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We investigate earthquake potential of megathrust earthquakes in Peru based on the interseismic coupling model at the subduction interface (ISC) (Villegas-Lanza et al. 2016). Northern Peru displays a shallow and weak ISC, whereas Central and Southern Peru are highly coupled. Recent studies in the Nankai-Tonankai subduction region in Japan indicate that slip deficit regions do not directly reflect the local frictional strength characteristics controlling fault slip behavior at the plate interface (Noda et al. 2021). Therefore, to investigate the necessary conditions for megathrust earthquake generation we calculate the difference between accumulated strain energy during the interseismic period, with fault fracture energy (G), for a given slip scenario. A scenario cannot occur unless the accumulated strain energy exceeds G. To calculate G we use a scaling between average fault slip and G for subduction interface earthquakes, obtained from the NEIC global dataset of finite fault slip rupture models (Hayes et. al, 2017), and the 2D finite width slip dynamic rupture model (Pulido 2022). We calculated the shear stress accumulation rate and total accumulated shear stress at the Peruvian subduction margin, based on the slip deficit rate model, and interseismic periods since the largest historical earthquakes for the Northern, Central and Southern segments of the subduction interface. Our results indicate that the Central segment in Peru has currently accumulated the largest amount of shear stress, corresponding to an earthquake up to Mw~8.8. Using the earthquake energy balance we quantified the necessary conditions for megathrust earthquake generation across the subduction margin in Peru.

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Background: The mental health impact of the COVID-19 crisis may differ from previously studied stressful events in terms of psychological reactions, specific risk factors, and symptom severity across geographic regions worldwide. Objective: To assess the impact of COVID-19 on a wide range of mental health symptoms, to identify relevant risk factors, to identify the effect of COVID-19 country impact on mental health, and to evaluate regional differences in psychological responses to COVID-19 compared to other stressful events. Method: 7034 respondents (74% female) participated in the worldwide Global Psychotrauma Screen – Cross-Cultural responses to COVID-19 study (GPS-CCC), reporting on mental health symptoms related to COVID-19 (n = 1838) or other stressful events (n = 5196) from April to November 2020. Results: Events related to COVID-19 were associated with more mental health symptoms compared to other stressful events, especially symptoms of PTSD, anxiety, depression, insomnia, and dissociation. Lack of social support, psychiatric history, childhood trauma, additional stressful events in the past month, and low resilience predicted more mental health problems for COVID-19 and other stressful events. Higher COVID-19 country impact was associated with increased mental health impact of both COVID-19 and other stressful events. Analysis of differences across geographic regions revealed that in Latin America more mental health symptoms were reported for COVID-19 related events versus other stressful events, while the opposite pattern was seen in North America. Conclusions: The mental health impact of COVID-19-related stressors covers a wide range of symptoms and is more severe than that of other stressful events. This difference was especially apparent in Latin America. The findings underscore the need for global screening for a wide range of mental health problems as part of a public health approach, allowing for targeted prevention and intervention programs., HIGHLIGHTS In a large global sample, COVID-19 was associated with more severe mental health symptoms compared to other stressful or traumatic events. The impact of COVID-19 on mental health differed around the world with an especially large impact in Latin America.

In subduction zones, stress is released by earthquakes and transient aseismic slip. The latter falls into two categories: slow slip and afterslip. Slow-slip events emerge spontaneously during the interseismic phase, and show a progressive acceleration of slip with a negligible contribution of synchronous tremors or microseismicity to the energy, or moment release(1-12). In contrast, afterslip occurs immediately after large and moderate earthquakes, decelerates over time, and releases between 20 and 400% of the moment released by the preceding earthquake(13-18). Here we use seismic and GPS data to identify transient aseismic slip that does not fit into either of these categories. We document a seismic-aseismic slip sequence which occurred at shallow depths along a weakly coupled part of the Andean subduction zone(19) in northern Peru and lasted seven months. The sequence generated several moderate earthquakes that together account for about 25% of the total moment released during the full sequence, equivalent to magnitude 6.7. Transient slip immediately followed two of the earthquakes, with slip slowing at a logarithmic rate. Considered separately, the moment released by transient slip following the second earthquake was more than 1,000% of the moment released during the earthquake itself, a value incompatible with classical models of afterslip. Synchronous seismic swarms and aseismic slipmay therefore definea stress-release process that is distinct from slow-slip events and afterslip.

Personal Network (PN) is an emerging concept which combines pervasive computing and strong user focus. The idea is that the user's personal devices organize themselves in a secure and private personal network transparently of their geographical location. This paper studies a PN architecture where devices form clusters using shared key cryptography over short range radio links on an ad hoc manner and where the otherwise isolated clusters are interconnected over the IP infrastructure using dynamic tunneling. This paper describes work undertaken in the context of the FP6-IST-IP-507102 'My personal Adaptive Global Net' IST-MAGNET project. MAGNET is a worldwide R&D project within Mobile & Wireless Communication beyond 3G.