We deployed a dense geodetic and seismological network in the Atacama seismic gap in Chile. We derive a microseismicity catalog of >30,000 events, time series from 70 GNSS stations, and utilize a ...transdimensional Bayesian inversion to estimate interplate locking. We identify two highly locked regions of different sizes whose geometries appear to control seismicity patterns. Interface seismicity concentrates beneath the coastline, just downdip of the highest locking. A region with lower locking (27.5°S–27.7°S) coincides with higher seismicity levels, a high number of repeating earthquakes and events extending toward the trench. This area is situated where the Copiapó Ridge is subducted and has shown previous indications of both seismic and aseismic slip, including an earthquake sequence in 2020. While these findings suggest that the structure of the downgoing oceanic plate prescribes patterns of interplate locking and seismicity, we note that the Taltal Ridge further north lacks a similar signature.
Plain Language Summary
Deformation along plate boundaries can occur seismically (i.e. through earthquakes) as well as aseismically (i.e. slipping slowly), and it is important to understand where each of these modes is dominant. Along the Chilean subduction contact, North‐Central Chile is the only place where aseismic deformation episodes have been observed so far. In order to study these processes in detail, we deployed and operated dense geodetic and seismological networks in this region. Analyzing the data collected by these networks, we find notable relationships between seismic and aseismic processes. Thousands of small earthquakes are found at the boundaries of locked regions, whereas no small earthquakes are found at their interior. Thus, implying such regions are mechanically coupled, that is, currently accumulating elastic deformation energy that will 1 day be released during a large earthquake. Along the North‐Central Chilean plate boundary, there is one region (around 27.5°S) that shows many signs of aseismic deformation. It is located where a chain of seamounts is being subducted, which is likely responsible for the different behavior of this segment.
Key Points
Microseismicity catalog and map of interplate locking derived for the Atacama 1922 seismic gap in North‐Central Chile
Seismicity in vicinity of plate interface coincides with downdip edge of high coupling
Seismo‐geodetic signals due to the subduction of the Copiapó ridge are prominent but negligible for the subducting Taltal Ridge
A novel residual a posteriori error estimator for the Oseen equations achieves efficiency and reliability by including multilevel contributions in its construction. Originates from the Multiscale ...Hybrid Mixed (MHM) method, the estimator combines residuals from the skeleton of the first-level partition of the domain, along with the contributions from element-wise approximations. The second-level estimator is local and infers the accuracy of multiscale basis computations as part of the MHM framework. Also, the face-degrees of freedom of the MHM method shape the estimator and induce a new face-adaptive procedure on the mesh’s skeleton only. As a result, the approach avoids re-meshing the first-level partition, which makes the adaptive process affordable and straightforward on complex geometries. Several numerical tests assess theoretical results.
Introducción. La deficiencia de fósforo (P) es una de las mayores limitantes para la producción de frijol (Phaseolus vulgaris L.), en especial en las regiones tropicales. La dentificación y el uso de ...cultivares tolerantes es esencial para reducir los costos de producción y la dependencia de los fertilizantes para suplir las necesidades de P. Objetivo. Describir el proceso de desarrollo y características agronómicas de la variedad UCR 55. Materiales y métodos. Esta variedad provino del cruzamiento NAB 44 // ROS 24 / G 13689, realizado en el Centro Internacional de Agricultura Tropical en Colombia. Fue evaluada de 1993 al 2000, por la Universidad de Costa Rica y el Ministerio de Agricultura y Ganadería. El desempeño agronómico y características de UCR 55 se determinaron con base en la evaluación de 6 viveros, 21 ensayos, 7 parcelas de validación y 5 parcelas comerciales, llevados a cabo en 15 localidades de Costa Rica. Resultados. UCR 55 es una variedad de grano negro opaco, con un peso promedio de 19,4 g en 100 semillas. En condiciones experimentales en suelos andisoles, obtuvo un rendimiento mayor a 1200 kg.ha-1 sin la adición de P. El rendimiento de UCR 55 en la etapa de validación fue de una media de 1336 comparado a 1000 kg.ha-1 del testigo comercial Guaymí. Además, UCR 55 rindió hasta 2345 kg.ha-1 en suelos volcánicos (Fraijanes) durante esta fase. UCR 55 posee una arquitectura erecta (tipo II), resistencia (valor ≤3) a Colletotrichum lindemuthianum y resistencia intermedia (valor ≤6) a Pseudocercospora griseola y a Thanatephorus cucumeris. Conclusiones. La adaptación de UCR 55 con suelos pobres en P (<10 ppm) y su resistencia a C. lindemuthianum, la hacen una variedad adecuada para la siembra de frijol en zonas con una altitud superior a 1000 msnm en Costa Rica.
Introducción. El frijol de grano rojo es el segundo más consumido en Costa Rica. El mercado penaliza el precio del grano rojo oscuro y exige variedades de tono claro y brillante, aunque, las personas ...productoras requieren cultivares resistentes a patógenos y de alto potencial de rendimiento. Objetivo. Describir el proceso de desarrollo y las principales características agronómicas de la variedad Tayní. Materiales y métodos. Esta variedad se derivó del cruzamiento triple Tío Canela 75 // SRC1-1-18 / SRC 1-12-1 realizado en 1999 en la Escuela Agrícola Panamericana (Honduras). Fue evaluada en Costa Rica entre el 2002 y el 2008, por el Instituto Nacional de Innovación y Transferencia en Tecnología Agropecuaria y la Universidad de Costa Rica. El comportamiento y características agronómicas de Tayní se determinaron con base en la información obtenida de la evaluación de 4 viveros de adaptación, 28 ensayos de rendimiento y 32 parcelas de validación, llevados a cabo bajo manejo del productor en 12 localidades de Costa Rica. La variedad se liberó el 23 de febrero del 2012 en Pueblo Nuevo, Upala, Alajuela. Resultados. Tayní es una variedad de grano rojo claro brillante, que obtuvo un rendimiento de 1450 kg.ha-1 bajo manejo de la empresa productora y de 2063 kg.ha-1 en condiciones experimentales. Posee un hábito de crecimiento tipo II, resistencia intermedia a Pseudocercospora griseola (mancha angular) y a Thanatheporus cucumeris (mustia hilachosa), y resistencia a los virus del mosaico común (gen I) y del mosaico dorado amarillo (gen bgm-I y QTL mayor SW12). La tonalidad del rojo de su grano (grado 5) es de mayor valor comercial que la de Cabécar (grado 6). Bajo condiciones lluviosas, el grano de Tayní se decolora menos que el de Cabécar (1,1 y 2,8%, respectivamente). Conclusiones. La tonalidad del color rojo del grano y menor porcentaje de decoloración, le dan a Tayní ventaja comercial con respecto a Cabécar, la variedad de grano rojo más sembrada en Costa Rica
We consider frictional contact problems in small strain elasticity discretized with finite elements and Nitsche method. Both bilateral and unilateral contact problems are taken into account, as well ...as both Tresca and Coulomb friction models. We derive residual a posteriori error estimates for each friction model, following (Chouly et al., in IMA J Numer Anal 38: 921–954, 2018). For the incomplete variant of Nitsche, we prove an upper bound for the dual norm of the residual, for Tresca and Coulomb friction, without any extra regularity and without a saturation assumption. We prove also local lower bounds. Numerical experiments allow to assess the accuracy of the estimates and their interest for adaptive meshing in different situations.
The aim of this paper is to introduce residual type a posteriori error estimators for a Poisson problem with a Dirac delta source term, in Lp norm and W1,p seminorm. The estimators are proved to ...yield global upper and local lower bounds for the corresponding norms of the error. They are used to guide adaptive procedures, which are experimentally shown to lead to optimal orders of convergence.
We discuss how slip conditions for the Stokes equation can be handled using Nitsche method, for a stabilized finite element discretization. Emphasis is made on the interplay between stabilization and ...Nitsche terms. Well-posedness of the discrete problem and optimal convergence rates, in natural norm for the velocity and the pressure, are established, and illustrated with various numerical experiments. The proposed method fits naturally in the context of a finite element implementation while being accurate, and allows an increased flexibility in the choice of the finite element pairs.
We propose a new family of multiscale hybrid mixed methods (MHM) for the reactive–advective–diffusive (RAD) equation in complex domains. It generalizes the MHM methods originally proposed in Harder, ...Paredes and Valentin (2013 and 2015) to polytopal meshes and covers all asymptotic regimes of the model within a single mathematical framework. As a result, the skeletal MHM method changes its structure automatically, from primal to mixed forms, depending on the asymptotic of local RAD solutions, which respond to multiscale basis functions at the element level. We establish the existence, uniqueness, and optimality of the MHM solution with respect to two-scale mesh parameters, relating it to the solution of a discrete primal hybrid version of the RAD model. Furthermore, we estimate the condition number of the matrices associated with the local problems responsible for upscaling, from which we establish upper limits for the condition number of the algebraic system associated with the MHM method. Numerical experiments validate theoretical results.
In this work we develop an a posteriori error estimator, of the hierarchical type, for the Local Projection Stabilized (LPS) finite element method introduced in 5, applied to the incompressible ...Navier–Stokes equations. The technique uses the solution of locals problems posed on appropriate finite dimensional spaces of bubble-like functions, to approach the error. Several numerical tests confirm the theoretical properties of the estimator and its performance.
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