By Patrick Garcia The October 16 6.3-magnitude quake was just a “foreshock” to the more powerful 6.6-magnitude quake that struck the same area in Cotabato Tuesday, according to the Philippine Institute of Volcanology and Seismology (Phivolcs). The earthquake that hit 13 days before turned out to be just a warning of what Tuesday’s devastation had to offer. A ‘foreshock’, not an ‘aftershock’ because of the similarity of their epicenters. In an interview with ABS-CBN, Phivolcs Science Research Specialist 2 Erlington Olabere said that the previous 6.3 quake now becomes a foreshock because it has a lower magnitude. The October 16 quake had an epicenter 23 kilometers southwest of Makilala in North Cotabato and killed at least seven people while more than 200 others were injured Tuesday's quake was much more powerful and destructive where Phivolcs traced the origin of the 6.6-magnitude earthquake 25 kilometers (km) southeast of Tulunan, Cotabato – near the epicenter of the October 16 quake, and killed at least nine people and left more than 400 others injured. Hundreds of houses were also either totally damaged or partially destroyed. “The damage caused by the previous quake to some establishments in Digos City in Davao del Sur worsened after this morning (Tuesday) quake,” said Leslie Francisco, spokesperson of the Office of Civil Defense in Davao region. Phivolcs said that they are still studying if the new event was due to movement of the same fault that caused the October 16 quake.