Nicaragua Migration ImageMARGINS/TUCAN 2004-6

(MacKenzie et al., submitted, 2009)

Moho

slabsurface

dVs/Vs

fast

slow

et al: Abers, Rondenay, Fischer

Conversion widths in stacked receiver functions

• Sharp discontinuities or gradients?(compositional or thermal?)

lag from conversion, sec

Back-arcMoho

Blue: data stack .03-1 Hz; Red: best-fit Gaussian

w = 1.9 sRmax = 7-8 km

Compositional?w = 1.6 sRmax = 5-8 km

Thermal?w = 6.1 sRmax=17-30 km

Receiver functions

w

R = 1/2fmx|T| ~ max. width of boundary, km

(MacKenzie et al., submitted, 2009)