Attenuation Relationships for Iran

The purpose of this study is to derive the attenuation relationships for PGA, PGV, and EPA parameters for areas within the seismic zones of Zagros, Alborz and Central Iran with rock and soil substructures. In order to do so, at first the available scientific data including the methods used for deriving attenuation relationships and the parameters involved have been gathered. Afterwards, all the efforts have been focused on gathering a thorough catalogue of earthquakes occurred in Iran. In this regard, a majority of the available catalogs in Iran have been gathered and corrected through different methods and finally a set of 89 earthquake events including 307 earthquake records with reliable data was chosen.

Since in order to derive the attenuation relationships it is essential to extract the parameters from the acceleration records, a great effort was placed on gathering the earthquake acceleration records of Iran. This resulted in building a database of a majority of the earthquake records up to the year of 2004. Afterwards, correction methods applicable to earthquakes records of Iran considering the type of machines used and the ground type were examined which resulted in certain guidelines for correction of earthquake acceleration record data related to Iran.

In the next step the needed parameters were extracted from the earthquake acceleration record data which were consequently divided into two seismic zones of Zagros, and Alborz and Central Iran according to tectonic conditions. After examination of the parameters and choosing the most appropriate among them, the attenuation relationships were derived for such parameters.     

榆阳区明长城典型遗址的雨蚀破坏模式分析

现有的夯土遗址雨蚀病害分类方式关注的是多次降雨后遗址破坏的静态结果,以识别病害、辨明病因为主要目的。为进一步研究水土作用方式在夯土雨蚀病害发育过程中的作用,明确雨蚀病害的动态发育过程,在现场调查的基础上对榆阳区明代夯土长城的雨蚀病害进行分类、统计、分析,综合考虑侵蚀模式、雨蚀动态响应过程和劣化程度三个方面提出雨蚀破坏模式,分别为干湿破坏、冲刷破坏和降雨导致的重力侵蚀三种,三种破坏模式的提出为研究夯土遗址雨蚀和降雨间的响应关系提供新思路。     

A palynological and geoarchaeological investigation into Bronze Age farming at Belderg Beg,Co. Mayo,Ireland

This contribution describes the results and interpretations of geoarchaeological and palynological analyses of a soil profile near to a ¹⁴C dated Bronze Age roundhouse in a sub-peat field system at Belderg Beg, north Mayo in western Ireland, which displayed field-scale evidence of tillage in the form of cultivation ridges. This evidence of arable cultivation was supported by the presence of quernstones in the roundhouse, but there was no supporting evidence from other forms of socio-economic analysis. Soil micromorphological analysis was employed to define how the ridges were created and with what tools; pollen analysis was used to characterise the surface vegetation and test the purpose of the ridges. The results unequivocally showed that a phase of ard cultivation was followed after a brief hiatus by ridge-and-furrow tillage. There were tentative indications of possible amendment of the earlier, ard-worked soil, and more definitive evidence of midden material addition to the ridged soil. An AMS radiocarbon assay on the base of peat overlying the ridges indicated that tillage occurred in the Mid to Late Bronze Age.     

The role of time-lapse bathymetric surveys in assessing morphological change at shipwreck sites

Data from time-lapse single-beam and multi-beam bathymetric surveys are used to assess the rate and scale of morphological change at shipwreck sites caused by anthropogenic forcing. The technique is illustrated by characterizing changes in wreck site morphology over two sites located on the east coast of Ireland – the Drogheda Boat site on the River Boyne and the Arklow Bank site in the Irish Sea. Results indicate that repeated bathymetric surveys accurately and rapidly capture morphological change, with time-lapse accretion–erosion models indicating possible erosion rates of up to 0.04 m per day and accretion rates of 0.36 m per day at dynamic riverine and marine sites in response to external triggers. These data are valuable in understanding site formation processes at fully submerged archaeological sites and in the derivation of high-resolution site formation models.     

中国森林面积缩减与生态环境的恶化

中国是一个森林资源比较贫乏的国家。更值得忧虑的是,几十年来,原本就十分贫乏的森林资源却遭到大规模的不合理的毁伐,面积缩减了24％。森林资源缩减,使生态环境严重恶化:旱涝灾害增加,土壤侵蚀严重,土地草原沙漠化,空气污染加剧,许多生物种类濒临灭绝。本文以大量数字和事实,尖锐而坦率地指出了我国人民面临的严峻问题,并提出了解决这一问题的方略。     

The effect of soil conditions on the long-term corrosion of buried tin-bronzes and copper

The object of this work was to relate the corrosion of tin-bronzes to the chemical condition of the soil in which they have been buried, most of them since the Bronze Age. Naturally, it was not easy to obtain recent hoards with their related soils, and considerable reliance had to be placed on recorded finds by taking recent soil samples from sites on which hoards were found over a hundred years earlier. Even so, with the exception of peat, a reasonable relationship appears to exist between the pH of the soil and the state of the metal. Acid soils are aggressive to metals and alkaline soils are benign. In no cases were sulphate reducing bacteria active in promoting corrosion. In the main, peat and peaty soils were benign in spite of their acidity, probably due to the protective action of polyphenols.     

降雨对榆阳区明长城单体建筑破坏模式的试验研究

前期调查分析可知,降雨对榆阳区明长城单体建筑的破坏形式包括水力侵蚀和重力侵蚀两大类,主要影响因素为降雨特征、遗址保存形态和遗址土的性质。为了进一步了解降雨对该类土遗址的破坏方式及主要影响因素作用特点,按照相似理论要求设计模型试验,研究了降雨对榆阳区明长城单体建筑的破坏模式。试验结果表明,降雨对遗址模型的破坏方式与前期调查分析结果基本一致,水力侵蚀方式有冲沟侵蚀、片流面蚀、流水淘蚀和流水冲蚀,重力侵蚀方式有坍塌和滑塌。一般A型暴雨条件下,各种水力侵蚀方式均有发生,重力侵蚀发生次数相对较少;B型暴雨条件下,主要发生片流面蚀,重力侵蚀破坏发生次数较多。通过模型试验得出的降雨对遗址模型的破坏方式及发生特点方面的结论,可以在一定程度上为降雨对该类遗址破坏的评估和防治提供参考。     

Estimation of temperatures beneath archaeological campfires using carbon stable isotope composition of soil organic matter

An Inceptisol and an Alfisol from Western Maryland were sampled by horizon and exposed to the elevated temperatures associated with heat transfer measured beneath campfires. Substantial loss in organic carbon and change in carbon stable isotope composition was observed, even after exposure to relatively low temperatures (200–400 °C). Analyses showed that a comparison of carbon isotope enrichment in organic matter beneath a suspected campfire site to that of unaltered soil would give quantitative information about the minimum effective campfire temperature. Application of these results may lead to particular insight for archaeological sites where soil surfaces have been eroded or otherwise truncated.     

Irrigated taro (Colocasia esculenta) farming in North Kohala,Hawai‘i: sedimentology and soil nutrient analyses

How did traditional farming transform the natural environment in the Hawaiian Islands? This question is one that has largely been addressed for rainfed farming of crops like sweet potato (Ipomoea batatas), but evidence is lacking for irrigated farming of the critical staple crop taro (Colocasia esculenta). We describe the results of soil nutrient and sedimentological analyses of deeply-stratified pondfield deposits representing a 600-year-long record of irrigated taro farming in the North Kohala District, Hawai‘i Island. Soil is categorized by particle size to determine modes of transport and deposition, and concurrent soil nutrient analyses were conducted to infer shifts in the source of sediments and changes associated with taro harvesting. The advent of farming is clearly detectable in sedimentology, the presence of charcoal found within sediments, and soil chemistry. However, diminished nutrient concentrations can be attributed largely to deposition of a mixture of upstream sediments. Overall, there is no clear evidence for nutrient draw-down by taro harvesting, but we cannot yet rule it out as a factor. This study demonstrates the inherent difficulty of correlating changes in soil nutrients evident in irrigated pondfields with the long term history of soil nutrient cycling.