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Los terremotos de los glaciares son terremotos glaciales
Göran Ekström1, Meredith Nettles, Geoffrey A Abers
1Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA. ekstrom@seismology.harvard.edu
Science (New York, N.Y.)
|September 27, 2003
Resumen
Los científicos descubrieron terremotos moderados bajo los glaciares, previamente no detectados debido a la radiación sísmica de baja y alta frecuencia. Estos terremotos glaciales implican un deslizamiento lento del hielo, que dura significativamente más que los terremotos tectónicos.
Área de la Ciencia:
- La geofísica es la geofísica.
- Glaciología glaciología.
- Sismología Sismología Sismología.
Sus antecedentes:
- Los terremotos moderados debajo de los glaciares han pasado en gran medida desapercibidos.
- Los métodos sísmicos tradicionales a menudo pasan por alto estos eventos debido a los patrones únicos de radiación sísmica.
Objetivo del estudio:
- Informar sobre la detección de terremotos moderados desconocidos anteriormente que ocurren debajo de grandes glaciares.
- Para caracterizar la fuente sísmica y el comportamiento de estos terremotos glaciales.
Principales métodos:
- Detección de eventos sísmicos utilizando un análisis avanzado de las formas de onda sísmica.
- Modelado inverso de ondas sísmicas de largo período a partir de un evento bien registrado.
Principales resultados:
- Decenas de terremotos moderados previamente desconocidos se detectaron debajo de los glaciares.
- La radiación sísmica de estos eventos se agota a altas frecuencias.
- El mecanismo de la fuente identificado como el deslizamiento hacia abajo del hielo glacial.
- La duración del terremoto glacial (30-60 segundos) es 15-30 veces más larga que los terremotos tectónicos de magnitud similar.
Conclusiones:
- Los terremotos glaciales representan un fenómeno sísmico distinto.
- El mecanismo de deslizamiento lento explica su evasividad anterior.
- Se justifica una mayor investigación sobre la sismicidad glacial.
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