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Lg-wave attenuation in the Australian crust.
- Source :
-
Tectonophysics . Oct2017, Vol. 717, p413-424. 12p. - Publication Year :
- 2017
-
Abstract
- We estimate the Lg-wave quality factor (Q) across the Australian continent from vertical-component Lg waveforms. A tomographic inversion is performed to construct an Lg attenuation model for 58 frequencies between 0.05 and 10.0 Hz. The available spatial resolution is approximately 1.5° × 1.5° for the 0.5–2.0 Hz band. At 1.0 Hz, the Lg-wave Q over the whole island continent varies from 50 to 1250 with an average value of 850. Significant regional variations in the Lg-wave Q images tie well with many geological features and boundaries in Australia. The cratons in western, northern and southern parts of Australia usually have higher Q values (700–1250), while the volcanic regions, sedimentary basins and orogenic areas in eastern Australia are characterized by increased attenuation (lower Q values, 50–650). We determine the frequency-dependent Q of Lg waves for different blocks across Australia, and find the frequency dependence of Q is much more complex than the traditional single power law representation. When combined with the assumed geometrical spreading relation, the Lg Q maps provide a new way of assessing potential ground motion across the continent for any event location. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00401951
- Volume :
- 717
- Database :
- Academic Search Index
- Journal :
- Tectonophysics
- Publication Type :
- Academic Journal
- Accession number :
- 125806452
- Full Text :
- https://doi.org/10.1016/j.tecto.2017.08.022