Dr. Anna Foster : The USArray Transportable Array... (17-11-2016)

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Dr. Anna Foster (Geotop)

The USArray Transportable Array: Making high-resolution, large-scale surface-wave studies (and many other things) possible

Jeudi 17 novembre 2016 à 13h30/ Thursday, November 17, 2016, 1:30pm

Local PK-7605, 201 ave. Président-Kennedy, UQAM

Résumé / Abstract :

The key to large-scale seismic studies is large-scale data collection: the USArray Transportable Array (TA) is a prime example of this. This array deployed approximately 400 seismometers at 70 km spacing for 2 years, before progressively moving across the contiguous United States. After over 10 years of data collection, this portion of the project is now complete and continuing in Alaska. The TA left behind a massive data set that has been used for many things, from the crust down to the core. Here, I will discuss a two-station method to make surface-wave phase-velocity measurements, including a correction for off-great-circle path arrivals, and show Love and Rayleigh wave phase-velocity maps from the complete array. These maps range from 25-125 s period, roughly representing the structure at 40-250 km depth, and provide interesting comparisons to observed surface features, and our present-day understanding of the upper mantle.  The results are useful for a better interpretation of the mantle structure, and can be used for the study of 3-D structure and anisotropy.