Effect of sodium chloride on the metabolic activity of halophilic bacteria isolated from the Lake Gardno estuary

The effect of different concentrations of sodium chloride on the metabolic activity of halophilic bacteria derived from the Lake Gardno estuary was studied using respirometric methods. The influence of salt was examined in two ways: the bacteria were preincubated in various concentrations of sodium chloride, and the cells used for respirometric measurements were supplied with substrates dissolved in water amended with various concentrations of the salt. Generally, an increase in the concentration of sodium chloride in the medium used for preincubation resulted in an increase in metabolic activity. Conversely, a decrease was noted when solutions of increasing salt content were employed to dissolve the substrate. The decrease in oxygen uptake noted when increased amounts of salt were added is proposed to be the result of the short period allowed for adaptation of cells to the higher salt concentrations.     

Gully erosion as a natural hazard: the educational role of geotourism

Gully erosion is one of the greatest natural hazards in the loess areas of E. (Eastern) Poland. At the same time, permanent gullies are a major tourist attraction and can provide a basis for the development of geotourism. The study objective was to assess the possibilities of using the loess gullies for educational purposes. Detailed studies were conducted within the municipality of Kazimierz Dolny, an area with an extremely high concentration of permanent gullies. The questionnaire survey of students and tourists (nearly 300 surveys were completed) showed that the respondents’ knowledge of geomorphology was limited, despite their familiarity with gullies. In most cases, they were unable to accurately identify the determinants of gully erosion, its negative effects and methods for preventing it. An assessment of the tourism and geotourism potential of the municipality made it possible to identify the sites (gullies) that can perform an educational function, with regard to gully erosion. The establishment of the Małopolska Vistula Gap Geopark, whose highlights will include numerous loess gullies, can pave the way for the development of geotourism.

     

The cryosphere and glacial permafrost as its integral component

Since Earth sciences have undertaken studies of other celestial bodies, its various fields have moved beyond the scope of study assigned to them by name. Interest in space makes it necessary to abandon research geocentrism and reverse relations when comparing the structure of the Earth with other celestial bodies. As an exceptional place in the universe, it should not be the Earth which constitutes a reference point, especially in cryospheric research, but rather the other celestial bodies of our planetary system. This approach, referred to as ??Spatial Uniformitarianism,?? is the basis for determining the place of ice in the environment and for assigning it to the lithosphere. Ice can be penetrated by frost just as other minerals and rocks, so the occurrence of permafrost may yet be attributed to glaciers and ice-caps. In the article, the occurrence of glacial permafrost has been worked out on the basis of a thermal classification of glaciers with a thorough understanding of the phenomenon. This allows us to specify permafrost??s presence beneath glaciers and ice-caps, a concept which had been needlessly vague. Further, by considering rock glaciers as a mixture of two types of rocks, and by understanding the importance of movement in their evolution, we are now closer to fruitfully determining their role in the environment, their geomorphological significance.     

Interfacial liquid water on Mars and its potential role in formation of hill and dune gullies

Gullies are among the most intriguing structures identified on the surface of Mars. Most common are gullies located on the slopes of craters which are probably formed by liquid water transported by shallow aquifers (Heldmann, J.L., Carlsson, E., Johansson, H., Mellon, M.T., Toon, O.B. [2007]. Icarus 188, 324-344). Two particular types of gullies are found on slopes of isolated hills and dunes. The hill-slope gullies are located mostly at 50°S, which is at the high end of latitudes of bulk of the gullies found so far. The dune gullies are found in several locations up to 65°S (Reiss, D., Jaumann, R., Kereszturi, A., Sik, A., Neukum, G. [2007]. Lunar Planet. Sci. XXXVIII. Abstract 1993), but the best known are those in Russel crater at 54°S. The hill and dune gullies are longer than others making the aquifers explanation for their formation unlikely (Balme, M., Mangold, N., Baratoux, D., Costard, F., Gosselin, M., Masson, P., Pnet, P., Neukum, G. [2006]. J. Geophys. Res. 111. doi:10.1029/2005JE002607). Recently it has been noted that thin liquid films of interfacial water can play a role in rheological processes on the surface of Mars (Moehlmann, D. [2008]. Icarus 195, 131-139. Kereszturi, A., Moehlmann, D., Berczi, Sz., Ganti, T., Kuti, A., Sik, A., Horvath, A. [2009]. Icarus 201, 492-503.). Here we try to answer the question whether interfacial liquid water may occur on Mars in quantities large enough to play a role in formation of gullies. To verify this hypothesis we have calculated thermal models for hills and dunes of various steepness, orientation and physical properties. We find that within a range of average expected values of parameters it is not possible to have more than a few monolayers of liquid water at depths greater than a centimeter. To create subsurface interfacial water film significantly thicker and hence to produce conditions for the slope instability, parameters have to be chosen to have their extreme realistic values or an additional source of surface heating is needed. One possibility for additional heating is a change of atmospheric conditions due to a local dust storm. We conclude that if interfacial water is responsible for the formation of the hill-slope gullies, our results may explain why the hill gullies are rare.     

Concepts and science for coastal erosion management - An introduction to the Conscience framework

The main objective of the Conscience project was to develop and test concepts, guidelines and tools for the sustainable management of erosion along the European coastline, based on the best available scientific knowledge and on existing practical experience. Four concepts are potentially capable of providing the nexus between scientific knowledge and management: coastal resilience, coastal sediment cell, favourable sediment status and strategic sediment reservoir. The project has tested the use of these concepts and found that they are useful, provided that they are positioned and linked within a logical structure that we shall call the Conscience “Frame of Reference”, defined in time and space and supported through data and monitoring. Practical experience in six coastal sites in Europe has shown that the use of this Frame of Reference together with these concepts can make management objectives explicit and transparent. It can therefore support the design of an appropriate, resilience based coastal erosion management practice.     

The concept of cryo-conditioning in landscape evolution — Comment to the paper published by Ivar Berthling and Bernd Etzelmüller,Quaternary Research 75 (2011) 378–384

The term “cryo-conditioning,” proposed by the authors for classifying specific landform association in periglacial landscapes, needs to be defined more precisely. A starting point could be the proper understanding of the term “Cryo-” in the various compound words found in various disciplines. This is also important for a correct understanding of the proposed concepts, since it concerns one of the most important processes in nature: the phase transition of water between solid and liquid. Cold-temperate transition surfaces in polythermal glaciers and at the permafrost base in their forelands can act as a specific hub between the glacial and periglacial domains.     

Seasonal melting of surface water ice condensing in martian gullies

In this work we consider when and how much liquid water during present climate is possible within the gullies observed on the surface of Mars. These features are usually found on poleward directed slopes. We analyse the conditions for melting of H₂O ice, which seasonally condenses within the gullies. We follow full annual cycle of condensation and sublimation of atmospheric CO₂ and H₂O, accounting for the heat and mass transport in the soil. During the summer, once the facets of the gullies are exposed to the Sun the water ice can melt and evaporate. Two mid latitude locations in both hemispheres are considered. The model includes both the rough geometry of the gullies as well as the slope of the surface where the gullies appear. It is an extension of the model developed to calculate condensation of CO₂ ice in troughs of different sizes, including polygonal features on Mars (Kossacki and Markiewicz, 2002, Icarus 160, 73; Kossacki et al., 2003, Planet. Space Sci. 51, 569). We have found, that water ice accumulated during winter can undergo transition to the liquid phase after complete sublimation of CO₂ ice. The amount of liquid water depends on water content in the atmosphere and on the local wind speed. It is probably not enough to destabilise the slope and cause flow of the surface material. However, even the small amounts of liquid water predicted, can play an important role in surface chemistry, in increasing the cohesive strength of the soil's surface layer and possibly may have some exobiological implications.     

Conditions for deposition of annually laminated sediments in small meromictic lakes: a case study of Lake Suminko (northern Poland)

A three-year field study was conducted in Lake Suminko, Poland, to gain an understanding of the limnological variables that influence the formation and spatial extent of annually laminated sediments in the lake. The water body is divided into three depth strata, the mixolimnion, chemocline and monimolimnion, each defined by distinct values of temperature, electrical conductivity and oxygen concentration. Typical for meromictic lakes, the monimolimnion remains perennially anoxic and is rich in dissolved solids and nutrients. The annual pattern of particle flux in Lake Suminko is closely related to biochemical processes in the euphotic zone. During winter months we observed very low accumulation rates of non-carbonaceous matter, while during the rest of the year, three periods of calcite deposition were recorded (April, July–August, and October–November). The periods of high calcite deposition corresponded with algal blooms and oxygen concentration maxima. Two principal factors contribute to meromixis in Lake Suminko: (1) the basin is sheltered, preventing wind mixing, and (2) biochemical processes in the lake associated with high lacustrine productivity. Meromictic conditions must control the formation and preservation of laminated sediments in the lake because preserved laminations occur only in areas where the lake floor lies below monimolimnetic waters.