Showing papers by "Geode published in 2017"
TL;DR: In this article, the authors present evidence for El Chichon in southern Mexico as the most likely source of a major tropical eruption in 540 CE, based on a refined reconstruction of the volcano's eruption history.
Abstract: A remarkably long period of Northern Hemispheric cooling in the 6th century CE, which disrupted human societies across large parts of the globe, has been attributed to volcanic forcing of climate. A major tropical eruption in 540 CE is thought to have played a key role, but there is no consensus about the source volcano to date. Here, we present evidence for El Chichon in southern Mexico as the most likely candidate, based on a refined reconstruction of the volcano’s eruption history. A new chronological framework, derived from distal tephra deposits and the world’s largest Holocene beach ridge plain along the Gulf of Mexico, enabled us to positively link a major explosive event to a prominent volcanic sulfur spike in bipolar ice core records, dated at 540 CE. We speculate that voluminous tephra fall from the eruption had a severe environmental impact on Maya societies, leading to temporary cultural decline, site abandonment, and migration within the core area of Maya civilization.
31 citations
TL;DR: In this article, the importance of PHTE (Potentially Harmful Trace Element) accumulation during pre-industrial times compared to recent accumulation, and the intimate relationship between landscape use and terrestrial PTPE transfers was investigated.
28 citations
TL;DR: The heuristic, technical and socio-economic limits and consequences of deploying an OTEC plant in Martinique are discussed to highlight respectively the impact of the OTEC power plant on the environment theimpact of the environment on the OT EC plant.
Abstract: Ocean thermal energy conversion (OTEC) is a form of power generation, which exploits the temperature difference between warm surface seawater and cold deep seawater Suitable conditions for OTEC occur in deep warm seas, especially the Caribbean, the Red Sea and parts of the Indo-Pacific Ocean The continuous power provided by this renewable power source makes a useful contribution to a renewable energy mix because of the intermittence of the other major renewable power sources, ie solar or wind power Industrial-scale OTEC power plants have simply not been built However, recent innovations and greater political awareness of power transition to renewable energy sources have strengthened the support for such power plants and, after preliminary studies in the Reunion Island (Indian Ocean), the Martinique Island (West Indies) has been selected for the development of the first full-size OTEC power plant in the world, to be a showcase for testing and demonstration An OTEC plant, even if the energy produced is cheap, calls for high initial capital investment However, this technology is of interest mainly in tropical areas where funding is limited The cost of innovations to create an operational OTEC plant has to be amortized, and this technology remains expensive This paper will discuss the heuristic, technical and socio-economic limits and consequences of deploying an OTEC plant in Martinique to highlight respectively the impact of the OTEC plant on the environment the impact of the environment on the OTEC plant After defining OTEC, we will describe the different constraints relating to the setting up of the first operational-scale plant worldwide This includes the investigations performed (reporting declassified data), the political context and the local acceptance of the project We will then provide an overview of the processes involved in the OTEC plant and discuss the feasibility of future OTEC installations We will also list the extensive marine investigations required prior to installation and the dangers of setting up OTEC plants in inappropriate locations
14 citations
TL;DR: In this article, the authors estimate sediment residence time in the stream network of two small headwater catchments (Laval and Moulin) characterized by a badlands landscape entrenched into Jurassic black marls of the Southern French Prealps.
Abstract: The aim of this study is to estimate the sediment residence time in the stream network of two small headwater catchments (Laval and Moulin) characterized by a badlands landscape entrenched into Jurassic black marls of the Southern French Prealps. The method is based on an intensive field survey of the alluvial storage along the main stream reaches from which a scaling law between the average thickness of alluvial deposits and their width was established in order to predict the volume of alluvial deposits in the entire stream network. To complete this approach, bedload sediment yield monitored over the last 30 years with topographic surveying of sediment retention basins are used. The assessment of sediment residence time is performed according to a steady-state assumption, validated by the long-term dynamic equilibrium of bedload sediment yields. The results highlighted very close values of residence time between the catchments, around 3 years, despite a one order of magnitude difference in drainage area. It is shown that the rate of increase of alluvial storage with drainage area is the same as for sediment yield. This is likely attributed to the high degree of confinement of the stream network, which prevent the formation of a floodplain or large internal alluvial fans. Implications of these results for the prediction of the effects of bioengineering works in controlling erosion are discussed.
9 citations
TL;DR: The authors examines the consequences of widespread and significant pricing errors and concludes that if market prices differ from intrinsic value but are unbiased estimates of it, certain systematic mispricing patterns will arise.
Abstract: This paper examines the consequences of widespread and significant pricing errors. If market prices differ from intrinsic value but are unbiased estimates of it, certain systematic mispricing patterns will arise. To remove these phenomena, market prices need to adjust away from traditional fundamental estimates of firm value. Whether this outcome is achieved however is unclear. The adjustment process requires information that is not readily available. Further, it is likely associated with risks. Several well-known and some less well-known empirical phenomena related to return predictability are compatible with the view that adjustments have historically been incomplete.
12 May 2017
Abstract: Chapter 12 The Western Mediterranean Sea Miquel Canals,1 Isabel Cacho,1 Laurent Carozza,2 José Luis Casamor,1 Galderic Lastras1 and Anna Sànchez1 1 GRC Geociències Marines, Dept. d’Estratigrafia, Paleontologia i Geociències Marines, Universitat de Barcelona, Campus de Pedralbes, Mart́ı i Franquès s/n, 08028 Barcelona, Spain 2 UMR 5602 Géode Géographie de l’Environnement, Maison de la Recherche de l’Université du Mirail 5, Allées A. Machado, 31058 TOULOUSE Cedex 1, France