Space-time maps with time on X-axis, constructed from slits 2 and 9 (See Fig. 1) and processed, in two coronal channels of AIA, 171 Å  and 193 Å. First two panels are for slit 2 (plume) and the last two are for slit 9 (interplume). The slanted solid line, marked in each panel, following the ridges is used for the propagation speed estimation. The horizontal dotted lines in each of these, enclose the rows averaged for wavelet analysis. Corresponding maps in 211 Å  are shown in Fig. 4.