Fig. 7
From: Ancient slabs beneath Arctic and surroundings: Izanagi, Farallon, and in-betweens
Vertical cross-sections of \({V}_{P}\) tomography showing main tectonic features. a–c Vertical cross-sections along three profiles as shown on the map d. The scale for \({V}_{P}\) perturbation (in %) is shown on the bottom right. The 410-km and 660-km discontinuities are shown in black solid lines. The thick black lines on the surface denote land areas. Areas with average hit counts < 20 are masked in white. The blue zones outlined by thin black lines are high-\({V}_{P}\) anomalies with amplitudes exceeding +0.25%. Red triangles: active volcanoes existing within ±2° of each profile; yellow stars: large earthquakes (M ≥ 6) that occurred during 1964–2016 within ±2° of each profile; green circles: points dividing the section equidistantly using the central angle of the earth, which correspond to those in d. On the map (d), red triangles: active volcanoes; thick green lines: plate boundaries