  We investigate the spatial and temporal variations of the high-degree mode
frequencies calculated over localized regions of the Sun during the extended
minimum phase between solar cycles 23 and 24. The frequency shifts measured
relative to the spatial average over the solar disk indicate that the
correlation between the frequency shift and magnetic field strength during the
low-activity phase is weak. The disk-averaged frequency shifts computed
relative to a minimal activity period also reveal a moderate correlation with
different activity indices, with a maximum linear correlation of about 72%.
From the investigation of the frequency shifts at different latitudinal bands,
we do not find a consensus period for the onset of solar cycle 24. The
frequency shifts corresponding to most of the latitudes in the northern
hemisphere and 30 degree south of the equator indicate the minimum epoch to be
February 2008, which is earlier than inferred from solar activity indices.
