Three-dimensional estimate of the lithospheric effective elastic thickness of the Line ridge

• A new bathymetry grid was used to calculate Te of the lithosphere.
• Te along the Line ridge exhibits segmentations.
• Most of the Te along the Line ridge are located at the 150–300 °C isotherms depth.
• The lithosphere beneath the Line ridge may have been weakened by thermal and fracture activities.

Using a new bathymetry grid formed with vertical gravity gradient anomalies and ship soundings (BAT_VGG), a 1° × 1° lithospheric effective elastic thickness (Te) grid of the Line ridge was calculated with the moving window admittance technique. As a comparison, both the GEBCO_08 and SIO V15.1 bathymetry datasets were used to calculate Te as well. The results show that BAT_VGG is suitable for the calculation of lithospheric effective elastic thickness. The lithospheric effective elastic thickness of the Line ridge is shown to be low, in the range of 5.5–13 km, with an average of 8 km and a standard deviation of 1.3 km. Using the plate cooling model as a reference, most of the effective elastic thicknesses are controlled by the 150–300 °C isotherm. Seamounts are primarily present in two zones, with lithospheric ages of 20–35 Ma and 40–60 Ma, at the time of loading. Unlike the Hawaiian-Emperor chain, the lithospheric effective elastic thickness of the Line ridge does not change monotonously. The tectonic setting of the Line ridge is discussed in detail based on our Te results and the seamount ages collected from the literature. The results show that thermal and fracture activities must have played an important role in the origin and evolution of the ridge.