Post by LATAGAW on Aug 26, 2005 13:21:26 GMT 8
[glow=red,2,300]3 fault lines risk 9 municipalities
Three active fault lines within the province are placing at least nine municipalities at a "danger zone" for earthquakes.
The biggest in scope is the fault line situated at Tayong Peak in Loay town that reaches as far as Sierra Bullones and Jagna towns.
Engineer Nolan Evangelista, seismic research analyst, told the Chronicle that at least two tremors are noticeable every year while weaker tremore are registered only in the intruments at the Philippine Institute of Volcanology and Seismology (Phivolcs) based in Ubujan district, this city.
The two other fault lines are situated in Anda town and another in Clarin-Tubigon area.
The nine municipalities listed as under the "danger zone" are Anda, Guindulman, Duero, Jagna, Loboc, Tubigon, Clarin, Inabanga and even Calape town.
The Philvocs official bared this after a massive landslide hitting sitios Balikbayan and Ilaud in barangay Mayana, Jagna town.
No less than 11 houses were destroyed during the landslide last Monday while residents within the 40-hectare radius surrrounding the site were advised not to sleep at night in their homes.
The area of the slope was estimated at 400 meters while the affected wall of the mountain damaged by the landslide reached to two kilometers.
Evangelista clarified that these landslides occurring in the area are not qualified to be categorized under tremors since landslides are caused by the soft composition of the soil material which usually happens at the start of the rainy season.
It may be recalled that the strongest quake recorded in the province hit Jagna town. The tremor was recorded at 6.8 magnitude on the Richter Scale on Feb. 8, 1990.
The fault line which could be the origin of the 1990 tremor is located offshore of Anda peninsula.
Records at Philvocs show that strong quakes (intensity 7) occur on a 50-year cycle while weaker tremors happen every 30 years.
STATE OF CALAMITY
Jagna Mayor Exuperio Lloren declared Brgy. Mayana under the state of calamity Wednesday, through a resolution passed by the SB members in accordance to the active landslide at Sitio Balik-bayan, Mayana, Jagna. Conse-quently, Gov. Erico Aumentado instructs all government offices to set up a 24-hour system of communication on steady alert.
Through an SB resolution, Brgy. Mayana was declared under the state of calamity Wednesday due to the active landslide afoot Sitio Balikbayan which broke Monday, July 11 and still dynamic up to present.
Being active, the landslide has already destroyed 11 houses and ruined the residents' farm produce.
Due to the constant falling of the rocks, residents feared for their safety and the condition of their farm products.
Apparently, Mayana is dependent on their farm products specifically rootcrops and spices as well as on their cutflower industry.
Now that the barangay is currently facing such calamity, residents dreaded the loss not just of their properties but also the source of their living.
Now that it is declared under the state of calamity, Mayana can now utilize its five percent calamity fund and can avail of the five percent calamity fund of the municipality to start rehabilitating the area.
The landslide was caused by the saturation of the base of the mountain.
According to the findings of the geologists from the Mines and Geosciences Bureau regional office, Al Emil G. Berador and Ma. Elena S. Lugo, the continuous rainfall seeping through the clay soil and the limestone contributed to the speedy percolation process.
The rain oozed through the limestone materials, trapped into the clayish soil instigated the saturation of the base.
Becoming saturated, the base has achieved its fullest capacity to hold the permeating water and the additional volume of the underground water cavity caused the base to subside, thus the upper part of the mountain collapsed resulting to the landslide.
As described by the geologists, the soil and the rocks are made of soft and absorbent materials.
The area of the slope was estimated to be about 300-400 meters and that of the hypotenuse was 700 meters. However, these dimensions are still increasing. The slope has developed a major fracture due to its continued motion and if these movements continue, the other half of the slope divided by the fracture would eventually collapse. Cracks in the ground proximate to the mountain are estimated to have an average increase from two meters to six meters and from six meters to 10 meters respectively.
The descending cracks seen in the ground originating from the slope to the proximate areas exhibited left-lateral movements, ending with an uplift of approximately one meter.
Due to the soft composition of the soil material, the ground proximate to the site has become mobile and does not show any sign of stability. Eleven houses were already damaged due to the mobility; trees were uprooted and their farm products damaged.
The ground immediate to the area has been moving downward at an average of three inches every minute, going towards the Jagna-Sierra Bullones Road, with a stretch of one to two kilometers and with a nearing distance of 50 meters from the mountain to the road.
Residents within the radius of 40 hectares surrounding the site are advised not to sleep at night in their respective houses.
Brerador said it would take time before the ground stabilizes.
With the onset of the rainy season, the residents of Mayana feared further catastrophe to arise from the landslide. The ground is still soft and the cracks in it provide passage for the easy penetration of the water.
Being so, the residents feared the further destruction of their farm products and other properties.
Junin Caberte, Executive Officer of the Provincial Disaster Coordinating Council said the provincial government is always ready when confronted with such calamities.
The province's Quick Response Team (QRT) is composed of the Provincial Disaster Coordinating Council (PDCC), Provincial General Services Office (PGSO), Department of Social Welfare and Development (DSWD).
The team had already distributed sacks of rice and boxes of sardines and noodles.
On the other hand, the Philippine National Red Cross (PNRC) has also distributed sacks of rice, sardines and noodles to the affected households.
Aumentado instructed all government agencies involved in disaster rehabilitation and management to assist the local government of Jagna in dealing with the incident and told the agencies concerned to put up a 24-hour system of communication on steady alert. [/glow]
Three active fault lines within the province are placing at least nine municipalities at a "danger zone" for earthquakes.
The biggest in scope is the fault line situated at Tayong Peak in Loay town that reaches as far as Sierra Bullones and Jagna towns.
Engineer Nolan Evangelista, seismic research analyst, told the Chronicle that at least two tremors are noticeable every year while weaker tremore are registered only in the intruments at the Philippine Institute of Volcanology and Seismology (Phivolcs) based in Ubujan district, this city.
The two other fault lines are situated in Anda town and another in Clarin-Tubigon area.
The nine municipalities listed as under the "danger zone" are Anda, Guindulman, Duero, Jagna, Loboc, Tubigon, Clarin, Inabanga and even Calape town.
The Philvocs official bared this after a massive landslide hitting sitios Balikbayan and Ilaud in barangay Mayana, Jagna town.
No less than 11 houses were destroyed during the landslide last Monday while residents within the 40-hectare radius surrrounding the site were advised not to sleep at night in their homes.
The area of the slope was estimated at 400 meters while the affected wall of the mountain damaged by the landslide reached to two kilometers.
Evangelista clarified that these landslides occurring in the area are not qualified to be categorized under tremors since landslides are caused by the soft composition of the soil material which usually happens at the start of the rainy season.
It may be recalled that the strongest quake recorded in the province hit Jagna town. The tremor was recorded at 6.8 magnitude on the Richter Scale on Feb. 8, 1990.
The fault line which could be the origin of the 1990 tremor is located offshore of Anda peninsula.
Records at Philvocs show that strong quakes (intensity 7) occur on a 50-year cycle while weaker tremors happen every 30 years.
STATE OF CALAMITY
Jagna Mayor Exuperio Lloren declared Brgy. Mayana under the state of calamity Wednesday, through a resolution passed by the SB members in accordance to the active landslide at Sitio Balik-bayan, Mayana, Jagna. Conse-quently, Gov. Erico Aumentado instructs all government offices to set up a 24-hour system of communication on steady alert.
Through an SB resolution, Brgy. Mayana was declared under the state of calamity Wednesday due to the active landslide afoot Sitio Balikbayan which broke Monday, July 11 and still dynamic up to present.
Being active, the landslide has already destroyed 11 houses and ruined the residents' farm produce.
Due to the constant falling of the rocks, residents feared for their safety and the condition of their farm products.
Apparently, Mayana is dependent on their farm products specifically rootcrops and spices as well as on their cutflower industry.
Now that the barangay is currently facing such calamity, residents dreaded the loss not just of their properties but also the source of their living.
Now that it is declared under the state of calamity, Mayana can now utilize its five percent calamity fund and can avail of the five percent calamity fund of the municipality to start rehabilitating the area.
The landslide was caused by the saturation of the base of the mountain.
According to the findings of the geologists from the Mines and Geosciences Bureau regional office, Al Emil G. Berador and Ma. Elena S. Lugo, the continuous rainfall seeping through the clay soil and the limestone contributed to the speedy percolation process.
The rain oozed through the limestone materials, trapped into the clayish soil instigated the saturation of the base.
Becoming saturated, the base has achieved its fullest capacity to hold the permeating water and the additional volume of the underground water cavity caused the base to subside, thus the upper part of the mountain collapsed resulting to the landslide.
As described by the geologists, the soil and the rocks are made of soft and absorbent materials.
The area of the slope was estimated to be about 300-400 meters and that of the hypotenuse was 700 meters. However, these dimensions are still increasing. The slope has developed a major fracture due to its continued motion and if these movements continue, the other half of the slope divided by the fracture would eventually collapse. Cracks in the ground proximate to the mountain are estimated to have an average increase from two meters to six meters and from six meters to 10 meters respectively.
The descending cracks seen in the ground originating from the slope to the proximate areas exhibited left-lateral movements, ending with an uplift of approximately one meter.
Due to the soft composition of the soil material, the ground proximate to the site has become mobile and does not show any sign of stability. Eleven houses were already damaged due to the mobility; trees were uprooted and their farm products damaged.
The ground immediate to the area has been moving downward at an average of three inches every minute, going towards the Jagna-Sierra Bullones Road, with a stretch of one to two kilometers and with a nearing distance of 50 meters from the mountain to the road.
Residents within the radius of 40 hectares surrounding the site are advised not to sleep at night in their respective houses.
Brerador said it would take time before the ground stabilizes.
With the onset of the rainy season, the residents of Mayana feared further catastrophe to arise from the landslide. The ground is still soft and the cracks in it provide passage for the easy penetration of the water.
Being so, the residents feared the further destruction of their farm products and other properties.
Junin Caberte, Executive Officer of the Provincial Disaster Coordinating Council said the provincial government is always ready when confronted with such calamities.
The province's Quick Response Team (QRT) is composed of the Provincial Disaster Coordinating Council (PDCC), Provincial General Services Office (PGSO), Department of Social Welfare and Development (DSWD).
The team had already distributed sacks of rice and boxes of sardines and noodles.
On the other hand, the Philippine National Red Cross (PNRC) has also distributed sacks of rice, sardines and noodles to the affected households.
Aumentado instructed all government agencies involved in disaster rehabilitation and management to assist the local government of Jagna in dealing with the incident and told the agencies concerned to put up a 24-hour system of communication on steady alert. [/glow]