The origin of thermal waters from the eastern flank of the Dead Sea Rift Valley (western Jordan)

Thermal waters emerging along the eastern flank of the northernmost part of the Dead Sea Rift Valley close to the Yarmuk river are dilute, Ca–SO₄–(HCO₃) and Na–Cl water types with measured temperatures of 35–60 °C and estimated teperatures, according to silica solubility, of 60–110 °C. They are fed only by present‐day recharged meteoric waters (Wadi Hasa, Al Himma and North Shuna thermal baths) and by meteoric waters contaminated with saline waters (El Ma'in thermal Bath). Although they have been known for a long time, there is still dispute about their origins and the source of heat. On the basis of new chemical and isotopic analyses, the saline waters could represent residual pockets of groundwater in equilibrium with those filling the Dead Sea depression before the last retreat of Lake Lisan at 17–15 kyr bp or with the ancient seawaters of the Sedom Lagoon in the early Pleistocene, in both cases unaffected by significant evaporation processes but chemically and isotopically modified by water/rock interaction.     

Mobile Wireless GRASS GIS for Handheld Computers Running GNU/Linux

Recent developments of the communication technologies in the last years opened a new dimension to Geographical Information Systems and Geoinformation Techno‐logies. This new dimension is mobility. It is simplifying data gathering, processing and presentation independent from the area of application. A new branch, Mobile Geoinformation Technologies, is based on wireless communication systems, mobile personal computers, positioning systems and GIS. There are some proprietary GIS software solutions for mobile or handheld devices available on the market, but they are more focused on data logging tasks than providing full powered GIS support or data processing functions. In this paper, we propose a mobile implementation of the free and easily expandable GRASS GIS software in combination with the GNU/Linux operating system run on handheld devices. This approach supports real time in the field computations, data processing and cooperation of several active mobile clients using wireless networking.     

The determination of deep temperatures by means of the CO-CO2-H2-H2O geothermometer: an example using fumaroles in the Campi Flegrei, Italy. A comment

Three points raised in the paper by Tedesco and Sabroux (1987) are dealt with. (1) The inconsistency between the water partial pressure calculated by Tedesco and Sabroux (1987) and saturation pressure is due to the improper use of the water-gas-shift reaction as a geothermometer. In fact Tedesco and Sabroux (1987) do not take into account the distribution of gas species between the coexisting vapour and liquid phases. (2) The depth of the steam reservoir is evaluated by Tedesco and Sabroux (1987) in too simplistic a way. This matter should be treated with greater care owing to the high social impact of any consideration on the Phlegraean Fields system. (3) The reliability of carbon monoxide determination at the concentration level encountered at Solfatara depends on the collection method rather than on the gas-chromatographic technique.     

Light curve fittings of active galactic nuclei using supernova explosions

In the starburst-warmers scenario, we have used a supernova (SN) explosion model to construct theoretical light curves for active galactic nuclei (AGN). The ionizing flux, in this model, should show variability according to the SN rate in the galaxy.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Finite element investigation on the static response of a composite catamaran under slamming loads

This paper presents the structural response of a fast and relatively small, composite materials catamaran to slamming loads. Finite element method is used to provide valuable information in order to optimise the design of the catamaran. The analysis is carried out using ANSYS 6.0 finite element software.The response of the structure to quasi-static slamming loads according to Det Norske Veritas High Speed and Light Craft crest landing and hollow landing rules [DNV, 1999] has been implemented and studied. An optimisation study for the structural response is carried out by changing the ply orientation in the vessel and suitable recommendations are made.     

Continental margin off Sergipe and Alagoas, northeastern Brazil: A reconnaissance geophysical study of morphology and structure

The stable continental margin of northeastern Brazil is unusually narrow, probably because of the small size and tropical character of the drainage basins of the hinterland, and correspondingly low rates of land erosion and marine sedimentation. The continental shelf, which is mainly a marine erosion surface, is also remarkably shallow, either because of upwarping or, more probably, because of the ineffectiveness of Pleistocene marine erosional processes on steeply sloping continental margins. Sediment accumulation is confined to the Sāo Francisco delta, seaward of which are fossil (?) lagoonal deposits, and to a poorly developed nearshore sand prism.The margin formed by seaward progradation of sediment on a subsiding basement, but the present morphology of the continental slope reflects chiefly Pleistocene canyon cutting and mass gravitational movements of sediment, which have exposed older strata in the upper slope. Beneath the continental slope is a magnetic anomaly (like the slope anomaly off the eastern U.S.A.), probably caused by a deeply buried dike of oceanic basalt, and apparently associated with a buried ridge which may have formed the seaward margin of the Sergipe—Alagoas Basin during the early history of the South Atlantic. Similar structures may be typical of the narrow easternmost part of the Brazilian margin.     

Benthic Community and Sediment Types: A Structural Analysis

Abstract. The distribution of the macrobenthic community, in relation to various physical and chemical characteristics of the sediment, was studied along the coast of Southern Tuscany (Central Tyrrhenian) in an area under the influence of the Ombrone River outflow.
The zonation of the benthos was found to be primarily under the control of a gradient of water movement, as is reflected by variations in the sediment structure from the coast to the open sea. This correlation is somehow influenced by secondary gradients such as the degree of mixing of the sediment and the deposition of terrigenous materials along the river plume.