemisphere to estimate the relation between the mass balance and global warming. Our results suggest that the meteorological factors that best correlate with mass balance are temperature and wind.

Editor D. Koutsoyiannis     

Bedrock versus superficial deposits in the Swiss Jura Mountains: what is the legitimate soil parent material?

Soils are generally considered to be the result of in situ weathered products of geological substrata. Nevertheless, the Earth's surface is mainly composed of superficial deposits made of sediments reworked during periods of climate instability (glaciation, aridification, flooding, etc.). But to what extent do these deposits influence present‐day soil development and/or lessen the contribution of the geological substratum? In the Swiss Jura Mountains, characterization and distribution of superficial deposits along a toposequence are used in order to decipher the polygenic sources of soil parent materials and question the importance of lithodependence in soil development. The in situ weathering material and the allochtonous deposits are discriminated through analysis of mineralogical composition, grain size distribution of the soil mineral fraction, and multivariate statistical treatment. As expected, calcite is dominant in the autochonous mineral phase, leading to high pH values in deep soil layers. However, the mineralogical composition of the surficial deposits is made of local mineral components mixed with allochtonous aeolian deposits. This exogenous material is dominated by quartz and phyllosilicates, and is reflected by low pH values in soil surficial horizons. The grain size distribution curves of the insoluble residue from bedrocks are unimodal and dominated by fine loam and clays. In contrast, surficial deposits display polymodal curves, demonstrating the contribution of various aeolian episodes and/or sources. Analysis of the surface texture of quartz sand grains shows glacial marks intersected by aeolian shock marks, indicating the posteriority of wind transportation. Loess material originates from Alpine moraines of the Swiss Plateau and is mixed with deposits originating from more proximal Jura moraines, diluting the Alpine signature. Consequently, the soil development does not follow the expected and conventional decalcification process, but is directly influenced by the origin of the primary sediments (even when present only in small amounts) and their evolution. Copyright © 2012 John Wiley & Sons, Ltd.     

RATES OF SOIL FORMATION ON BLACK MESA,NORTHEAST ARIZONA: A CHRONOSEQUENCE IN LATE QUATERNARY ALLUVIUM

A chronosequence of 17 soils in late Quaternary alluvium on Black Mesa, northeast Arizona, permits quantification of rates of pedogenesis in a semi-arid region. Based on 24 tree-ring, radiocarbon, and archaeological dates, soil ages range from about 100 to 20,000 to 30,000+ years. Data indicate that ochric, cambic, argillic, natric, and calcic horizons form within about 100, 500, 1000, 3000, and 15,000 years, respectively, whereas mollic epipedons form within 1000 years. Bk horizons with Stage I, I+, II+, and III carbonate morphologies form within about 1000, 4000, 10,000, and 15,000 years, respectively. Thickness of Bt and Bk horizons, and Harden profile development and clay accumulation index values increase in a linear manner with increasing soil age. High resolution dating suggests rates of pedogenesis on Black Mesa are rapid relative to those documented elsewhere in the southwest United States and in the Rocky Mountains. Rates of soil formation recorded on Black Mesa, however, necessarily incorporate the combined effects of slight variations in elevation, climate, vegetation, topography, and parent materials throughout the region, as well as the influence of additions of atmospheric dust at the soil surface. [Key words: soil, pedogenesis, soil geomorphology, Quaternary, Arizona.]