Distribution of local velocity gradients derived from C¹⁸O velocity centroids. (a) Local velocity gradient magnitude map derived from Fig. 5b. (b) C¹⁸O (J = 1 −0) peak intensity map is overlaid with the normalized velocity gradient vectors. The blue and red arrows represent the average directions of the local velocity gradients in sub-regions indicated by the blue and red dashed boxes, respectively. Figures 6c and d is similar to Figs. 6a and b, but derived from Fig. 5e. In Fig. 6c, the three regions showing high velocity gradients are indicated by the three black dashed boxes. In each panel, the beam size is shown in the lower right corner, the two Planck cold clumps (G008.67+22.14 and G008.52+21.84) are indicated by the two open blue circles.