Volcanica最新文献

{"title":"Towards the development of the first permanent volcano observatory in Argentina","authors":"S. Garcia, G. Badi","doi":"10.30909/vol.04.s1.2148","DOIUrl":"https://doi.org/10.30909/vol.04.s1.2148","url":null,"abstract":"Argentina is a country that presents a complex situation regarding volcanic risk, where a total of 38 volcanoes are considered active. Although Argentina has no major cities close to these volcanoes, the continuous increase in economic activity and infrastructure near the Andean Codillera will increase exposure to volcano hazards in the future. Further, volcanic activity on the border between Argentina and Chile poses a unique challenge in relation to volcano monitoring and the management of volcanic emergencies. Additionally, due to atmospheric circulation patterns in the region (from West to East), Argentina is exposed to ashfall and ash dispersion from frequent explosive eruptions from Chilean volcanoes. Considering this, the Servicio Geológico Minero Argentino (SEGEMAR) decided to create and implement a Volcanic Threat Assessment Program, which includes the creation of the the first permanent volcano observatory for the country, the Observatorio Argentino de Vigilancia Volcánica (OAVV). Previously the Decepcion Island volcano observatory was created as a collaboration between the Instituto Antártico Argentino (IAA) and the Museo Nacional de Ciencias Naturales (MNCN) from the Consejo Superior de Investigaciones Científicas (CSIC). Argentina es un país que presenta una compleja situación con respecto al riesgo volcánico, donde un total de 38 volcanes son considerados activos. Aunque Argentina no tiene ciudades importantes cerca de estos volcanes, el continuo incremento de la actividad económica y la infraestructura cerca de la Cordillera de los Andes, generará en el futuro un aumento en la exposición a estos peligros. Además, la actividad volcánica en la frontera entre Argentina y Chile constituye un desafío único en relación con el monitoreo de volcanes y la gestión de emergencias volcánicas. Adicionalmente, debido a los patrones de circulación atmosférica en la región (desde el oeste hacia el este), Argentina está expuesta a la caída y dispersión de cenizas de las frecuentes erupciones explosivas de volcanes chilenos. Teniendo esto en cuenta, el Servicio Geológico Minero Argentino (SEGEMAR) decidió crear e implementar un programa de evaluación de amenazas volcánicas, que incluye, la creación del primer observatorio permanente de volcanes para el país, el Observatorio Argentino de Vigilancia Volcánica (OAVV). Previamente, el Observatorio Volcanológico de la Isla Decepción fue creado como una colaboración entre el Instituto Antártico Argentino (IAA) y el Museo Nacional de Ciencias Naturales (MNCN) del Consejo Superior de Investigaciones Científicas de España (CSIC).","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43066826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcano observatories and monitoring activities in Guatemala","authors":"A. Roca, Edgar Roberto Mérida Boogher, Carla Maria Fernanda Chun Quinillo, Dulce María Esther González Domínguez, G.A. Chigna Marroquin, F. J. Juárez Cacao, Peter Darwin Argueta Ordoñez","doi":"10.30909/vol.04.s1.203222","DOIUrl":"https://doi.org/10.30909/vol.04.s1.203222","url":null,"abstract":"The tectonic and volcanic environment in Guatemala is large and complex. Three major tectonic plates constantly interacting with each other, and a volcanic arc that extends from east to west in the southern part of the country, demand special attention in terms of monitoring and scientific studies. The Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH) is the institute in charge of executing these actions at the national and civil level.In recent years, INSIVUMEH has formed a volcanology team consisting of multi-disciplinary personnel that conducts the main volcanological monitoring and research activities. These activities include: seismic and acoustic signal analysis, evaluation and analysis of the volcanic hazards, installation and maintenance of monitoring equipment, and the socialization and dissemination of volcanic knowledge. Of all the volcanic structures in Guatemala, three volcanoes (Fuego, Pacaya, and Santiaguito) are in constant eruption and require all of the available resources (economic and human). These volcanoes present a wide range of volcanic hazards (regarding type and magnitude) that make daily monitoring a great challenge. One of the greatest goals achieved by the volcanology team has been the recent development of a Relative Threat Ranking of Guatemala Volcanoes, taking into account different parameters that allow improved planning in the future, both in monitoring and research. El ambiente tectónico y volcánico de Guatemala es extenso y complejo. Tres grandes placas tectónicas, que interactúan constantemente entre sí, y un arco volcánico, que se extiende de este a oeste en la parte sur del país, exigen especial atención en términos de monitoreo y estudios científicos. El Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH) es el instituto encargado de ejecutar estas acciones a nivel nacional y civil. En los últimos años, INSIVUMEH ha formado un equipo de vulcanología conformado por personal multidisciplinario que realiza las principales actividades de seguimiento e investigación vulcanológica. Estas actividades incluyen: análisis de señales sísmicas y acústicas, evaluación y análisis de peligros volcánicos, instalación y mantenimiento de equipos de monitoreo, y socialización y difusión del conocimiento volcánico. De todas las estructuras volcánicas de Guatemala, tres volcanes (Fuego, Pacaya y Santiaguito) están en constante erupción y requieren todos los recursos disponibles (económicos y humanos). Estos volcanes presentan una amplia gama de peligros volcánicos (en cuanto a tipo y magnitud), haciendo que el monitoreo diario sea un gran desafío. Uno de los mayores logros del equipo de vulcanología ha sido el desarrollo reciente de un Ranking de Peligrosidad Relativa de los Volcanes de Guatemala, tomando en cuenta diferentes parámetros que permitan una mejor planificación en el futuro, tanto en el monitoreo como en la investigación.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47261848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of active volcanoes in Peru by the Instituto Geofísico del Perú","authors":"Roger Machacca Puma, José Alberto Del Carpio Calienes, Marco Antonio Rivera Porras, Hernando Jhonny Tavera Huarache, Luisa Macedo Franco, Jorge Andrés Concha Calle, Ivonne Alejandra Lazarte Zerpa, Riky Gustavo Centeno Quico, Nino Celestino Puma Sacsi, José Luis Torres Aguilar, Katherine Andrea Vargas Alva, John Edward Cruz Igme, Lizbeth Velarde Quispe, Javier Vilca Nina, Alan Reinhold Malpartida Garay","doi":"10.30909/vol.04.s1.4971","DOIUrl":"https://doi.org/10.30909/vol.04.s1.4971","url":null,"abstract":"Volcano monitoring in Peru is carried out by the Instituto Geofísico del Perú (IGP), through its Centro Vulcanológico Nacional (CENVUL). CENVUL monitors 12 out of 16 volcanoes considered as historically active and potentially active in southern Peru and issues periodic bulletins about the volcanic activity and, depending on the alert-level of each volcano, also issues alerts and warnings of volcanic unrest, ash dispersion, and the occurrence of lahars. The information generated by CENVUL is disseminated to the civil authorities and the public through different information media (newsletters, e-mail, website, social media, mobile app, etc.). The IGP volcanology team was formed after the eruption of Sabancaya volcano in 1988. Since then, geophysical and geological studies, volcanic hazards assessments, and multidisciplinary monitoring realized by the IGP, have provided a comprehensive understanding of volcanic activity in Peru and forecast future eruptive scenarios. Currently, 80% of the historically active and potentially active volcanoes in Peru are equipped with networks of multiparameter instruments, with the seismic monitoring being the most widely implemented. In this report, we present the situation of volcanic monitoring in Peru, the monitoring networks, the techniques employed, as well as efforts to educate and inform the public and officials responsible for disaster risk management.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44708866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcano monitoring and hazard assessments in Chile","authors":"A. Amigo","doi":"10.30909/vol.04.s1.0120","DOIUrl":"https://doi.org/10.30909/vol.04.s1.0120","url":null,"abstract":"Volcanism in Chile occurs in a variety of tectonic settings but mostly in the context of oceanic-continental plate collision, including 92 potentially active volcanoes. There have been more than 30 documented eruptions in the last few centuries. The Servicio Nacional de Geología y Minería (SERNAGEOMIN) is a statutory agency of the Government of Chile responsible for volcano monitoring and hazard assessments across the country. After the impacts derived from volcanic activity at the end of the 20th century, SERNAGEOMIN created the Volcano Hazards Program and the Observatorio Volcanológico de Los Andes del Sur (OVDAS). Despite this effort, most volcanoes in Chile remained unmonitored. In 2008, the aftermath of the eruption of Chaitén led to a nationwide program in order to improve eruption forecasting, development of early warning capabilities and our state of readiness for volcanic impacts through hazard assessments. In the last decade responses to volcanic crises have been indubitably successful providing technical advice before and during volcanic eruptions. El volcanismo en Chile ocurre en una amplia variedad de regímenes tectónicos, aunque principalmente en el contexto de la colisión de placas. Alrededor de 92 volcanes son considerados potencialmente activos y más de 30 presentan actividad histórica documentada en los últimos siglos. El Servicio Nacional de Geología y Minería (SERNAGEOMIN) es la agencia gubernamental responsable de la evaluación de peligros y monitoreo de la actividad volcánica en el país. Como consecuencia de los impactos derivados de las erupciones volcánicas ocurridas hacia finales del siglo pasado, SERNAGEOMIN creó el Programa de Riesgo Volcánico y el Observatorio Volcanológico de los Andes del Sur (OVDAS). No obstante, a pesar de este esfuerzo la mayoría de los volcanes en Chile se mantenían sin monitoreo. Luego de los impactos derivados de la erupción del volcán Chaitén en 2008, un nuevo programa nacional fue creado con el fin de fortalecer la vigilancia y la evaluación de los peligros volcánicos en el país. En la última década, la respuesta a crisis volcánicas ha sido exitosa, proporcionando apoyo técnico en forma previa y durante erupciones.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49038787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nicaraguan volcanic monitoring program of the Instituto Nicaragüense de Estudios Territoriales","authors":"Eveling Espinoza, José Armando Saballos Peréz, Martha Navarro Collado, Virginia Tenorio Bellanger, Teresita Olivares Loaisiga, Martha Ibarra Carcache, David Chavarría González, Dodanis Matus Sanchez, Elvis Mendoza Rivera","doi":"10.30909/vol.04.s1.163181","DOIUrl":"https://doi.org/10.30909/vol.04.s1.163181","url":null,"abstract":"The Instituto Nicaragüense de Estudios Territoriales (INETER) is the institution responsible for volcano monitoring in Nicaragua. The Volcanology Division of the General Directorate of Geology and Geophysics currently monitors six active volcanoes by means of seismology, gas measurements, optical webcams, and visual and satellite observations. The volcano monitoring network that INETER maintains is in continuous expansion and modernization. Similarly, the number of technical and scientific personnel has been growing in the last few years. 2015 was the busiest year of the last two decades: Momotombo volcano erupted for the first time in 110 years, a lava lake was emplaced at the bottom of Masaya volcano’s Santiago crater, and Telica volcano experienced a phreatic phase from May to November. Although we have increased our monitoring capabilities, we still have many challenges for the near future that we expect to resolve with support from the national and international geoscientific community. El Instituto Nicaragüense de Estudios Territoriales (INETER) es la institución responsable de la vigilancia volcánica en Nicaragua. Su División de Vulcanología actualmente vigila seis volcanes activos por medio de sismicidad, emisiones de gases, cámaras ópticas, observaciones visuales y teledetección satelital. La red de monitoreo de volcanes que mantiene INETER está en continua expansión y modernización. Del mismo modo, el número de personal técnico y científico ha estado creciendo en los últimos años. El año 2015 fue el año más ocupado que tuvimos en las últimas dos décadas, debido a que el volcán Momotombo entró en erupción por primera vez en los últimos 110 años, se emplazó un lago de lava en el fondo del cráter Santiago (volcán Masaya), y el volcán Telica experimentó una fase freática de mayo a noviembre. A pesar del progreso realizado, todavía tenemos muchos desafíos para el futuro cercano que esperamos lograr con los recursos nacionales y de la comunidad geocientífica internacional.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42717272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcanic monitoring and hazard assessment in El Salvador","authors":"Rodolfo Antonio Castro Carcamo, E. Gutiérrez","doi":"10.30909/vol.04.s1.183201","DOIUrl":"https://doi.org/10.30909/vol.04.s1.183201","url":null,"abstract":"The Salvadorean volcanic range forms part of Central America Volcanic Arc and is located on the Pacific ring of fire. El Salvador is a country with at least twenty Holocene-active volcanic structures and where most of the population, including the metropolitan area of San Salvador, live near a volcanic complex. Currently, there are six active volcanoes that are continuously monitored by the Observatorio de Amenazas y Recursos Naturales, which is part of the Ministerio del Medio Ambiente y Recursos Naturales. Volcano monitoring involves seismic, geochemical, and visual monitoring techniques, among others. In addition to volcano monitoring and with the aim of early warning of future eruptions, volcanic hazard maps and networks of local observers have been developed. These initiatives together with the general directorate of civil protection, seek to meet the goal of reducing risk from volcanic activity in El Salvador.  La cadena volcánica salvadoreña forma parte del Arco Volcánico de América Central y está localizada dentro de la zona conocida como cinturón de fuego del Pacífico. El Salvador es un país donde se encuentran al menos 20 estructuras volcánicas que han estado activas durante el Holoceno y donde la mayor parte de la población, incluyendo la ciudad capital San Salvador, está ubicada en las proximidades de algún complejo volcánico. Actualmente, seis volcanes activos son continuamente monitoreados por el Observatorio de Amenazas y Recursos Naturales, que es parte del Ministerio del Medio Ambiente y Recursos Naturales. El monitoreo volcánico se realiza mediante técnicas de monitoreo sísmicas, geoquímicas, visuales, entre otras. Como complemento del trabajo de monitoreo, se han desarrollado mapas de amenaza volcánica y redes de observadores locales constituyendo así sistemas de alerta temprana ante futuras erupciones. Estas iniciativas, en conjunto con la dirección general de la protección civil, persiguen el objetivo de reducir el riesgo por actividad volcánica en El Salvador.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47207097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hazard assessment studies and multiparametric volcano monitoring developed by the Instituto Geológico, Minero y Metalúrgico in Peru","authors":"Rigoberto Aguilar Contreras, Edu Taipe Maquerhua, Yanet Antayhua Vera, Mayra Ortega Gonzales, Fredy Apaza Choquehuayta, Luis Cruz Mamani","doi":"10.30909/vol.04.s1.7392","DOIUrl":"https://doi.org/10.30909/vol.04.s1.7392","url":null,"abstract":"Urban development in the areas surrounding active volcanoes has led to increasing risks in southern Peru. In order to evaluate the hazard, the Instituto Geológico, Minero y Metalúrgico (INGEMMET) created a Volcano Observatory (OVI) to carry out detailed geological investigations to understand eruption histories and provide volcanic hazard maps. The generation of geological information on volcanoes has allowed the identification of scenarios and zoning of potentially impacted areas. This information has also allowed OVI to implement surveillance networks giving priority to the volcanoes that pose the greatest risk to the population, infrastructure, and economic activities. Since 2006, OVI has been running volcanic monitoring networks with a multidisciplinary approach, improving real-time transmission, and making timely forecasts. Based on geological information and the risk posed by the volcanoes, the greatest efforts have been made to monitor Sabancaya, Misti, Ubinas, and Ticsani volcanoes. Following the order of priorities, monitoring of Coropuna, Huaynaputina, Tutupaca and, Yucamane volcanoes has also been developed. In addition, OVI carries out routine education activities and diffusion of information that serve to manage volcanic risk in Peru. El desarrollo urbano en zonas aledañas a volcanes activos ha conllevado a la generación de riesgos cada vez mayores en el sur del Perú. Con la finalidad de evaluar el peligro, el Instituto Geológico, Minero y Metalúrgico (INGEMMET) creó un observatorio vulcanológico (OVI) para realizar estudios geológicos detallados que permitan conocer las historias eruptivas y elaborar mapas de peligros volcánicos. La generación de información geológica sobre los volcanes ha permitido la identificación de escenarios y la zonificación de áreas con potencial a ser afectadas. Esta información también ha permitido al OVI implementar sus redes de monitoreo priorizando los volcanes que representan mayor riesgo para la población, la infraestructura y las actividades económicas. Desde el año 2006, el OVI viene implementando redes de vigilancia volcánica con un enfoque multidisciplinario, mejorando la transmisión en tiempo real y realizando pronósticos oportunos. En base a la información geológica y el nivel de riesgo de los volcanes, se han puesto los mayores esfuerzos en monitorear los volcanes Sabancaya, Misti, Ubinas y Ticsani. Siguiendo el orden de prioridades, el OVI ha comenzado, también, el monitoreo de los volcanes Coropuna, Huaynaputina, Tutupaca y Yucamane. Además, el observatorio desarrolla actividades permanentes de educación y difusión de la información que sirven a la gestión del riesgo volcánico en el Perú.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48010916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracking secondary lahar flow paths and characterizing pulses and surges using infrasound array networks at Volcán de Fuego, Guatemala","authors":"A. Bosa, Jeffrey B. Johnson, S. De Angelis, J. Lyons, A. Roca, Jacob F. Anderson, A. Pineda","doi":"10.30909/vol.04.02.239256","DOIUrl":"https://doi.org/10.30909/vol.04.02.239256","url":null,"abstract":"Lahars are one of the greatest hazards at many volcanoes, including Volcán de Fuego (Guatemala). On 1 December 2018 at 8:00pm local Guatemala time (2:00:00 UTC), an hour-long lahar event was detected at Volcán de Fuego by two permanent seismo-acoustic stations along the Las Lajas channel on the southeast side. To establish the timing, duration, and speed of the lahar, infrasound array records were examined to identify both the source direction(s) and the correlated energy fluctuations at the two stations. Co-located seismic and acoustic signals were also examined, which indicated at least 5 distinct energy pulses within the lahar record.  We infer that varying sediment load and/or changes in flow velocity is shown by clear fluctuations in the acoustic and seismic power recorded at one of the stations. This particular event studied with infrasound provides insight into how lahars occur around Volcán de Fuego.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45686548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thick crust, hydrous magmas, and the paradox of voluminous cold magmatism","authors":"Cin-Ty A. Lee, Boda Liu","doi":"10.30909/vol.04.02.227238","DOIUrl":"https://doi.org/10.30909/vol.04.02.227238","url":null,"abstract":"Andesites are refined and “cold” magmas compared to their basaltic parents, yet large volumes of andesites are generated at continental arcs. We show that large andesitic plutons are favored when arc crust attains a thickness of ~60 km while mafic plutons are small and favored when arc crust is thin. Using simple thermal models, we show that large, long-lived and relatively cold partially molten zones, sustained by recharge of hydrous basaltic magmas, are favored at depth when arc crust is thick due to the reduced efficiency of heat loss with increasing crustal thickness. Thin crust and drier magmas favor hotter and thinner partially molten zones. Our study provides an explanation for the apparent paradox that the most voluminous magmas in continental arc settings are cold. The origin of andesites may be linked to the interplay between magmatic differentiation, the availability of water, and the processes that control crustal thickness.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44732841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Segment tip geometry of sheet intrusions, I: Theory and numerical models for the role of tip shape in controlling propagation pathways","authors":"R. Walker, T. Stephens, C. Greenfield, S. Gill, D. Healy, S. Poppe","doi":"10.30909/vol.04.02.189201","DOIUrl":"https://doi.org/10.30909/vol.04.02.189201","url":null,"abstract":"Inferences about sheet intrusion emplacement mechanisms have been built largely on field observations of intrusion tip zones: magmatic systems that did not grow beyond their observed state. Here we use finite element simulation of elliptical to superelliptical crack tips, representing observed natural sill segments, to show the effect of sill tip shape in controlling local stress concentrations, and the potential propagation pathways. Stress concentration magnitude and distribution is strongly affected by the position and magnitude of maximum tip curvature κmax. Elliptical tips concentrate stress in-plane with the sill, promoting coplanar growth. Superelliptical tips concentrate maximum tensile stress (σmax) and shear stress out-of-plane of the sill, which may promote non-coplanar growth, vertical thickening, or coplanar viscous indentation. We find that σmax =  Pe(1+ 2(√[aκmax]), where Pe is magma excess pressure and a is sill half length. At short length-scales, blunted tips locally generate large tensile stresses; at longer length-scales, elliptical-tipped sills become more efficient at concentrating stress than blunt sills.","PeriodicalId":33053,"journal":{"name":"Volcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47670527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}