Education for sustainable development for Tokyo Bay: Developing a practice framework of university-based coastal ESD

This paper reviews the initial phase of a coastal education for sustainable development program for Edomae, the innermost reaches of Tokyo Bay. The program has been steered by a working group of Tokyo University of Marine Science and Technology faculty members from different academic backgrounds. Although the process began with conventional educational ideas, the ESD practice framework evolved to include more interactive activities. The overall goal is to pursue discussions of a plan for the sustainable use of Tokyo Bay in the coastal communities through a university–community partnership by developing Edomae ESD leaders in the coastal community.     

Stability Behavior and Thermodynamic States of Iron and Manganese in Sandy Soil Aquifer,Manukan Island,Malaysia

A total of 20 soil samples were collected from 10 boreholes constructed in the low lying area, which included ancillary samples taken from the high elevation area. Redox processes were investigated in the soil as well as groundwater in the shallow groundwater aquifer of Manukan Island, Sabah, Malaysia. Groundwater samples (n = 10) from each boreholes were also collected in the low lying area to understand the concentrations and behaviors of Fe and Mn in the dissolved state. This study strives to obtain a general understanding of the stability behaviors on Fe and Mn at the upper unsaturated and the lower-saturated soil horizons in the low lying area of Manukan Island as these elements usually play a major role in the redox chemistry of the shallow groundwater. Thermodynamic calculations using PHREEQC showed that the groundwater samples in the study area are oversaturated with respect to goethite, hematite, Fe(OH)₃ and undersaturated with respect to manganite and pyrochroite. Low concentrations of Fe and Mn in the groundwater might be probably due to the lack of minerals of iron and manganese oxides, which exist in the sandy aquifer. In fact, high organic matters that present in the unsaturated horizon are believed to be responsible for the high Mn content in the soil. It was observed that the soil samples collected from high elevation area (BK) comprises considerable amount of Fe in both unsaturated (6675.87 mg/kg) and saturated horizons (31440.49 mg/kg) compared to the low Fe content in the low lying area. Based on the stability diagram, the groundwater composition lies within the stability field for Mn²⁺ and Fe²⁺ under suboxic condition and very close to the FeS/Fe²⁺ stability boundary. This study also shows that both pH and Eh values comprise a strong negative value thus suggesting that the redox potential is inversely dependent on the changes of pH.     

Inferred ultrahigh-temperature metamorphism of amphibolitized olivine granulite from the Sør Rondane Mountains, East Antarctica

This paper reports the first evidence of ultrahigh-temperature (UHT) metamorphism from the Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, which is evident as orthopyroxene + spinel symplectite in an amphibolitized mafic granulite. The granulite consists of olivine, orthopyroxene, clinopyroxene, pargasitic amphibole, plagioclase, and ilmenite, and it possesses a within-plate alkali basalt signature. The local bulk chemical composition of symplectite, major and trace element compositions, and thermodynamic calculations for the symplectite, suggest the presence of garnet at the high-pressure stage and that the symplectite formed from garnet, olivine, and primary orthopyroxene by decompression from more than 12 kbar at 1000 °C. The granulite records a subsequent amphibolite-facies overprint (<700 °C at <6 kbar) that involved the chemical re-equilibration of several phases. The obtained pressure–temperature (P–T) conditions and P–T path are different from the UHT metamorphism from the Schirmacher Hills, central Dronning Maud Land, which is considered to have occurred in a back-arc tectonic setting. The relatively high-P conditions and the decompression path reconstructed in the present study are similar to those reported for southern India, Sri Lanka, and part of northeastern Mozambique, possibly reflecting continental thickening and exhumation during the main collision event between East and West Gondwana.     

Glacial hazards in the Rolwaling valley of Nepal and numerical approach to predict potential outburst flood from glacial lake

In recent years, climate change and retreating glaciers constitute a major hazard in the Himalaya of South Asia. Glacial lakes are rapidly developing or increasing due to climate change. The rapid development of the lake may cause outburst of the lake. The outburst discharge from the glacial lake can cause catastrophic flooding and disaster in downstream area. Therefore, it is necessary to investigate the impact of climate change on glacial lakes and to understand the characteristics of the glacial lake outburst. In this study, the field assessment of Tsho Rolpa Glacial Lake in the Himalaya of Nepal has been presented and the impact of climate change on this glacial lake has been discussed. The Tsho Rolpa Glacial Lake is the largest and most potentially dangerous glacial lake in Nepal. In addition, a numerical model has been also developed for computing the characteristics of glacial lake outburst due to moraine dam failure by seepage and water overtopping. The numerical model is tested for the flume experimental cases. The simulated results of the outburst discharge, the dam surface erosion, and the temporal variation of the moisture movement in the dam are compared with those obtained from the hydraulic model experiments. The moisture profile calculated by numerical model was agreeable with the experimental moisture profile. The simulated failure surface of the dam due to seepage by considering the suction in slope stability analysis gave more agreeable results than the Janbu's simplified method. The results of the outburst discharge and dam surface erosion also agreed with the experimental results.     

The period–luminosity relation for type II Cepheids in globular clusters

We report the result of our near-infrared observations ( JHK _s) for type II Cepheids (including possible RV Tau stars) in galactic globular clusters. We detected variations of 46 variables in 26 clusters (10 new discoveries in seven clusters) and present their light curves. Their periods range from 1.2 d to over 80 d. They show a well-defined period–luminosity relation at each wavelength. Two type II Cepheids in NGC 6441 also obey the relation if we assume the horizontal branch stars in NGC 6441 are as bright as those in metal-poor globular clusters in spite of the high metallicity of the cluster. This result supports the high luminosity which has been suggested for the RR Lyr variables in this cluster. The period–luminosity relation can be reproduced using the pulsation equation     assuming that all the stars have the same mass. Cluster RR Lyr variables were found to lie on an extrapolation of the period–luminosity relation. These results provide important constraints on the parameters of the variable stars.
Using Two Micron All-Sky Survey (2MASS) data, we show that the type II Cepheids in the Large Magellanic Cloud (LMC) fit our period–luminosity relation within the expected scatter at the shorter periods. However, at long periods (   P > 40  d, i.e. in the RV Tau star range) the LMC field variables are brighter by about one magnitude than those of similar periods in galactic globular clusters. The long-period cluster stars also differ from both these LMC stars and galactic field RV Tau stars in a colour–colour diagram. The reasons for these differences are discussed.     

Estimation of potential energy curves, dissociation energies, franck-condon factors and r-centroids of comet interesting molecules

The experimental potential energy curves for the different electronic states of molecules like CN, CO and CS observed in comets are constructed by using the Rydberg-Klein-Rees method as modified by Vanderslice et al. The ground state dissociation energies are determined by curve fitting technique using the five parameter Hulburt-Hirschfelder (H-H)function. The estimated dissociation energies are 7.63 ± 0.187, 10.95 ±0.224 and 7.27 ± 0.152 eV for CN, CO and CS respectively. These values are in good agreement with the literature values. Estimated dissociation energies of CN, CO and CS are used in the relation given by Gaydon and ionization potentials are evaluated for CO and CS molecules. The estimated ionization potentials are 13.92and 12.15 eV for CO and CS molecules respectively. The r-centroids and Franck-Condon factors (FC Factors) for the band system of a ³Π_r – X¹Σ⁺ (a – X) and A¹Π – X ¹Σ⁺ (A -X) of CN, A ²Π_i – X²Σ⁺ (A – X) and B²Σ⁺-X²Σ⁺ (B – X) of CO and a ³Π_r – X¹Σ⁺ (a – X) of CS molecules have been calculated employing an approximate analytical methods of Jarmain and Fraser and Nicholls and Jarmain. The absence of the bands in these systems are explained. This revised version was published online in July 2006 with corrections to the Cover Date.     

High nutrients in the coastal area after heavy rain observed in the central Seto Inland Sea in July 2012

Temporary enhancement of the nutrient concentrations in the coastal area was observed after heavy rain in the central Seto Inland Sea in July 2012. After passage of a stationary front accompanied by heavy rain, the river outflow was enhanced, and low salinity and high nutrient concentrations were detected near the mouths of rivers. The offshore salinity and nutrients increased and decreased, respectively, which suggested that a snapshot event, such as heavy rain, could influence the short-term variation of the coastal marine environmental conditions, such as the salinity and nutrient distributions.     

On spectral and statistical characteristics of shallow water waves

Spectral, zero up-crossing and Tucker's methods of analysis are examined for shallow water wave records. Among the wave height parameters H_s and are most reliable and consistent irrespective of the analysis technique. Tucker analysis, though simple, seems versatile for estimating these wave height parameters. The standard period parameters are less consistent. For practical purposes every period that might reasonably occur has to be considered along with their corresponding height estimate. Joint distribution of heights and periods is in agreement with the function proposed by CNEXO.     

Analysis of the global relationship of biennial variation of sea surface temperature and air-sea heat flux using satellite data

We investigated the phase difference and the cross correlation coefficient between the band-pass filtered biennial variations of sea surface temperature (SST) and air-sea heat flux estimated by the monthly mean 2°×2° satellite data of Advanced Very High Resolution Radiometer (AVHRR) and Special Sensor Microwave/Imager (SSM/I) from July 1987 to June 1991. Judging from the phase difference, it can be determined whether the biennial variation of SST is controlled by local thermal air-sea interaction or oceanic processes of horizontal transport. When the local air-sea heat flux controls the biennial variation of SST, the phase of SST advances /2 (6 months) against that of the air-sea heat flux. In contrast, when the biennial variation of SST is controlled by the oceanic process, the phase difference between the SST and the air-sea heat flux becomes 0 or (12 months). In this case, two types of the phase differences are determined, depending on which variability of SST and air-sea heat flux is larger. The close thermal air-sea interaction is noticeable in the tropics and in the western boundary current region. The phase difference of /2 appears mainly in the north Pacific, the southeast Indian Ocean, and the western tropical Pacific; zero in the eastern tropical Pacific and the northeast and equatorial Atlantic; and that of in the central equatorial Pacific and north of the intertropical convergence zone (ITCZ) of the Atlantic. Phase differences of 0, , or /2 are possible in the western boundary current regions. This fact indicates that each current plays a different role to the biennial variation of SST. It is inferred that SST anomalies in the tropics are mutually correlated, and the process in which marked SST anomalies in the tropics are transferred to the remote area was probed. In the equatorial Pacific, the SST anomaly is transferred by the long planetary wave. On the other hand, it is found from the phase relationship and the horizontal correlation of SST that the SST anomaly in the central and western equatorial Pacific is connected through atmospheric mediation. It is suggested that the biennial variation of SST in the eastern Indian Ocean is affected by heat transport due to the Indonesian throughflow from the western tropical Pacific. It is found that the mentioned pattern of the interannual variation of SST in the tropical Atlantic as a dipole is not tenable.