Sunday, May 22, 2011

Earthquake in the Philippines, May 23, 2011: M5.7 quake shakes Occidental Mindoro

Following the Isabela earthquake, another earthquake of 5+ magnitude rocked the Philippines in just over a day.

The newest temblor struck Mamburao, Occidental Mindoro at 12:42 a.m. on May 23. It was of tectonic origin and has an intermediate depth of 106 kilometers, according to the Philippine Institute of Volcanology and Seismology's (Phivolcs) latest earthquake bulletin.

The quake was reported at the following intensities in the following areas:

Intensity IV - Ilijan, Batangas
Intensity III - Tagaytay City; Malate, Manila; Pto. Galera;
Alabang, Muntinlupa; Clark,Pampanga
Intensity II - Malolos, Bulacan
Intensity I - Nichols, Pasay

The above intensities are defined by the Philvolcs as:

Intensity I (Scarcely Perceptible) - Perceptible to people under favorable circumstances. Delicately balanced objects are disturbed slightly. Still Water in containers oscillates slowly.

Intensity II (Slightly Felt) - Felt by few individuals at rest indoors. Hanging objects swing slightly. Still Water in containers oscillates noticeably.

Intensity III (Weak) - Felt by many people indoors especially in upper floors of buildings. Vibration is felt like one passing of a light truck. Dizziness and nausea are experienced by some people. Hanging objects swing moderately. Still water in containers oscillates moderately.

Intensity IV (Moderately Strong) - Felt generally by people indoors and by some people outdoors. Light sleepers are awakened. Vibration is felt like a passing of heavy truck. Hanging objects swing considerably. Dinner, plates, glasses, windows and doors rattle. Floors and walls of wood framed buildings creak. Standing motor cars may rock slightly. Liquids in containers are slightly disturbed. Water in containers oscillate strongly. Rumbling sound may sometimes be heard.

There have been no immediate reports of damage from the quake.

The Philippines sits on the Pacific Ring of Fire where volcanic and seismic activities are more frequent than in most areas of the world.