| This thesis discusses the results of seismic tomography experiments investigating the internal structure of the East Pacific Rise (EPR) and its discontinuities. The EPR is not a linear feature but is partitioned by transform faults and non-transform offsets. Within the group of ridge-axis offsets, overlapping spreading centers (OSC) are of particular interest as they are restricted to fast-spreading mid-ocean ridges such as the EPR.; Three seismic refraction surveys centered at an axial discontinuity—the 9°03'N overlapping spreading center, at the center of the fastest spreading segment at 17°30'S, and on the flanks of the same segment, are used to investigate the structure of the EPR and its variability with along-axis segmentation. Counter to earlier predictions, we observe that the 9°03'N overlapping spreading center at the distal end of the 9°N segment does not have a reduced magma supply. |
