Search Results (7)

Background/Objectives: Previous works on the epidemiology of pediatric trauma during the COVID-19 lockdown observed a decrease in pediatric surgical emergency consultations and fracture referrals. None of those works describes a unique situation in which there is the coexistence of another opposing factor, like an earthquake, that influences the number of injured children’s referrals. Therefore, this study aimed to investigate the influence of earthquakes during the COVID-19 lockdown on pediatric injury pattern referrals at a tertiary care hospital in a urban setting. Methods: A retrospective single-center case-control study comprised a time interval at the time of the COVID-19 lockdown, starting with a day when the biggest earthquake happened and finishing at the end of the confinement period in Zagreb, Croatia (22 March–27 April 2020). The control group comprised the identical time interval in 2019. We identified all successive pediatric trauma patients referred to the Pediatric Emergency Department. Demographics and leading injury characteristics were analyzed. Results: We analyzed data from 1166 patients. In the case group, the median age was lower than in the control group but without gender differences. We detected a decrease in Pediatric Emergency Department referrals and a reduced proportion of pediatric trauma patients in the case group. Additionally, the proportion of shoulder/elbow injuries and head injuries was higher, and the proportion of foot/ankle injuries was lower in the case period than in the control period. Conclusions: Earthquakes during the COVID-19 lockdown changed the pattern of pediatric injuries. These data can be used to restructure health resources during similar conditions to provide optimal health care to children. Full article

The April 2010 earthquake (Mw = 7.2), which occurred about 40 km to the southeast of the city of Mexicali, Mexico, caused significant damage to buildings. To improve knowledge of the seismic response of the soil due to the occurrence of earthquakes, a response spectrum at 5% damping was calculated. A comparison between the spectral ordinates obtained in this study and the spectra proposed by the regulations of the Federal Electricity Commission (CFE for its acronym in Spanish) in its seismic design for civil works manual, which is currently used as the design standard throughout the country, was made. We calculated response spectra using records from the April 2010 earthquake and a stratigraphic profile of the city to calculate a transfer function. We first corrected the records for site effect due to stations being over sedimentary soil, and then used them as Green functions to perform a numerical simulation of propagation through the stratigraphic profile to obtain a simulated surface record from which response spectra were calculated. Additionally, ambient seismic noise was measured at the same site to get the dominant period (To). We observed that the transfer function was similar to the spectral quotient up to 5 Hz and that To calculated in both ways gave similar values. The comparison suggests that the design spectrum of the CFE regulation can be considered as a representative spectrum for Mexicali for periods greater than 1.3 s, but not for the zone of short periods. Full article

Spatiotemporal distribution of early afterslip is essential for seismic hazard evaluation and determination of fault friction properties. In this study, we used early post-seismic COSMO-SkyMed (19 February 2014–08 April 2014) and long-term Sentinel-1 (16 October 2014–17 June 2020) observations from multiple platforms over different periods to create a rate decay model driven by post-seismic afterslip. The combined observations provide full coverage of the post-seismic deformation following the 2014 Yutian Mw 6.9 earthquake that occurred at the southwestern end of the Altyn Tagh Fault. The observation and modeling results showed that post-seismic deformation was characterized by left-lateral strike-slip movement with minor normal slip, which was consistent with that of co-seismic rupture. The maximum early afterslip (7–55 days) was as large as approximately 0.09 m with a depth of 7 km in the west of co-seismic rupture, and the maximum long-term afterslip was about 0.24 m. The simulated post-seismic deformation caused by poroelastic rebound and viscoelastic relaxation suggests that the afterslip mechanism controls the post-seismic deformation. The coupling pattern of the aftershock and afterslip indicates that the aftershock was mainly caused by the afterslip. The post-seismic spatiotemporal features of the 2014 Yutian earthquake have significant implications for analyzing seismic hazards at the southwestern end of the Altyn Tagh Fault. Full article

The Fukushima Daiichi nuclear power plant accident happened after the devastating earthquake in the Pacific coastal area of Japan on 11 March 2011. After the accident, radioactive materials spread out over a wide area in Japan. Radioactive materials were retained on soil surfaces, causing environmental problems. Among the radioactive materials, cesium (¹³⁷Cs) has a long half-life of 30.2 years, and it remains near the surface soil; therefore, it is necessary to remove soil contaminated by ¹³⁷Cs. The contaminated soil layer of inhabited areas in Fukushima was already removed before April 2020. However, the remediation method of Cs with other radioactive materials needs further study, as the large quantity of contaminated soil is not easy to preserve. Electrokinetic (EK) treatment is one of the soil remediation technologies that utilizes EK phenomena at the interface between contaminated soils by transferring ions from the soil. We have developed a new type of EK method in which a cathode is placed on the surface of the soil and an anode is place inside the soil. By applying DC voltage in between the electrodes, the Cs ions can be removed from the contaminated soil. The removed Cs ions are gathered near to the cathode, and if the cathode can adsorb the Cs ions, then only the cathode needs to be preserved, solving the problem of storing a large amount of soil. We have been working to prepare a new type of cathode that can be effective in adsorbing Cs ions and at the same time easier to store and handle. We used natural zeolite and rice husk charcoal (kuntan) to prepare this electrode, which showed good potential for adsorbing Cs ions. The electrode showed flexibility, which is helpful for storing it in the same way as pasture rolls. However, the experiments were conducted in the laboratory with non-radioactive Cs; field experiments and observations are needed for practical applications of this method, as well as the new electrodes. Full article

The Lisbon metropolitan area (LMA, central-west of Portugal) has been severely affected by different geohazards (flooding episodes, landslides, subsidence, and earthquakes) that have generated considerable damage to properties and infrastructures, in the order of millions of euros per year. This study is focused on the analysis of subsidence, as related to urban and industrial activity. Utilizing the A-DInSAR dataset and applying active deformation areas (ADA) processing at the regional scale has allowed us to perform a detailed analysis of subsidence phenomena in the LMA. The dataset consisted of 48 ascending and 61 descending SAR IW-SLC images acquired by the Sentinel-1 A satellite between January 2018 and April 2020. The line-of-sight (LOS), mean deformation velocity (VLOS) maps (mm year⁻¹), and deformation time series (mm) were obtained via the Geohazard Exploitation Platform service of the European Space Agency. The maximum VLOS detected, with ascending and descending datasets, were −38.0 and −32.2 mm year⁻¹, respectively. ADA processing over the LMA allowed for 592 ascending and 560 descending ADAs to be extracted and delimited. From the VLOS measured in both trajectories, a vertical velocity with a maximum value of −32.4 mm year⁻¹ was estimated. The analyzed subsidence was associated to four ascending and three descending ADAs and characterized by maximum VLOS of −25.5 and −25.2 mm year⁻¹. The maximum vertical velocity associated with urban subsidence was −32.4 mm year⁻¹. This subsidence is mainly linked to the compaction of the alluvial and anthropic deposits in the areas where urban and industrial sectors are located. The results of this work have allowed to: (1) detect and assess, from a quantitative point of view, the subsidence phenomena in populated and industrial areas of LMA; (2) establish the relationships between the subsidence phenomena and geological and hydrological characteristics. Full article

Two large earthquakes, the Maduo M_S 7.4 earthquake and the Menyuan M_S 6.9 earthquake, have been successfully recorded on the Chinese mainland, since the data of the CSES satellite were put into service for earthquake prediction work on the Chinese mainland at the end of April 2020. Obvious variations in O⁺ density and electron density were found during our weekly data processing work during 5–11 May 2021 and 28 December 2021–2 January 2022, respectively. Two warnings of impending events around the anomalous areas within two weeks had been reported immediately after the anomaly appearance. The Maduo M_S 7.4 earthquake occurred on 22 May 2021 and the Menyuan M_S 6.9 earthquake on 8 January 2022, during these two warning periods. More details were revealed after these two large shocks occurred. Ionospheric enhancement took place on 8 May 2021, with a magnitude of 41.6% for O⁺ density and 22.2% for electron density, a distance of 680 km from the Maduo epicenter, 14 days prior to the event. Before the Menyuan earthquake, ionospheric enhancement took place on 28 December 2021, as well as during its revisiting orbit on 2 January 2022, with a magnitude of 47.3% for O⁺ density and 38.4% for electron density, an epicentral distance of 120 km, 11 and 6 days prior to this event. The Kp index was also examined to avoid the influence from solar activities. Despite this, accurate earthquake prediction is not possible due to much uncertainty, such as the correct location and magnitude of an impending event. Thus, long-term practice and comprehensive investigation of the seismo-ionospheric influence are necessary in the future. Full article

Nepal was hit by a 7.8 magnitude earthquake on 25 April 2015, followed by numerous aftershocks, including a 6.8 magnitude earthquake on 26 April and a 7.2 magnitude earthquake on 12 May. Using two household surveys of a panel of 377 households conducted in February 2016 and March 2020 in one of the hardest-hit mountain villages, we found that most of the households recovered well, having better housing, increased income, improved awareness about disaster risk, and better infrastructure facilities than before the earthquake. Notably, the poverty headcount index reduced by 16% from 2016 to 2020, and more than 90% of the households reconstructed into earthquake-resistant houses with financial and technical support, mainly, from the government. The village has increased the quality and length of rural roads; there is also wider coverage of clean water supply and better functioning school buildings and hospitals. Similarly, the subjective well-being of the people, gauged using the Oxford Happiness Questionnaire (OHQ), has also increased. These aspects combined indicate improved community resilience and the sustainable development of the village. However, the progress differs significantly across gender, caste/ethnic as well as income groups, which calls for inclusive reconstruction and recovery policies as well as disaster risk reduction (DRR) frameworks at a local level to contribute to community resilience and sustainable mountain development. Full article