A magnitude-5.7 quake rocked parts of Luzon, including parts of Metro Manila, Monday night, a day after a magnitude-6.1 quake hit Northern Luzon.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said the quake was recorded at 6:37 p.m., and was tectonic in origin.
In its bulletin, it said the epicenter was 12 km northeast of Lubang Island in Southern Luzon.
Phivolcs said the quake was felt at:
An Intensity IV quake is “moderately strong,” or “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,” Phivolcs said.
An Intensity III quake is described as “weak” while an Intensity II quake is “slightly felt.”
While it said no damage was likely, Phivolcs warned of possible aftershocks after the quake.
Phivolcs director Renato Solidum Jr. said the quake was not connected with the magnitude-6.1 quake that hit Northern Luzon Sunday.
Solidum said Sunday’s quake stemmed from the Manila Trench while MOnday’s quake was traced to the Lubang Fault.
The United States Geological Survey measured the quake at magnitude 5.4, and estimated the epicenter at 57 km west-northwest of Batangas; 88 km south-southwest of Manila; or 90 km northwest of Calapan, Mindoro.
Separate reports on dzBB said the quake was felt in Manila, Quezon City, Taguig, Batangas, and Mindoro. – KBK, GMA News
Here is a more detailed intensity map of the quake early this evening, March 21, 2011 from USGS.