it with the SC-B(I) in panel (b), which begins in time with some delay. Obviously, both SCs look almost identical. However, time lag between their onset times at 80.8 MHz is about 11 minutes. Let us examine the panels (c), (d) and (e). Due to favorable observing conditions, the pairs of IPPs at any given moment are in alignment with the TID wavefronts. This explains the possibility of almost simultaneous detection of similar SCs in different places. At the same time, the crest C1 looks not straight along its length. In panel (c) it has a noticeable break point near $5^\circ$ in longitude that divides the crest on eastern and western parts. Thus, the eastern part shows a shear in the moving direction relative to the western part. Both parts propagate synchronously though (see the animation in Figure 4). This spatial displacement likely results in the time lag between the SC-G(I) and the SC-B(I). Indeed, from 09:48 UT to 09:58 UT – the SC-G(I) life time – the IPPs corresponding to the CALLISTO BIR antenna locate exactly on the western part of the crest C1. Only at 09:58 UT, when the IPP reaches the valley (white plus on dTEC map 