Theory of a New Manila Bay Fault Line are UNVERIFIED

In a number of articles that surface yesterday, Dr. Kelvin Rodolfo claims that a new fault line has been discovered in Manila Bay.

Rodolfo, a Filipino geologist whose research focuses on ground subsidence, made the claims based on satellite data supposedly showing “vertical land movement in Metro Manila, indicating to them possible existence of another fault in this largest and earthquake-prone Philippine urban hub.”  (See “Another Fault In Metro Manila”)

The geologist further says:

“Some areas below that line are rising faster than those above it – we might have a fault there.”

…

Data he presented show the fast-rising areas include those south of Manila, the Philippines’ capital, and north of Taguig City.

Land elevation there could be rising as much as 10 mm/year to 15 mm/year, the data further indicate.

Rodolfo and colleagues discovered such land movement using satellite data from their investigation of subsidence in Metro Manila and its vicinity.

Rodolfo’s findings on the location of the fault are somewhat confusing, because in another article published on the same day he claims the fault not to be in Manila Bay but  “near the cities of Caloocan, Malabon and Navotas.”

Because of the gravity of the claim and the enormity the implications, such a findings must necessarily be validated by other scientists.

Rodolfo’s claims are incidental to the work of research he has been doing on “ground subsidence” where he theorizes that the excessive pumping of groundwater is causing parts of Metro Manila to sink at a rapid rate.  His incidental findings could mean that he may be appreciating data supposedly showing the rising of land in relation to the sinking of land due to ground water extraction.

Moreover, in accordance with the deductive logic of the scientific process, Rodolfo’s hypothesis does not conclusively eliminate other explanations for the “rise of land”.

In another article on the supposed “new fault”, this time in Manila Standard, Dr. Renato Solidum says Rodolfo’s finding have yet to be verified.

But Director Renato Solidum, of the Philippine Volcanology and Seismology,  said parallel studies are being made.

“Phivolcs has been doing interferometry also there are many observations needed to explain why there is subsidence and relate it to fault,” he said.

In verifying the existence of a new seismic fault, numerous techniques must be used to confirm or at least see if findings are consistent across a number of techniques.

Apart from satellite data, scientists also use interferometry which is  “a family of techniques in which waves, usually electromagnetic, are superimposed in order to extract information about the waves.

“Interferometry is an important investigative technique in the fields of … …seismology,“

To further illustrate the need to validate findings using a variety of techniques, we have to consider the work done in other areas where it was claimed that a new fault was detected.  Here is an article on the Lake Tahoe Fault:

Using a new high-resolution imaging technology, known as bare-earth airborne LiDAR (Light Detection And Ranging), combined with field observations and modern geochronology, USGS scientists, and their colleagues from the University of Nevada, Reno; the University of California, Berkeley; and the U.S. Army Corps of Engineers, have confirmed the existence of previously suspected faults.