Polar plots representing MSTID velocities (m/s) and azimuths for local fall, for the four selected networks, AS (top-left), CA (top-right), HW (bottom-left) and NZ (bottom-right), in the analysed period. Colour code: black for LT 00–04 h, light blue for LT 04–08 h, dark blue for LT 08–12 h, red for LT 12–16 h, green for LT 16–20 h and grey for LT 20–24 h (Figure extracted from Hernandez-Pajares et al. 2012).