Detection of Major River Bed Changes in the River Ebro (north-eastern Spain)

Detection of major river bed changes in River Ebro (northeastern Spain

Paleogeografía sísmica de zonas costeras en la Península Ibérica: su impacto en el análisis de terremotos antiguos e históricos en España

This paper presents three examples of ancient earthquakes occurring in coastal areas of the S and SE of the Iberian Peninsula (218 BC, AD 40-60 and AD 1048) with the aim of illustrating the use of geological and archaeological data in their macroseismic characterization. Historical information for ancient earthquakes that occurred in Spain prior to the 10th century is scarce or non-existent. This paper shows that the current state of knowledge on palaeoseismology and archaeoseismology on these ancient events clearly exceeds the existing historical information allowing the increase of macroseismic information points by using the ESI-07 scale (Environmental Seismic Intensity). Consequently, the geologic analyses of ancient earthquakes contribute to their understanding and parametric evaluations, and improve further advances in seismic hazard assessments. The most significant issue outlined in the present paper is the analysis of the ancient palaeogeography of the affected areas. The studied examples analysed were located in open estuarine areas that have been filled by fluvial sediments or anthropogenic fills over time. The effects of the 218 BC earthquake-tsunami event in the Gulf of Cadiz are analysed in estuarine areas, and especially in the ancient Roman Lagus Ligustinus (Guadalquivir Depression marshes); the effects of the earthquake in AD 40-60 is analysed in the old Roman city of Baelo Claudia located in the Bolonia Bay (Strait of Gibraltar); and the effects of the earthquake of AD 1048on the ancient Sinus Ilicitanus (Bajo Segura Depression) during Muslim times. Descriptions from Roman and Arabic geographers are cross-checked with existing palaeogeographic models based on geological data. This type of analysis results in ancient macroseismic scenarios for the interpretation of theoretical distributions of intensities and environmental effects supporting the concept of “seismic palaeogeography” proposed in this paperEl presente trabajo recoge tres ejemplos de terremotos antiguos (218 AC, 40-60 AD y 1048 AD) ocurridos en zonas litorales del S y SO de la Península Ibérica con la intención de ilustrar el uso de datos geológicos y ar¬queológicos en la caracterización macrosísmica de los mismos. En la mayor parte de los sísmos ocurridos con anterioridad al siglo X d.C. la información documental histórica que se posee es muy escasa o inexistente. El presente trabajo muestra que el actual estado de conocimiento en paleosismología y arqueosismologia sobre este tipo de terremotos sobrepasa con creces la información documental histórica, permitiendo la multiplica¬ción de los puntos de información macrosísmica mediante el uso de la escala ESI-07 (Environmental Seismic Intensity). Consecuentemente, el análisis geológico de los terremotos antiguos mejora su conocimiento y análisis paramétrico, permitiendo avanzar la evaluación de la peligrosidad sísmica de las zonas afectadas. El aspecto que se pone de especial relieve en este trabajo es el análisis de la paleogeografía existente en la antigüedad, ya que todas las zonas (afectadas) analizadas en este trabajo corresponden a zonas estuarinas abiertas que se han ido rellenado por aportes fluviales o de forma artificial con el tiempo. Se analizan los efectos del terremoto de 218 AC en las zonas estuarinas del Golfo de Cádiz y muy especialmente en el antiguo Lacus Ligustinus (marismas del Guadalquivir) durante época romana; los efectos del terremoto de 40-60 AD en la antigua Bahía de Baelo Claudia (Estrecho de Gibraltar); y los efectos del terremoto de 1048 AD en el antiguo Sinus ilicitanus (Depresión del Bajo Segura) durante época musulmana. Se han cotejado descripciones de geógrafos romanos y árabes con modelos basados en datos geológicos. Este tipo de análisis ha permitido generar antiguos escenarios macrosísmicos basados en la paleogeografía y reinterpretar las distribuciones teóricas de intensidades y los efectos ambientales de los terremotos estudiados que es a lo que se refiere el concepto de “paleogeografía sísmica” propuesto en este trabajoThis work has been funded by the Spanish-FEDER research projects CGL2012-37281 C02.01 (QTECTBETICA-USAL), CGL2012-33430 (CSIC) and CGL2013-42847-R (UNED

The role of cover crops in irrigated systems: Soil salinity and salt leaching

Soil salinity and salt leaching are a risk for sustainable agricultural production in many irrigated areas. This study was conducted over 3.5 years to determine how replacing the usual winter fallow with a cover crop (CC) affects soil salt accumulation and salt leaching in irrigated systems. Treatments studied during the period between summer crops were: barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Soil water content was monitored daily to a depth of 1.3 m and used with the numerical model WAVE to calculate drainage. Electrical conductivity (EC) was measured in soil solutions periodically, and in the soil saturated paste extracts before sowing CC and maize. Salt leaching was calculated multiplying drainage by total dissolved salts in the soil solution, and use to obtain a salt balance. Total salt leaching over the four winter fallow periods was 26 Mg ha−1, whereas less than 18 Mg ha−1 in the presence of a CC. Periods of salt gain occurred more often in the CC than in the fallow. By the end of the experiment, net salt losses occurred in all treatments, owing to occasional periods of heavy rainfall. The CC were more prone than the fallow to reduce soil salt accumulation during the early growth stages of the subsequent cash crop

Estructuras de licuefacción sísmica en el yacimiento romano de La Magdalena, Complutum s. IV AD (Madrid, España)

la antigua ciudad romana de Complutum (Alcalá de Henares, Madrid) fue fundada en el s. I AD y fue una de las ciudades más importantes de Hispania. Complutum fue destruida, abandonada bruscamente, reubicada y reconstruida en una nueva localización en el s. IV AD. Las causas de la destrucción y la nueva localización de la ciudad son aún una incógnita para la arqueología. En este trabajo se muestran diferentes efectos arqueosismológicos de terremotos (EAEs) afectando al yacimiento de La Magdalena (una explotación agrícola situada a 4 km al NE del núcleo urbano de Complutum). El efecto geológico de origen sísmico que afectó al yacimiento es la licuefacción. Se pueden observar diques de arena y cráteres de gravas por explosión afectando a instalaciones romanas, como cisternas, casas o tumbas. Simultáneamente al abandono de La Magdalena también fueron abandonadas de forma brusca la ciudad de Complutum y varias villas romanas a lo largo del valle del Henares, en algunos casos con EAEs que pueden asociarse al mismo evento que destruyó el yacimiento de La Magdalena. Estos EAEs podrían estar generados por un terremoto de Mw = 5.0-6,6, utilizando los límites empíricos de licuefacción y ruptura cosísmica de la fallaInstituto Geológico y Minero de España, EspañaDepartamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaTrébede, Patrimonio Cultural, S.L., EspañaUniversidad de Salamanca, EspañaFacultad de Ciencias, Universidad Autónoma de Madrid, EspañaDepartamento de Ingeniería del Terreno, Escuela Politécnica Superior de Ávila, Universidad de Salamanca, EspañaDepartamento de Edafología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, EspañaFacultad de Ciencias, Universidad Nacional de Educación a Distancia, EspañaDepartamento de Geología, Universidad de Alcalá de Henares, Españ

Seismically induced liquefaction structures in La Magdalena archaeological site, the 4th century AD Roman Complutum (Madrid, Spain)

The ancient Roman city of Complutum(Alcalá deHenares,Madrid), founded in the 1st century AD,was one of the most important cities ofHispania. The old Roman citywas destroyed, abruptly abandoned, relocated close by and rebuilt during the late 4th century AD. Destruction of the city and its relocation has not yet been explained by archaeologists. In this paper,with ourmultidisciplinary approach, we identify and characterize earthquake archaeological effects (EAEs) affecting the archaeological site, the La Magdalena, an agricultural holding 4 km from the core of Complutum. The most important EAEs in the site are liquefactions (sand dikes and explosive sand-gravel craters) affecting Roman structures, such as water tanks (cisterns), houses and graves. Ground liquefaction generated significant ground cracks, explosive craters and folds in foundations of buildings. Several other Roman sites throughout the valleywere also abandoned abruptly during the 4th century AD, in some caseswith EAEs of similar origin. This suggests the occurrence of a 5.0–6.6 Mw seismic event in the zone, in accordance with the minimum empirical limit of seismically-induced liquefaction and the maximum surface rupture length of the Henares fault.Instituto Geológico y Minero de España, EspañaDepartamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaFacultad de Ciencias, Universidad Autónoma de Madrid, EspañaTrébede, Patrimonio Cultural, S.L., EspañaDepartamento de Ingeniería del Terreno, Escuela Politécnica Superior de Ávila, Universidad Salamanca, EspañaDepartamento de Edafología, Universidad Politécnica de Madrid, EspañaFacultad de Ciencias, Universidad Nacional de Educación a Distancia, EspañaDepartamento de Geología, Universidad de Alcalá de Henares, Españ

Effect of Hemolysis on the Cardiac Troponin I and Creatinine Assay on the Siemens Dimension Vista Analyzer

Background: Cardiac troponin (cTn) and creatinine concentrations are critical to support the emergency department in the diagnosis of acute myocardial infarction and management of stroke. Pre-analytical conditions that affect the accuracy of results jeopardize patient care. Investigators have reported that as high as 8.8% of the specimens collected in the emergency department are hemolyzed and that hemolysis can cause a negative interference in cTn concentration, but no current studies on the impact of hemolysis on cTn I or creatinine concentration on the Siemens Dimension Vista® using lysed erythrocytes (hemolysate) have been published. Here, we evaluate the effect of hemolysis on the Siemens Dimension Vista cTnI and creatinine assays. Hemolysis effect on the Beckman Synchron DxC® creatinine assay was also studied. Methods: Discarded serum specimens were used to create low, borderline and high pools for cTnI and creatinine. Target average concentration for the low, medium and high pools were \u3c 0.04 ng/mL, 0.04-0.20 ng/mL, and \u3e0.2 ng/mL for cTnI, and 0.3-0.8 mg/dL, 1.2-1.5 mg/dL, and 4.5-5.5 mg/dL for creatinine. The cTnI medium pool and the creatinine low pool were intentionally created to overlap the clinical decision limits for ruling out myocardial infarction or examine renal function in stroke patients. A hemolysate was obtained by treating an ethylenediaminetetraacetic acid plasma specimen to one freeze-thaw cycle. Increasing volumes of the hemolysate (1, 5, 10, 20, and 50 uL) were added to each of five aliquots of each pool. The final Hb concentration was estimated based on the hemolysis index (range 5 - 600 mg/dL; Hb index 4 = 100-200 mg/dL). cTnI and creatinine concentrations were measured in triplicate. Siemens Dimension Vista cTnI assay is a homogeneous luminescent oxygen channeling immunoassay. The analytical measurable range (AMR) is 0.015-40 ng/ml. The Siemens Dimension Vista and the Beckman Synchron DxC creatinine assays use the modified kinetic Jaffe reaction to measure a red chromophore at 510-520 nm. ThAMR for the Siemens Dimension Vista and the Beckman Synchron DxC are 0.2-20 mg/dL and 0.1-25 mg/dL respectively. The average concentration for each aliquot was subtracted from the baseline (no added hemolysate). Recovery was calculated as a percentage of the baseline concentration. Recovery of 100±5% and 100±10% was considered acceptable for cTnI and creatinine respectively. Results: Moderate hemolysis produces a negative interference in the cTnI and creatinine assays in a concentration-dependent manner. For the Siemens Dimension Vista, % recovery for cTnI for the medium pool was 100 mg/dL, and150 mg/dL. Recovery for creatinine for the low and medium pools was \u3c 90% at Hb concentrations \u3e 200 mg/dL. The Beckman creatinine % recovery was acceptable for all the pools in the presence of up to 600 mg/dL of Hb. Conclusions: We have demonstrated that hemolysis may compromise the diagnosis of acute myocardial infarction and the management of stroke. Moderate hemolysis decreased cTnI and creatinine concentrations at the medical decision limits. Clinicians should be cautioned on the interpretation of cTnI and creatinine concentrations in specimens presenting moderate hemolysis