'Earthquake swarms' to be expected, might continue for weeks

The recent string of earthquakes in Batangas is to be expected and the public should be constantly on guard for their safety.

So-called "earthquake swarms" are normal following a big earthquake as the pressure on a fault eases up, geologist Dr. Mahar Lagmay told GMA News' Howie Severino on GMA News To Go on Monday morning, April 10.

"Normal naman yon... Tuluy-tuloy yon, kasi nag-aadjust ang siwang sa lupa," Lagmay said, saying that aftershocks could still happen weeks after the Magnitude 5.5 quake that hit Batangas on April 4.

When asked for comment on PHIVOLCS' assurance that there is no danger of tsunamis in the area, Lagmay explained that the possibility of tsunamis depends on the movement of the underlying fault.

"Pag ang galaw ay pahalang, hindi naman nadi-displace ang tubig. Pero pag ang galaw ay paangat, nagkakaroon ng disturbance sa tubig (at) yun ang nagge-generate ng tsunami," he explained.

Lagmay also warned that the threat of a strong earthquake continues to loom over Metro Manila. He explained that the Mabini Fault that caused the Batangas quakes is different from the West Valley Fault that runs under the nation's capital.

"Magkaibang fault po ito... pero kailangan po lagi paghandaan (ang lindol sa Maynila)," he said.

"Constant threat yan and we need to be constantly prepared. Nangyari man ang Batangas (quake) o hindi, the threat will always be there," Lagmay added. — TJD, GMA News