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Ice fractures when subject to stress that exceeds the material failure strength. Previous studies have found that a von Mises failure criterion, which places a bound on the second invariant of the deviatoric stress tensor, is consistent with empirical data. Other studies have suggested that a scaling effect exists, such that larger sample specimens have a substantially lower failure strength, implying that estimating material strength from laboratory-scale experiments may be insufficient for glacier-scale modeling. In this paper, we analyze the stress conditions in crevasse onset regions to better understand the failure criterion and strength relevant for large-scale modeling. The local deviatoric stress is inferred using surface velocities and reanalysis temperatures, and crevasse onset regions are extracted from a remotely sensed crevasse density map. We project the stress state onto the failure plane spanned by Haigh–Westergaard coordinates, showing how failure depends on mode of stress. We find that existing crevasse data are consistent with a Schmidt–Ishlinsky failure criterion that places a bound on the absolute value of the maximal principal deviatoric stress, estimated to be 158±44 kPa. Although the traditional von Mises failure criterion also provides an adequate fit to the data with a von Mises strength of 265±73 kPa, it depends only on stress magnitude and is indifferent to the specific stress state, unlike Schmidt–Ishlinsky failure which has a larger shear failure strength compared to tensile strength. Implications for large-scale ice flow and fracture modeling are discussed. [ABSTRACT FROM AUTHOR]

Aims: To obtain more insight into the variability of the CFTRmutations found in immigrant cystic fibrosis (CF) patients who are living in Europe now, and to estimate the test sensitivity of different frequently used methods of DNA analysis to detect CF carriers or patients among these Turkish or North African immigrants. Methods: A survey among 373 European CF centers asking which CFTRmutations had been found in Turkish and North African CF patients. Results: 31 and 26 different mutations were reported in Turkish and North African patients, identifying 64.2 (113/176) and 87.4 (118/135) alleles, respectively (p< 0.001). The mean sensitivity (detection rate) of three most common CFTRmutation panels to detect these mutations differed between Turkish and North African people, 44.9 (79/176) versus 69.6 (94/135) (p< 0.001), and can be increased to 57.4 (101/176) and 79.3 (107/135) (p< 0.001), respectively, by expanding these panels with 13 mutations which have been found on two or more alleles. Conclusion: 35.8 and 12.6, respectively, of CF alleles in Turkish and North African patients living in Europe now had not been identified. Among these populations, the test sensitivity of common CFTRmutation panels is insufficient for use in screening programs in Europe, even after expansion with frequent Turkish and North African mutations. This raises questions about whether and how to implement CF carrier and neonatal screening in a multiethnic society. [ABSTRACT FROM AUTHOR]

On June 17, 2017, a large landslide occurred in the Karrat Fjord, West Greenland. The slide entered the sea, and the ensuing tsunami caused the loss of four lives in the nearby village of Nuugaatsiaq. We here describe how the combination of techniques has allowed an analysis of the evolution of the landslide prone area before and after the June 17 2017 event. We use a combination of optical imagery and spaceborne Synthetic Aperture Radar data, DEM analysis and seismology to pinpoint time and location of events. This has revealed that the area initiated movement in 2009, with several surface deformation and surface change episodes leading to the main landslide event in June 2017. Following the latter, complex and temporally varying spatial deformation patterns has been observed on the slope. [ABSTRACT FROM AUTHOR]