Phivolcs: Metro Manila areas prone to liquefaction

[kagalingan]

Specifically daw sa city of manila mataas daw tubig kaya prone to liquefaction.

Buti dito sa place ko eh adobe daw lupa.

To geologist yatta. Adobe na ba pinakamaganda pagtayuan or ano pa ba mas ok na lupa and saan location?

Phivolcs: Metro Manila areas prone to liquefaction


Helen Flores (The Philippine Star) - April 25, 2019 - 12:00am

MANILA, Philippines — Some areas in Metro Manila are prone to liquefaction or the loosening of waterlogged soil underground, blamed largely for the tilting or collapse of many buildings in Dagupan City in Pangasinan during the killer earthquake in July 1990.

Science Undersecretary and Philippine Institute of Volcanology and Seismology (Phivolcs) director Renato Solidum Jr. issued the warning to explain what may have caused the Emilio Aguinaldo College (EAC) building in Manila to move and lean toward an adjacent building during the magnitude 6.1 earthquake last Monday.

The 1990 Luzon earthquake killed over 1,600 people, mostly in Baguio City, Pangasinan and Nueva Ecija.

Phivolcs defines liquefaction as “a phenomenon, when loosely consolidated sediment soil deposits lose their strength and appear to flow as fluids.”

Solidum, a geologist, confirmed that the area of EAC – located on San Marcelino Street in Ermita – is prone to liquefaction.

The official, however, was uncertain whether liquefaction really triggered the tilting of the building.

He said liquefaction could be triggered by an intensity 7 quake. Manila, he said, felt the tremor last Monday at intensity 5.

There were no other reported signs of liquefaction such as cracks on the roads and water and sand shooting upward from crevasses on the ground, he added.

“Definitely, (the EAC area) is prone to liquefaction, but it (tilting of the building) could also be due to (poor) foundation and design of the building,” Solidum told The STAR.

He said liquefaction could be addressed with proper design of the edifice.

Public Works Secretary Mark Villar has asked school officials not to utilize the building anymore.

The earthquake came at a time when Manila and Pasay were preparing for massive reclamation projects in Manila Bay.

These projects include Horizon Manila, the New Manila Bay International Community, the Solar City urban center and the expansion of the Manila Harbour Center in Tondo.

Fisherfolk and environmental groups are strongly protesting the Manila Bay reclamation projects, saying these will result in severe flooding if they push through.

In an article published in The STAR in 2013, Filipino-American geologist Kelvin Rodolfo said it might not need even a strong earthquake to cause serious damage to or destroy reclaimed areas in Manila Bay.

He said in 1968, a magnitude 7.3 earthquake in Casiguran, Quezon destroyed many structures built on river deposits near the mouth of the Pasig River. The six-story Ruby Tower in Binondo collapsed, killing 260 people. He said Casiguran was 225 kilometers away from Manila.

Disaster officials, meanwhile, reported earthquake damage in Muntinlupa and Pasay.

Cupang Bridge, which also traverses Baybayin Road, had “tilting column piers” and “buckled column piers,” according to the initial damage assessment report prepared by the Muntinlupa Disaster Risk Reduction and Management Council (MDRRMO) last Tuesday.

Cracks between three and six inches wide were also found on the façade of Barangay Sucat hall. Cracks were also detected on the walls of smaller buildings nearby.

The façade of the Pasay City General Hospital also sustained some damage, according to Salvador Villarin III, head for operations of the city government’s engineering office. – With Ghio Ong

Read more at https://www.philstar.com/headlines/2...YAzttldzS5Z.99

[yebo]

The cities of Manila, Malabon, Valenzuela, Pasay, Parañaque and several Cavite cities on the fringes of Manila Bay are land formed from the deltas of various rivers. These are all aluvial deposits where liquifaction can occur.

On the other hand the cities of Quezon City, Marikina, Pasig, San Juan, Mandaluyong and Makati are all on top of what is called the "Guadalupe Schist", named after that big rock formation you see on Guadalupe on the Pasig river. This rock was from volcanic deposits of ash that have been compacted and formed the "adobe" and "escombro" that you now find when you dig under these cities. Escombro is not adobe but the softer less compacted version of it, normally found on top of the adobe.

[ice15]

From the same article...

He said liquefaction could be triggered by an intensity 7 quake. Manila, he said, felt the tremor last Monday at intensity 5.

There were no other reported signs of liquefaction such as cracks on the roads and water and sand shooting upward from crevasses on the ground, he added.

“Definitely, (the EAC area) is prone to liquefaction, but it (tilting of the building) could also be due to (poor) foundation and design of the building,” Solidum told The STAR.

He said liquefaction could be addressed with proper design of the edifice.

It's poor design of the building. A quick search will show you that some countries' building codes have been updated to mitigate liquefaction.

IMO, EAC/DPWH/Manila City should investigate how the building was approved and who designed the building.

[uls]

pag nag big one sa NCR sigurado breakdown of law and order yan

mad max dystopia

violence, looting and all

[minicarph]

pag nag big one sa NCR sigurado breakdown of law and order yan

mad max dystopia

violence, looting and all

Kaya dapat kayo lagi kayo maging fit

Ive watched all the seasons of Walking dead (walking zombie apocalypse) , The Last Ship (virus apocalypse),The Strain (vampire apocalypse) , Black Summer (running zombie apocalypse) , Jericho (nuclear apocalypse)

Hinde ako nanonood nyan to be like Rick Grimes or Carol, kasi cheesy characters

I wanted to be like Shane, The Governor and Neegan.


Ngaun pa lang meron na ako enforcer tiga south, Si Kuya Big.

[dreamur]

The cities of Manila, Malabon, Valenzuela, Pasay, Parañaque and several Cavite cities on the fringes of Manila Bay are land formed from the deltas of various rivers. These are all aluvial deposits where liquifaction can occur.

On the other hand the cities of Quezon City, Marikina, Pasig, San Juan, Mandaluyong and Makati are all on top of what is called the "Guadalupe Schist", named after that big rock formation you see on Guadalupe on the Pasig river. This rock was from volcanic deposits of ash that have been compacted and formed the "adobe" and "escombro" that you now find when you dig under these cities. Escombro is not adobe but the softer less compacted version of it, normally found on top of the adobe.

Is Taguig or just BGC also sitting on this rock?

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[minicarph]

Dream, dating base yan BGC, malamanag madami tunnels dyan , kaya nga wala lelectrical lines dyan kasi pinadaan nanila sa escape tunnels kuryente lol

[XTO]

pag nag big one sa NCR sigurado breakdown of law and order yan

mad max dystopia

violence, looting and all

swertihan na lang. pag natapat at the wrong place yun na.

si ob napapaligiran ng maraming food at tubig tapos nasa game room lang na wala sa high rise kaya no prob.

[yebo]

Is Taguig or just BGC also sitting on this rock?

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BGC i know has adobe underneath. Taguig and Muntinlupa no idea. These 2 cities are on that stretch of land in between Manila Bay and Laguna de Bai. It may have adobe underneath but those lands near Laguna lake may be loose deposits on top. Afaik those areas around Laguna lake used to be marshes.

Laguna lake is like Taal lake, it is the sunken caldera of an extinct volcano. The remnant of its crater is what is now Talim Island. Same as with Manila Bay, the islands of Corregidor and Caballo are the remnants of its crater. Note that this super volcano is NOT EXTINCT and is classified as potentially active.

[minicarph]

BGC i know has adobe underneath. Taguig and Muntinlupa no idea. These 2 cities are on that stretch of land in between Manila Bay and Laguna de Bai. It may have adobe underneath but those lands near Laguna lake may be loose deposits on top. Afaik those areas around Laguna lake used to be marshes.

Laguna lake is like Taal lake, it is the sunken caldera of an extinct volcano. The remnant of its crater is what is now Talim Island. Same as with Manila Bay, the islands of Corregidor and Caballo are the remnants of its crater. Note that this super volcano is NOT EXTINCT and is classified as potentially active.

Grabe ang lalaking volcano naman yan, totoo yata nun una panahon giant ang mga tao, syempre kung giant ang volcano noon, tapos giant din ang volcano, lumalabas pareho lang proportional 1:100 ganun

Siguro yun mga malalaking puno natin ngsun, damo lang sa kanila noon

[kagalingan]

The cities of Manila, Malabon, Valenzuela, Pasay, Parañaque and several Cavite cities on the fringes of Manila Bay are land formed from the deltas of various rivers. These are all aluvial deposits where liquifaction can occur.

On the other hand the cities of Quezon City, Marikina, Pasig, San Juan, Mandaluyong and Makati are all on top of what is called the "Guadalupe Schist", named after that big rock formation you see on Guadalupe on the Pasig river. This rock was from volcanic deposits of ash that have been compacted and formed the "adobe" and "escombro" that you now find when you dig under these cities. Escombro is not adobe but the softer less compacted version of it, normally found on top of the adobe.

naalalal ko nung pinatubo eruption madami din ash ah. So magform din ba adobe yun?

Tapos iba pa pala yung west valley fault.

Maghigpit na talaga sa high-rise. Ilan years ko na ba pinupush ito zoning. Kasi ang earthquake is like a war. You just cannot rebuild in an instant. Tapos si highrise pag bumagsak ang dami madadamay jan so masagwa ang domino.

[chronicle]

you can check if your area is prone to liquefaction or unstable.
Philippine Flood Hazards Map

[Yatta]

To see how far you are from a fault download the PHIVOLCS Fault Finder app. Also available for iOS.

The PHIVOLCS FaultFinder - Apps on Google Play

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[kagalingan]

Dapat trabaho ito ng local government eh. Pero ganun talaga buhay pag barangay system kasi ang namununo squatter tapos mga trabahador squatter din. Kung kelan lang nagkaproblema doon lang kikilos.

Ilan years na kagalingan account ko sa tsikot. Puro ako zoning zoning zoning. Eh makanature ako tao kaya forward thinker ako. Sige lang high rise pa more!!!!

Phivolcs seeks audit on structures built before 1992

Helen Flores (The Philippine Star) - April 27, 2019 - 12:00am

MANILA, Philippines — The Philippine Institute of Volcanology and Seismology (Phivolcs) has called for a manual structural audit of all structures in Metro Manila and nearby provinces that were built before 1992 to determine if they could withstand the “Big One.”

The Big One refers to a magnitude 7.2 earthquake that could be generated by the West Valley Fault, which state seismologists warned is “ripe for movement.”

Department of Science and Technology Undersecretary and Phivolcs director Renato Solidum Jr. said structures, including houses, built before 1992 might be weaker and unable to withstand strong earthquakes.

“There should be a manual structural audit of all the buildings in Metro Manila and nearby areas to ensure that the weak structures would either be retrofitted or demolished,” Solidum said.

He said in 1992 more earthquake resistance standards were included in the National Building Code.

Solidum made the appeal after the magnitude 6.1 tremor that hit Luzon on Monday damaged several structures, including a four-story Chuzon supermarket in Porac, Pampanga, which left 18 people dead.

The tremor, which was triggered by a “blind fault” in Castillejos, Zambales, was felt in many parts of Luzon, including Metro Manila.

In Manila, a building of the Emilio Aguinaldo College leaned towards its adjacent building after the quake, which many believed was due to liquefaction.

Aftershocks from the magnitude 6.1 tremor are expected to last for several weeks, according to Solidum.

Phivolcs has been warning the public of the possible magnitude 7.2 earthquake from the West Valley Fault that could kill about 48,000 people in Metro Manila, Bulacan, Cavite, Rizal, Laguna and Pampanga.

This developed as earthquakes continued to hit different parts of the country yesterday.

A magnitude 4.4 tremor struck some seven kilometers southwest of San Nicolas, Ilocos Norte at 3 a.m.

It was felt at Intensity 4 – classified as moderately strong – in San Nicolas and Intensity 3 in Sarrat, Ilocos Norte.

A magnitude 4 quake also hit seven km northeast of Albuera, Leyte at 10:44 a.m. yesterday.

It was felt at Intensity 3 in Ormoc City.

At 1:26 p.m., a magnitude 5.5 tremor struck 70 km off General Luna, Surigao del Norte.

It was felt at Intensity 2 in Surigao City.

The tremor was followed by several aftershocks, most of which were unfelt.

The National Risk Reduction and Disaster Management Council (NDRRMC) in an updated report yesterday said there are now 18 people killed in last Monday’s tremor. The number of missing persons went down to seven individuals from 14.

NDRRMC spokesman Edgar Posadas said most of the fatalities were from Pampanga, particularly from the collapsed Chuzon Supermarket in Porac town.

The number of quake-related injuries in Central Luzon – Zambales, Bataan and Pampanga – has increased to 282 individuals, while 909 families or 3,381 persons from 13 cities and municipalities were directly affected by the tremor.

Phivolcs earlier said the frequent occurrence of tremors in the country is not uncommon, considering the country’s geographical location.

Phivolcs, however, urged those who are buying new properties in the country to make use of the application that could determine if the area is near or on top of an active fault.

The application, FaultFinder, can be accessed through the Phivolcs’ website, Home.

Arturo Daag, Phivolcs chief science research specialist, also urged building developers to observe the five-meter buffer zones on both sides of the active fault.

Phivolcs earlier reported over 3,000 structures are exposed to ground rupture once the West Valley Fault moves. – With Jaime Laude

Read more at https://www.philstar.com/headlines/2...GC7ut6EECFH.99

[chronicle]

The great purge ang mangyayari.


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