Copyright 1994 by the American Geophysical Union. Further electronic distribution is not allowed. This sudden change in structure is probably a fourth-order discontinuity as defined by Macdonald et al . The western boundary fault continues north to about 45 00'N where it becomes buried by younger flows. Sea Beam bathymetry of northern Cleft segment.
White ribbons are center beam of sidescan.
White is high reflectivity, and black is low reflectivity or shadows. Each swath is 1 km on each side with 1048 pixels across total swath. See Figure 3b for full names of abbreviations. Approximate latitudinal limits of sidescan swaths shown in Figure 4 are indicated by arrows. Interpretative map of sidescan in Figure 3a for northern Cleft segment.