The third asymptotic distribution of largest magnitudes in the Balkan earthquake provinces

Summary The third asymptotic distribution of the theory of largest values is applied to sixteen earthquake provinces in the Balkan area. The model which assumes an upper magnitude limit fits the observations better than the first distribution. Graphs and tables provide estimates of return periods of largest magnitudes.Communication presented at the XV General Assembly of the European Seismological Commission in Krakow, 22–28 September, 1976.     

Moving socio-hydrologic modelling forward: unpacking hidden assumptions,values and model structure by engaging with stakeholders: reply to “What is the role of the model in socio-hydrology?”*

ABSTRACT

The arguments presented in Melsen et al. advance ideas in the “Panta Rhei” decade (2013–2022) of the International Association of Hydrological Sciences, which focuses on change in hydrology and society. While we reiterate that, despite acknowledged shortcomings, the enterprise of integrating societal feedbacks into hydrological models is beneficial in prediction and adaptive management, we also agree with the sentiments of the authors. In response, we offer concrete steps the socio-hydrologic community can take to educate modellers to become aware about unconscious biases embedded in model structure and clearly communicate assumptions. We stress the need for “knowledge brokers” that can help modellers work with stakeholders, instead of doing everything themselves. We also caution, however, against the danger of over-reaching. Young scholars already pay a big price by having to master both the natural and social sciences. As coupled human–water problems increase in societal importance, along with calls for more holistic thinking, we also need to promote an academic culture that rewards reaching across the aisle.     

泥炭黄腐植酸产率的测定方法探讨

将实测的泥炭黄腐植酸平均含碳比用于容量法直接测定泥炭黄腐植酸产率的计算中，所得结果与间接差减法相比较无系统左偏差，避免了间接法繁琐手续，且与泥炭腐植酸总量测定连续进行，提高工效。对于平衡产率为１６．３３％的试样，用本法多次测定的相对标准偏差为２．５％。     

A MODEL OF INTEGRATED RANDOM INITIAL VALUES AND RANDOM FORCING AND ITS PRELIMINARY EXPERIMENT

A simple quasi-geostrophic barotropic vorticity equation model is used as the dynamic frame of themodel in this paper.Considering that there are many random errors in model's initial values of meteorolo-gical data,and that it is not perfectly complete about model's physical processes (for example,take no ac-count of the interaction between atmosphere and underlying surface,radiation,etc.),we add the random for-ced term to the model and use the Monte-Carlo method with random initial values.A statistical-dynamicintegrated model is thus built up,and a numerical forecasting experiment of 500hPa monthly mean height fieldof January 1983 has been carried out.The experiment result proves that the forecasting result of the model,considering random forcing and random initial values at the same time,is better than that by the pure dynamicmodel,the random initial value model and the random forced model.     

地磁日变幅的时空变化

本文利用13个全国Ⅰ类基准地磁台和3个Ⅱ类地磁台的《地磁观测报告》,通过对偏角、水平和垂直三分量日变幅值求季平均、年平均以及年滑动平均,再用各种均值点图,从而发现,(1)三分量日变幅皆有以一年为周期的季节变化和以约11年为周期的太阳黑子周变化;(2)三分量日变幅随地磁纬度的变化存在区域性,在区域内日变幅值与地磁纬度有明显的线性关系。此外,本文还对分析结果作了进一步的讨论。     

Improving Numerical Weather Prediction in Low Latitudes by Optimizing Diffusion Coefficients

The horizontal diffusion coefficients of the operational model (T42L9) in numerical weather prediction are optimized by the steepest descent search of multi-dimensional optimization. In order to improve prediction accuracy in low latitudes, the optimum horizontal diffusion coefficients are chosen, with changing variation of the basic diffusion coefficient with the passage of time, and later forecasts are also made better. In view of the averages of forecast verifications of 9 cases, the forecasts with optimum diffusion coefficients are an improvement on operational forecasts. It means that the forecasts are got much better with optimum values of some important parameters by optimization in numerical weather prediction.     

Relative stabilities of sedimentary rearranged sterenes as calculated by molecular mechanics: a key to unravel further steroid diagenesis

Molecular mechanics calculations of rearranged cholestenes revealed that diacholest-13(17)-enes with 10α stereochemistry are more stable than their 10β counterparts and that a partly rearranged sterene with a Δ⁸ double bond and 10β, 14β stereochemistry (compound 7) is relatively stable at thermodynamic equilibrium. The calculated data are in good agreement with sedimentary and experimental data and thus reinforce recent propositions for early-stage diagenesis of steroids.     

A fracture-mechanical cellular automaton model of seismicity

We present a cellular automaton model which simulates the process of seismogenesis using rules for evolution which are derived from the field of fracture mechanics, and include an interplay of positive and negative feedbacks. We describe the implementation of this model, and its analysis, in a massively parallel environment using the Connection Machine. Starting from a lattice with a fractal distribution of fracture toughnesses, theb value evolves in a way which closely mimics both the evolutions ofb value observed in the laboratory and derived from earthquake catalogues, reaching a broad and irregular maximum in the period preceding a major event, and declining rapidly during catastrophic failure. We conclude that the processes modelled are a reasonable representation of those occurring in Nature, and that the cellular automaton paradigm is a valuable way of simulating these processes on a large scale in an economical manner.