High altitude infrared spectroscopic evidence for bound water on Mars

The reflectivity of the Martian surface has been measured between 2.0 and 4.0 μ. A broad absorption band is observed which has a minimum at 2.85μm. The position and shape of the band is compared to features in numerous terrestrial minerals. Bound water in the Martian surface material is the most likely cause of the observed band. The strength of the observed band suggests a bound water content of approx. 1% by weight. The band is inconsistent with > a few % limonito or hydrated polymeric carbon suboxide. A mean particle radius ～100μm is deduced. The quality of bound water derived has a range of geological, climatic, and exobiological implications     

Gaschromatographisehe Untersuchung einiger Systeme aus Tonmineralien und organischen Stoffen

Gas chromatographic studies of simple organic -montmorillonite systems were carried out over the temperature range 40–90° C. Experimentally derived heats of absorption and relative activity coefficients indicate that the polar group of compounds studied exhibits organic-silicate interaction over the entire temperature range. The chromatographic separation of a group of non-polar hydrocarbons is most effective over the temperature range 40–70° C, when a layer of adsorbed water is present between silicate sheets. In this case organic-water interactions are important and the chromatographic separation is largely dependent upon relative solubility of hydrocarbons in the adsorbed water. Over the temperature range 70–90° C chromatographic separation of the hydrocarbons is effected by organic-silicate interactions in the absence of adsorbed water. It is suggested that these processes are in principle effective in natural sedimentary columns.

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Herrn Prof. Dr.Carl W. Correns zum 70. Geburtstag gewidmet.     

Thermal migration of water on the Galilean satellites

We have modeled the thermal migration of water on the Galilean satellites under the assumption of ballistic molecular trajectories. We find that water migrating owing to solar radiation on an ice-covered satellite will build up in the temperate latitudes, in general not reaching the poles. As much as 50 m of ice may have been lost by this process from the equatorial regions of Europa over the age of the solar system. The disappearance of patches of ice—for instance, the bright rays surrounding some impact craters—from the equatorial regions of Ganymede and Callisto may approach a value (the irreversible evaporation rate) three orders of magnitude larger than the net equatorial loss rate for ice-covered Europa. The presence of water ice pole caps on Ganymede extending to the latitudes at which thermal migration becomes important suggests that some process distributed an extensive, thin covering of water on the satellite, and that the equatorial regions were subsequently cleared by the thermal process.     

Evaporation of ice in planetary atmospheres: Ice-covered rivers on mars

The evaporation rate of water ice on the surface of a planet with an atmosphere involves an equilibrium between solar heating and radiative and evaporative cooling of the ice layer. The thickness of the ice is governed principally by the solar flux which penetrates the ice layer and then is conducted back to the surface. These calculations differ from those of Lingenfelter et al. [(1968) Science161, 266–269] for putative lunar channels in including the effect of the atmosphere. Evaporation from the surface is governed by two physical phenomena: wind and free convection. In the former case, water vapor diffuses from the surface of the ice through a lamonar boundary layer and then is carried away by eddy diffusion above, provided by the wind. The latter case, in the absence of wind, is similar, except that the eddy diffusion is caused by the lower density of water vapor than the Martian atmosphere. For mean Martian insolations the evaporation rate above the ice is ～ 10^?8 g cm^?2 sec^?1. Thus, even under present Martian conditions a flowing channel of liquid water will be covered with ice which evaporates sufficiently slowly that the water below can flow for hundreds of kilometers even with quite modest discharges. Evaporation rates are calculated for a wide range of frictional velocities, atmospheric pressures, and insolations and it seems clear that at least some subset of observed Martian channels may have formed as ice-choked rivers. Typical equilibrium thicknesses of such ice covers are ～ 10 to 30 m; typical surface temperatures are 210 to 235°K. Ice-covered channels or lakes on Mars today may be of substantial biological interest. Ice is a sufficiently poor conductor of heat that sunlight which penetrates it can cause melting to a depth of several meters or more. Because the obliquity of Mars can vary up to some 35°, the increased polar heating at such times seems able to cause subsurface melting of the ice caps to a depth which corresponds to the observed lamina thickness and may be responsible for the morphology of these polar features.     

Response of hematological and biochemical parameters to heavy metal exposure: Implications in environmental monitoring

The use of selected hematological and biochemical parameters as indicators of metal exposure in aquatic organisms was evaluated. The hematological and biochemical parameters examined include glucose, hematocrit and aminotransferase levels in golden shiners exposed to cadmium. Cadmium exposure produced significant alterations in the levels of glucose, aspartate aminotransferase and alanine aminotransferase; however, hematocrit was not altered by exposure to cadmium. In addition, the comparative activity of Na/K adenosine triphosphatase (ATPase) was evaluated in the fathead minnow, golden shiner and bluegill sunfish. Basal Na/K ATPase activity was lowest in golden shiner (1·01 μmol Pi/mg protein/h) and highest in bluegill sunfish (1·45 μmol Pi/mg protein/h). While a stimulation of Na/K ATPase activity was observed at an exposure concentration of 1 μg Cd/liter in the fathead minnow and bluegill sunfish, inhibition of enzymatic activity was observed at higher exposure concentrations (10 and 100 μg Cd/liter). Gill Na/K ATPase activity in golden shiner was not significantly influenced by cadmium exposure. The observed insensitivity of ATPase in shiner may, in part, be related to higher background and accumulated concentrations of cadmium in gill tissue.     

The filtering effect of orbit correction on geopotential errors

Summary The geophysical interpretation of satellite tracking residuals generally ignores the filtering effect of initial orbit correction on the true errors of the model. While the filtered information is usually regarded as lost, knowing the spectral characteristics of the filter is a great aid in the detailed interpretation of residuals, especially of global data sets. In this regard, we derive the filter characteristics (admittances) of orbit correction in the presence of geopotential-caused trajectory errors. We then apply the filter to determine the likely power of the lost radial information in crossover differences of sea heights determined from satellite altimetry or in the latitude lumped coefficients derived from them. For example, we find that resonant geopotential information with periods longer than the corrected orbit's arc length is largely lost in residual crossover data. Results are given for GEOSAT, ERS-1 and TOPEX/Poseidon in their Exact Repeat Missions, using calibrated variancecovariance matrices of the harmonic geopotential coefficients of several recent Earth gravity models. To prove that filtering is important, we first employed a simple cut of all perturbing terms with periods longer than the general tracking period (4 days for GEOSAT and ERS-1, and 10 days for TOPEX). But the cut is too crude a method from a theoretical viewpoint, and thus, we developed two new filters. A comparison of their admittances explains the differences (and sometimes anomalous behaviour) between them and the cut. Many numerical examples (single-satellite crossover errors and latitude lumped coefficient errors, as projected from the variance-covariance matrices) are presented.This paper has been presented during the Panel on Satellite Dynamics, at COSPAR 1994, in Hamburg, Germany.     

Background,conceptual structure and organizational-administrative establishing of a “sustainable development strategy” for Coral Islands

Minitope coral islands represent one third of the islands located in the tropical Indo-Pacific. Subsistence farming and extensive agriculture dominate the traditional structure of income. As the lack of natural resources, infrastructure and capital restrict the developmental changes, the islands' natural environment has been utilized as economic potential. Planning and realization of land use systems introduced have, however, often been based on an insufficient data basis and have often inadequately considered the consequences of human impacts on the natural environment and its controlling factors. The result was environmental degradation and ecological destruction, affecting also the population's socioeconomic situation and in some cases rendering alternative land use impossible. Therefore, the long-term utilization of coral islands and, hence, the economic development of those countries require a specific development strategy. Based on the environmental and socioeconomic consequences of touristic utilization of coral islands in the Maldivian Archipelago, the model for a sustainable development strategy and its aims are derived, and the objectives, the conceptual structure, and the way of establishing them organizationally and administratively are presented.     

The last lavas erupted during the main phase of the Siberian flood volcanic province: results from experimental petrology

The final lavas of the Siberian flood basalts are a ∼1,000 m thick section of meimechites, high-alkali, high-titanium, hydrous lavas that contrast sharply with the tholeiites that precede them. This paper presents a phase equilibrium study indicating that a candidate primary meimechite magma with 1 wt% water originated at ∼5.5 GPa and 1,700°C, both hotter and shallower than other estimates for melting beneath continental lithosphere. The experiments also suggest that a higher volatile content was involved in meimechite source genesis. Both the absence of orthopyroxene in any experiment and the close field association with carbonatites suggest that the meimechite source region may have been metasomatized with a CO₂-rich fluid. A small additional quantity of CO₂ and water would move magma origination to ∼1,550–1,600°C.