INTERPRETATION OF SMALL TO MODERATE SEISMICITY UNDER IRAZÚ VOLCANO

 

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Библиографические подробности
Авторы: Cascante-Matamoros, Monserrat, Hernán Porras-Espinoza, Hernán Porras-Espinoza
Формат: artículo original
Статус:Versión publicada
Дата публикации:2017
Описание:Historically, Irazú volcano has experienced sporadic volcano-tectonic seismicity. Based on this seismic activity, we have calculated a total of 7 focal mechanisms using the polarity of first arrivals, and have calculated stress inversion using the PTB method. The results indicate that the seismic activity is between 0-6 km deep, mainly in the W flank of the volcanic massif. Focal mechanisms show a diverse cinematics, the angles of the planes have an average of 55°, and the direction of inclination is toward the SWW. Stress inversion suggests a pure extension with a value of R’= 0,5. Therefore, the depth of the seismic events and the average angle of the planes makes us suppose that the brittle-ductile transition is above the one theoretically established. We suggest that the seismic source under the Irazú Volcano is directly related to the presence of magma near the surface, which causes the thinning of the crust and the related normal faults.
Страна:Portal de Revistas UNA
Институт:Universidad Nacional de Costa Rica
Repositorio:Portal de Revistas UNA
Язык:Español
OAI Identifier:oai:ojs.www.una.ac.cr:article/9377
Online-ссылка:https://www.revistas.una.ac.cr/index.php/geografica/article/view/9377
Ключевое слово:Irazú volcano
seismicity
focal mechanism
normal faults
volcán Irazú
sismicidad
mecanismos focales
fallas normales