Continent-Wide Maps of 5-50 S Rayleigh-Wave Attenuation for Eurasia Inferred from Maps of 1-Hz Lg Coda Q and its Frequency Dependence
Abstract
The crust of southern Eurasia is characterised by low Q values (200-450) for 1-Hz Lg coda everywhere from Spain to China. The north-south extent of that low-Q zone varies from being relatively narrow in western Europe to being very broad from the Middle East to China. Those variations in both magnitude and width first became apparent with the development of continent-wide tomographic maps of Lg coda Q. The most recent mappings of Lg coda Q values at 1 Hz, completed over the past year, show that the four regions of lowest Q values occur in regions marked by high levels of seismicity. Q instable regions of Eurasia varies between about 450 and 900 with the highest values occurring in the Indian shield, the East European Craton, the Siberian Craton, and the Khasakh Platform. The maps reveal relatively, and unexpectedly, low values of Q in the Siberian Trap region of Siberia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2006
- Accession Number
- ADA468833
Entities
People
- Brian J. Mitchell
- Lianli Cong
Organizations
- Saint Louis University