Poisson's Ratio Structure Beneath the Nazca Ridge

Ridge-like lower mantle structure beneath South Africa

[1] Recent (ScS-S) results from probing the deep structure beneath southern Africa display strong delays of up to 10 s at distances beyond 90 . Such delays could be explained by long-period tomographic models containing smooth (weak) features with the addition of rough (strong) D00 structure (3–9% drops in shear velocities). However, these structures cannot explain the (SKS-S) differentials sam...

Upper mantle anisotropy beneath Peru from SKS splitting: Constraints on flat slab dynamics and interaction with the Nazca Ridge

Imaging the Deep Seismic Structure Beneath a Mid-Ocean Ridge: The MELT Experiment

The Mantle Electromagnetic and Tomography (MELT ) Experiment was designed to distinguish between competing models of magma generation beneath mid-ocean ridges. Seismological observations demonstrate that basaltic melt is present beneath the East Pacific Rise spreading center in a broad region several hundred kilometers across and extending to depths greater than 100 kilometers, not just in a na...

Imaging the deep seismic structure beneath a mid-ocean ridge: the MELT experiment

The Mantle Electromagnetic and Tomography (MELT) Experiment was designed to distinguish between competing models of magma generation beneath mid-ocean ridges. Seismological observations demonstrate that basaltic melt is present beneath the East Pacific Rise spreading center in a broad region several hundred kilometers across and extending to depths greater than 100 kilometers, not just in a nar...

Serial monogamy and sex ratio bias in Nazca boobies.

Biased operational sex ratios (OSRs) can drive sexual selection on members of the over-represented sex via competition for mates, causing higher variance and skew in reproductive success (RS) among them if an individual's quality is a persistent characteristic. Alternatively, costs of reproduction may degrade breeding performance, creating the opportunity for members of the limiting sex to swit...