Structure of the central Terror Rift, western Ross Sea, Antarctica

The Terror Rift is a zone of post-middle Miocene faulting and volcanism along the western margin of the
West Antarctic Rift System. A new seismic data set from NSF geophysical cruise NBP04-01, integrated with the
previous dataset to provide higher spatial resolution, has been interpreted in this study in order to improve
understanding of the architecture and history of the Terror Rift. The Terror Rift contains two components, a
structurally-controlled rollover anticlinal arch intruded by younger volcanic bodies and an associated synclinal basin.
Offsets and trend changes in fault patterns have been identified, coincident with shifts in the location of depocenters that
define rift sub-basins, indicating that the Terror Rift is segmented by transverse structures. Multiple phases of faulting
all post-date 17 Ma, including faults cutting the seafloor surface, indicating Neogene rifting and possible modern
activity.