Ambient noise station-correlation spectra for USArray stations

P12A-TA secondary stations.

L12A-TA M10A-TA M11A-TA M12A-TA M13A-TA N09A-TA N10A-TA N11A-TA N12A-TA N13A-TA
O08A-TA O09A-TA O10A-TA O11A-TA O12A-TA P08A-TA P09A-TA P10A-TA P11A-TA Q08A-TA
Q09A-TA Q11A-TA Q12A-TA R09A-TA R10A-TA S09A-TA
DUG-US