ACTIVE F

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LINES I

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PHIL

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LESSON 3:

THE FAULT LINES IN THE PHILIPPINES

Fault lines Affected areas

1. Central Philippine Fault Entire Ilocos Norte, Aurora, Quezon, Masbate, Eastern Leyte, Southern Leyte, Agusan Del Norte, Agusan Del Sur, Davao Del Norte.

2. Marikina Valley Fault Montalban, San Mateo, Marikina, Pasig, Taguig, Muntinlupa, San Pedro,Binan, Carmona, Santa Rosa, Calamba, Tagaytay, Oriental Mindoro.

3. Western Philippine Fault Luzon Sea, Mindoro Strait, Panay Gulf, Sulu Sea.

4. Eastern Philippine Fault Philippine Sea

5. Southern of Mindanao Fault

Moro Gulf, Celebes Sea

PHIVOLCS - PHILIPPINE INSTITUTE OF VOLCANOLOGY AND SEISMOLOGY

Marikina Fault Line – is the most geologically active fault line in the Philippines.

- it is located in East of Metro Manila and cuts through all the modern and progressive portions of Manila, Rizal, Marikina City, Quezon City such as Eastwood, Rockwell, Ortigas Center, Bonifacio Global City, Ayala Center, and Alabang.

- it was renamed to West Valley Fault.

Director of Phivolcs

- Director Raymundo Punongbayan Why is it he renamed the Marikina Valley

Fault?

- because it caused panic to the residents of Marikina, as well as most of the business community within the inclusive areas.

Seismologist - said that once the West Valley Fault Line moved, it can lead to the eruption of Taal volcano just what happened in June 1990 earthquake when the Central Philippine Fault moved.

THE CENTRAL PHILIPPINE FAULT ZONEPFZ- PHILIPPINE FAULT ZONE - is a transition zone with slow slip and creep activity.

It comprises the Guinyangan Fault, Masbate Fault, and Central Luzon Fault.

This is found to be the site and sources of fault creep activity, slow slip event and great earthquakes in the archipelago.

Willis(1937) and Allen(1962)

- studied the PFZ.

- they said that PFZ is comparable to San Andreas Fault in California because on its geologic features, faulting and seismic characteristics.

Magnitudes and intensities of earthquakes

Seismograph- can measure the strength of an earthquake.

Analyzing a seismogram enables seismologist to determine the time, focus, and epicenter, as well as the amount of energy released by the movement of the rock masses.Magnitude and Intensity- are the two strength of an earthquake.

Ritcher Scale- designed by Dr. Charles F. Ritcher of the California Institute of Technolog.

- is the best known logarithmic scale in measuring the magnitude( strength of the shock waves) of earthquakes.

MODIFIED VERSION OF THE RITCHER SCALE

Magnitude General Description

Damage Expected

8 and up National Disaster Complete Destruction

7 to 8 Major Earthquake Major damage to all buildings; crust’s surface cracks

6 to 7 Destructive earthquake

Collapse of some structures

5 to 6 Damaging earthquake

Poorly constructed buildings are damaged

4 to 5 Strong earthquake

Trees broken; sleepers are awakened

3 to 4 Small earthquake Some fragile are broken

0 to 3 Tremor Barely felt, but sound of tinkling glass can be heard.

Level of Earthqua

ke

Instrumental

Detected only by Seismograph

I Instrumental Detected only by seismograph

II Feeble Noticed only by sensitive people

III Slight Resembling vibrations caused by heavy traffic

IV Moderate Felt by people walking; rocking of free-standing objects

V Rather strong Sleepers awakened and bells ring

VI Strong Trees sway, some damage from overturning and falling objects

VII Very strong General alarm, cracking of walls

VIII Destructive Chimneys fall and there is some damage to buildings

IX Ruinous Ground begins to crack, houses begins to collapse, and pipes reak

X Disastrous Ground badly cracked and many buildings are destroyed. There are some landslides.

XI Very disastrous Few buildings remain standing; bridges and railways destroyed, water, gas, electricity and telephones out of action

XII Catastrophic Total destruction; objects are thrown into the air, much heaving, shaking, and distortion of the ground.

EARTHQUAKE IN THE PHILIPPINES

Pacific Ring of Fire

- where the philippines is located and it is a series of interconnected seismic plates that cause earthquakes and volcanic eruptions.

- the country sits on the Philippine plate, which is sandwiched by the Pacific Plate and Indian Plate.

LIST OF THE MOST POWERFUL EARTHQUAKES

Date Magnitude Place

March 06, 2002 6.8 Palimbang in Mindanao

February 15, 2003 6.2 Masbate

November 18, 2003 6.5 Samar

October 08, 2004 6.5 Mindoro

October 04, 2009 6.6 Moro Gulf, Mindanao

July 23, 2010 7.6 Moro Gulf, Mindanao

What are those examples of damages that caused by earthquakes?

Earthquakes pose hazards to humans. The vibrations can cause the

considerable shaking of the ground. Tsunami in its English equivalent means

“seismic sea waves”. Thy can be caused by the following

phenomena: The formation of an earthquake: What are they?

What happen if the two oceanic plates meet and collide with one another?

What if the two colliding plates moved? What is the energy released? When the waves travels and enter

shallower water in the coastal area. What will happened?

If the speed of the tsunami is diminished, but the wave height is increased drastically. What will be the cause?

ANSWERS:

The energy stored between them. The denser plates subducts and the lighter

plate is up thrusted. The energy released is transferred to the

water. It begins to increase in heights and

produces a series of rushing waves. It can cause destruction of life and of

property by floating debris and the impact of water.

THANK YOU GEMINI FOR LISTENING!!!

HAPPY WEEKEND!!!