Analysis of microseismicity framing ML > 2.5 earthquakes at The Geysers geothermal field, California

Preparatory mechanisms accompanying or leading to nucleation of larger earthquakes have been observed at both laboratory and field scales, but conditions favoring the occurrence of observable preparatory processes are still largely unknown. In particular, it remains a matter of debate why some earthquakes occur spontaneously without noticeable precursors as opposed to events that are preceded by an extended failure process. In this study, we have generated new high‐resolution seismicity catalogs framing the occurrence of 20 ML > 2.5 earthquakes at The Geysers geothermal field in California. To this end, a seismicity catalog of the 11 days framing each large event was created. We selected 20 sequences sampling different hypocentral depths and hydraulic conditions within the field. Seismic activity and magnitude frequency distributions displayed by the different earthquake sequences are correlated with their location within the reservoir. Sequences located in the northwestern part of the reservoir show overall increased seismic activity and low b values, while the southeastern part is dominated by decreased seismic activity and higher b values. Periods of high injection coincide with high b values and vice versa. These observations potentially reflect varying differential and mean stresses and damage of the reservoir rocks across the field. About 50% of analyzed sequences exhibit no change in seismicity rate in response to the large main event. However, we find complex waveforms at the onset of the main earthquake, suggesting that small ruptures spontaneously grow into or trigger larger events

Estrategias de los padres para cuidar la salud de sus hijos en edad escolar en el municipio de Tocancipá

69 páginasLa familia es la base de la sociedad donde cada persona interviene en actividades, roles y relaciones interpersonales que permiten la formación de sus integrantes. Es en la familia donde los niños aprenden los principales hábitos de vida y prácticas de cuidado que generalmente perduran hasta el final de la vida. Al revisar el aumento de número de enfermedades crónicas de la región Sabana Centro y el bajo conocimiento que los escolares tienen de algunas prácticas saludables, surge este proyecto con el objetivo de describir las estrategias de los padres para cuidar la salud de sus hijos en edad escolar, en el municipio de Tocancipá, uno de los municipios más pujantes de esta región. Para ello, se realizó una investigación cuantitativa, descriptiva, de tipo trasversal que permitió conocer dichas estrategias, con un propósito futuro de mantenerlas o mejorarlas, como se evidencia más adelante

Preparatory Slip in Laboratory Faults: Effects of Roughness and Load Point Velocity

Aseismic slip may occur during a long preparatory phase preceding earthquakes, and what controls it remains poorly understood. In this study, we explored the role of load point velocity and surface roughness on slow slip during the preparatory stage prior to stick-slip events. To that end, we conducted displacement-rate controlled friction experiments by imposing varying load point velocities on sawcut granite samples with different surface roughness at a confining pressure of 35 MPa. We measured the average slip along the fault with the recorded far-field displacements and strain changes, while acoustic emission sensors and local strain gages were used to capture local slip variations. We found that the average amount of aseismic slip during the preparatory stage increases with roughness, whereas precursory slip duration decreases with increased load point velocity. These results reveal a complex slip pattern on rough faults which leads to dynamic ruptures at high load point velocities

Seismicity during and after stimulation of a 6.1 km deep enhanced geothermal system in Helsinki, Finland

In this study, we present a high-resolution dataset of seismicity framing the stimulation campaign of a 6.1 km deep Enhanced Geothermal System (EGS) in Helsinki suburban area and discuss the complexity of fracture network development. Within St1 Deep Heat project, 18 160 m3 of water was injected over 49 days in summer 2018. The seismicity was monitored by a seismic network of near-surface borehole sensors framing the EGS site in combination with a multi-level geophone array located at ≥ 2 km depth. We expand the original catalog of Kwiatek et al. (2019) and provide the community with the dataset including detected seismic events and earthquakes that occurred two month after the end of injection, totalling to 61 163 events. We relocated events of the catalog with sufficient number of available phase onsets and moment magnitudes between Mw −0.7 and Mw 1.9 using the double-difference technique and a new velocity model derived from a post-stimulation vertical seismic profiling campaign. The analysis of the fault network development at reservoir depth of 4.5–7 km is one primary focus of this study. To achieve this, we investigate 191 focal mechanisms of the induced seismicity using cross-correlation based technique. Our results indicate that seismicity occurred in three spatially separated clusters centered around the injection well. We observe a spatio-temporal migration of the seismicity during the stimulation starting from the injection well in northwest (NW) – southeast (SE) direction and in northeast (NE) direction towards greater depth. The spatial evolution of the cumulative seismic moment, the distribution of events with Mw ≥ 1 and the fault plane orientations of focal mechanisms indicate an active network of at least three NW–SE to NNW-SSE orientated permeable zones which is interpreted to be responsible for migration of seismic activity away from the injection well. Fault plane solutions of the best-constrained focal mechanisms as well as results for the local stress field orientation indicate a reverse faulting regime and suggest that seismic slip occurred on a sub-parallel network of pre-existing weak fractures favorably oriented with the stress field, striking NNW-SEE with a dip of 45° ENE, parallel to the injection well.Peer reviewe

Limited Earthquake Interaction During a Geothermal Hydraulic Stimulation in Helsinki, Finland

We investigate induced seismicity associated with a hydraulic stimulation campaign performed in 2020 in the 5.8 km deep geothermal OTN-2 well near Helsinki, Finland as part of the St1 Deep Heat project. A total of 2,875 m3 of fresh water was injected during 16 days at well-head pressures <70 MPa and with flow rates between 400 and 1,000 L/min. The seismicity was monitored using a high-resolution seismic network composed of 10 borehole geophones surrounding the project site and a borehole array of 10 geophones located in adjacent OTN-3 well. A total of 6,121 induced earthquakes with local magnitudes urn:x-wiley:21699313:media:jgrb55848:jgrb55848-math-0001 were recorded during and after the stimulation campaign. The analyzed statistical parameters include magnitude-frequency b-value, interevent time and interevent time ratio, as well as magnitude correlations. We find that the b-value remained stationary for the entire injection period suggesting limited stress build-up or limited fracture network coalescence in the reservoir. The seismicity during the stimulation neither shows signatures of magnitude correlations, nor temporal clustering or anticlustering beyond those arising from varying injection rates. The interevent time statistics are characterized by a Poissonian time-varying distribution. The calculated parameters indicate no earthquake interaction. Focal mechanisms suggest that the injection activated a spatially distributed network of similarly oriented fractures. The seismicity displays stable behavior with no signatures pointing toward a runaway event. The cumulative seismic moment is proportional to the cumulative hydraulic energy and the maximum magnitude is controlled by injection rate. The performed study provides a base for implementation of time-dependent probabilistic seismic hazard assessment for the project site

Big Data y áreas de oportunidad para la proyección del Sistema Inteligente de Transporte en Bogotá, Colombia

Today, the large cities of Colombia – especially Bogotá, due to the growth of its population (9.3 million with the arrival of immigrants) – demand the projection of intelligent public and private transport systems, as an achievement of the mobility policy of the Bogota Humana administration. Hence, this question arises: What are the challenges and areas of opportunity of adapting Big Data to project an Intelligent Transportation System for all citizens in Bogotá? Based on this question, our aim is to determine the contributions that Big Data offers as a collection center for the projection of an intelligent system for the city. Our research was proposed with a qualitative approach and a descriptive study. The review of some studies developed using Big Data techniques and content data analysis of their organized structure by the District Mobility Secretariat in Bogotá was included. The results allow guiding the contributions of Big Data after analyzing the structure of indicators offered by the data set. From these, we found gaps and voids that are concerning for the Intelligent Transportation System that is expected in the future for Bogotá.Hoy en día, en las grandes ciudades de Colombia, en especial en Bogotá, y debido al crecimiento de su población (9,3 millones con la llegada de inmigrantes), se exige una demanda de aporte a la proyección de sistemas inteligentes de transporte públicos y privados como un logro de la política de movilidad de la administración de la Bogotá Humana. De ahí surge el interrogante: ¿cuál es el desafío y las áreas de oportunidad de adaptar un Big Data en la proyección de un Sistema Inteligente de Transporte para todos los ciudadanos en Bogotá? A partir de esta pregunta, se propone determinar los aportes que el Big Data ofrece como centro de acopio en la proyección de un sistema inteligente para la ciudad. La indagación se plantea desde un enfoque cualitativo y un estudio descriptivo. Se incluye la revisión de algunos estudios realizados mediante las técnicas del Big Data y del análisis de datos de contenido de la estructura organizada de estos por la Secretaría Distrital de Movilidad en Bogotá. Los resultados permiten orientar los aportes del Big Data después de analizar la estructura de indicadores que ofrecen estos el conjunto de datos. A partir de estos, se encuentran brechas y vacíos preocupantes para el Sistema Inteligente de Transporte que se espera en el futuro para Bogotá

A Multistep docking and scoring protocol for congeneric series: Implementation on kinase DFG-out type II inhibitors

AIM: Rescoring of docking-binding poses can significantly improve molecular docking results. Our aim was to evaluate postprocessing docking protocols in order to determine the most suitable methodology for the study of the binding of congeneric compounds to protein kinases. MATERIALS & METHODS: Diverse ligand-receptor poses generated after docking were submitted to different relaxation protocols. The Molecular Mechanics Poisson-Boltzmann (Generalized Born) Surface Area approach was applied for the evaluation of the binding affinity of complexes obtained. The performance of various Molecular Mechanics Poisson-Boltzmann (Generalized Born) Surface Area methodologies was compared. RESULTS: The inclusion of a postprocessing protocol after docking enhances the quality of the results, although the best methodology is system dependent. CONCLUSION: An examination of the interactions established has allowed us to suggest useful modifications for the design of new type II inhibitors

Empoderamiento político de la mujer en el municipio de el Carmen de Viboral

RESUMEN: El presente trabajo fue el resultado de un proceso investigativo en relación al empoderamiento político de la mujer a través de historias de vida, comprendiendo el sistema sexo-género como una estructura social que establece relaciones de poder asimétricas entre los sexos. En este contexto, el empoderamiento de las mujeres es una estrategia que pretende restablecer dicha desigualdad, otorgando a las mujeres la capacidad de decidir tanto sobre los asuntos individuales y colectivos. A continuación, se encontrarán los resultados y aspectos importantes desarrollados durante la ejecución del proyecto de investigación, sus conclusiones finales y demás información importante para la titulación como Trabajadores Sociales.ABSTRACT: The present is the result of an investigative process to the political empowerment of women through life stories, understanding the sex-gender system as a social structure that establishes asymmetric power relations between the sexes. In this context, the empowerment of women is a strategy that aims to restore such inequality, giving women the ability to decide on both individual and collective issues. Below, you will find the results and important aspects developed during the execution of the research project, its final conclusions and other important information for the qualification as Social Workers

Study ab-initio of the stability of the structural and electronic properties of Bi1-xMgxO

Usando el método en primeros principios, hemos investigado las propiedades estructurales y electrónicas del compuesto Bi1-xMgxO con concentraciones, variando del 0%, 25%, 50%, 75% y 100% x del Bismuto en la fase NaCl. Los cálculos se realizaron en el marco de la teoría densidad funcional usando el método de ondas planas aumentadas y linealizadas (FP-LAPW), los efectos de intercambio y correlación se trataron usando la Aproximación del Gradiente Generalizado (GGA) implementado en el método Perdew - Burke- Ernzerhof [1].Using the method in first-principles, we have investigated the structural and electronic properties of the compound Bi1-xMgxO with concentrations varying of 0%, 25%, 50%, 75% and 100% x of bismuth in the phase NaCl.We  have  used  the Full  Potential  Linearized  Augmented  Plane  Wave  Method  (FP-LAPW).  The  exchange and  correlation  effects  are  treated  using  the  Generalized Gradient Approximation (GGA) as it is implemented in the Perdew - Burke- Ernzerhof- method [1]