Six earthquakes struck in the Moro Gulf off the coast of the southern Philippine Island of Mindanao early Saturday local time. The USGS measured one of the quakes at magnitude 7.3, although local seismologists measured the quake at magnitude 6.9. Initial findings by the Philippine Institute of Volcanology and Seismology also indicated that the quake could've come from as deep as 600 Km beneath the surface. This was followed up by a smaller aftershock- thought to be a magnitude 5.4 some 10 minutes later, which was in turn followed by a 7.4 quake just under an hour later. Seismologists believe that the epicenter for both the initial quakes and following aftershocks took place at least 500km under the surface.
Local officials were trying to determine if there were any damage or casualties. The Hawaii-based Pacific Tsunami Warning Center issued no tsunami alerts for the Moro Gulf.
Most recently, a magnitude 5.4 earthquake struck the Indonesian island of Sumatra some 1600 miles to the south and west of Mindanao. This wasn't even the strongest seismic event of the year in that part of Indonesia, as a magnitude 7.7 quake hit the island back in April.