Former Environment Sec. and Ramon Magsaysay Awardee Angel C. Alcala has alerted local government units in Dumaguete City, and the towns of Valencia, Sibulan, San Jose, and Amlan to the possibility of earthquakes and a flashflood from the Twin Lakes of Balinsasayao and Danao in Sibulan town because of the existence of four geologic faults that intersect at the southern edge of Lake Danao.
In an e-mailed statement titled Unsolicited Advice for Gov. Roel Degamo, Alcala said that while the probability of this scenario is not known, it is possible.
The same scenario happened earlier in Mt. Parker/Lake Maughan in South Cotabato, is possible.
He said that the Twin Lakes in Sibulan are separated by a normal fault, and the level of Lake Balinsasayao is higher than that of Lake Danao.
Another fault, he explained, is the Amlan fault about 1,400 meters west of the Lake. “Movements along these intersecting faults near or within the two Lakes during an earthquake could trigger a rupture on their walls, allowing water to seep, and eventually result in the collapse of the walls. Should this happen, flush flooding and massive mass movement or landslides would occur,” Dr. Alcala wrote.
Alcala urged Governor Degamo and the mayors of the three other towns to request the Philippine Institute of Volcanology & Seismology and the Mines & Geosciences Bureau to inspect the Talinis-Lake Balinsasayao area to determine whether the recent earthquake had affected the area, and to recommend appropriate actions on the part of the LGUs.
He also asked them to make the survey report public.
Last week, Phivolcs director Renato Solidum Jr. and MGB director Leo Jasareno gave a lecture to journalists and government officials in Dumaguete City on the science behind earthquakes and tsunamis.
Both officials of the Department of Science & Technology also called on all local government officials to lead in the mapping of the geological hazards in their own barangays and municipalities, and prevent people from building their homes in the vicinity of faults or in places exposed to floods and tsunamis.
“It is ironical,” Alcala noted, “that these events, which cause untold suffering of our people, are the very ones that caused the formation of the Philippines in the past geological ages.”
