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11.
C. Linares I. J. Mirón R. Carmona R. Sánchez J. Díaz 《Stochastic Environmental Research and Risk Assessment (SERRA)》2016,30(6):1565-1574
In general, there are few studies that analyse the impact of low temperatures on mortality, and even fewer that extend this analysis to specific causes of mortality. This study had a twofold aim: Firstly, to analyse the trend in natural-, circulatory- and respiratory-cause mortality associated with cold waves in Castile-La Mancha (Spain) across a period of analysis of 34 years, which would confer an important degree of temporal representativeness on the results obtained; and secondly, to ascertain whether this impact had decreased over the years. Time series analysis using multivariate ARIMA models with data on daily natural-, circulatory- and respiratory-cause mortality in Castile-La Mancha. The independent variables were minimum daily temperature, mean daily pressure and mean daily relative humidity. We controlled for seasonalities and trend of the series, as well as influenza epidemics, cold-wave duration and chronological number in any given year. Data were stratified in three ten-year stages, i.e., 1975–1985, 1986–1996 and 1997–2008. The mortality trigger temperature was set at a minimum daily temperature of ?2 °C, corresponding to the 4th ‰ of the minimum temperature series for the winter months considered. The impact on daily natural-cause mortality for each degree that the minimum daily temperature was below ?2 °C was: 10.4 % (95 % CI 9.6–11.2) in the first decade; 11.9 % (95 % CI 11.0–12.8) in the second decade; and fell to 1.6 % (95 % CI 0.9–2.3) in the third. This same pattern was observed for circulatory- and respiratory-cause mortality, with the effect of cold being greater for respiratory causes. Socio-economic factors -both of adaptation and demographic- could account for this sharp decrease in mortality associated with low temperatures. These results question climate models which predict the effects of cold over long-term time horizons, while maintaining the risk attributable to low temperatures constant. Studies similar to ours should be undertaken in other regions to confirm whether it is solely local characteristics that explain this pattern or, on the contrary, whether the pattern is generalised. 相似文献
12.
The geoarchaeological record of the Phoenician necropolis of Al Bass (Lebanon) provides information concerning the geomorphological evolution of a late Holocene tombolo. Physical and chemical analysis of sediments indicates that the cemetery (9th century B.C.) was located near a littoral lagoon, between the dunes of a cuspate spit pointing toward the island of Tyre. From the sea apex of this spit, the moles mentioned in historical chronicles were constructed. Once mainland and island were connected, at the northern coast (where the port of Sidon was located), a sediment trap was formed, which quickly filled with silt. Afterwards, an extensive field of sand dunes buried all the archaeological remains from Phoenician to Roman times. © 2008 Wiley Periodicals, Inc. 相似文献
13.
José R. Martínez Catalán Ricardo Arenas Jacobo Abati Sonia Sánchez Martínez Florentino Díaz García Javier Fernández Suárez Pablo González Cuadra Pedro Castiñeiras Juan Gómez Barreiro Alejandro Díez Montes Emilio González Clavijo Francisco J. Rubio Pascual Pilar Andonaegui Teresa E. Jeffries James E. Alcock Rubén Díez Fernández Alicia López Carmona 《Comptes Rendus Geoscience》2009,341(2-3):114-126
Ophiolites of different Paleozoic ages occur in North-West (NW) Iberia in a rootless suture representing the remnants of the Rheic Ocean. Associated allochthonous terranes in the hanging- and foot-walls of the suture derive from the former margins, whereas the relative autochthon corresponds to the Paleozoic passive margin of northern Gondwana. The Paleozoic tectonic evolution of this part of the circum-Atlantic region is deduced from the stratigraphical, petrological, structural and metamorphic evolution of the different units and their ages. The tectonic reconstruction covers from Cambro-Ordovician continental rifting and the opening of the Rheic Ocean to its Middle to Upper Devonian closure. Then, the Variscan Laurussia–Gondwana convergence and collision is briefly described, from its onset to the late stages of collapse associated with the demise of the orogenic roots. 相似文献
14.
Modelling Syntectonic Sedimentation: Combining a Discrete Element Model of Tectonic Deformation and a Process-based Sedimentary Model in 3D 总被引：1，自引：0，他引：1
This paper presents a new numerical program able to model syntectonic sedimentation. The new model combines a discrete element
model of the tectonic deformation of a sedimentary cover and a process-based model of sedimentation in a single framework.
The integration of these two methods allows us to include the simulation of both sedimentation and deformation processes in
a single and more effective model. The paper describes briefly the antecedents of the program, Simsafadim-Clastic and a discrete
element model, in order to introduce the methodology used to merge both programs to create the new code. To illustrate the
operation and application of the program, analysis of the evolution of syntectonic geometries in an extensional environment
and also associated with thrust fault propagation is undertaken. Using the new code, much more complex and realistic depositional
structures can be simulated together with a more complex analysis of the evolution of the deformation within the sedimentary
cover, which is seen to be affected by the presence of the new syntectonic sediments. 相似文献
15.
Estimation of daytime downward longwave radiation under clear and cloudy skies conditions over a sub-humid region 总被引：1，自引：0，他引：1
Facundo Carmona Raúl Rivas Vicente Caselles 《Theoretical and Applied Climatology》2014,115(1-2):281-295
Downward longwave radiation (LW ↓ ) is a relevant variable for meteorological and climatic studies. Good estimates of this term are vitally important in correct determining of the net radiation, which, in turn, modulates the magnitude of the terms in the surface energy budget (e.g., evaporation). In remote sensing applications, the determination of daytime LW↓ is required for estimation of the net radiation using satellite data. LW↓ is not directly measured in weather stations and then is estimated using models with surface air temperature and humidity as input. In this paper, we identify the best models to estimate daytime downward longwave radiation from meteorological data in the sub-humid Pampean region. Several well-known models to estimate LW↓ under clear and cloudy skies were tested. We use downward radiation components and meteorological data registered at Tandil (Argentina) from 2006 to 2010 (840 days). In addition, we propose two multiple linear regression models (MLRM-1 and MLRM-2) to estimate LW↓ at the surface for all sky conditions. The new equations show better performance than the others models tested with root mean square errors between 12 and 16 W m?2, bias close to zero and best agreements with measured data (r 2?≥?0.85). 相似文献
16.
The ancient city of Lixus, today situated on a hill on the right bank of the River Loukkos, 4km from the coast, was founded on the shore of a brackish lagoon that was sheltered from Atlantic storms. This geographical context provided the city with one of the best Phoenician harbors and abundant fishing resources, and allowed access to the Gharb cattle farming resources and cereal production systems. In this study, the historical evolution of the Loukkos estuarine environment is reconstructed through geomorphological and sedimentological analyses, combined with cartographic, archaeological, and geographical data. The outcomes reveal the progressive infilling of the estuarine lagoon of Lixus and its transformation into the current estuary and floodplain. The recent history of this estuary records four successive stages: (1) an initial stage associated with the maximum Holocene marine transgression (5500 to 5320 cal. yr B.P.) that reached the interior of the estuary; (2) a sheltered brackish tidal lagoon stage in Phoenician and Roman times; (3) a period of progressive infilling of the estuarine lagoon, from late Roman times to the Middle Ages (11th to15th centuries); (4) a period of rapid expansion of intertidal marshes (17th to 19th centuries) that saw the formation of the modern estuarine plain and meandering channel system (20th century). © 2009 Wiley Periodicals, Inc. 相似文献
17.
Andrés Carmona 《Earth, Moon, and Planets》2010,106(2-4):71-95
Protoplanetary disks are composed primarily of gas (99% of the mass). Nevertheless, relatively few observational constraints exist for the gas in disks. In this review, I discuss several observational diagnostics in the UV, optical, near-IR, mid-IR, and (sub)-mm wavelengths that have been employed to study the gas in the disks of young stellar objects. I concentrate in diagnostics that probe the inner 20 AU of the disk, the region where planets are expected to form. I discuss the potential and limitations of each gas tracer and present prospects for future research. 相似文献
18.
We test for the existence of long-term trends in 25- to 50-year long series of monthly rainfall, average river discharges, and minimum air temperatures in Colombia. The Empirical Mode Decomposition method is used as a mathematical filter to decompose a given time series into a finite number of intrinsic mode functions, assuming the coexistence of different frequency oscillatory modes in the series, and that the residual captures the likely existing long-term trends. The Mann-Kendall test for autocorrelated data is used to assess the statistical significance of the identified trends, and the Sen test is used to quantify their magnitudes. Results show that 62 % of river discharge series exhibit significant decreasing trends between 0.01-1.92 m 3 s ?1 per year, which are highly consistent downstream albeit with different ratios between the trend magnitudes and mean discharges. Most minimum temperature series (87 %) exhibit increasing trends (0.01-0.08 °Cyr ?1). Results for precipitation series are inconclusive owing to the mixing between increasing trends (41 %, between 0.1-7.0 mm yr ?1) and decreasing trends (44 %, between 0.1-7.4 mm yr ?1), with no clear-cut geographical pattern, except for the increasing trend identified along the Pacific region, consistent with the increasing trend identified in the strength of the Chocó low-level wind jet off the Pacific coast of Colombia, an important moisture source of continental precipitation. Our results contribute to discerning between signals of climate change and climate variability in tropical South America. 相似文献
19.
Javier Almendros Jesús M. Ibez Enrique Carmona Daria Zandomeneghi 《Journal of Volcanology and Geothermal Research》2007,160(3-4):285-299
We analyze data from three seismic antennas deployed in Las Cañadas caldera (Tenerife) during May–July 2004. The period selected for the analysis (May 12–31, 2004) constitutes one of the most active seismic episodes reported in the area, except for the precursory seismicity accompanying historical eruptions. Most seismic signals recorded by the antennas were volcano-tectonic (VT) earthquakes. They usually exhibited low magnitudes, although some of them were large enough to be felt at nearby villages. A few long-period (LP) events, generally associated with the presence of volcanic fluids in the medium, were also detected. Furthermore, we detected the appearance of a continuous tremor that started on May 18 and lasted for several weeks, at least until the end of the recording period. It is the first time that volcanic tremor has been reported at Teide volcano. This tremor was a small-amplitude, narrow-band signal with central frequency in the range 1–6 Hz. It was detected at the three antennas located in Las Cañadas caldera. We applied the zero-lag cross-correlation (ZLCC) method to estimate the propagation parameters (back-azimuth and apparent slowness) of the recorded signals. For VT earthquakes, we also determined the S–P times and source locations. Our results indicate that at the beginning of the analyzed period most earthquakes clustered in a deep volume below the northwest flank of Teide volcano. The similarity of the propagation parameters obtained for LP events and these early VT earthquakes suggests that LP events might also originate within the source volume of the VT cluster. During the last two weeks of May, VT earthquakes were generally shallower, and spread all over Las Cañadas caldera. Finally, the analysis of the tremor wavefield points to the presence of multiple, low-energy sources acting simultaneously. We propose a model to explain the pattern of seismicity observed at Teide volcano. The process started in early April with a deep magma injection under the northwest flank of Teide volcano, related to a basaltic magma chamber inferred by geological and geophysical studies. The stress changes associated with the injection produced the deep VT cluster. In turn, the occurrence of earthquakes permitted an enhanced supply of fresh magmatic gases toward the surface. This gas flow induced the generation of LP events. The gases permeated the volcanic edifice, producing lubrication of pre-existing fractures and thus favoring the occurrence of VT earthquakes. On May 18, the flow front reached the shallow aquifer located under Las Cañadas caldera. The induced instability constituted the driving mechanism of the observed tremor. 相似文献
20.