A note on the polarographic behavior of the Cu(II) ion selective electrode in seawater

The non-Nernstian behavior of a solid-state cupric ion-selective electrode in seawater is attributed to a reduction of Cu²⁺ at the surface in accordance with a suggestion made in the literature. This ‘polarographic’ behaviour was demonstrated by showing that the electrode potential is affected by molecular oxygen in solution.     

Morphological and geological aspects related to large slope failures on oceanic islands: The huge La Orotava landslides on Tenerife, Canary Islands

Huge volcanic landslides are one of the most hazardous geomorphological processes that can occur during the evolution of volcanic ocean islands. The causes of these phenomena, however, are very complex and combine non-volcanic and volcanic factors. In the Canary Islands, more than 20 events have been detected during the last decades. A detailed analysis was carried out for La Orotava amphitheatre on Tenerife in order to understand the relationship between geomorphological and geological aspects and huge volcanic landslides. The results indicated four major features that play a significant role in such mass movements: deep erosive canyons, high coastal cliffs, widespread residual soils and structural axes. High coastal cliffs and deep erosive canyons locally reduce the stability conditions and control both the seaward and the lateral boundary of the landslide. Weak residual soils formed above phonolitic pyroclastic deposits occur repeatedly in the stratigraphic column of La Orotava and are characterised by their large extent. Thus, one of these soils may have evolved into the slip surface of the failure. Part of the head scarp of the amphitheatre is defined by a volcanic rift zone, as indicated by the measurement of dike orientation and a density map of eruptive vents. The four features are not able to trigger a failure, but to destabilise the volcano flank and determine the boundary of the slide. Therefore, information on depth and orientation of canyons; location and height of coastal cliffs; stratigraphic repetition, extension and thickness of residual soils and orientation and density of dikes and eruptive vents along structural axes should be incorporated into a hazard assessment on large landslides on volcanic islands.     

Ingredients and Recipes for Model Galaxy Formation

We present the basic ingredients and recipes used in an analytical model of galaxy formation to follow the evolution of the baryons inside dark matter haloes whose clustering is described elsewhere. This revised version was published online in July 2006 with corrections to the Cover Date.     

Streamflow variability and its relationship with climate indices in western rivers of Argentina

The objective of this study was to examine the streamflow variability of Argentinean Andean basins (22°–52°S). Trends and step changes of seven hydrological variables were analysed. In addition, relationships between the hydrological variables and Pacific Decadal Oscillation (PDO), Niño 3.4, and Southern Annular Mode (SAM) indices were analysed. Most streamflow variables showed upward trends in the northwest and central-western basins, while downward trends were identified in the Patagonia (southwestern) region. Streamflow of the central-western and Patagonian basins was positively correlated with the Niño 3.4 index. Moreover, an inverse relationship with the SAM was found in watersheds south of 37°S. Positive step changes associated with the PDO phases in the north and central-western basins in the mid-1970s were detected, while negative step changes resulted in Patagonia between 1970 and 2000. This research provides new evidence of the influence of major climate modes on streamflow variability in the western rivers of Argentina.     

Recent advances in the chemistry and properties of atmospheric nucleants: a review

Summary A survey is carried out of recent progress in the investigation of weather-active atmospheric nucleants. Emphasis is placed on the work date during the last decade, and some resulting implications are discussed.