MANILA, Philippines — There have been over 200 aftershocks recorded since Masbate and nearby provinces were rocked by a Magnitude 6.6 earthquake on Tuesday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.
According to a detailed sequence of the earthquakes posted by Phivolcs on Wednesday, this includes the Magnitude 5.1 earthquake that hit 12 kilometers southwest of Cataingan on early Wednesday morning.
READ: Magnitude 5.2 earthquake jolts Masbate
State seismologists also revealed that the largest movement was preceded by what they call as foreshocks, or earthquakes before the main earthquake or mainshock.
“This earthquake was preceded by several foreshocks (pink dots) including the M4.9 and M4.6 earthquakes on August 11 and 17, respectively,” Phivolcs said.
“As of 10:30 am of 19 August 2020, there are already more than 200 aftershocks (blue-green dots) recorded including the M5.1 earthquake,” it added.
Just hours after the earthquake, it was already reported that there were 24 aftershocks that followed, the strongest then being a Magnitude 3.8 movement. Phivolcs previously said minor to moderate aftershocks are expected, although they are not discounting the possibility of a stronger quake.
READ: 24 aftershocks follow 6.6 magnitude quake in Masbate
The agency also noted that the similar foreshocks were also recorded back in 2003, when Masbate was also rocked by a strong Magnitude 6.2 earthquake — which created a 23 kilometer surface rupture.
Phivolcs suggests that the recent movement was caused by a “strike-slip faulting associated with the left-lateral movement” of the Philippine fault line’s Masbate segment.
“Masbate had also experienced a strong earthquake last 2003, which produced a 23-km long surface rupture. The 2003 Masbate earthquake also recorded foreshocks similar to the recent event,” Phivolcs said.
As of now, Masbate is enduring the effects of the strong earthquake, which led to extensive damage to infrastructures which local officials estimate to be way above P20 million.
It has also presented another dilemma for local governments as the earthquake displaced people currently in quarantine due to the COVID-19 pandemic.