Day-to-day PSDs of the original vertical acceleration signal of station M11B for the (a) spring season and for the (b) vertical signal acceleration corrected from the compliance component using monthly spring stacked scTFFR and (c) the monthly autumn stacked scTFFR. The PSDs have been estimated using a 4-pi spheroidal window with |$N_w=$| 900 s, |$N_o=$| 450 s and a median average.