61 research outputs found
Manejo del agua en períodos de sequía
La sequía es un fenómeno pasivo y no se considera una catástrofe natural propiamente dicha, pero su impacto puede ser muy severo. La disminución resultante en las reservas de agua causa conflictos de intereses entre los usuarios. Los agricultores piensan en su medio de vida y en la futura viabilidad de sus negocios. Los alcaldes de las ciudades, por otro lado, están preocupados porque puede que no haya agua suficiente disponible para la población. La gente en las zonas urbanas odian ver que los grifos de sus casas se queden sin agua. Los ambientalistas se preocupan por las condiciones de los cauces naturales y de los lagos
Radiocarbon dating in near-Eastern contexts:Confusion and quality control
Near-Eastern archaeology has long remained oblivious to radiocarbon dating as unique historical calendars brought about a perception that C-14 dating is superfluous. Circular chronological reasoning may occur as a result. There is now strong C-14 evidence that the early part of Egyptian history seems older than age assessments currently in vogue among scholars. It is vital to apply systematic and high-quality C-14 dating to each and every excavation in the Near East to measure time with the same yardstick. Such a strategy will enable chronological comparison of different areas at an excavation site and also between sites and regions, independent of cultural deliberations. This is essential for proper interpretation of archaeological layers and association with data from other fields. Radiocarbon (C-14) is the most common radiometric dating tool applied in archaeology, geosciences, and environmental research. Stringent quality control is required to build up a reliable C-14 chronology for the historical periods in Near-Eastern contexts. Important aspects of quality control involve regular laboratory intercomparisons, transparent duplicate and triplicate analysis of selected samples, conventional versus accelerator mass spectrometry (AMS) (i.e. sample size), sample selection and association. Finally, bones may provide short-lived dates in important stratigraphic archaeological contexts
Early Bronze Jericho:High-precision C-14 dates of short-lived palaeobotanic remains
Reliable series of high-precision radiocarbon dates in a stratified archaeological context are of great importance for interdisciplinary chronological and historical studies. The Early Bronze Age in the Near East is characterized by the beginning of the great civilizations in Egypt and Mesopotamia, as well as by urbanization in the Levant. We present stratified high-precision dates of short-lived material of Tell es-Sultan (Jericho), covering Late Proto-Urban/EB I, EB II and EB III layers from Trench III. Our calibrated dates, refined by Bayesian sequence analysis involving Gibbs sampling, are ca. 150-300 yr older than conventional archaeological age assessments. The corpus of C-14 dates measured in the first decades after the discovery of 14C dating should not be taken too seriously. The C-14 dates of Jericho measured by the British Museum 14C laboratory in 1971 appear to be erroneous
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