13 research outputs found
Depth-wise distribution and roughness analysis of the fresh-looking mounds on Concepcion Bank summit plateau.
<p>(A) Shaded relief of the Bank indicating area illustrated in B (color code for seafloor orientation identical to cross sections in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g005" target="_blank">Fig 5</a>). (B) Seafloor orientation map of the SW quadrant of the summit plateau with white dots highlighting the location of the fresh-looking mound forming a belt of up to 4 km width, close to the 600 m isobath. Colour code in A. Location in A and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g007" target="_blank">Fig 7</a>. (C) DEM detail showing scattered mounds amidst the sediment wave field. (D) Mound roughness vs. depth. Each mound is represented by a circle where diameter is proportional to mound area. Roughness has been quantified using the Vector Ruggedness Measure (VRM; Hobson [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.ref063" target="_blank">63</a>]).</p
General bathymetric map of the Canary Islands Seamount Province (CISP).
<p>Note the seamounts, islands and other relevant physiographic features as well as the regional surface current system. The Canary Basin, the Canary Ridge, the Canary Channel and its diapir belt extending northwards are indicated. Numbers attached to seamounts and islands represent individual oldest age estimate where available, after Van den Bogaard [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.ref028" target="_blank">28</a>]. AC: Azores Current. CC: Canary Current. CUC: Canary Upwelling Current. NEC: North EquatorialCurrent. SV: Selvagens. L: Lanzarote. F: Fuerteventura. GC: Gran Canaria. TF: Tenerife. LP: La Palma. EH: El Hierro. Bathymetry in meters from GEBCO.</p
Geomorphologic features of the Concepcion Bank.
<p>The summit plateau slope break (SPB) and the flank foot (FF) separate the main morphologic domains of the bank: (i) the summit plateau, (ii) the flanks, and (iii) the surrounding abyssal seafloor.</p
Depth and slope analysis of Concepcion Bank.
<p>(A) Depth and slope histograms. (B) Depth vs. slope plot and depth and slope histograms of the summit plateau. Dashed lines in the depth vs. slope plot indicate depths where slope changes markedly, thus helping identifying four depth ranges with distinct slope gradients and trends (158–500 m increasing, 500–750 m fairly constant, 750–1,000 m slightly decreasing, beyond 1,000 m increasing). (C) Depth vs. slope plot and depth and slope histograms of the bank flanks.</p
Slope and depth values of the summit plateau, flanks and surrounding deep seafloor of Concepcion Bank according to the depth profiles in Fig 5.
<p>Slope and depth values of the summit plateau, flanks and surrounding deep seafloor of Concepcion Bank according to the depth profiles in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g005" target="_blank">Fig 5</a>.</p
Bathymetry of Concepcion Bank and surrounding deep seafloor.
<p>(A) Bathymetric map from multibeam data (bright colours) and GEBCO (dull colours). The dashed lines delimit the three SWNW oriented parallel depth sectors described in section 4.4. (B) Bathymetric cross section along a SE-NW direction. Significant changes in slope are indicated. See location in A. Vertical exaggeration is 14:1. Summit location is indicated by a black triangle with a label showing its depth in meters.</p
Relationship between the depth of the summit plateau slope break (SPB) and the depth of the flank foot (FF) at Concepcion Bank.
<p>(A) Polar histogram showing the SPB depth (dashed line) vs. FF depth (continuous line). (B) Correlation plot between SPB depth and FF depth per geographic sector (NE to NW). (C) Above: Height difference between FF depth and SPB depth (crosses) and the mean value of this difference (dashed line). Below: SPB and FF depths around the bank.</p
Depth profiles of rim scarps extended in a clockwise direction from N.
<p>Rim scarps are located on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g007" target="_blank">Fig 7</a>. Vertical exaggeration is 20:1.</p
Internal waves hypothesis.
<p>Sketch illustrating the hypothesis of breaking internal waves as the main mechanism explaining the presence of the sediment wave field and the associated depth-restricted narrow belt of cold-water coral mounds on the SW sector of Conception Bank summit plateau. The bathymetric section is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g002" target="_blank">Fig 2B</a>. See location in the shaded-relief DTM included in this figure.</p
Distribution and properties of sediment waves at the Concepcion Bank summit plateau.
<p>(A) Shaded relief image showing the general distribution of sediment waves. (B) Details of the sediment wave field on the SW quadrant of the summit plateau, with colours representing different average crest directions and white arrows showing the interpreted wave migration directions. X-X’ and Z-Z’ lines locate sub-bottom profiles shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g009" target="_blank">Fig 9</a>. Scattered isolated positive features aligned approximately NS, close to the western boundary of the sediment wave field, are mounds that are imaged in Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g010" target="_blank">10</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g011" target="_blank">11</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156337#pone.0156337.g012" target="_blank">12</a>. (C) Polar diagram of the directions of sediment wave crests, with colours representing different crest directions according to B and length of sectors representing direction frequencies. (D) Crest direction vs. average crest depth plot. (E) Average crest depth frequency histogram. (F) Depth profiles across a sediment wave train. The brown solid line shows depth according to the Digital Elevation Model (DEM) of Concepcion Bank (left vertical scale), and the black solid line shows depth variation after subtracting the slope local trend along profile (detrended, right vertical axis). See location in B. Vertical exaggeration is 5:1 for the brown line and 15:1 for the black line.</p