Oxygen Isotope Evidence for Chemical Interaction of Ki lauea Historical Magmas with Basement Rocks

Klauea historical summit lavas have a wide range in matrix ¹⁸O_VSMOWvalues (4·9–5·6) with lower values in rockserupted following a major summit collapse or eruptive hiatus.In contrast, ¹⁸O values for olivines in most of these lavasare nearly constant (5·1 ± 0·1). The disequilibriumbetween matrix and olivine ¹⁸O values in many samples indicatesthat the lower matrix values were acquired by the magma afterolivine growth, probably just before or during eruption. BothMauna Loa and Klauea basement rocks are the likely sources ofthe contamination, based on O, Pb and Sr isotope data. However,the extent of crustal contamination of Klauea historical magmasis probably minor (< 12%, depending on the assumed contaminant)and it is superimposed on a longer-term, cyclic geochemicalvariation that reflects source heterogeneity. Klauea's heterogeneoussource, which is well represented by the historical summit lavas,probably has magma ¹⁸O values within the normal mid-ocean ridgebasalt mantle range (5·4–5·8) based on thenew olivine ¹⁸O values. KEY WORDS: Hawaii; Klauea; basalt; oxygen isotopes; crustal contamination     

Measuring the k–S–p relations on DNAPLs migration

Migration characteristics of dense non-aqueous phase liquids (DNAPLs) in the subsurface can be expressed as a water–DNAPL two-phase system based on mainly the k–S–p relations, which describe the relations among relative permeability (k), degree of water saturation (S), and capillary pressure head (p). The aims of this research are to develop an experimental system with new type of probes, such as the electrical conductivity probe for measuring the degree of water saturation and the hydrophilic and hydrophobic tensiometer for measuring the pore water and DNAPL pressures, and also to estimate the results obtained from the developed experimental system. From these tests, the excellent k–S–p relations were obtained and the efficiency and validity of this developed experimental system have been confirmed in terms of the concept of the scaling coefficient calculated by interfacial tensions.     

Tokaido — megalopolis of Japan

The Tokaido east coast road has been the main road of Japan since Mediaeval times, and the journey from Tokyo at one end to Kyoto or Osaka at the other, which used to take a fortnight, can now be completed in about three hours by bullet train, and an even faster linear-motor car is likely to be in operation in the near future.Already during the 18. cent., Edo (Tokyo) was the largest city in the world, with a population over a million, and the rapid urbanization of Japan's population since Meiji times, and particularly during the post-WW II period, has been quite unprecendented. In 1950, the median size of place was 13,000 and by 1975 it was 140,000. About 60 million lived in the Tokaido zone.The Kanto, Nobi and Osaka plains, adjacent to the good harbours of Tokyo, Ise and Osaka bays, enjoying the relatively mild climate of the Pacific coast, and being within 600 km of each other, have been the focii of urban and industrial development in Japan. The emergence of Tokaido megalopolis was boosted by capital investment in this zone, and was contingent upon the industriousness and high level of education of the people.The concept of megalopolis in Japan is popularly associated with rapid urbanization, poly-nuclear and linear form, and concentration of population, capital and information, all of which elements are typified by the Tokaido zone. The linear megalopolis pattern has been postulated as a more efficient growth form for high-dense society than the radial metropolitan pattern. It has even been suggested that megalopolis is a concept perceived by the intellect, its physical structure determined by information networks, metropolis being perceived by the eye and its physical structure being determined by transport and energy networks.Quite irrespective of the concept of megalopolis, there can be no denying that Japan's society is a high-dense society. In 1975, 57% of the population lived in Densely Inhabited Districts (DIDs) at minimum densities of 40 persons per hectare, and these DIDs covered only 2.2% of the land area of Japan. The current trend is for more and more people to live in DIDs, but for overall DID densities to decrease. During the past 25 years, there has been a huge influx of population into the Tokaido zone, and while until 1960 the greatest increases were in the three main metropolitan centres, as these became saturated, rapid urbanization spread into the neighbouring prefectures. Since the mid-sixties, the central metropolitan wards have begun to lose residents, but the daytime population has continued to increase, giving rise to increasingly complex commuting patterns. To give an example, the commuting field of Yokohama includes almost all the prefectures of Tokaido megalopolis.Like the image of megalopolis itself, life in Tokaido megalopolis has its good and bad aspects. Although per capita space in dwellings is increasing somewhat, housing is extremely expensive and people commute long distances. Incomes are high but environmental problems persist. There is a U-turn phenomenon, but metropolitan suburbs remain a popular choice of residence.Central management functions and knowledge and information oriented occupations are predominantly concentrated in Tokyo and Osaka, the two main nodes of Tokaido megalopolis. In the intermediate cities, new employment opportunities are stimulated by the expansion of second-level managerial functions. The transport and communications networks of Tokaido are becoming congested as mobility and information flow increase.Planning in the eighties will be affected by the switch from industries dependent on raw materials to knowledge intensive industries; from investment in production to investment in public facilities and pollution control. Within Tokaido megalopolis, there is room for local governments to expand efforts to improve the existing situation, and at its fringes to avert some of the less desirable consequences of rapid urbanization.     

Transition enthalpies and entropies of high pressure zinc metasilicates and zinc metagermanates

The enthalpies of transition at T= 298 K between zinc metasilicate assemblages, measured by molten oxide solution calorimetry, are:

Relationship of the landslide distribution to geology in Hokkaido, Japan

The island of Hokkaido, Japan, is subdivided into nineteen regions on the basis of regional geology and landslide distribution. Four major geologic zones characterize these regions, as follows: (1) Volcanic Rock Zone, (2) “Green Tuff” Zone, (3) Mudstone Zone, and (4) Serpentinite “Green Rock” Zone. Each zone is marked by landslides of a distinctive type. In addition, we have analyzed the relationship between landslide distribution and geologic structure for several areas.     

The partitioning of Pt-Re-Os between solid and liquid metal in the Fe-Ni-S system at high pressure: Implications for inner core fractionation

Coupled ¹⁸⁶Os/¹⁸⁸Os and ¹⁸⁷Os/¹⁸⁸Os enrichments of plume-derived lavas have been suggested to reflect contributions of materials from the outer core (Brandon et al., 1998). This hypothesis is based on the assumption that the Earth’s liquid outer core has high Pt/Os and slightly high Re/Os ratios as a result of the crystallization of the solid inner core, and shows coupled enrichments in the ¹⁸⁶Os/¹⁸⁸Os and ¹⁸⁷Os/¹⁸⁸Os ratios, reflecting the decay of ¹⁹⁰Pt and ¹⁸⁷Re to ¹⁸⁶Os and ¹⁸⁷Os, respectively. Partitioning experiments of Pt-Re-Os between solid and liquid metal were performed at 5-20 GPa and 1250-1400 °C, to examine the effects of pressure in the Fe-Ni-S system. The ratios (D_Os/D_Pt, D_Os/D_Re) of measured partition coefficients of Pt, Re and Os are almost constant with increasing pressure. D_Os/D_Pt increases significantly, whereas D_Os/D_Re decreases, with increasing sulphur content in the liquid metal. On the basis of the present experimental results, it is unlikely that the required Pt-Re-Os fractionation is generated during inner core crystallization, assuming that the light element in the Earth’s core is sulphur.     

The characteristic distribution of silica over the East China Sea shelf slope

The localized near-bottom water with silica content higher than that in the adjacent shelf water was observed to exist at the eastern margins of the East China Sea continental shelf. The core of the high silica water possessed the silica content corresponding to that in the Kuroshio at depths greater than on the shelf. The mixing analysis of water masses using temperature (T) and silica (Si) showed that the core water can be produced through the vertical mixing of intermediate water of the Kuroshio deeper than 100 m. This study provides us a conclusion that the intermediate water of the Kuroshio is strongly mixed on the shelf slope and then upwelled to form the ridge-like distribution of water masses with low temperature and high silica content at the shelf edge.     

Possible climate change/variability and human impacts,vulnerability of drought-prone regions,water resources and capacity building for Africa

ABSTRACT

This review article discusses the climate, water resources and historical droughts of Africa, drought indices, vulnerability, impact of global warming and land use for drought-prone regions in West, southern and the Greater Horn of Africa, which have suffered recurrent severe droughts in the past. Recent studies detected warming and drying trends in Africa since the mid 20th century. Based on the Fourth Assessment Report of the Intergovernmental Panel on Climate Change and the Coupled Model Intercomparison Project Phase 5 (CMIP5), both northern and southern Africa are projected to experience drying, such as decreasing precipitation, runoff and soil moisture in the 21st century and could become more vulnerable to the impact of droughts. The daily maximum temperature is projected to increase by up to 8°C (RCP8.5 of CMIP5), precipitation indices such as total wet day precipitation (PRCPTOT) and heavy precipitation days (R10 mm) could decrease, while warm spell duration (WSDI) and consecutive dry days (CDD) could increase. Uncertainties of the above long-term projections, teleconnections to climate anomalies such as ENSO and the Madden-Julian Oscillation, which could also affect the water resources of Africa, and capacity building in terms of physical infrastructure and non-structural solutions are also discussed. Given that traditional climate and hydrological data observed in Africa are generally limited, satellite data should also be exploited to fill the data gap for Africa in the future.

Editor D. Koutsoyiannis; Associate editor N. Ilich     

Finite‐element analysis of laminated rubber bearing of building frame under seismic excitation

Finite element analysis is carried out for a building frame supported by laminated rubber bearings to simultaneously investigate global displacement and local stress responses under seismic excitation. The frame members and the rubber bearings are discretized into hexahedral solid elements with more than 3 million degrees of freedom. The material property of rubber is represented by the Ogden model, and the frame is assumed to remain in elastic range. It is shown that the time histories of non‐uniform stress distribution and rocking behavior of the rubber bearings under a frame subjected to seismic excitation can be successfully evaluated, and detailed responses of base and frame can be evaluated through large‐scale finite element analysis. Copyright © 2015 John Wiley & Sons, Ltd.