Negros Earthquake, July 14, 2011: 3.9-magnitude quake hits Sipalay City

Negros Occidental has been struck by an earthquake anew on July 14. According to the Philippine Volcanology and Seismology (Phivolcs), a magnitude 3.9 temblor was recorded off 42km Southeast of Sipalay City at 7:19 in the morning.

 The red dot is the epicenter of the July 14, 7 a.m. Negros Earthquake | Source: Phivolcs

The quake, which was tectonic in origin and was 1km deep, was felt at Intensity 1 at Sipalay City, Negros Occidental.

There have been no reports of damage from this quake.

Since July 11, more than 20 quakes had struck Negros with the strongest recorded at 4:47 a.m. on July 12 which measured 6.2 magnitude on the Richter Scale.

The Philippines sits on the Pacific Ring of Fire where earthquakes frequently occur.

Earthquake of 5.3 magnitude strikes General Santos City

Residents in some areas of the Philippines rather had a shaky morning as two 5+ magnitude quakes jolted different provinces in the country.

As previously reported here on Noypistuff, Occidental Mindoro was hit by a 5.7-magnitude temblor at 12:42 am today, May 23. Just over 2 hours after, another quake struck General Santos City, Mindanao which registered at magnitude 5.3 on the Richter scale.

According to the Philippine Institute of Volcanology and Seismology (Phivolcs), the epicenter of the newest quake was recorded off 75 kilometers (km) Southeast of General Santos City. The tectonic quake has a depth of 139 km.

There have been no immediate reports of damage from the earthquake. The Institute also does not expect tsunami nor aftershocks from the General Santos quake.

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.

Earthquake and 8 aftershocks jolt Isabela, Philippines

Earthquake in the Philippines on May 21, 2011 Update

An earthquake of 5.5 magnitude struck the northern Philippine province of Isabela at 9:08 p.m. on May 21st which was followed by 8 more earthquakes or aftershocks within 12 hours after the first quake. This is according to the Philippine Institute Volcanology and Seismology's (Phivolcs) earthquake bulletin.

The map shows the epicenter (red dot) of the quakes | Source: Phivolcs

The initial quake was felt at the following intensities in the following areas:

Intensity V - Ilagan, Isabela
Intensity IV- Tuguegarao City, Cagayan; Penablanca, Cagayan; Quirino Province; Tumawini, Isabela; Baler, Aurora
Intensity II - Baguio City; Tabuk, Kalinga

All the temblors were of tectonic origin with Ilagan, Isabela as a common epicenter.

Here are the time and magnitude of each aftershock:

21 May 2011 - 10:12 PM, Magnitude 3.4
21 May 2011 - 10:20 PM, Magnitude 2.4
22 May 2011 - 12:19 AM, Magnitude 2.1
22 May 2011 - 12:52 AM, Magnitude 2.3
22 May 2011 - 01:44 AM, Magnitude 3.3
22 May 2011 - 02:19 AM, Magnitude 2.3
22 May 2011 - 03:48 AM, Magnitude 2.6
22 May 2011 - 09:25 AM, Magnitude 2.4

Six more quakes jolted other Philippine provinces on May 21st.

There have been no reports of damage from the quakes as of present time.

Multiple earthquakes in one day is not unusual in the Philippines since it lies on the Pacific Ring of Fire where volcanic and seismic activities are more frequent.