Top panel shows the X- and H-components recorded at Manila and San Fernando magnetic observatories, respectively, from 4 to 6 August 1972. Data at San Fernando have been digitized from the original source and data at Manila have been digitized from Salcedo (1973) giant. Scanned magnetograms are included in Appendix A. Bottom panel shows hourly data of the H-component recorded at Kakioka (KAK, grey) and Hermanus (HER, green) magnetic observatories and the Dst index (black) from Kyoto World Data Center.