Fig. 1. Europan Class 2 ridges

Examples of Class 2 ridges (Greenberg et al., 1998a) exhibit identifying traits. These ridges are elevated, frequently in a platform-shape, and are internally striated. They are wider than the doublet Class 1 ridges but are generally narrower than bands. Class 2 ridges are bilaterally symmetrical and have a pronounced central groove. Examples include: (1) a ridge located in the antijovian wedges region (E12 orbit; C2 in Fig. 4a), which strongly resembles Ridge C2a, the ridge we examine in Section II.B; (2) a ridge found on the leading side near the "E11 band" (Sec. III.B.3); (3) a ridge on the trailing side (E6 orbit), near Androgeos Linea; and (4) Ridge B (Fig. 2a), which is cut by Ridge C2a.