Extracting CMB diffractions by Super-virtual Interferometry


A supervirtual interferometry (SVI) method is presented that enhances the signal-to-noise ratio of core mantle boundary (CMB) diffractions by O(sqrt(N)), where N is the number of inline receivers that record the CMB diffractions from more than one event. Here, the events are chosen to be inline with the receivers along the same great circle. Results with synthetic data and teleseismic records recorded by USArray stations demonstrate that formerly unusable records with low signal-to-noise ratio (SNR) can be transformed into ones with high SNR where the CMB diffractions are clearly visible. Another benefit is that SVI allows for the virtual recording of an earthquake at stations not deployed during the time of the earthquake. This means that transient arrays such as USArray can extend the aperture of one recorded earthquake from the West coast to the East coast, even though the teleseism might have only been recorded during the West Coast deployment. In summary, SVI applied to teleseismic data can significantly enlarge the catalog and increase the aperture of usable records for analyzing CMB diffractions. The potential drawback of this method is that it generally provides the correct kinematics of CMB diffractions, but does not necessarily preserve correct amplitude information.

AGU Fall Meeting Abstracts