Copyright 1994 by the American Geophysical Union. Further electronic distribution is not allowed. Figure 1 . Simplified Sea Beam map of portion of area of Plate 1 showing features discussed in text. 20 m. Temperature anomaly contours of megaplumes are from Baker et al .
Stars show location of high-temperature vents.
SCR is Split Cone Ridge. Index map at lower right shows location of mapped area. Inset at upper left shows locations of NOAA towed camera tracks made between 1987 and 1991. Figure 2 . Location shown in Figure 1.