Earth and Planetary Sciences ETDs

Publication Date

Fall 12-4-2019


Syn-rift igneous addition is necessary for successful continental breakup. Past investigations of passive margins have focused on strike perpendicular structure, but potential field anomalies indicate that significant crustal variations may be present. Data from 21 ocean bottom seismometers was acquired as part of the Eastern North American Margin Community Seismic Experiment and was used for tomographic inversion to create 2D velocity models of the margin that are representative of crustal structure. Crustal thickness varies along-strike from ~20 km to ~24 km and a high velocity (Vp > 7 km/s) layer is present at the base of the crust above the Moho. The high velocity layer is interpreted as magmatic addition to the margin and has a significantly variable thickness along both velocity models. This suggests that magmatic addition to the margin is more variable on smaller scales than previously thought. Additionally, a region where elevated lower crustal velocities are missing is coincident to the Northern Fracture Zone and may be evidence of long-lived segmentation.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Lindsay Lowe Worthington

Second Committee Member

Brandon Schmandt

Third Committee Member

Maria Beatrice Magnani




Continental Rifting, Active Source Seismology, Eastern North American Margin, Magmatic Addition, Velocity Modeling, Ocean Bottom Seismometers

Document Type