DUMAGUETE CITY The Philippine Institute of Volcanology and Seismology (Phivolcs) seismic station in Sibulan, Negros Oriental on Friday disclosed that small earthquakes continue to be experienced by residents of Valencia town.
Engr. Jose Molas, who heads the Phivolcs-Sibulan station, said he believes the minor tremors are still aftershocks of the big one that shook Valencia and neighboring areas last January 27.
The earthquake, with its reference location in Dauin town, was recorded at Magnitude 4.7 with Intensity 4 being reported in this capital city and in Sibulan.
Molas said hundreds of earthquakes have since been reported, of varying strengths though less than M-4.7, since January to date.
The latest earthquakes that Molas reported were one on Thursday at 7:37 p.m., and prior to that, two on Feb. 24, one on Feb. 25, two on Feb. 26, none on Feb. 27, and one on Feb. 28.
These were so small and lasted for less than three seconds each and could not be plotted at the Phivolcs-Sibulan seismic monitoring station, he added.
It cannot be ascertained yet when these tremors, which Phivolcs attribute to a local fault, will stop but Molas assured that the earthquake activities are dwindling.
Meanwhile, a Phivolcs team from Manila has confirmed that earthquakes can be felt every now and then in Negros Oriental because of the presence of two faults, the Southern Negros fault and the Negros fault system in the North of the province.
Aside from the faults, the Negros trench is also situated nearby, according to Phivolcs research specialist 2 Raymond Patrick Maximo.
There will be earth movements every now and then in the province because of the sources, but as to when and where cannot be determined, he added.
The Phivolcs official said as long as there are active faults in the area, earthquakes can be expected.
He said the office is willing to conduct an information and education campaign through requests from the local government units concerned, to teach the locals on how to be prepared through lectures.
Maximo said Mt. Talinis (also known as Cuernos de Negros) is considered a potentially active volcano due to the presence of thermal manifestation but no recorded eruption in the past 10,000 years was reported.
A volcano is classified as active and potentially active if it has recorded eruptions within the 10,000 years cut off period.
The Phivolcs team from the agency's central office is in town to investigate two phenomena in Dauin townthat of the water turning blue in the Masaplod River, and the perceived widening hole of the Mag-aso Cave that is emitting steam.
Source: Philippine News Agency