Large Events Research Articles

Maximum Magnitude of Induced Earthquakes in Rate and State Friction Framework

Abstract We analyze the evolution of the rupture radius and maximum magnitude (Mmax) of injection-induced earthquakes on faults obeying rates and state friction. We define the radii of two different slip modes, aseismic (Ra) and seismic slip (Rs), and derive an expression for maximum magnitude evolution. If the flow rate is sufficiently high, the seismic moment grows with the scaled injection volume, Qt/wS, as M∼Cf(Qt/wS)3/2, in which Cf depends on the initial stress level, S is storage coefficient, and w is the thickness of the reservoir. These findings are confirmed using numerical simulations conducted with varied initial states. The simulations show that Rs behaves as a rupture arrest radius and Ra behaves as the minimum possible radius of aseismic creep at a given injection volume. The Mmax evolution curve can be steeper if the fault is slightly critically stressed. A high-flow rate results in frequent seismic events, starting at relatively low-injected volume, which helps track the evolution of Mmax, providing a way to anticipate the risk of a large event. Conversely, a low-flow rate allows for a larger volume injection without seismic events but may lead to sudden large events without precursory events.

A novel trace-based sampling method for conformance checking

It is crucial for organizations to ensure that their business processes are executed accurately and comply with internal policies and requirements. Process mining is a discipline of data science that exploits business process execution data to analyze and improve business processes. It provides a data-driven approach to understanding how processes actually work in practice. Conformance checking is one of the three most relevant process mining tasks. It consists of determining the degree of correspondence or deviation between the expected (or modeled) behavior of a process vs the real one observed and revealed from the historical events recorded in an event log during the execution of each instance of the process. Under a big data scenario, traditional conformance checking methods struggle to analyzing the instances or traces in large event logs, increasing the associated computational cost. In this article, we study and address the conformance-checking task supported by a traces selection approach that uses representative sample data of the event log and thus reduces the processing time and computational cost without losing confidence in the obtained conformance value. As main contributions, we present a novel conformance checking method that (i) takes into account the data dispersion that exists in the event log data using a statistic measure, (ii) determines the size of the representative sample of the event log for the conformance checking task, and (iii) establishes selection criteria of traces based on the dispersion level. The method was validated and evaluated using fitness, precision, generalization, and processing time metrics by experiments on three actual event logs in the health domain and two synthetic event logs. The experimental evaluation and results revealed the effectiveness of our method in coping with the problem of conformance between a process model and its corresponding large event log.

IT-based health event surveillance in mass gathering - Kumbh Mela 2021, Haridwar, Uttarakhand

The Kumbh Mela is a large religious mass gathering event organised in India. During April 01 to April 30, 2021, Kumbh Mela was organized in Haridwar, Uttarakhand, India in the amid of COVID-19 pandemic. To detect and respond to unusual health events, a special surveillance model was established during Kumbh Mela-2021, Haridwar. The Kumbh module of Integrated Health Information Platform (IHIP) is utilized for real time data capturing. An Emergency Operations Centre (EOC) established to monitor COVID-19 and other disease situations through IHIP. Capacity building of Rapid Response Teams (RRT) was conducted. The special surveillance monitored 24 diseases/ syndromes. Kumbh mela area was divided into 4 zones with total 75 health facilities. A total of 31021 cases were reported on IHIP, including 86% communicable diseases (CDs), 8% non-communicable diseases (NCDs) and 6% unusual syndrome. Among total CDs, 27% acute febrile illness (AFI), 25.3% acute respiratory illness (ARI), 19% water borne diseases (WBDs), 15% COVID-19 and 14% others encountered. Out of total NCDs, 67% trauma, 25% dog bite, 8% others. A total of 36 early warning signals generated and responded, of which 22% WBDs, 22% ARI, 17% COVID-19, 14% AFI, 11% unusual syndrome and 14% others. The special disease surveillance helped monitoring health event alerts and health condition alerts. EOC monitored early warning signals and facilitated early detection and quick response to public health threats. Acute febrile illnesses emerged as a leading cause of morbidity. Future Mass Gathering events like Kumbh Mela should include disease surveillance as part of planning and augment capacity to diagnose and management of acute febrile illness.

Trust, interrupted: how did Brazil lose citizen trust in government after the 2014 World Cup?

Numerous people pay attention to large sporting events such as the Olympics and the football World Cup and derive a sense of national pride. As such, a large number of governments tend to support a national team for worldwide mega sporting events. The outcome of mega sporting events might affect citizens’ trust in government because this is a sort of government performance and solidifies national identity. However, few research studies have empirically estimated the impact of mega sporting events’ results on citizens’ trust in government. For this reason, this article is aimed at investigating how the 2014 World Cup affected Brazilian citizens’ trust in government. In particular, the article assesses how the disastrous defeat of Brazil by Germany affected Brazilian citizens’ trust in government. The results show that the outcome of the World Cup 2014 reduced Brazilian trust in government.

Ozone source attribution in polluted European areas during summer 2017 as simulated with MECO(n)

Abstract. Emissions of land transport and anthropogenic non-traffic emissions (e.g. industry, households and power generation) are significant sources of nitrogen oxides, carbon monoxide and volatile organic compounds (VOCs). These emissions are important precursors of tropospheric ozone and affect air quality. The contribution of the emission sectors to ozone cannot be measured directly but can only be calculated using sophisticated atmospheric chemistry models. For this study we apply the MECO(n) model system (MESSy-fied ECHAM and COSMO models nested n times) equipped with a source attribution method to investigate the contribution of various sources to ground-level ozone in Europe. Compared to previous source apportionment studies for Europe, for the first time we apply a combined NOx–VOC tagging implemented in an online nested global–regional chemistry–climate model to achieve a finer resolution over central Europe (12 km) but concurrently incorporating the effect of long-range transport. We distinguish 10 different source sectors and 4 geographical source regions, analysing especially the contribution from the land transport sector. Our analysis focuses on large ozone events during summer in four different regions, two major polluted regions (Po Valley and Benelux) and two more remote regions (Iberian Peninsula and Ireland). The analysis concentrates on results for summer 2017, during which measurement campaign EMeRGe took place. Measurement data from this campaign are used for model evaluation. Our analysis shows that European land transport emissions contribute largely (42 % and 44 %, respectively) to ground-level NOy mixing ratios over Benelux and the Po Valley. Due to the overall lower ozone production efficiency over Benelux compared to the Po Valley, however, the contributions to ground-level ozone are larger in the Po Valley (12 %) compared to Benelux (8 %). In line with previous publications using different source apportionment methods, our results underline the large importance of long-range transport of ozone, especially from North America (Benelux, Ireland), but also from Africa (Iberian Peninsula), and provide additional information about the sectoral contribution not available before. Our analysis shows that the contributions of European emissions from land transport and anthropogenic non-traffic sectors strongly increase with increasing values of MDA8 (daily maximum 8 h average) ozone over the Po Valley and in the Benelux region. Accordingly, these two sectors drive large MDA8 values in these regions. Inter-comparisons of results for 2018 and with a coarser model resolution (50 instead of 12 km) show that these results are robust with respect to inter-annual variability and model resolution. Comparing our results with results from other source attribution methods we find that the contributions to ozone from individual sectors, which have large NOx but rather low VOC emissions, are estimated to be lower, if their emissions of NOx and VOCs are regarded concurrently.

No paleoclimatic anomalies are associated with the late Eocene extraterrestrial impact events

Two distinct extraterrestrial impacts events struck the Earth less than 25,000 years apart in the late Eocene, approximately 35.65 million years ago. These resulted in the Popigai (northern Siberia) and Chesapeake Bay (eastern North America) impacts structures, the largest of the Cenozoic era. To examine the paleoclimatic consequences attributed to the late Eocene Chesapeake and Popigai extraterrestrial impact events, we present multispecies planktonic and benthic foraminiferal oxygen (δ18O) and carbon (δ13C) isotope records. Here we generate data from the Gulf of Mexico, Deep Sea Drilling Project Site 94 covering 35.85 to 35.49 million years ago. No isotopic anomalies or excursions were recorded across the impact horizons. However, ~100,000 years before the impacts, a negative 0.75‰ δ18O shift occurs in planktonic foraminifera, coincident with a 0.25‰ positive change in benthic foraminifera. We interpret this as a warming of ~2 °C in the surface ocean, accompanied by 1 °C deep water cooling, but these modifications are before and not coeval with the impact horizons. Despite the close succession of two or more large extraterrestrial impact events within a short space of time (less than 25,000 years), our study from the Gulf of Mexico indicates no detectable paleoclimatic response.

Fe/O Variations Relative to Source Longitude and Heliospheric Current Sheet in Large Solar Energetic Particle Events

The Fe/O enhancements exhibit significant variations in gradual solar energetic particle (SEP) events. Several causes have been suggested including transport effects in the interplanetary space and flare contribution. In this study, we investigate the relationship between the integrated Fe/O ratios of 27 gradual SEP events, locations of associated solar flares, and positions along the heliospheric current sheet (HCS) between 2010 and 2014. We employ synchronic potential field source surface (PFSS) extrapolations at 2.5R ⊙, derived in near real-time using Artificial Intelligence (AI)-generated far side and Helioseismic and Magnetic Imager (HMI) magnetograms, referred to as AIHMI-PFSS extrapolations. We examine low-energy (∼0.5 MeV/nucleon) Fe and O ion measurements obtained from Suprathermal Ion Telescope on Solar Terrestrial Relations Observatories and Ultra Low Energy Isotope Spectrometer on Advanced Composition Explorer. We found a moderate anticorrelation between the Fe/O ratios and the absolute longitudinal separation angles from the source regions to the spacecraft magnetic footpoints. Furthermore, we investigate the variations in Fe/O ratios with respect to the separation angle, grouped by the same and opposite polarity sectors of the SEP source regions. We found that the mean and median Fe/O values are higher in the same polarity group compared to the opposite polarity group, with the largest contrast at separation angles between 25° and 50°, where the values are approximately 3 times larger. The results imply that the enhanced Fe/O ratios in the examined gradual SEP events are likely associated with direct source regions, while the HCS affects particle transport.

A Series of (Net) Spin-down Glitches in PSR J1522–5735: Insights from the Vortex Creep and Vortex Bending Models

Through a detailed timing analysis of Fermi-LAT data, the rotational behavior of the γ-ray pulsar PSR J1522−5735 was tracked from 2008 August (MJD 54692) to 2024 January (MJD 60320). During this 15.4 yr period, two overrecovery glitches and four antiglitches were identified, marking a rare occurrence in rotation-powered pulsars (RPPs). The magnitudes of these (net) spin-down glitches were determined to be ∣Δν g/ν∣ ∼ 10−8, well above the estimated detectability limit. For the two overrecovery glitches, the respective recovery fractions Q are 2.1(7) and 1.4(2). Further analysis showed no substantial variations in either the flux or pulse profile shape in any of these events, suggesting that small (net) spin-down glitches, unlike large events observed in magnetars and magnetar-like RPPs, may occur without leaving an impact on the magnetosphere. Within the framework of the vortex creep and vortex bending models, antiglitches and overrecoveries indicate the recoupling of vortex lines that moved inward as a result of a crustquake; meanwhile, the apparent fluctuations in the spin-down rate after the glitches occur as a result of the coupling of the oscillations of bent vortex lines to the magnetosphere.

Analysis of stress changes on the Poso fault caused by large inland earthquakes: Case study of the 2017 Mw 6.6 Poso and the 2018 Mw 7.5 Palu-Donggala earthquakes

The 2017 Mw 6.6 Poso and the 2018 Mw 7.5 Palu-Donggala represent significant seismic events in central Sulawesi Island. These events transferred the stress to the surrounding faults, which can promote or inhibit the critical condition in a fault, thus evaluating the stress transfer from these earthquakes is crucial for a comprehensive understanding of fault behaviour. In this study, we investigate the effect of these large events by resolving the accumulated Coulomb stress change onto a multi-strike segment of the Poso fault. Additionally, we also used GPS measurement (Global Strain Rate Model) to estimate the increase in tectonic stress rate due to coupling of triple-junction plate convergence. The 2017 Poso earthquake induces positive stress changes (7 kPa to 27 kPa) in the central segment, negative changes (–4 kPa to –10 kPa) in the northern segment, and less significant effects in the southern segment. The 2018 Palu-Donggala earthquake imparts a notably high negative Coulomb stress (–16 kPa to –27 kPa) across the entire northern segment. Cumulatively, both earthquakes reduce Coulomb stress predominantly in the northern part of the Poso fault, suggesting a delayed critical point. Furthermore, the analysis of the Coulomb stress changes time function indicates that stress accumulation in the northern Poso fault is more modulated by large earthquakes, while stress accumulation in the southern segments may be more controlled by longterm tectonic stress loading. The stress accumulation model developed in this study can provide a guidance in better understanding further earthquake risk mitigation in central Sulawesi.

Large solar energetic particles and solar radio emissions during Cycle 25. A comparative analysis of trends and characteristics with cycles 23 and 24

Solar energetic particles (SEPs) affect space weather in both the heliosphere and on Earth. The present study investigates the occurrences of large SEP events focusing on their influence on the Earth, as well as their correlation with solar radio bursts (SRBs). The velocity dispersion analysis (VDA) is used to calculate the release times of large SEP events from their launch locations, as well as their apparent path length that connects them to interplanetary magnetic fields lines. According to the study, 122 large SEP events impacted the planet Earth from 1997 to 2024. The comparison of occurrence rates with previous solar cycles (SCs) suggests that SC 25 will peak with greater solar activity than the cycle 24 in terms of large SEP occurrences since large SEP events correlate well with the pattern of the sunspot cycle progression. In general, a few (35 out of 122) large SEP events are typically released from the Sun at times that coincide with the peak of associated solar flares and the onsets of corresponding SRBs indicating no delay while the rest have delayed in the release. The projected apparent lengths (L) range from 1.0 to 3.0 AU, with L exceeding 1.5 AU due to particle scattering and launch site pitch angles. The majority (115/122) of SEP occurrences are accelerated by shock waves from solar flares, CMEs, and fast plasma flow in the magnetic reconnection regions. Relevant SRBs for space weather study as they precede large SEP events diagnose the properties of particle populations propelled by solar flares and CMEs. This study finds that 90% of the large SEP events are preceded by solar radio emissions of type II, III and IV; and WAVES/STEREO revealed ∼76% of SRBs have continuation in IP medium indicating the dynamics of associated shocks and electron beams traveling along open and quasi-open magnetic field lines. Thus, SRB monitoring continues to be a valuable tool for studying space weather and understanding physical phenomena in the solar corona and IP medium, such as particle populations that cause large SEP occurrences.

A comparative analysis of fire-weather indices for enhanced fire activity prediction with probabilistic approaches

BackgroundWeather conditions play a crucial role in driving fire activity in Mediterranean France. Previous research has demonstrated the influence of these conditions on the likelihood of large fire events over the world. However, certain limitations persist regarding the representation of fire weather in probabilistic models. AimThe objective of this paper is to develop an efficient method to rate fire danger by identifying the best representation of weather data for fire activity prediction in Mediterranean France. MethodsWe evaluated the performance of meteorological variables and the most common fire-weather indices (FWIs) worldwide as predictors of fire occurrence and size using the Firelihood framework, a probabilistic Bayesian model of fire activity. These models were compared to a fire activity baseline model incorporating only spatial and temporal effects but no explicit fire-weather information to allow for an in-depth study of information not captured by fire-weather indices. Key resultsThe results indicate that relying solely on fire-weather indices is insufficient for efficient rating of fire activities. The inclusion of spatial and seasonal effects in the models is crucial for improving the indices' performance. While the Canadian FWI remains the most skillful indicator among the tested indices, using new combinations of several of its subcomponents further increases accuracy. Various performance analyses, including threshold selections, were carried out to comparatively assess those improvements. ConclusionsThe approach shows that probabilistic models informed with appropriately constructed fire-weather indices substantially improve various aspects of fire activity predictions in the Mediterranean area.

Fire-Image-DenseNet (FIDN) for predicting wildfire burnt area using remote sensing data

Predicting the extent of massive wildfires once ignited is essential to reduce the subsequent socioeconomic losses and environmental damage, but challenging because of the complexity of fire behavior. Existing physics-based models are limited in predicting large or long-duration wildfire events. Here, we develop a deep-learning-based predictive model, Fire-Image-DenseNet (FIDN), that uses spatial features derived from both near real-time and reanalysis data on the environmental and meteorological drivers of wildfire. We trained and tested this model using more than 300 individual wildfires that occurred between 2012 and 2019 in the western US. In contrast to existing models, the performance of FIDN does not degrade with fire size or duration. Furthermore, it predicts final burnt area accurately even in very heterogeneous landscapes in terms of fuel density and flammability. The FIDN model showed higher accuracy, with a mean squared error (MSE) about 82% and 67% lower than those of the predictive models based on cellular automata (CA) and the minimum travel time (MTT) approaches, respectively. Its structural similarity index measure (SSIM) averages 97%, outperforming the CA and FlamMap MTT models by 6% and 2%, respectively. Additionally, FIDN is approximately three orders of magnitude faster than both CA and MTT models. The enhanced computational efficiency and accuracy advancements offer vital insights for strategic planning and resource allocation for firefighting operations.

Shear Behavior and Acoustic Emission Characteristics of Propped Rough Fractures

AbstractShearing stimulation with proppant is widely used in geothermal and hydrocarbon reservoirs. However, the shear behavior associated with proppant-proppant and proppant-fracture interactions has not been clearly elaborated. This paper investigates surface damage and the interactions between proppant and surface roughness through direct shear tests with acoustic emission (AE) monitoring. The AE events show distinct spatial and temporal distribution patterns under the influence of proppant. The small magnitude AE events, representing proppant slipping and crushing, start to occur in large areas from the beginning of the shear deformation, and the large magnitude AE events occur mostly at the peak and during the residual phase and are concentrated on asperities. Crushed proppant grains and asperities form a gouge layer that prevents further damage to the fracture surface, reduces shear dilation and promotes aseismic creep. Fine proppant grains tend to remain intact, while the coarse proppant grains tend to be crushed. Our results suggest that acoustic emission characteristics can be used to infer different stages of shear behavior of propped fractures. These findings enhance our understanding of the shear behavior of propped fractures and provide evidence for monitoring their conditions using seismic signals.

Comparing prediction efficiency in the BTW and Manna sandpiles

The state-of-the-art in the theory of self-organized criticality reveals that a certain inactivity precedes extreme events, which are located on the tail of the event probability distribution with respect to their sizes. The existence of the inactivity allows for the prediction of these events in advance. In this work, we explore the predictability of the Bak–Tang–Wiesenfeld (BTW) and Manna models on the square lattice as a function of the lattice length. For both models, we use an algorithm that forecasts the occurrence of large events after a fall in activity. The efficiency of the prediction can be universally described in terms of the event size divided by an appropriate power-law function of the lattice length. The power-law exponents are projected to be 2.75 and 3 for the Manna and BTW models respectively. The scaling with the exponent 2.75 is known for collapsing of the entire size-frequency relationship in the Manna model. However, the correspondence between events on different lattices in the BTW model requires a variety of exponents where 3 is the largest. This indicates that in thermodynamic limit, prediction does exist in the Manna but not in the BTW model, at least based on inactivity. The difference in the universality classes may underline the difference in the prediction.

Fracture caging in a lab fault to prevent seismic rupture during fluid injection

Seismic risk associated with deep fluid injection is a major holdback for geothermal energy development. Currently adopted mitigation measures include traffic light protocol and cyclic stimulation methods that retroactively limit injection pressures and flowrates based on observed seismic activity to hopefully reduce the likelihood of triggering large seismic events. Fracture caging presents an alternative proactive approach to seismicity mitigation that does not require flow rate or injection pressure limits. The caging concept is to pre-drill boundary wells around injection wells to contain all injected fluid. Prior experimental and numerical work demonstrated successful caging of tensile hydraulic fractures but did not investigate caging in shear faults. To fill this knowledge gap, this study focuses on caging of injection-induced shear fractures in a critically stressed lab-scale shear fault. Experiment variables include mechanical versus hydraulic shearing and cage size by varied well spacing. Acoustic activity was monitored using two calibrated acoustic emission systems, each having a different sensitivity bandwidth. This constitutes what we call Caged Geothermal Systems (CGS) as a modified version of Enhanced Geothermal Systems (EGS), but with CGS using more wells, an accelerated drilling timetable, much higher flow rate limits, and less proppant. We demonstrate successful caging in a lab-scale shear fault with a high recovery of the injected fluid and prevention of large critical rupture events.

Quick Groundwater Flow to Tropical Savanna Springs (Mataranka, Northern Territory, Australia)

The Mataranka Springs Complex is a regional groundwater discharge for the Cambrian Limestone Aquifer (CLA) of the Northern Territory (Australia) and forms the headwaters for the environmentally sensitive Roper River. Whilst a regional groundwater contribution to the spring flow is well established, the absence of cover over the CLA in the vicinity of the springs and the prevalence of karst suggest that a component of quick flow during the wet season is possible. A quick flow contribution to the springs was evaluated using a biweekly monitoring programme for several environmental tracers (major ions, stable isotopes of water, and 222Rn) at two large springs (Rainbow Spring and Bitter Spring) and at one minor spring (Fig Tree Spring) over a two-year period that included a relatively dry (2019–2020) and a relatively wet (2020–2021) rainy season. There were limited variations in all tracers at Rainbow and Bitter springs throughout the monitoring programme, indicating an absence or a minimal contribution from quick flow. In contrast, all tracers responded to large rainfall events at a scale of days to weeks in Fig Tree Spring, consistent with a component of quick flow. However, the tracer response at Fig Tree was complex and possibly involved a combination of quick flow, unsaturated zone processes, and changes in the geochemical environment in the aquifer. Quick flow may be favoured in the parts of the Mataranka Springs Complex, where flow paths flow through the karstic tufa layer overlying the CLA.

Seasonal dynamics of water-use strategies and response to precipitation in different habitats of Nitraria L.

Nitraria L. is a dominant shrub in arid areas and its survival is hampered by low and unpredictable precipitation and uncertain future water conditions. However, little is known about the shrub’s water requirements or its response to precipitation. We determined the water utilization strategies of Nitraria L. species in habitats with different soil textures using the isotopic composition of xylem water and those of potential water sources (groundwater and vadose zone soil water). We used the MixSIAR model to quantify the relative contribution of potential water sources to shrub water in different soil textures. Our results showed that (1) The dynamic characteristics of water use of Nitraria L. species differed in different soil textures. In gravel soils, water in all soil layers was recharged by precipitation, and the shrub water source was controlled by precipitation with significant seasonal changes. In sandy and clay soils, shallow soil water was recharged by precipitation infiltration, but deep soil water was recharged by capillary rise. Nonetheless, the shrub water sources exhibited considerable seasonal fluctuations. During wet seasons, the shrub’s primary water sources were in shallow and mid-soil depths. However, during the dry season, the shrubs relied on groundwater, with more than half of their water originating in deep soil layers. (2) Nitraria L. species generally responded significantly to precipitation events, and those that survived in three soil textures were able to rapidly switch water sources to varying degrees. In particular, in sandy and gravelly soils, the proportion of deep soil water (24.3 %) and groundwater (16.2 %) used by Nitraria L. plants decreased significantly after a large precipitation event (e.g., 18.8 and 11.9 mm), shifting to a predominantly transient use of shallow soil water (48.5 %). Nitraria L. could shift water-absorbing soil layers according to the availability of potential water sources in different soil textures. This flexibility allows them to access the most readily available water more rapidly. Such optimal ecological adaptation can ensure that the plants will have an advantage in future predicted water shortage conditions.

Modeling the impacts of open biomass burning on regional O3 and PM2.5 in Southeast Asia considering light absorption and photochemical bleaching of Brown carbon

Open biomass burning in Southeast Asia has significant adverse impacts on air quality in the region and in downwind areas. These biomass burning events emit large amounts of light absorbing brown carbon (BrC). Once in the atmosphere, the light absorbing capacity of BrC is reduced by various oxidation processes. However, few modeling studies have been conducted to explicitly examine light absorption and bleaching on the prediction of ozone (O3) and fine particulate matter (PM2.5). In this study, a modified Community Multiscale Air Quality (CMAQ) model that explicitly tracks the concentrations of light absorbing and non-light absorbing organic aerosol components from different emission sources and the bleaching of BrC due to photooxidation and OH oxidation is applied to widespread open biomass burning events in March 2018 in Southeast Asia. Open biomass burning accounts for as much as 20–40 ppb (30–50%) of the maximum daily average 8-h ozone (MDA8 O3) and 40–120 μg m−3 (60–90%) of the daily average PM2.5 in the emission source regions. Compared to a simulation without BrC light absorption, the predicted MDA8 O3 and PM2.5 are as much as 16 ppb and 16 μg m−3 lower, respectively, than a simulation with light absorption. This confirms that neglecting the UV light absorption of BrC can lead to significant overpredictions of O3 and PM2.5 during the open biomass burning periods, which may lead to an overestimation of the adverse impacts of biomass burning on public health in Southeast Asia. The addition of BrC bleaching results in a 0.5–1% increase in MDA8 O3 and 1–5% increase in PM2.5 compared to the case without BrC bleaching. The results of this study indicate that light absorption by BrC needs to be considered in chemical transport modeling of large open biomass burning events. The BrC bleaching process is relatively slow and neglecting this process does not significantly change the predictions of MDA8 O3 and PM2.5 during open biomass burning.

Seismic radial anisotropy in southeastern Tibetan Plateau and its implications for regional geodynamic evolution

The southeastern Tibetan Plateau exhibits intricate crustal tectonics, encompassing recent seismic megathrust events. Previous research suggested the presence of north-south-oriented channelized viscous flow within the crust. However, recent investigations have unveiled a notable northeast-southwest-oriented geological structure, potentially rigid, intersecting with the presumed crustal channelized flow. Several questions persist regarding the composition of the northeast-southwest-oriented structure, the continuity of crustal channelized flow, and the interplay between them. In this study, dispersion data from a dense seismic array are employed to significantly refine regional crustal models for shear wave velocity and radial anisotropy through ambient noise tomography. The resulting high-resolution model further reveals the style of the crustal deformation and supports the interpretation that the northeast-southwest structure, which shows higher velocity and significant negative radial anisotropy, results from mafic material at the base of crust, obstructing the crustal channelized flow. However, the northeast-southwest structure is not as rigid as the Sichuan Block and exhibits depth-dependent deformation. The interpretation proves useful in further understanding regional earthquake focal mechanisms and strain distribution. Additionally, this research identified a region of generalized negative radial anisotropy in the crust of the western Chuan-Dian fragment, suggesting a reduced horizontal channel crustal flow in this area. Drawing upon various geophysical and geological evidence, we present a geodynamic evolution model, proposing a sequence of events: Permian plume activity resulting in mafic material at the base of the crust near Anninghe-Zemuhe fault, northward advancement of the east Himalayan syntaxis inducing crustal compressional stress field, reduced lower crustal channel flow in the western Chuan-Dian fragment leading to the regional east-west extension, and initiation of the Xianshuihe fault causing shift of strain concentration and depth-dependent deformation near the Anninghe-Zemuhe fault. The geodynamic model provides valuable insights into the regional distribution of crustal strain and the underlying mechanisms of large seismic events.

Classification of pediatric soft and bone sarcomas using DNA methylation-based profiling

Pediatric sarcomas present heterogeneous morphology, genetics and clinical behavior posing a challenge for an accurate diagnosis. DNA methylation is an epigenetic modification that coordinates chromatin structure and regulates gene expression, determining cell type and function. DNA methylation-based tumor profiling classifier for sarcomas (known as sarcoma classifier) from the German Cancer Research Center (Deutsches Krebsforschungszentrum) was applied to 122 pediatric sarcomas referred to a reference pediatric oncology hospital. The classifiers reported 88.5% of agreement between histopathological and molecular classification confirming the initial diagnosis of all osteosarcomas and Ewing sarcomas. The Ewing-like sarcomas were reclassified into sarcomas with BCOR or CIC alterations, later confirmed by orthogonal diagnostic techniques. Regarding the CNAs profile, osteosarcomas had several chromosomal gains and losses as well as chromothripsis, whereas Ewing sarcomas had few large events, such as amplifications of chromosomes 8 and 12. The molecular classification together with clinical and histopathological assessment could improve the diagnosis of pediatric sarcomas although there are limitations to deal with more rare classes. This study provides an increase in the number of sarcomas evaluated for DNA methylation profiling in the pediatric population.