Are you ready to rock with an M 7.2 Earthquake?

Are you ready if a magnitude 7.0 earthquakewith an epicenter originating from the Valley Fault System (VFS, Marikina) jolts you right now at your office? Is your family at home ready? What preparations have you done at this point? Have you bolted your tall cabinets and other freestanding furnitures to adjacent walls and fastened flourescent lights to the ceiling? Have you stocked a first aid cabinet with supplies? Does your office have a well-developed emergency plan? Does your office or company have an emergency team that is tasked to execute your emergency plan? How often have you conducted an emergency drill this year? Has your office or company coordinated with local authorities: the fire department, the police department and emergency rescue services for an evaluation of your emergency plan? Do you know how to administer first aid? How often have you donated blood this year? 

I have no intention to alarm you but aren't you curious why the Philippine Institute of Volcanology and Seismology (Phivolcs) is promoting a culture of preparedness and the Department of Public Works and Highways (DPWH) has been checking the safety of public structures (like schools) for about two years now. The most recent activity of the DPWH is the proposed removal of large advertising billboards and soon, the demolition of old public school buildings. 

"The Marikina Valley Fault, located in the eastern part of the study area, is the fault expected to cause the largest impact in the metropolis. Recent studies revealed that the Valley Fault caused at least 2, perhaps 4, earthquakes within the last 1400 years, the approximate return period is less than 500 years, and no event along the West Valley Fault is not known after the 16th century. This means that active phases of the Valley Faults are approaching. Many research studies indicate that the estimated magnitude will be around 7 or more."

from MMEIRS Map & Database Output Navigation System:

http://www.phivolcs.dost.gov.ph/Html/AboutStudy.htm

Accessed on Feb. 1, 2006

If the 16th Century is from 1500 to 1599, and we add 500 years (earthquake return period), that would give us 2000 to 2099.

CONCLUSIONS: MAGNITUDE AND FREQUENCY OF LARGE EARTHQUAKES ON THE MARIKINA VALLEY FAULT SYSTEM 
Empirical relations between rupture lengths and magnitudes of historic earthquakes in similar tectonic environments also argue for earthquakes of magnitude 6-7 on the Marikina Valley fault system. The ~30-km-long northern half of the west Marikina Valley fault, whose trace is marked by young, fault-related landforms, corresponds with earthquakes of this size. Although there is a possibility that a much longer section of the fault ruptured during earthquakes as large as magnitude 7.5, landforms suggesting repeated rupture of the west Marikina Valley fault southward beyond the Pasig River have yet to be identified ( Fig. 1B). The geomorphically expressed trace of the east Marikina Valley fault is even shorter (18 km long), so the chance of an earthquake larger than magnitude 7 on the faults of the Marikina Valley system seems small. 

from The U.S. Geological Survey Site: http://earthquake.usgs.gov/regional/pacnw/paleo/manila/index.html

from Fostering Disaster-Resistant Communities in the Philippines, http://www.pdc.org/PDCNewsWebArticles/2005MarikinaCity/

The image above is a portion of Marikina City, showing Barangays Barangka, Tañong, Provident Villages, and Jesus Dela Peña.  A part of the fault line,  the dark jagged area is very clear in the image. A red underline marks it on the image. Do you see the Marikina River forming a "U"? On its left is where Riverbanks Mall can be located. Above that "U" is Loyola Memorial Park.  In addition, there are several schools, colleges and universities that lie directly on the fault line. 

"The Ateneo campus in Loyola Heights is especially vulnerable to such an earthquake, since it is in the vicinity of the Valley Fault System (VFS).

The VFS, formerly known as the Marikina Valley Fault System, is a system of faults that runs across the eastern side of Metro Manila.

This fault system stretches from the mountainous areas of Rizal in the north, passing through Quezon City, Marikina, Taguig, and Muntinlupa, all the way to Tagaytay in the south."

from "After earthquake disaster in Asia: Is the Ateneo prepared? " By Kris Danielle P. Suarez 
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