|GLORIA survey of the East Pacific Rise near 3.5° S: tectonic and volcanic characteristics of a fast spreading mid-ocean rise|
Searle, R. (1984). GLORIA survey of the East Pacific Rise near 3.5° S: tectonic and volcanic characteristics of a fast spreading mid-ocean rise. Tectonophysics 221(3-4): 319-344
In: Tectonophysics. ELSEVIER SCIENCE BV: New York; London; Amsterdam. ISSN 0040-1951; e-ISSN 1879-3266, meer
Geological structures > Faults
Vehicles > Underwater vehicles > Unmanned vehicles > Towed vehicles > Gloria
A long-range, sidescan sonar (GLORIA) survey of an approximately 100-km square area of the East Pacific Rise crest between 3 degree S and 4 degree S extends results obtained in the same area by Lonsdale (1977) using Deep-tow. The axial, linear volcano was found to be continuous over a distance of 75 km. The presence of major inward and outward facing fault scarps was confirmed, but the GLORIA data show several distinct differences between the two fault sets. The inward dipping faults are more numerous, several distinct differences between the two fault sets. The inward dipping faults are more numerous, more closely spaced, and longer than the outward dipping ones, and their dip-slopes backscatter sound more extensively than those of the outward dipping faults; moreover, most of them appear to be formed within 2 km of the axis, whereas the majority of the outward dipping faults begin to develop between 5 and 8 km from the axis. These differences suggest that the two sets of faults have different origins. The horizontal pattern of inward dipping faults is similar to those observed on other mid-ocean rises at all spreading rates.