In 2015, an estimated 856,723 refugees, predominantly from Syria, Afghanistan, and Iraq arrived in Greece as an entry point into the European Union. The border of the Former Yugoslav Republic of ...Macedonia closed in March 2016, blocking a popular route for refugees through Europe, and left around 60,000 people stranded in Greece.
A mixed-method study was conducted among refugees in the regions of Attica, Epirus, and Samos between November 2016 and February 2017. The epidemiological survey showed that depending on study sites between 73% and 100% of the refugees suffered from anxiety disorder. The explanatory qualitative study aimed to understand refugees' mental health and narratives of social suffering in regards to experienced violence, the effect of current border closures, and the lack of an onward journey.
The explanatory qualitative study included 47 in-depth interviews and five focus group discussions with refugees purposely recruited through the concomitant epidemiological survey, representing both genders and a range of nationalities and ages. Data were thematically analysed to identify emergent patterns and categories using NVivo 11.
The refugees overwhelmingly reported experiencing uncertainty and lack of control over their current life and future, which caused psychosocial distress and suffering. The passivity of life in refugee camps aggravated feelings of meaninglessness and powerlessness. The disruption of key social networks and absence of interactions with the surrounding Greek society led to feelings of isolation and being unwelcome.
Refugees in Greece experience psychosocial distress and social suffering as a consequence of their uncertain and disrupted lives and the loss of social networks. Faster and transparent asylum procedures, the development of meaningful and empowering activities, and fostered social interactions with the surrounding society would contribute to alleviating their psychosocial suffering.
•Living conditions in Greek refugee camps generate or increase psychosocial distress.•Refugees experience uncertainty, life disruption, and the loss of social networks.•Social suffering elucidates links between distress and the socio-political context.•Distresses are preventable, but the political will to address them is lacking.
We use fault maps and fault propagation evidences available in the literature to examine geometrical relations between parent faults and off-fault splays. The population includes 47 worldwide crustal ...faults with lengths from millimetres to thousands of kilometres and of different slip modes. We show that fault splays form adjacent to any propagating fault tip, whereas they are absent at non-propagating fault ends. Independent of fault length, slip mode, context, etc., tip splay networks have a similar fan shape widening in direction of long-term propagation, a similar relative length and width (∼30 and∼10% of parent fault length, respectively), and a similar range of mean angles to parent fault (10–20°). We infer that tip splay networks are a genetic and a generic property of faults indicative of their long-term propagation. Their generic geometrical properties suggest they result from generic off-fault stress distribution at propagating fault ends.
We investigate the fine-scale geometry and structure of the San Andreas Fault near Parkfield, CA, and their role in the development of the 1966 and 2004 ∼M6 earthquakes. Long-term surface fault ...traces indicate that structural heterogeneities associated with secondary reverse and normal fault structures are present at both rupture tips, near Middle Mountain and Gold Hill. Detailed analysis of almost 50 years of high-resolution seismicity reveals a fault plane that has been twisted into a helicoid between Middle Mountain and Gold Hill. Numerical models support our conclusion that this shape is the result of long-term torqueing of a strong stuck patch surrounded by a weak creeping region. The changes in fault friction behavior and related geometric discontinuities act as barriers to rupture propagation of moderate size earthquakes at Parkfield, and as areas of concentrations where rupture initiates. Our study demonstrates also that smooth strike-slip faults with large cumulative offset can form new fault segments at a late stage in their evolution.
•The San Andreas fault plane near Parkfield has been deformed into a helicoid over the long-term.•The torque results from the strength contrast between locked and creeping zones.•Complex structures at surface correspond with the tips of the stuck patch at depth.•Stress concentrations at the tips of the stuck patch control rupture development of M6 events.
Natural earthquake slip profiles have a generic triangular shape which the available rupture dynamics models fail to reproduce. Long‐term faults are embedded in long‐damaged crustal material, and the ...properties of the long‐term damage vary both across and along the faults. We examine the effects of the predamaged state of the medium on the earthquake slip distributions. We simulate long‐term damage by the decrease in the elastic modulus of the medium around the fault. We model the dynamic crack‐like rupture of a slip‐weakening planar, right‐lateral strike‐slip fault, and search which geometries and elastic properties of the long‐term damage produce a triangular slip profile on the rupture. We find that such a profile is produced only when a laterally heterogeneous preexisting damage zone surrounds the ruptured fault. The highest on‐fault slip develops in the most compliant region of the damage zone, and not necessarily above the earthquake hypocenter. The coseismic slip decreases in zones of stiffer damage. The amount of coseismic slip dissipated in the damage zone is large, at least 25–40% of maximum on‐fault slip, and can occur over large distances from the fault. Our study thus emphasizes that off‐fault preexisting damage should be considered for an accurate description of earthquake ruptures. It also motivates a reformulation of the available earthquake source inversion models since most of them do not include the inelastic deformations that occur in the near field of the earthquake ruptures.
Key Points
Off‐fault long‐term damage controls earthquake slip
Rupture models with along‐fault variability in long‐term damage properties reproduce generic shape of natural earthquake slip profiles
Coseismic strain dissipated off the main fault is significant and occurring over large distances
We use high‐resolution earthquake locations to characterize the three‐dimensional structure of active faults in California and how it evolves with fault structural maturity. We investigate the ...distribution of aftershocks of several recent large earthquakes that occurred on continental strike slip faults of various structural maturity (i.e. various cumulative fault displacement, length, initiation age and slip rate). Aftershocks define a tabular zone of shear deformation surrounding the mainshock rupture plane. Comparing this to geological observations, we conclude that this results from the re‐activation of secondary faults. We observe a rapid fall off of the number of aftershocks at a distance range of 0.06‐0.22 km from the main fault surface of mature faults, and 0.6‐1.0 km from the fault surface of immature faults. The total width of the active shear deformation zone surrounding the main fault plane reaches 1.0‐2.5 km and 6‐9 km for mature and immature faults, respectively. We find that the width of the shear deformation zone decreases as a power law with cumulative fault displacement. Comparing with a dynamic rough fault model, we infer that the narrowing of the shear deformation zone agrees quantitatively with earlier estimates of the smoothing of faults with displacement, both of which are aspects of fault wear. We find that earthquake stress drop decreases with fault displacement and hence with increased smoothness and/or slip rate. This may result from fault healing or the effect of roughness on friction.
Plain Language Summary
Active fault zones worldwide are 3D features made of a parent fault and secondary faults and fractures that damaged the surrounding medium. During and soon after a large earthquake, these structures are reactivated, highlighted by numerous smaller events—aftershocks. Their distribution allows us to characterize the zone of shear deformation around the fault plane. In this study, we show that the width of the shear deformation zone is narrower around mature faults than around immature faults. It decreases as a power law with cumulative fault displacement which we infer to be the result of the smoothing of the fault with wear through geological times. We also find that the stress drop of mainshocks decrease with fault smoothness or slip rate, both of which correlate with maturity. Our study provides some relations to better understand and anticipate the size of off‐fault deformation reactivated during and after an earthquake, based on geological fault parameters.
Key Points
Across strike distribution of aftershocks of large earthquakes describe the width of the shear deformation zone around large faults
The zone of active shear deformation scales with fault roughness and narrows as a power law with fault displacement
Earthquake stress drop decreases with fault displacement and hence fault roughness or displacement rate
It is still debated whether lockdown conditions in response to the coronavirus disease 2019 (COVID-19) health crisis seriously affected children’s sleep. For young children, some studies identified ...more insomnia, while others only transient disturbances, or even no effect. Based on the premise of mother–child synchrony, a well-known dynamic established in child development research, we hypothesized that principally, the children whose mothers perceived the lockdown as stressful and/or responded maladaptively, suffered sleep disturbances. The main objective of this study was to identify the family profiles, variables, and lockdown responses most linked to insomnia in young children. The sample consisted of 165 mothers, French vs. Swiss origin (accounting for different lockdown severities), of children 6 months to 5 years old. Validated sleep, stress, and behavior scales were used. Multiple regression, age-matched clustering, and structural equation modeling analyses provided evidence that insomnia in young children is indeed strongly linked to the mother’s reaction to the pandemic and lockdown. Specifically, reactions such as COVID-19 fear/anxiety and obsessive COVID-19 information seeking coincide with heightened vigilance, cascading into reduced child social contact, outings, and increased screen viewing, ultimately culminating in child insomnia and behavioral problems. Mother education level and child day care quality (e.g., home-schooling) were also identified as strong insomnia predictors.
The S1222a marsquake detected by InSight on 4 May 2022 was the largest of the mission, at MwMa ${M}_{w}^{Ma}$ 4.7. Given its resemblance to two other large seismic events (S1000a and S1094b), which ...were associated with the formation of fresh craters, we undertook a search for a fresh crater associated with S1222a. Such a crater would be expected to be ∼300 m in diameter and have a blast zone on the order of 180 km across. Orbital images were targeted and searched as part of an international, multi‐mission effort. Comprehensive analysis of the area using low‐ and medium‐resolution images reveals no relevant transient atmospheric phenomena and no fresh blast zone. High‐resolution coverage of the epicentral area from most spacecraft are more limited, but no fresh crater or other evidence of a new impact have been identified in those images either. We thus conclude that the S1222a event was highly likely of tectonic origin.
Plain Language Summary
During its time on Mars, NASA's InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission recorded over 1,300 seismic events, known as “marsquakes.” Of these, a number were identified as coming from meteoroid impact cratering events on the surface. The largest event identified by InSight, labeled S1222a, bore some similarities to two large impact events recorded earlier in the mission. In order to investigate whether the S1222a event might also have been caused by an impact event, we undertook a comprehensive search of the region in which the marsquake occurred. We did not identify any fresh craters in the area, implying that the marsquake was likely caused by geological processes.
Key Points
The S1222a marsquake detected by InSight on 4 May 2022 somewhat resembled previous impact‐generated events
We performed an image search in the estimated source region, using data from multiple Mars orbiter missions
No new impact crater has been discovered in this area, pointing to a tectonic origin for the quake
Abstract
The InSight mission has operated on the surface of Mars for nearly two Earth years, returning detections of the first marsquakes. The lander also deployed a meteorological instrument package ...and cameras to monitor local surface activity. These instruments have detected boundary layer phenomena, including small-scale vortices. These vortices register as short-lived, negative pressure excursions and closely resemble those that could generate dust devils. Although our analysis shows that InSight encountered more than 900 vortices and collected more than 1000 images of the Martian surface, no active dust devils were imaged. In spite of the lack of dust devil detections, we can leverage the vortex detections and InSight’s daily wind speed measurements to learn about the boundary layer processes that create dust devils. We discuss our analysis of InSight’s meteorological data to assess the statistics of vortex and dust devil activity. We also infer encounter distances for the vortices and, therefrom, the maximum vortex wind speeds. Surveying the available imagery, we place upper limits on what fraction of vortices carry dust (i.e., how many are bona fide dust devils) and estimate threshold wind speeds for dust lifting. Comparing our results to detections of dust devil tracks seen in space-based observations of the InSight landing site, we can also infer thresholds and frequency of track formation by vortices. Comparing vortex encounters and parameters with advective wind speeds, we find evidence that high wind speeds at InSight may have suppressed the formation of dust devils, explaining the lack of imaged dust devils.
Deformation mechanisms, long-term kinematics and evolution of fold and thrust belts subjected to erosion are studied through 2D analogue experiments involving large convergence. First-order ...parameters tested include (1) decollements and/or plastic layers interbedded at different locations within analogue materials and (2) synconvergence surface erosion. Weak layers, depending on their location in the model, favour deformation partitioning characterized by the simultaneous development of underplating domains in the inner part of the wedge (basal accretion) and frontal accretion where the wedge grows forward. Interaction between tectonics and surface processes influences this behaviour. Development of antiformal thrust stacks controlled by underplating shows small- and large-scale cyclicity. Thin plastic layers induce folding processes, which are studied at wedge scale. Recumbent and overturned folds, with large inverted limbs, develop in a shear-induced asymmetric deformation regime via progressive unrolling of synclinal hinges. Surface erosion and underplating at depth induce further rotation (passive tilting) and horizontalization of fold limbs. Model results give insights to discuss the mechanisms responsible for the large-scale structures (i.e. antiformal nappe stacks, klippen and kilometre-scale recumbent fold-nappes) encountered in several mountain belts such as the Montagne Noire (French Massif Central), the Galicia Variscan belt (Spain) and the northern Apennines (Italy).
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