Eastern Asian hydrometeorology simulation using the Regional Climate System Model

We present the hydrometeorology of eastern Asia during April 1995 simulated by the Regional Climate System Model. The amount and location of simulated monthly precipitation agrees well with observations. Soil water content variation was closely correlated with precipitation. Land-surface evaporation and the surface energy budget were strongly controlled by soil moisture content. A sensitivity test with reduced initial soil moisture content suggested that near-surface soil moisture spins up quickly after heavy precipitation events. However, variations in the initial soil moisture field may alter details of the simulated precipitation which can introduce further complexity in climate simulations.     

Implications of ozone depletion for surface-water photochemistry: Sensitivity of clear lakes

Increased ultraviolet-B radiation (UV-B) in aquatic ecosystems brought about by stratospheric ozone depletion may result in increased formation rates of photochemical reaction products in the surface waters of aquatic ecosystems. In this study, the potential impact of increases in lower wave-length radiation on the formation of hydrogen peroxide (H₂O₂) and singlet oxygen (¹O₂) was modelled for lakes over a range of dissolved organic carbon (DOC) concentrations. The impact of increased UV-B radiation on the production of carbon monoxide (CO) was also calculated for two humic stained systems. The relative increases of H₂O₂ and¹O₂ production were greater in the clear lakes (70% increase in photochemical reaction rates near the surface) than the coloured systems (25%). Production of CO in the study sites also increased under depleted ozone conditions implying increased DOC losses to the overlying atmosphere.     

The Preparation and Evaluation of Bastnäsite Reference Materials IGS 40 and 41

Two bastnäsites - rare-earth fluocarbonate ores - from Mountain Pass, California, each weighing 40 kg, were ground to -200 mesh (75 μm), homogenized, sub-sampled into 432 containers and issued to interested laboratories for analysis in 1979. The methods used for the determination of rare-earth oxides, are discussed and the analytical results have been evaluated statistically. Rare-earth analysis remains a difficult field and, in the two samples, only nine elements have been assigned recommended concentrations. Appendices list the participating laboratories, the main determinations and information on the determination of other elements and oxides.     

Suq el-lahamin — An arab market place in the Old City of Jerusalem

The roofed-over market street, known as Suq el-Lahamin and located in the Old City of Jerusalem, has been in existence since 1152 AD. The street itself has been in existence since 70 AD. within the span of 125 m the Suq is comprised of 83 shops with none of the shopkeepers owning the site of their business. The concentration of shops and obvious grouping of similar types of businesses led to the formulation of a questionnaire to help answer a series of questions some of which were: rent-ownership patterns, means of transporting merchandise to the shops, and shop hours. Of a more personal nature some of the other questions asked were: the amount of rent paid, marriage status, and the number of sons and daughters in each shopkeeper's family.     

Comparison of Major and Trace Element Analyses by ICP, XRF, INAA and ID Methods

Element concentration data for a set of silicate igneous rocks have been determined by four independent analytical methods: inductivelycoupled plasma emission spectroscopy (ICP), instrumental neutron activation analysis (INAA), x-ray fluorescence (XRF), and isotope dilution mass spectrometry (ID). The results show excellent agreement among elements determined by more than one technique, and demonstrate the suitability of commercially available ICP instrumentation for the routine analysis of geologic material compared to other standard methods.     

Tectonic effects of old very large meteoritic impacts on Earth showing on satellite imagery: a review and speculations

Examples are given of circular features over 100 km diameter on the Earth's surface. It is suggested that some of these are the eroded remains of the effects of very large impacts after a brittle crust had developed. Some of the tectonic effects of major impact events are reviewed using experimental evidence and established ground examples, and the resulting geological patterns to be anticipated are described. Such past events may have had a widespread influence on our present geology, and speculative suggestions are made of the types of existing phenomena that could be attributed to this cause in some local cases of such features as regional metamorphism, cratons, island arcs, arcuate ophiolites and greenstone belts, large rotational movements, thermal anomalies, introduction of new materials to our planet, biological and magnetic effects.     

Magma genesis in a battered Moon: Effects of basin-forming impacts

Magma genesis in the Moon could have been significantly altered by large impacts if they melted solidified residual liquids and late cumulates from the ‘magma ocean’. Calculations of the heat required to melt these materials, under different assumed conditions, are compared to estimates of the total kinetic energy of the Imbrium impact. For a significant amount of these materials to have been melted, they must have been near their solidus temperatures, the impacts must have been very large, and the lunar lithosphere must have been locally heated at depths of 70 to 140 km. Unless the Imbrium impact released at least the maximum estimated kinetic energy, only larger impacts, e.g., the proposed ‘Gargantuan’ impact, could have augmented the intrinsic lunar heat budget enough to locally alter the abundance, timing of eruption, and chemical compositions of lunar magmas. The mechanical and thermal energy generated by such an impact could have been critical in creating (1) the higher concentrations of radioactive elements in the Imbrium/Procellarum area by migration of residual liquids driven by differential lithospheric thickness; and (2) hybrid mare basalts (representing varying proportions of late cumulates and/or residual liquids incorporated into primitive magmas rising from the partially molten lunar interior). Complete compositional spectra of lunar basalts are to be expected, from primitive mare basalts to pure KREEP and to Ti-rich varieties. Comparison of the Gargantuan/Imbrium area with ancient basins in the eastern nearside area suggests that the interplay between the Moon's internal heat engine and the timing of large impacts was a crucial factor in determining the time of tunar volcanism and the chemical composition of the lavas.