Fig. 2: Edifice morphometric parameters.
From: Signatures of widespread Surtseyan volcanism at the northern Reykjanes ridge
a–h Bathymetric profiles across the Northern Reykjanes Ridge. Profiles south of ~63.2°N are marked blue, profiles north of ~63.2°N are marked red. Location is shown in Fig. 1b. Direction of all profiles is NW-SE. R: Relative Roughness. (i–k) Topographic profiles across the Reykjanes Peninsula. Location is shown in Fig. 1c. l Morphometric variability along 44 topographic profiles across the Reykjanes Ridge and Reykjanes Peninsula. The scatter plot shows relative large-scale ( > 20 m) surface roughness (defined as the standard deviation of slope) plotted against latitude. Profiles corresponding to (a–k) are highlighted in blue, while additional profiles are shown in orange. Error bars represent 99% confidence intervals derived from the slope variability within each profile. Semi-transparent shaded areas mark zones of interpreted relatively rough and smooth morphology. Dashed horizontal lines indicate average relative roughness values measured for these intervals. Latitude refers to the center point of each profile. All roughness values, coordinates, and associated uncertainties are summarized in Supplementary Table S1. The full set of profile locations is shown in Supplementary Fig. S2. Selected profiles on a joint depth axis are shown in Supplementary Fig. S3. m Height versus width for submarine cones from the Reykjanes Ridge north of ~63.2°N (green; this study). Grey, blue and purple circles indicate volcanoes mapped and characterized between ~63.2°N and ~57.83°N27. Orange circles indicate submarine volcanoes associated with the 1963 Surtsey eruption9. White circle indicates exposed Surtseyan Black Point volcano30. Semi-transparent orange and pink areas indicate morphometric fields for effusive flat-topped28 and shield volcanoes29 for comparison27. Dashed line indicate the average height-width ratios of volcanoes south of 63.2°N (0.13) and north of 63.2°N (0.07), as well as the height-width ratio (H/W) of 0.12, that has been proposed to distinguish explosive volcanism in deep-sea ( > 0.12) and shallow water ( < 0.12) with potential interaction of eruption columns with the sea surface89.
