Abstract. The republic of Georgia is a mountainous and tectonically active area that is vulnerable to landslides. Because landslides are one of the most devastating natural hazards, their detection and monitoring is of great importance. In this study we report on a previously unknown landslide in central Georgia near the town of Sachkhere. We used a set of Advanced Land Observation Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data to generate displacement maps using interferometric synthetic aperture radar (InSAR). We detected a sliding zone of dimensions 2 km north-south by 0.6 km east-west that threatens four villages. We estimated surface displacement of up to ∼ 30 cm/yr over the sliding body in the satellite line-of-sight (LOS) direction, with the largest displacement occurring after a local tectonic earthquake. We mapped the morphology of the landslide mass by aerial photography and field surveying. We found a complex set of interacting processes, including surface fracturing, shear and normal faults at both the headwall and the sides of the landslide, local landslide velocity changes, earthquake-induced velocity peaks, and loss in toe support due to mining activity. Important implications that are applicable elsewhere can be drawn from this study of coupled processes.We used inverse dislocation modelling to find a possible dislocation plane resembling the landslide basal décollement, and we used that plane to calculate the volume of the landslide. The results suggest a décollement at ∼ 120 m depth, dipping at ∼ 10 • sub-parallel to the surface, which is indicative of a translational-type landslide.
ABSTRACT:Slope deformation is one of the typical geohazards that causes an extensive economic damage in mountainous regions. As such, they are usually intensively monitored by means of modern expertise commonly by national geological or emergency services. Resulting landslide susceptibility maps, or landslide inventories, offer an overview of areas affected by previously activated landslides as well as slopes known to be unstable currently. Current slope instabilities easily transform into a landslide after various triggering factors, such as an intensive rainfall or a melting snow cover. In these inventories, the majority of the existing landslide-affected slopes are marked as either stable or active, after a continuous investigative work of the experts in geology. In this paper we demonstrate the applicability of Sentinel-1A satellite SAR interferometry (InSAR) to assist by identifying slope movement activity and use the information to update national landslide inventories. This can be done reliably in cases of semi-arid regions or low vegetated slopes. We perform several analyses based on multitemporal InSAR techniques of Sentinel-1A data over selected areas prone to landslides.
Slope deformation is one of the typical geohazards that causes an extensive economic damage in mountainous regions. As such, they are usually intensively monitored by means of modern expertise commonly by national geological or emergency services. Resulting landslide susceptibility maps, or landslide inventories, offer an overview of areas affected by previously activated landslides as well as slopes known to be unstable currently. Current slope instabilities easily transform into a landslide after various triggering factors, such as an intensive rainfall or a melting snow cover. In these inventories, the majority of the existing landslide-affected slopes are marked as either stable or active, after a continuous investigative work of the experts in geology. In this paper we demonstrate the applicability of Sentinel-1A satellite SAR interferometry (InSAR) to assist by identifying slope movement activity and use the information to update national landslide inventories. This can be done reliably in cases of semi-arid regions or low vegetated slopes. We perform several analyses based on multitemporal InSAR techniques of Sentinel-1A data over selected areas prone to landslides.
SummaryAdditional chromosomal abnormalities (ACA) are rather common in Ph+ acute lymphoblastic leukemia (ALL). However, their prognostic significance in the era of protein tyrosine kinase inhibitors and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still poorly known. A recent study [1] has shown that ACA exert unfavorable effect upon HSCT results in adult patients with Ph+ALL. Patients and methodsWe have performed a retrospective analysis of treatment results for a mixed cohort of the patients with Ph+ ALL, including 19 children (aged 5 -18 y.o.) and 46 adults (aged 19 -57 y.o.) who received allo-HSCT at our Institute over 2008 to 2015. Among sixty-five subjects with Ph+ ALL, the results of standard cytogenetic studies were available for 53 patients. ResultsThirty-three patients of 53 (51%) exhibited an isolated t(9;22) translocation. ACA were revealed in 20/53 patients (31%), including 13/53 (20%) subjects with 3 and more chromosome abnormalities. Chromosomes 1, 5, 7, 8, 9, 22 were most commonly affected with additional anomalies. Structural abnormalities attributable to ACA were imbalanced in 16 patients (80%), whereas only 4 patients (20%) showed balanced translocations. In a univariate analysis, significance was shown for the donor type (matched related and unrelated vs haploidentical, p=0.02), clinical stage at HSCT (1 st remission vs other stages, p=0.01, for EFS only), additional chromosomal abnormalities (ACA-negative vs ACA-positive, p=0.04, for OS only), and, in particular, complex chromosomal aberrations (<3 anomalies vs ≥3 anomalies, p=0.01, for OS only). According to multivariate analysis, the number of additional chromosomal abnormalities per karyotype (HR 2.79, р=0.01, for OS only) and clinical stage at HSCT (HR 2.15, 95% CI 1.13-4.09; р=0.01, for EFS only) are independent prognostic factors for clinical outcomes. ConclusionThe study has shown that complex chromosomal anomalies and the stage of disease at the moment of HSCT are independent prognostic factors in a mixed cohort of Ph+ ALL patients treated with hematopoietic stem cell transplantation. KeywordsAcute lymphoblastic leukemia, Ph 1 -positive, allo-HSCT, additional chromosomal abnormalities.
Abstract. Central Georgia is an area strongly affected by earthquake and landslide hazards. On 29 April 1991 a major earthquake (Mw = 7.0) struck the Racha region in Georgia, followed by aftershocks and significant afterslip. The same region was hit by another major event (Mw = 6.0) on 7 September 2009. The aim of the study reported here was to utilize interferometric synthetic aperture radar (InSAR) data to improve knowledge about the spatial pattern of deformation due to the 2009 earthquake. There were no actual earthquake observations by InSAR in Georgia. We considered all available SAR data images from different space agencies. However, due to the long wavelength and the frequent acquisitions, only the multi-temporal ALOS L-band SAR data allowed us to produce interferograms spanning the 2009 earthquake. We detected a local uplift around 10 cm (along the line-of-sight propagation) in the interferogram near the earthquake's epicenter, whereas evidence of surface ruptures could not be found in the field along the active thrust fault. We simulated a deformation signal which could be created by the 2009 Racha earthquake on the basis of local seismic records and by using an elastic dislocation model. We compared our modeled fault surface of the September 2009 with the April 1991 Racha earthquake fault surfaces and identify the same fault or a sub-parallel fault of the same system as the origin. The patch that was active in 2009 is just adjacent to the 1991 patch, indicating a possible mainly westward propagation direction, with important implications for future earthquake hazards.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.