PhiVolcs says 18 quakes from

two Bohol faults in past week

TAGBILARAN CITY, Bohol, Oct 26 (PIA)—The local earthquake monitoring stations of the Philippine Institute of Volcanology and Seismology (PHIVOLCS) in Bohol has noted the recent successive activities exhibited by two of the four noted faults in Bohol.

In fact, from October 16 to October 26, Bohol’s South Offshore fault has moved 18 times, while the East Bohol Fault moved 6 times in the past 10 days.

In PHIVOLCS latest earthquake information, it shows that last October 25 alone, the seismographs in the earthquake monitoring stations in Bohol and nearby areas recorded 8 earthquakes, six of those originating from east or west of Loay, while the remaining two would originate from east of Anda.

At the recent Kapihan sa PIA, Bohol PHIVOLCS chief Engr Nolan Evangelista noted that the recent activities in Bohol have been mostly emanating from the south offshore fault, and the east Bohol Fault, as contrasted with the North Bohol Fault which moved in 2013 and the Maribojoc Fault.

The fault, which did not move much then, has shown a series of activities that jolted many of the residents of southern Bohol, like the tremor that was observed October 25, at 10:52 PM which was recorded at magnitude 2.9 and was traced originating from 015 kms South 09° west of Loay.

That same day, movements monitored by PHIVOLCS include the 1.8 magnitude quake that happened 11:12 PM from 8 kilometers deep, 006 South 05° East of Loay, 5:44 PM with 1.7 magnitude reading from3 kilometers deep 15 South 09° West of Loay, the 1:23 AM 1.6 magnitude from 34 km deep, 11 south 16° east of Loay, the 12:25 AM with 1.5 magnitude from 34 kms deep, 11 South 16 ° east of Loay and the 12:00 AM 2.3 magnitude shake originating from 8 kilometers deep, 8 South and 03° east of Loay.

For those concerned with the successive movements, Engr. Evangelista said one good thing about constant small jolt is that it dissipates the energy build-up and this can weaken the pent-up energies which could snap anytime and cause a strong one.

And since the movements are generally from offshore Bohol fault, a 4.0 magnitude and larger can be enough to produce a considerable tsunami that would sweep into low lying towns, Evangelista warned.

Over this, the seismologist pressed on communities planning on the designation of high grounds as safe evacuation sites in the event of a tsunami.

The fact is, when it happens, Engr Evangelista said communities would only have a lead time of at least 5 minutes to run and get to the safe site, before the swell sweeps.

This window would be lost if people would not know what to do and where to go when the earthquake generates a tsunami that would sweep on the low lands.

Two more earthquakes were are monitored originating from the East Bohol Fault: one which happened 6:35 AM which generated 2.5 magnitude quake originating some 6 kilometer deep, 21 North 74°east of Anda and at 5:25 AM from 01 kilometers deep producing 3.2 magnitude quake that was traced from 21 North 84° east of Anda.

By the following day, October 24, PhiVolcs noted 5 seismic activities: 11:47 PM producing a 3.3 magnitude jolt for 3 kilometer deep west of Loay, one three minutes earlier with 2.6 magnitude form 4 kilometers deep still from west of Loay, , 4:46PM with 2.5 magnitude quake from east of Mabini from the east Bohol fault and at 3:46 PM with a 2.1 magnitude tremor originating from 26 kilometer deep, west of Lila.

Tw0 more tremors would be recorded on the 23rd: one at 8:08 P producing 1.6 magnitude movement traced some .33 kilometers deep West of Balilihan and 12:01 Am 2.0 magnitude some 9 kilometers deep east of Loay.

Another two more earthquakes were recorded on October 22: the 9:53 PM producing 4.2 magnitude jolt from the east of Loay and another at 11:26 AM from33 kilometers deep producing 1.4 magnitude tremor from east of Panglao.

On October 21, PhiVolcs noted 4 movements: 9:23 PM at 1.9 magnitude from east of Panglao, another at 3:01 PM producing 3.0 magnitude from 05 kilometers west of Loay, another 1.9 magnitude at 2:08 AM again from east of Loay and some 2.0 magnitude quake at 2:06 AM from west of Lila.

There were two more quakes monitored in October 20 all from Loay-Lila areas, two on the 19th again from Loay-Lila, one on the 18th from east of Pilar and 5 on the 16th mostly from East Bohol Fault.

Over all, in the last ten days, PHIVOLCS tracked 32 movements, all emanating from the three of four known Bohol faults, majority of which would come from the south offshore Bohol fault. (RAHC/PIA_7/Bohol)

DISASTER PREPAREDNESS. Should anything happen from the south Bohol offshore fault and produce a higher magnitude could generate a tsunami that could sweep lowland areas in southern Bohol in a matter of five minutes, according to PHIVOLCS Bohol head Engr Nolan Evangelista. Here, community preparedness plays so much to reduce the risks and mitigate loss of lives. (PIABohol)