1992/03/10 by Christopher Small, David T. Sandwell · 60 citations
Earth and Planetary Sciences · #earthquake and tectonic studies #Geological and Geochemical Analysis #Geology and Paleoclimatology Research #Ridge #Geology #Amplitude #Gravity anomaly #Geodesy #Gravimetry #Vertical deflection #Mid-ocean ridge #Ridge push #Surface roughness #Physics #Optics #Paleontology #Geotechnical engineering
paper · doi:10.1029/91jb02465
published in Journal of Geophysical Research Atmospheres 97(B3), 3235-3245 (American Geophysical Union)
openalex publication_date 1992/03/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Fast and slow spreading ridges have radically different morphologic and gravimetric characteristics. In this study, altimeter measurements from the Geosat Exact Repeat Mission (Geosat ERM) are used to investigate spreading rate dependence of the ridge axis gravity field. Gravity roughness provides an estimate of the amplitude of the gravity anomaly and is robust to small errors in the location of the ridge axis. We compute gravity roughness as a weighted root mean square (RMS) of the vertical deflection at 438 ridge crossings on the mid‐ocean ridge system. Ridge axis gravity anomalies show a decrease in amplitude with increasing spreading rate up to an intermediate rate of ∼60–80 mm/yr and almost no change at higher rates; overall the roughness decreases by a factor of 10 between the lowest and highest rates. In addition to the amplitude decrease, the range of roughness values observed at a given spreading rate shows a similar order of magnitude decrease with transition between 60 and 80 mm/yr. The transition of ridge axis gravity is most apparent at three relatively unexplored locations on the Southeast Indian Ridge and the Pacific‐Antarctic Rise; on these intermediate rate ridges the transition occurs abruptly across transform faults.