Douglas R. Toomey

TL;DR: In this paper, tomographic inversion images were used to image three anomalously high velocities, two of which extend from near the surface to a depth of about 3 km and the third one does not extend to the surface.

TL;DR: In this paper, the authors estimate the thermal structure and melt distribution of the lower crust in this region and allow them to compare it to shallow crustal and mantle structure, which is not compatible with models that require a large, segment-scale redistribution of melt within the crust.

TL;DR: In this paper, three-dimensional images of crustal seismic structure beneath the East Pacific Rise show pronounced axial heterogeneity over distances of a few kilometres, consistent with a zone of higher crustal temperatures midway between two discontinuities in the morphology of the rise axis.

TL;DR: 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 narrow region of high melt concentration beneath the spreading center, as predicted by some models.

TL;DR: In this paper, the authors used graph theory to estimate ray paths and travel times through strongly heterogeneous and densely parameterized seismic velocity models, and used a jumping strategy to minimize a functional that includes the penalty function, horizontal and vertical smoothing constraints, and prior model assumptions; all constraints applied to model perturbations are normalized to remove bias.