LunarEX—a proposal to cosmic vision

While the surface missions to the Moon of the 1970s achieved a great deal, scientifically much was also left unresolved. The recent plethora of lunar missions (flown or proposed) reflects a resurgence in interest in the Moon, not only in its own right, but also as a record of the early solar system including the formation of the Earth. Results from recent orbiter missions have shown evidence of ice or at least hydrogen within shadowed craters at the lunar poles.     

Oxidation kinetics of Cu(I) in seawater: implications for its existence in the marine environment

A variety of photochemical and thermochemical processes may lead to the formation of Cu(I) in the upper water column. A thermodynamic model based on measured steady state levels of H₂O₂ in the photic zone indicates that a significant proportion of total dissolved Cu is present as Cu(I).The oxidation kinetics of Cu(I) in seawater have been studied to assess the potential for Cu(I) to accumulate at significant steady state levels when it is generated by non-equilibrium processes.     

State of the marine environment reports--a need to evaluate their role in marine environmental protection and conservation

This paper discusses the rationale behind the preparation of state of the marine environment (SOME) reports, and the need to evaluate their role in marine environmental protection and conservation. Many SOME reports exist, and are being planned or prepared, but are the intended audiences known, are the reports recognized for their many value-added benefits during preparation, and are they being used effectively when completed? It is proposed that a detailed evaluation is needed of SOME reporting and reports, covering audience(s), role(s), influence, and lessons learned or overall benefits.     

Gulfwatch: monitoring spatial and temporal patterns of trace metal and organic contaminants in the Gulf of Maine (1991-1997) with the blue mussel, Mytilus edulis L

Gulfwatch, established in 1991, is an international contaminant monitoring program in which the blue mussel, Mytilus edulis, is used as an indicator of the level and extent of contamination in the Gulf of Maine. Since 1991, trace metals, PAHs, PCBs, and OC pesticides have been measured in mussel tissues at 56 sites. The distribution of most metals was relatively uniform throughout the Gulf with the exception of Ag, Pb and Cr. However, the concentration of organic contaminants increased in a north-to-south direction. High concentrations of contaminants were correlated with large human population density and proximity to large rivers. Temporal analysis of five sites revealed that the majority of contaminant concentrations were either unchanged or decreasing. The concentrations of most contaminants were lower than the median of the National Status and Trends (NS & T) Mussel Watch with the exceptions of Cr, Hg, Pb and sigma PCB24. Hg concentrations at > 80% of the Gulfwatch sites exceeded the NS & T median +1 SD. Gulfwatch continues as a primary contaminant monitoring program in the Gulf of Maine.     

Patterns of development of lavaka,Madagascar's unusual gullies

Lavaka (Madagascar's abundant gullies) show a complex pattern of development. Fourteen independent measures of size and shape in 93 lavaka were investigated by principal components analysis and discriminant function analysis. Typical lavaka start either as wounds and raw patches on mid-hillside that develop step-like head scarps, or as toe slopes collapsed by seepage, slumping, or undercutting. They become deep, raw, vertical-sided, teardrop- to heart-shaped gashes that may be deepest and broadest uphill. As the walls retreat, slump, and become overgrown, lavaka become longer, broader, gentler, and partly filled concavities. They can grow to reach from the valley floor to the hill crest (or even beyond the crest) before healing over. Unless excessive erosion creates tors and inselbergs, they heal over and end up as unremarkable hillside reentrants and side-valleys.     

Late Archean metamorphism in the Buksefjorden region,Southwest Greenland

Standard state thermodynamic data extracted from experimental studies and applied to mineral assemblages in orthogneisses, metasedimentary gneisses and metabasites show that conditions of late Archean (2,850 m.y.) upper amphibolite facies were P _solid7.0 kb, T630° C, and rose to P _solid10.5 kb, T810° C in adjacent granulite facies. The estimates of solid pressure for the granulite facies suggest a late Archean crustal thickness of ca. 35 km, comparable to present day continental crust. Upper amphibolite facies assemblages were in equilibrium with about one half P _solid, while granulite assemblages equilibrated at much lower , varying from about one tenth P _solid in quartzofeldspathic gneisses to one third P _solid in more basic layers.     

Effects of vapor-phase deposition processes on the optical,chemical, and magnetic properties OE the lunar regolith

The processes of solar wind sputtering and meteoritic impact vaporization have created materials in the lunar regolith which were deposited from a vapor phase. Although the quantity of such exotic condensed substances should theoretically be comparable with that of materials which have been melted by impacts, their existence in the fines has not been generally recognized. We have investigated the physical and chemical properties of materials deposited from vapors generated by hydrogen-ion sputtering and thermal evaporation of lunar and artificial ferrosilicates. Both processes are highly reducing. The deposits are enriched in Fe, have large, nonselective, optical absorptivities, and contain abundant sub-microscopic, superparamagnetic grains of metallic Fe which exhibit the characteristicg=2.1 ESR resonance. The sputter-deposited films are enriched in heavy elements. Thus the hypothesis that the lunar fines contain several percent of materials deposited from the vapor phase accounts in a natural manner for many of the unusual optical, physical and chemical properties of lunar soils. The vapor-deposits are probably concentrated in the agglutinate particles of the regolith.