Slope-Weighted Eccentricity: Automatic Terrain Classification of
Atlantic Ocean Crust
Abstract
The shapes and directionality of bathymetry at slow-spreading ridges are
key to understanding the magmatic or tectonic emplacement of the crust.
Magmatic terrain is marked by linearly fault-bounded abyssal hills,
while tectonic terrain is marked by long-lived detachment faults,
forming Oceanic Core Complexes (OCCs). However, the quantitative
description of these crustal regimes is still limited. We develop a
novel automated terrain classification technique and test it at the
13-15° N section of the Mid-Atlantic Ridge. The algorithm uses the
Slope-Weighted Eccentricity (SWE) of the horizontal eigenvalues to
represent surface directionality and reveal crustal tectonic fabric. The
application of this new technique yields results consistent with
qualitative interpretation. Thus, it provides both new insights into the
mid-oceanic ridge spreading and the potential to automate such mapping
with different sets of grids, such as gravity and magnetic data in
regions further away from the ridge where sediments mask sea-bed
features.