4 research outputs found

    Improving landslide inventories by combining satellite interferometry and landscape analysis: the case of Sierra Nevada (Southern Spain)

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    An updated and complete landslide inventory is the starting point for an appropriate hazard assessment. This paper presents an improvement for landslide mapping by integrating data from two well-consolidated techniques: Differential Synthetic Aperture Radar (DInSAR) and Landscape Analysis through the normalised channel steepness index (ksn). The southwestern sector of the Sierra Nevada mountain range (Southern Spain) was selected as the case study. We first propose the double normalised steepness (ksnn) index, derived from the ksn index, to remove the active tectonics signal. The obtained ksnn anomalies (or knickzones) along rivers and the unstable ground areas from the DInSAR analysis rapidly highlighted the slopes of interest. Thus, we provided a new inventory of 28 landslides that implies an increase in the area affected by landslides compared with the previous mapping: 33.5% in the present study vs. 14.5% in the Spanish Land Movements Database. The two main typologies of identified landslides are Deep-Seated Gravitational Slope Deformations (DGSDs) and rockslides, with the prevalence of large DGSDs in Sierra Nevada being first revealed in this work. We also demonstrate that the combination of DInSAR and Landscape Analysis could overcome the limitations of each method for landslide detection. They also supported us in dealing with difficulties in recognising this type of landslides due to their poorly defined boundaries, a homogeneous lithology and the imprint of glacial and periglacial processes. Finally, a preliminary hazard perspective of these landslides was outlined.Universidad de Granada/CBUAMarie Curie Actions B-RNM-305-UGR18 A-RNM-508-UGR20 P18-RT-3632ERDF through the project RISKCOAST' of the Interreg SUDOE Programme SOE3/P4/E0868Project MORPHOMED' from the Spanish Ministry of Science (MCIN)/State Research Agency (SRA) PID2019-107138RB-I00Ramon y Cajal' Programme of the Spanish Ministry of Science RYC-2017-23335NoR 6373

    Análisis de fábrica microtectónica Falla de Alhama de Murcia y sus implicaciones en los escenarios de riesgo sísmico de Lorca

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    En este trabajo se propone una metodología que permita cuantificar y estudiar la distribución de clastos en las rocas de falla de la falla de Alhama de Murcia (FAM) a partir de láminas delgadas y microtomografía computarizada (Micro-CT), obteniendo modelos 3D, dimensión fractal (D) y orientación preferente de fábrica que permitan caracterizar las propiedades mecánicas y cinemáticas de los distintos dominios en la zona de falla. De forma complementaria se han propuesto como hipótesis escenarios sísmicos en Lorca (Murcia) con el fin de entender cómo el estudio de las rocas de falla puede afectar a la implementación de escenarios

    Geomorphological assessment as basic complement of InSAR analysis for landslide processes understanding

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    Landslide research has benefited greatly from advances in remote sensing techniques. However, the recent increase in available data on land surface movement provided by InSAR techniques can lead to identifying only those areas that were active during data acquisition as hazardous, overlooking other potentially unsafe areas or neglecting landslide-specific geological settings in hazard assessments. Here, we present a case study that serves as a reminder for landslide researchers to carefully consider the geology and geomorphology of study areas where complex active movements are detected using InSAR technology. In an area extensively studied using InSAR and UAV-related techniques, we provide new insights by applying classical approaches. The area is the coastal stretch of La Herradura, and its importance lies in the fact that it has served as an illustrative example in the Product User Manual of the European Ground Motion Service, a platform that provides ground motion data on a European scale. Our approach is to revisit the area and carry out qualitative geological and geomorphological assessments supported by UAV surveys and GIS spatial analysis on a broader scale than previously published investigations. Our classical approach has yielded the following new observations, crucial for risk assessment and land management: active landslides identified by InSAR techniques since 2015 are bodies nested within large mass movements that affect entire slopes. A variety of processes contribute to slope dynamics, such as large slumps, marble rock spreading and block sliding, and surface rock falls and topples. The revised delineation of the landslide bodies reveals an area almost five times larger than previously mapped. These new findings in a well-known area highlight (1) the importance of updating and downscaling previous maps and (2) the ongoing importance of classical fieldwork and desk studies as basic complements to modern InSAR analyses.Funding for open access publishing: Universidad de Granada/CBUA.“Ramón y Cajal” Programme (RYC-2017-23335) of the Spanish Ministry of Science“MORPHOMED” (PID2019-107138RBI00) funded by MCIN/SRA (State Research Agency/https://doi.org/10.13039/501100011033)FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades/Projects (A-RNM-508-UGR20 and P18-RT-3632)Plan Andaluz de Investigación, Desarrollo e Innovación 2020 (Junta de Andalucía)Programme Garantía Juvenil of the Spanish Governmen

    Continuing outcomes relevant to Evista: Breast cancer incidence in postmenopausal osteoporotic women in a randomized trial of raloxifene

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    Background: The randomized, double-blind Multiple Outcomes of Raloxifene Evaluation (MORE) trial found that 4 years of raloxifene therapy decreased the incidence of invasive breast cancer among postmenopausal women with osteoporosis by 72% compared with placebo. We conducted the Continuing Outcomes Relevant to Evista (CORE) trial to examine the effect of 4 additional years of raloxifene therapy on the incidence of invasive breast cancer in women in MORE who agreed to continue in CORE. Methods: Women who had been randomly assigned to receive raloxifene (either 60 or 120 mg/day) in MORE were assigned to receive raloxifene (60 mg/day) in CORE (n = 3510), and women who had been assigned to receive placebo in MORE continued on placebo in CORE (n = 1703). Breast cancer incidence was analyzed by a log-rank test, and a Cox proportional hazards model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. Results: During the CORE trial, the 4-year incidences of invasive breast cancer and estrogen receptor (ER)-positive invasive breast cancer were reduced by 59% (HR = 0.41; 95% CI = 0.24 to 0.71) and 66% (HR = 0.34; 95% CI = 0.18 to 0.66), respectively, in the raloxifene group compared with the placebo group. There was no difference between the two groups in incidence of ER-negative invasive breast cancer during CORE (P = .86). Over the 8 years of both trials, the incidences of invasive breast cancer and ER-positive invasive breast cancer were reduced by 66% (HR = 0.34; 95 % CI = 0.22 to 0.50) and 76% (HR = 0.24; 95% CI = 0.15 to 0.40), respectively, in the raloxifene group compared with the placebo group. During the CORE trial, the relative risk of thromboembolism in the raloxifene group compared with that in the placebo group was 2.17 (95% CI = 0.83 to 5.70). This increased risk, also observed in the MORE trial, persisted over the 8 years of both trials. Conclusions: The reduction in invasive breast cancer incidence continues beyond 4 years of raloxifene treatment in postmenopausal women with osteoporosis. No new safety concerns related to raloxifene therapy were identified during CORE. © Oxford University Press 2004, all rights reserved
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