Fig. 6: Thin lithosphere with flat lithosphere–asthenosphere boundary (LAB) versus thick lithosphere.
From: Discovery of flat seismic reflections in the mantle beneath the young Juan de Fuca Plate
A schematic diagram showing two different models of the LAB. a Thin lithosphere and flat LAB: The top reflector imaged in the seismic sections (Fig. 3) is interpreted as the top of the LAB (blue). The deeper reflectors are interpreted as a presence of melt pockets (red ellipses). Pre-stack migrated traces at the crossing of three seismic profiles with the ridge perpendicular seismic reflection profile (black-white dashed line in Fig. 1) are shown. The red dotted lines represent isotherms calculated using the plate-cooling model62. Bathymetry is shown at an angle to add ‘depth’ to the two-dimensional illustration. The yellow triangles indicate hydrothermal vent fields. b Thick and heterogeneous lithosphere: The isotherms are represented by grey dashed lines obtained by the approach3 described in Methods. The thick blue line marks the base of the thick and heterogeneous lithosphere. The red dashed curve is the 1200 °C isotherm based on the plate-cooling model in (a).
