Global warming and climate change: science and politics

The threat of dangerous climate change from anthropogenic global warming has decreased. Global temperature rose from 1975 to 1998, but since then has levelled off. Sea level is now rising at about 1.5mm per year based on tide gauges, and satellite data suggests it may even be falling. Coral islands once allegedly threatened by drowning have actually increased in area. Ice caps cannot possibly slide into the sea (the alarmist model) because they occupy kilometres-deep basins extending below sea level. Deep ice cores show a succession of annual layers of snow accumulation back to 760,000 years and in all that time never melted, despite times when the temperature was higher than it is today. Sea ice shows no change in 30 years in the Arctic. Emphasis on the greenhouse effect stresses radiation and usually leads to neglect of important factors like convection. Water is the main greenhouse gas. The CO2 in the ocean and the atmosphere are in equilibrium: if we could remove CO2 from the atmosphere the ocean would give out more to restore the balance. Increasing CO2 might make the ocean less alkaline but never acid. The sun is now seen as the major control of climate, but not through greenhouse gases. There is a very good correlation of sunspots and climate. Solar cycles provide a basis for prediction. Solar Cycle 24 has started and we can expect serious cooling. Many think that political decisions about climate are based on scientific predictions but what politicians get are projections based on computer models. The UN’s main adviser, the IPCC, uses adjusted data for the input, their models and codes remain secret, and they do not accept responsibility for their projections

Paleo-landscapes of the Northern Patagonian Massif, Argentina

The dominant geomorphological unit of the Northern Patagonian Massif landscape is a regional planation surface, eroded across the crystalline basement (plutonic and metamorphic rocks), eruptive rocks of the Gondwana cycle (Early to Middle Carboniferous), and Jurassic volcanic rocks. The most important active climate during the genesis of this surface had a very significant role, developing intense chemical weathering extending to variable depths with the corresponding degradation of the rocky material exposed at the surface. Remnants of the weathering profiles, both outcropping and fossilized by burial, are identified and described. Such a particular mega-landform was developed in a cratonic environment, mainly as a product of deep weathering, and it is interpreted as a denuded surface, an etchplain formed by corrosion followed by erosion. The analysis of the relationships between relief, saprolite, and rock cover throughout time suggests that the most important factor for the classification of the present landscape is the duration of exposure of the crystalline basement at the surface, from the end of the Paleozoic and during the entire Mesozoic. This conclusion has essential relevance for the evaluation of the effects of Mesozoic tectonics and the powerful weathering under certain climatic conditions. It is estimated that this paleosurface would have initiated its development towards the end of the Paleozoic, but later modifying also the Jurassic volcanic rocks that preceded the rifting processes that lead to the opening of the Southern Atlantic Ocean. Finally, the tectonic activity during the early Tertiary produced the exhumation of the planation surface, which was buried by its own regolith, reactivating erosion surfaces and small drainage basins. However, it is possible that some areas of the planation surface had never been covered by other rocks, other than its own overlying weathering products. Our results suggest that the landscape features should not be assigned to Quaternary morphogenesis, but instead, they have evolved over a very long time, perhaps 100 Ma or even more. These observations refer to Mesozoic times, and therefore the time scale used for the discussion of the geomorphology of the Northern Patagonian Massif should be enlarged to properly analyze the evolution of the ancient landscapes of this cratonic region. This chapter contributes to the analysis of comparative studies of global geomorphology of cratonic areas, where planation surfaces record very long periods in which the speed of crustal deformation is highly compensated by planation processes.Centro de Investigaciones Geológica

Pseudokarst and speleothems in the Chihuido Granite, province of Mendoza, Argentina

The core of the Chihuido Anticline is located precisely at Cerro Chihuido, Malargue, southern Mendoza province, Argentina. This anticline represents the outcropping pre-Jurassic platform of the margin of the Neuquen Basin, which is composed of three volcano-sedimentary units separated by angular unconformities. The older unit corresponds to the volcano-sedimentary complex named as El Fortin, which concludes with the intrusion of a thick rhyolite-monzogranite dyke. The dyke, together with plutons corresponding to the Gondwana magmatism, is exposed on a paleosurface whose relief has been partly fossilized by much modern pyroclastic rocks. The thickness of the dyke varies from 0.2 km to almost 1 km. In this landscape, the dyke is the most remarkable topographic and geological characteristic, not only for its huge dimensions but also for its numerous weathering cavities that provide it with a quite peculiar aspect. Typical pseudokarst landforms are represented by tafoni cavities. The nature of pseudokarst is portrayed by selective erosion along joint planes and andesite composition blocks included in the dyke. In the wall of some cavities within the almost vertical dyke, opal speleothems have been formed from silica released by rock weathering. The speleothems were studied by means of optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction. The study of these minor features of the granitic landscape, such as tafoni, and the associated speleothems, the description of their morphology, and the analysis of their composition are the main objectives of this chapter.Facultad de Ciencias Naturales y Muse

The exhumation of the Northern Patagonian Massif Gondwana Planation surface due to uprising during the Oligocene

The altiplano (or high plain) of the Northern Patagonian Massif is a large, 100,000 km2 geomorphological unit that rose from sea level to at least 1,200 metres above sea level (m a.s.l.) in Early Oligocene times, as a consequence of epeirogenic uplift. This uniform tableland feature is essentially a Cretaceous planation surface carved on Paleozoic igneous and metamorphic rocks of the Northern Patagonian Massif. This planation surface had been preserved by a thin and scattered cover of Maastrichtian-Danian marine sediments and Late Oligocene-Early Miocene basaltic flows. Erosion since Middle Miocene times at this tableland has exposed much of the Gondwana planation surface and developed numerous basaltic plateaus by relief inversion.Facultad de Ciencias Naturales y Muse

Tropical Geomorphology and long-term landscape evolution

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Tropical rivers and geomorphology

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Volcanoes

Volcanic eruption is the most spectacular of all landscape-forming processes, and has a fascination for the scientist and the ordinary man alike. This book gives an up-to-date account of the mechanism of volcanic activity, the products of eruption, and especially the many varieties of landform produced by vulcanism. It also describes the processes of weathering and erosion that attack volcanoes and lava flows, and discusses the course of landscape evolution in volcanic areas. The numerous examples of eruptions, disasters, landforms, and scientific investigations are drawn from all over the world, with some emphasis on volcanic features of Australasia. The distribution of volcanoes is explained in conjunction with modern ideas of the evolution of the earth's crust, and the final chapter discusses methods used to predict eruptions as well as what to do when an eruption occurs. Volcanoes is aimed at the level of undergraduate geomorphology students, but will be of interest to geologists, geophysicists, and hydrologists. It is also a suitable introduction to volcanoes for schools and for the general reader. Like other volumes of the Introduction to Systematic Geomorphology series it is well illustrated with diagrams and photographs

A rapid course in english for students of economics

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Gondwana Landscapes in southern South AmericaArgentina, Uruguay and southern Brazil /

XXVI, 545 p. 313 illus., 211 illus. in color.onli

Inselbergs and monoliths: a comparative review of two iconic Australian landforms, Uluru (Ayers Rock) and Burringurrah (Mount Augustus)

The concept of \u27monolith\u27 is considered with reference to two imposing inselbergs in semi-arid Australia, Uluru (Ayers Rock) and Burringurrah (Mount Augustus). Individually each has been described as the \u27largest monolith in Australia\u27. To assess this comparison we outline the geology, morphology and geomorphic history of each. Both consist of sedimentary rock, but they differ in almost all other aspects including dimensions, lithological variations, geological evolution, tectonics, rock structures, operating processes and ages of both the landforms and the underlying rocks. The term \u27monolith\u27 has been used to describe such a wide range of features involving so many criteria that we prefer not to use \u27monolith\u27 as a geomorphic term. In relation to the inselbergs described here, the use of the term \u27monolith\u27 has led to needless and unhelpful comparisons between these two remarkable landforms