The German Research Centre for Geosciences (GFZ) said a magnitude 5.7 earthquake struck Mindanao in the southern Philippines at 12:31 p.m. UTC on the 18th.
The epicenter was at 8.85 degrees north latitude and 126.51 degrees east longitude, with a depth of 10 km.
Earlier, at about 9:43 a.m. on the 10th, a magnitude 7.4 earthquake occurred off the east coast of Mindanao. The epicenter was at 7.25 degrees north latitude and 126.69 degrees east longitude, and the hypocenter depth was measured at 53 km.
At the time, the Philippine Institute of Volcanology and Seismology warned that there was a high possibility of additional damage from aftershocks following the strong quake. In fact, according to the EMSC and the USGS, magnitude 5.9 and 5.6 aftershocks occurred in succession immediately after the main shock.
The Philippines is located on the Pacific Ring of Fire, a seismic belt where earthquakes are frequent worldwide. According to EMSC statistics, over the past 10 years the Philippines has experienced an annual average of 826 earthquakes.