The high elevations of the Transantarctic Mountains (TAMs) have been suggested to be flexural in origin, but to date, the thermal contribution to uplift has yet to be quantified. Here, we present new P- and S-wave tomography images of the upper-mantle seismic structure beneath the central to northern TAMs, which reveal two, focused low-velocity anomalies beneath Ross Island and Terra Nova Bay that laterally extend beneath the TAMs front and that are connected by a low-velocity region constrained offshore within the Victoria Land Basin. The focused low velocities are interpreted as shallow regions of partial melt, connected by a broad region of slow (warm) upper mantle associated with Cenozoic extension along the Terror Rift. Thermal loading constraints based on our tomographic results are used to update flexural uplift models for the TAMs. Our findings confirm that thermal buoyancy is a principal component leading to the uplift of the TAMs but suggest that the thermal loading is variable along the TAMs front.
- Received 9 November 2016.
- Revision received 23 January 2017.
- Accepted 27 January 2017.
- ©The Authors
Gold Open Access: This paper is published under the terms of the CC-BY license.