Seismic scattering and shallow structure of the moon in oceanus procellarum

Long, reverberating trains of seismic waves produced by impacts and moonquakes may be interpreted in terms of scattering in a surface layer overlying a non-scattering elastic medium. Model seismic experiments are used to qualitatively demonstrate the correctness of the interpretation. Three types of seismograms are found, near impact, far impact and moonquake. Only near impact and moonquake seismograms contain independent information. Details are given in the paper of the modelling of the scattering processes by the theory of diffusion.Interpretation of moonquake and artificial impact seismograms in two frequency bands from the Apollo 12 site indicates that the scattering layer is 25 km thick, with a Q of 5000. The mean distance between scatterers is approximately 5 km at 25 km depth and approximately 2 km at 14 km depth; the density of scatterers appears to be high near the surface, decreasing with depth. This may indicate that the scatterers are associated with cratering, or are cracks that anneal with depth. Most of the scattered energy is in the form of scattered surface waves.Communication presented at the Lunar Science Institute Conference on Geophysical and Geochemical Exploration of the Moon and Planets, January 10–12, 1973.     

Community and Population Responses of the Macroinfauna to Physical Factors over a Range of Exposed Sandy Beaches in South-central Chile

Ten exposed sandy sites covering a range from reflective to dissipative beaches were sampled in south-central Chile to evaluate: (1) spatial changes in species richness, abundance and biomass of the intertidal macroinfauna in response to changes in mean grain size, beach face slope and beach type, and (2) spatial changes in abundance, biomass and body sizes of the most abundant species in response to changes in the physical factors. The number of species, abundance and biomass per beach in general decreased with increasing particle size and beach face slope (steeper beaches) and increased from reflective to dissipative conditions. The best fit for number of species was with Dean's parameter, a measure of beach type, whereas for abundance and biomass the best fits were found with particle size. The isopod Excirolana braziliensis and the anomuran Emerita analoga increased in abundance and biomass towards dissipative conditions, whereas Excirolana hirsuticauda showed the opposite trend in biomass and was significantly larger in beaches with steeper profiles. It is concluded that responses to changes in beach type are more pronounced at community level than within species populations.     

DEVEX-disdrometer evaluation experiment: Basic results and implications for hydrologic studies

Increasing our understanding of the small scale variability of drop size distributions (DSD), and therefore of several bulk characteristics of rainfall processes, has major implications for our interpretation of the remote sensing based estimates of precipitation and its uncertainty. During the spring and summer of 2002 the authors conducted the DEVEX experiment (disdrometer evaluation experiment) to compare measurements of natural rain made with three different types of disdrometers collocated at the Iowa City Municipal Airport in Iowa City, Iowa in the Midwestern United States. This paper focuses on the evaluation of the instruments rather than analysis of the hydrometeorological aspects of the observed events. The comparison demonstrates discrepancies between instruments. The authors discuss the systematic and random effects in terms of rainfall quantities, drop size distribution properties, and the observed drop size vs. velocity relationships. Since the instruments were collocated, the effects of the natural variability of rain are reduced some with time integration, isolating the instrumental differences. The authors discuss the status of DSD measurement technologies and the implications for a range of hydrologic applications from remote sensing of rainfall to atmospheric deposition to soil erosion and sediment transport in the environment. The data set collected during the DEVEX experiment is made available to the research community.     

Book reviews

Astrophysics and Space Science -     

铝钒土中有效铝和活性硅的测定

铝钒土是用来提取氧化铝的重要经济矿石,而氧化铝被冶炼为金属铝。评价铝钒土矿石的经济价值有两个重要指标：有效铝和活性硅。有效铝就是指利用模拟Bayer工艺条件下可以提出来的Al2O3的净含量。活性硅就是指在Bayer工艺条件下可以与NaOH反应的硅化物的含量。在低温Bayer冶炼工艺中,反应硅主要来源于黏土成分的溶解,随着工艺温度的提高,溶解的石英组分也会增加活性硅的含量。由于溶解的硅最后以硅铝钠方式沉淀下来,需要消耗NaOH,对成本有很大影响,所以活性硅的含量是铝矾土的重要指标。     

HPA—S高温高压消解铂族金属

铂族金属元素（Pt、Pd、Ir、Rh、Ru、Os）在很多重要的领域中被广泛地应用。如被用作汽车催化剂的基本组成元素,以控制车辆排气污染;在石油行业用作精炼催化剂,并且在各类材料工艺学以及珠宝行业大量被使用。     

Green space planning and land use: An assessment of urban regional and green structure planning in Greater Copenhagen

Geografisk Tidsskrift, Danish Journal of Geography 106(2):7–20, 2006

In its Regional Plan of 2005, The Greater Copenhagen Authority (abbreviated as “HUR” in Danish) places special emphasis on the future recreational values associated with the regional green structure. In this paper, the development of the urban green structure in Greater Copenhagen is elaborated upon, focusing on land use changes and the effectiveness of regionally coordinated planning measures. EU MOLAND data are used to analyse the development of the region's green structure during the period 1954 to 1998. Analysis of two “green wedges” within the green structure illustrates that the development of the green recreational areas is the result of both formal and more informal planning initiatives. Development has shown equal phases that correspond to the applied regional planning measures and the general economic conditions. However, local preferences in the involved municipalities likewise have played an important role and have resulted in different urbanisation pressure within the two wedges. Land use has transformed from an agricultural to a primarily recreational landscape. In some areas, however, urbanisation pressure has resulted in residential and green industrial areas instead of the planned recreational land use. Based on its historical development it is concluded that future preservation and development of the green structure in Greater Copenhagen requires regional planning measures to be incorporated into municipal plans. In this way the increasingly independent municipalities will comply to objectives of the Regional Plan 2005.     

Geochemistry of the Uintjiesberg kimberlite, South Africa: petrogenesis of an off-craton, group I, kimberlite

The Uintjiesberg kimberlite diatreme occurs within the Proterozoic Namaqua–Natal Belt, South Africa, approximately 60 km to the southwest of the Kaapvaal craton boundary. It is a group I, calcite kimberlite that has an emplacement age of 100 Ma. Major and trace element data, in combination with petrography, are used to evaluate its petrogenesis and the nature of its source region. Macrocryst phases are predominantly olivine with lesser phlogopite, with very rare garnet and Cr-rich clinopyroxene. Geochemical variation amongst the macrocrystic samples (Mg# 0.85–0.87, SiO₂=27.0–29.3%, MgO=26.1–30.5%, CaO=10.9–13.5%) is shown to result from 10% to 40% entrainment and partial assimilation of peridotite xenoliths, whereas that shown by the aphanitic samples (Mg# 0.80–0.83, SiO₂=19.1–23.0%, MgO=17.9–23.9%, CaO=16.5–23.7%) is consistent with 7–25% crystal fractionation of olivine and minor phlogopite. Changing trajectories on chemical variation diagrams allow postulation of a primary magma composition with 25% SiO₂, 26% MgO, 2.3% Al₂O₃, 5%H₂O, 8.6% CO₂ and Mg#=0.85.

Forward melting models, assuming 0.5% melting, indicate derivation of the primary Uintjiesberg kimberlite magma from a source enriched in light rare earth elements (LREE) by 10× chondrite and heavy REE (HREE) by 0.8–2× chondrite, the latter being dependent on the proportion of residual garnet. Significant negative Rb, K, Sr, Hf and Ti anomalies present in the inferred primary magma composition are superimposed on otherwise generally smooth primitive mantle-normalized trace element patterns, and are inferred to be a characteristic of the primary magma composition. The further requirement for a source with chondritic or lower HREE abundances, residual olivine with high Fo content (Fo₉₄) suggests derivation from a mantle previously depleted in mafic melt but subsequently enriched in highly incompatible elements prior to kimberlite genesis. These requirements are interpreted in the context of melting of continental lithospheric mantle previously enriched by metasomatic fluids derived from a sublithospheric (plume?) source.     

Ermittlung der QNH-werte aus dem luftdruckfeld der synoptischen bodenkarte

Резюме Дабление воздуха, переснитанное иа уровень моря по стандартной атмосфере в Q-коде обозчачается через QNH. Давление воздуха пересчитанное на уровень моря по высотной барометрической формуле обознаеается через QFF. Для целей авиационной службы погоды должны быть известны значения QNH, однако Зе барическое поле на синоптических картах выражается через QFF. С помощью рис. 1 для соответствующей температуры воздуха на станцин и ее высоты н. у. м. можно определить разность значений QFF—QNH при давленин QFF=1000мб. Далее по табл. 2 можно определить поправку для каждого значения QFF отличного от значения QFF при ином давлении, чем 1000мб путем умножения табулированного значения ва разность QFF—1000мб и его алгебраического сложения со значением, полученным по рис. 1.