3 quakes hit Luzon, Visayas

MANILA, Philippines—(UPDATE 3) Three earthquakes, two of them in the northern Luzon area, occurred in the country Tuesday, the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

The first quake, which had a magnitude of 5.7, occurred at 3:58 a.m. The epicenter was estimated at 29 kilometers northeast of Laoag City.

It had a shallow depth of 40 kilometers and was tectonic in origin.

It was felt at Intensity 5 in Burgos, Pasuiquin, Laoag, Sarrat and Batac, all in Ilocos Norte; Intensity 4 in Sinait in Ilocos Sur, Buguey and Gonzaga in Cagayan and Lubuagan, Kalinga Apayao; Intensity 2 in Callo, Penablanca, Sta. Ana, and Tuguegarao all in Cagayan; and Intensity 2 in Vigan, Ilocos Sur and Baguio City.

At Intensity 5, an earthquake can be felt by people indoors and outdoors with strong shaking and rocking felt throughout a building.

The agency said they expected damage to be reported and aftershocks to occur.

At 4:44 a.m., another quake occurred in the Visayas region, this time at magnitude 3.8 with the epicenter estimated at 16 kilometers northeast of Ormoc City.

The shallow quake had a depth of five kilometers and the Phivolcs said it was tectonic in origin.

The tremor was felt as Intensity 2 in Barangay (village) Tongonan, Ormoc City and Kananga, Leyte.

At 7:01 a.m., another quake occurred in northern Luzon. The last quake was measured at magnitude 3.2 with the epicenter estimated at 39 kilometers northeast of Laoag City.

This quake was also shallow with a depth of 12 kilometers and was also tectonic in origin.

It was felt at Intensity 2 in Pasuquin, Ilocos Norte.

Intensity 5 means the earthquake is strong enough to rouse people from sleep and everybody feels the shaking. Intensity 4 means almost all of the people indoors feel the ground movement and that objects could be seen moving due to the shaking. Intensity 3 means many people indoors feel the movement but people outside might not feel the movement. Intensity 2 means people at rest may feel the tremor.

The Philippines has one of the longest fault systems in the world, the Philippine Fault Zone, running from Northern Luzon down to Mindanao. This fault zone is also sandwiched by the Manila Trench out in the sea to the west and the Philippine Trench also out in the sea to the east.

The country also lies in a region known as the Pacific Ring of Fire that is volcanically and seismologically active due to a network of faults and continental plates, with about 80 percent of the earthquakes in the world occurring in this area.

The Philippines experiences from 20 to 25 earthquakes every day, most of them imperceptible.

SOURCE: http://newsinfo.inquirer.net/breakingnews/regions/view/20100323-260316/3-quakes-hit-Luzon-Visayas