Monday, December 21, 2020

Magnitude 4.9 earthquake

Magnitude 4.9 earthquake - Philippine Sea, 23 km southwest of Polillo Island, Quezon, Calabarzon, Philippines, on Tuesday, 22 Dec 2:14 am (GMT +8) 

Magnitude 4.9 earthquake near Tanay, Rizal, Calabarzon, Philippines, was reported only 21 minutes ago by the German Research Centre for Geosciences (GFZ), considered one of the key international agencies that monitor seismic activity worldwide. The earthquake occurred at a shallow depth of 10 km beneath the epicenter early morning on Tuesday 22 December 2020 at 2:14 am local time. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.

A monitoring service identified a second report from the Philippine Institute of Volcanology and Seismology (PHIVOLCS) which listed the quake at magnitude 4.9 as well. A third agency, the European-Mediterranean Seismological Centre (EMSC), reported the same quake at magnitude 4.9.

Based on the preliminary seismic data, the quake was probably felt by many people in the area of the epicenter. It should not have caused significant damage, other than objects falling from shelves, broken windows, etc.

In Paete (pop. 26,900) located 33 km from the epicenter, the quake should have been felt as light shaking.

Weak shaking might have been felt in Pililla (pop. 30,400) located 34 km from the epicenter, Tanay (pop. 60,000) 35 km away, Morong (pop. 49,600) 39 km away, Rodriguez (pop. 134,400) 42 km away, Santa Cruz (pop. 108,100) 44 km away, Binangonan (pop. 219,200) 46 km away, Taytay (pop. 231,500) 48 km away, Quezon City (pop. 2,761,700) 56 km away, and Manila (pop. 1,600,000) 63 km away.

VolcanoDiscovery will automatically update magnitude and depth if these change and follow up if other significant news about the quake become available. 

Tuesday, November 24, 2020


Seismic Accelerograph can be referred to as a strong-motion instrument or seismograph, or simply an earthquake accelerometer. They are usually constructed as a self-contained box, which previously included a paper or film recorder[1] (an analogue instrument) but now they often record directly on digital media and then the data is transmitted via the Internet.

Seismic Accelerographs are useful for when the earthquake ground motion is so strong that it causes the more sensitive seismometers to go off-scale. There is an entire science of strong ground motion, that is dedicated to studying the shaking in the vicinity of earthquakes (roughly within about 100 km of the fault rupture).

Seismic Accelerographs record the acceleration of the ground with respect to time. This recording is often called an accelerograms, strong-motion record or acceleration time-history. From this record strong-motion intensity measures (IMs, also called parameters) can be computed.

The simplest of which is peak ground acceleration (PGA). Other IMs include Arias intensity, peak ground velocity (PGV), for which the accelerogram needs to be integrated once, peak ground displacement (PGD), for which double integration is required. Often a response spectrum is computed to show how the earthquake would affect structures of different natural frequencies or periods. These observations are useful to assess the seismic hazard of an area.

Within the accelerograph, there is an arrangement of three accelerometer sensing heads. In recent low-cost instruments these are usually micro-machined (MEMS) chips that are sensitive to one direction.[5] Thus constructed, the accelerometer can measure full motion of the device in three dimensions.

The Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings which was published in newspaper of general circulation requires building to install certain number of ERI and at different locations. It shall cover all existing buildings, both government and private, located in Seismic Zone 4 in the entire Philippines except Palawan and Tawi-Tawi located in Zone 2.

As well as their engineering applications, accelerograms are also useful for the study earthquakes from a scientific viewpoint. For example, accelerograms can be used to reconstruct the detailed history of rupture along a fault during an earthquake, which would not be possible with seismograms from standard instruments because they would be too far away to resolve the details. An example of an accelerograph array that was established to improve knowledge of near-source earthquake shaking as well as earthquake rupture propagation is the Parkfield Experiment, which involved a massive set of strong motion instrumentation.

Unlike the continually recording seismometer, accelerometers nearly always work in a triggered mode. That means a level of acceleration must be set which starts the recording process. For analogue and older digital instruments this makes maintenance much more difficult without a direct Internet connection (or some other means of communication). Many trips have been made to accelerometers after a large earthquake, only to find that the memory was filled with extraneous noise, or the instrument was malfunctioning.

The installation of the instrument shall form part of the requirements for the Annual Certificate of Inspections for existing buildings and as a pre-condition for the issuance of Certificate of Occupancy for new buildings covered by the guidelines.

Accelerometers are used to monitor the response of structures to earthquakes. Analysis of these records along with the shaking recorded at base of the structure can improve building design, through earthquake engineering.

Sunday, November 22, 2020


The  instrument  shall  be  located  so  that  access  by  qualified  technical  personnel is maintained  at   all  times  and  is  unobstructed  by  room  contents.  A  sign  stating "MAINTAIN  CLEAR  ACCESS     TO  THIS  INSTRUMENT"   shall   be  posted  in  a conspicuous location. No instrument shall be located in refuge area.

The preferred  locations  of  the instruments  are  in small,  seldom  used  rooms or closets  near  a  column  (in  a   vertically-aligned  stack),  with  adequate  space  to securely  mount  the  instrument  and  an  approved  protective  enclosure  attached securely to the floor.  The location shall be marked on the submitted structural and architectural floor plans and properly approved.

2. Buildings with Three (3) or More Accelerographs

For buildings with 3 or more accelerographs, the instruments   shall be located in the  ground  floor/lowest  basement,  middle  floor,  and  floor  below  the  roof.  The locations of the instruments are selected to provide the maximum  information of the  building response from a major earthquake. Such information would form part of the valuable data in understanding the   building's behavior during major seismic event.

3. Orientation of Instruments

All  instruments  shall be  installed  with the  same  orientation  relative  to  the  building, with  the  orientation   chosen  such  that  the     reference  or  long  dimension     of the instrument    is  aligned  with  a  major  axis  of  the  building.    The  orientation  of  the instruments    shall   be clearly marked on the submitted structural and architectural plans.    The  owner/supplier  shall  certify  that  the  instruments  are  oriented  as  per plan and confirmed by the concerned Building Official.


Immediately  after  the  occurrence  of  magnitude  6  earthquake  or  greater,  the  Building Official shall require the owner to retrieve the data and to have the data interpreted by a  Certified  Civil/Structural  Engineer.  The  data  and interpretation  shall  be  submitted  by the  Owner  to  DPWH  for  storage,  post-earthquake  safety  evaluation  of  the  buildings and emergency response demands through the concerned Building Official.


Data  storage  and  archiving  shall  be  at  DPWH Central  Office  or  other  data  centers designated  by  the  DPWH.  The  ASEP,  upon  written  request  to  the  DPWH,  shall  be provided by the said data.


Upon compliance  of the building owners to these guidelines and implementing rules on earthquake  recording  instrumentation,  the  Building  Official  shall  issue  a  Certificate  of Installation  of  Earthquake  Recording  Instrumentation.  The  Certificate  must  be  posted in  a  conspicuous  place,  properly  protected/secured  in  the  ground  floor  lobby  of  the building as well as at the site of each instrument. 


The mixing/combination of the seismic equipment's peripherals and parts with other brands or maker must not be done because these systems and parts are not inter- operable(or if they are, it diminishes its accuracy) and will definitely contribute to the dysfunctionality of the machine in time.


Each  component  of  seismic  monitoring  system  shall  be  tested  individually  and  as  a complete   system   for   proper   functioning   of   all   operational   features.   Only   test equipment  from  company  with  international  testing  certification  shall  be  allowed  to make  the  testing.  Only  calibrated  results  shall  be  subjected  to  commissioning  and acceptance,  and  shall  qualify  towards  the  issuance  of  the  necessary  permits  by  the Office of the Building Official.  Test results must be signed by the respective suppliers  and shall be  submitted to the Building Official, as a requirement for the  certification of the Building Official who will commission the instrument.

The owner of the building shall be responsible for the protection and maintenance of the site of the ERI as prescribed in this IRR.

Building Owner, Building Official, and Supplier shall inspect, test, and commission the seismic  monitoring  system  together  to  ensure  that  the  systems  are  in  proper operational condition and comply with the requirements of these guidelines.


The   seismic  monitoring   system   shall   have   a   maintenance   clearance   as   per   the requirement  of  the  National  Structural  Code  of  the  Philippines  under  Section  105.2. "Maintenance and service shall be provided by the owner of the building."

  • The supplier shall provide guarantee that the system shall have a maintenance period  for at least 10 years.

For  the  service   period,  the  maximum   service  interval  is  one  year.     The  three Recording  accelerographs  shall  be  integrated  together  to  function  in  unison  that a  failure  in  one  unit  shall  not  hinder  the  progress  of    the  entire  building  seismic monitoring  system.  The  accelerograph  shall  be  equipped  with  fault  detection  and alarm  that  in  the  event  of  a  fault,  the  building  owners  shall  call  the  supplier,  and report  the  fault  to  Building  Official.  Calibration  testing  shall  be  made  in  a  per  year basis to ensure that the integrated systems are in its proper operational efficiency. 

The equipment obsolescence shall not   hinder the proper continuous operation of the equipment  throughout  the  10yearsduration.  When  the  equipment's  supplier  finds  that the  instrument must be removed from the  building for repair, there must be a service unit as a temporary replacement to continue the   collection of data, if and when there is an occurrence of an earthquake during the duration of the repair.


If any provision of these Guidelines  and Implementing Rules  on Earthquake  Recording Instrumentation  for  Buildings or  the  application thereof to any person or  circumstance is  declared  unconstitutional  or  invalid  by  any  competent  court,  the  other  sections  and provisions hereof which are not affected thereby shall continue  to  be in  full force and effect.


All  Department  Orders,  Rules  and    Regulations,  Memoranda,  Circulars  and    other issuances in consistent here with or contrary to the provisions of these Guidelines and Implementing  Rules  on  Earthquake  Recording  Instrumentation     for  Buildings  are hereby superseded or modified accordingly.


These  Guidelines  and  Implementing  Rules  on  Earthquake  Recording  Instrumentation for  Buildings  shall  take  effect  fifteen  days after  its  publication  once a  week  for  three (3) consecutive weeks in a newspaper of general circulation.

    1. D. Skoinik et. Al. A Quantitative Basis for Building Instrumentation Specifications, NSF CMMI Researchand Innovation Conference 2009 (Hawaii)
    2. M. Celebi. Seismic Instrumentation of Buildings: Special GSA/USGS Project (2002).
    3. Guideline for ANSS Seismic Monitoring of Engineered Civil Systems- Version 1.0
    4. National Building Code of the Philippines (PD 1096)
    5. National Structural Code of the Philippines (NSCP) 2010 5th Edition
    6. Industry Code and Standards
    7. National Fire Protection Association
    8. NFPA 70 National Electrical Code
    9. NFPA 72 National Fire Alarm Code
    10. Factory Manual Engineering and Research Corporation

Wednesday, November 18, 2020



Technology on building instrumentation for seismic monitoring has improved tremendously in the past decade. The purpose of the Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings is to provide information on the specifications and uses of earthquake recording instruments for buildings as provided in Section 105.2 of the National Structural Code of the Philippines 2010 Volume 1, 6th Edition (NSCP 2010).

Further, the Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings provide earthquake instrumentation schemes for certain buildings to record building response during major seismic events for subsequent analysis and provide immediate alarm annunciation to ensure that the building occupants can be moved to safety as per the Building Emergency Evacuation Plan (BEEP) of the National Disaster Risk Reduction Management Council (NDRRMC), which is the basis for the guidelines of earthquake drills in the Philippines.

Installation of earthquake recording instruments was first required in the National Structural Code of the Philippines 1992, 4th Edition, wherein structural engineers were only interested in the strength design capacity on the buildings based on seismic parameters provided in the Uniform Building Code (UBC) of the United States, referral code of the NSCP. Structural code developers started to recognize the importance of not only strength but serviceability and performance as well. The experiences from the 1994 Northridge Earthquake in the US and the 1995 Kobe Earthquake in Japan gave credence to these considerations. DPWH therefore deemed it necessary to improve our understanding of the building response based on real seismic event from local earthquake generators by enforcing placement of earthquake recording instrumentation for buildings as the NSCP provision was reiterated in 2001, 5th Edition, as well as in the latest 2010, 6th Edition. The NSCP 2010 states that "Unless waived by the building official, every building in Seismic Zone 4 over fifty (50) meters in height shall be provided with not less than three (3) approved recording accelerographs. The accelerographs shall be interconnected for common start and common timing."

The Philippines needs to have its own earthquake baseline data for validating the seismic design parameters used during and future structural design of buildings, in order to support earthquake disaster mitigation efforts. Hence, the waiver stated in the NSCP 2010 is temporarily suspended until such time that considerable sets of adequate earthquake records have been obtained for various specified types of buildings and relevant provisions in the NSCP have been amended. However, for the purposes of the Earthquake Recording Instrumentation for Buildings, the Department of Public Works and Highways has identified buildings in Table 1 to be necessarily installed by the said seismic monitoring system.


Section 102 of the National Building Code of the Philippines, otherwise known as PD 1096, states that: "It is hereby declared to be the policy of the State to safeguard life, health, property, and public welfare, consistent with the principles of sound environmental management and control; and to this end, make it the purpose of this Code to provide for all buildings and structures, a frame work of minimum standardsand requirements to regulate and control their location, site, design, quality of materials, construction, use, occupancy, and maintenance".

In conformance with the said Section 102 and as provided in the NSCP 2010, these Guidelines and Implementing Rules on Earthquake Recording Instrumentation for Buildings were developed to primarily safeguard lives, and for clear understanding of the actual dynamic behavior of buildings/structures under earthquake loading and confirm the structural design parameters used or to be adopted in compliance to the specific provisions of the NSCP. The recorded data will be used to improve the safety provisions of local structural code there by reducing loss of lives and limbs as well as properties during future damaging earthquakes, and to improve our understanding of the behavior and potential damage of building under the dynamic load of earthquakes. This will be achieved through the development of an integrated network that measures the earthquake source, transmitted ground motions structural response. These measurements will be correlated with observations of structural response to evaluate the current design and construction practices in order to minimize damage to buildings during future earthquakes. The response data from several buildings in a particular area or several areas will also be used as the basis for the government's earthquake disaster mitigation/remedial and rehabilitation strategies including its emergency response and relief operations programs.

The seismic recording and instrumentation machine must be used to set off alarms at specified intensity levels triggering real-time alarm information and may also trigger automatic switch off for utilities such as gas lines, electric power lines and elevators as may be prudent in case of such high intensity earthquake. The recorded data are also important parameters for buildings' safety re-evaluation and resumption of occupancy including post-earthquake evaluation of buildings. These safety alarm systems have been proven worldwide that they have mitigated secondary consequences of earthquake disasters and have saved countless of lives, or at least minimize the loss of lives.


  • ACCELERATION. The rate at which the velocity of a particle with time as recorded by seismic accelerograph (expressed in Gal or cm/sec squared).
  • ACCELEROMETER. A sensing equipment that measures seismic acceleration and pass the information to the accelerograph for further processing and conversion to the intensity, velocity and displacement.
  • ACTIONS (GROUND MOTION). A general term including all aspects of ground motion, namely acceleration velocity and displacement from an earthquake or other energy source.
  • BANDWIDTH. The frequency range that the accelerometer operates, measured inHertz (Hz).
  • CERTlFIED CIVIL/STRUCTURAL ENGINEER. A civil engineer with special qualifications to practice structural engineering with appropriate training in seismic instrumentation to be conducted by ASEP in coordination with DPWH.
  • CHANNEL. A path along which information (as data or voice) in the form of electrical signal, passes; a band of frequencies of sufficient width for a single radio or television communication.
  • CLUSTERED BUILDINGS. A group of buildings (enumerated in Table 1) built close together having similar design, construction, occupancy and function on a sizable tract of land. Each building should be treated separately. 
  • DAMPING. The energy dissipation properties of a material or system under cyclic stress. 
  • DISPLACEMENT. The measured distance traveled by a particle from an initial position.
  • ENVIRONMENT. The aggregate of surrounding things, conditions, or influences that may affect the operability of an instrumentation device such as accelerograph, velocitimeter, etc.
  • ERI. Earthquake Recording Instrumentations
  • FTP. File Transfer Protocol
  • GB. Giga Byte
  • GALS. A unit of ground acceleration with conversion as follows: 1 gal = 1 cm/square s, 981.5 gals = 1g where 1 g = 9.815 m/square s (NSCP Sec. 208.2) g. Acceleration due to gravity equals o 9.81 m/sec2or 32.2 ft/sec2
  • .INTENSITY. A descriptive scale (such as Philippine Intensity Scale, Modified Mercalli Intensity Scale and Shindo Scale) that indicates the local effects and potential damage produced by an earthquake on the Earth's surface as it affects humans, animals, structures and natural objects such as bodies of water.
  • IP 67. The Ingress Protection rating system is a classification system showing the degrees of protection of the instrumentation device from solid objects and liquids. The first number refers to the solid objects, normally dust. If the first number is 0, there is no protection provided. A number 5 refers to limited protection against dust. The number 6 is for total protection against dust. The second number of the IP rating system refers to protection against immersion between 15 cm to 1m for 30 minutes.
  • IP. Internet Protocol
  • MICROTREMORS. A low amplitude ambient vibration of the ground caused by manmade or atmospheric disturbances.
  • NATURAL FREQUENCY. The number of wave cycles per second which a system tend to oscillate in the absence of any driving or damping force.
  • NTP. Network Time Protocol.
  • PEAK GROUND ACCELERATION (PGA). The maximum ground acceleration at a specific location for time interval. 
  • PERIOD. The time interval required for one full cycle of wave.
  • REFUGE AREA. An area inside a building, where people evacuate or assemble during a disaster or emergency i. e, fire, which is appropriate for other events but not for earthquake.
  • RESPONSE SPECTRUM. A plot of the peak or amplitude of steady-state response (displacement, velocity and acceleration) of a series of oscillators of varying natural frequency that are forced into motion by the same base vibration or shock.
  • RMS. Root Mean Square
  • SEISMIC ACCELEROGRAPH. Accelerograph that records the acceleration of particles on the surface of the earth as a function of time, which is called an accelerogram. The accelerograph generally records three (3) mutually perpendicular components of motion in the vertical and two (2) orthogonal horizontal directions.
  • SEISMOGRAPH. A generic term used to describe a recording device that detects ground motion due to earthquake. Typically, this will comprise a recorder and a seismometer, which is a sensor that detects the velocity of the ground. Usually very sensitive than accelerograph and will easily detect a blast at a range of 100km.
  • SFTP. Secure FileTransfer Protocol
  • SIR. Seismic Instrumentation Room
  • STRONG M0TION. Ground motion of sufficient amplitude to be of interest in evaluating the damage caused by earthquakes or nuclear explosions.
  • TCP. Transmission Control Protocol
  • TIME HISTORY. The sequence of values of any time-varying quantity (such as a ground motion measurement) at a set of equal time intervals.
  • TRI-AXIAL. The characteristics of an accelerometer to provide ground shaking sensing in three (3) dimensions commonly known as x, y, z (i.e., transverse, longitudinal, and vertical).
  • VELOCITIMETER. An instrument used to measure velocity of a particle.
  • VELOCITY. A measure of the rate of motion of a particle expressed as the rate of change of its position in a particular direction with time


1. Application

The requirements of Earthquake Recording Instrumentation (ERI) shall apply to all existing buildings listed in Table 1, located in Seismic Zone 4 (entire Philippines except, Palawan and Tawi-Tawi located in Zone 2), prior to issuance of Certificate of Occupancy. Building Permits shall only be issued on buildings required for seismic instrumentation when site or location of Seismic Instrumentation Room (SIR) has been indicated or incorporated in the plan. Table 1 shows the types of buildings required to be installed with earthquake recording instrumentation located in cities and municipalities within 200-km radius from a Type A faults as specified in the NSCP 2010 and as indicated from the active fault maps issued by the Philippine Institute of Volcanology and Seismology (PHIVOLCS). For buildings located in cities and municipalities outside of the 200-km radius, only the installation of a single accelerograph may be placed at the ground floor/lowest-basement level.

For clustered buildings with completely similar design and construction, it should follow the same requirement for a single building.

2. Instrumentation of Selected Building

All owners of existing buildings listed in Table 1 shall provide accessible seismic instrumentation room for the installation of appropriate earthquake recording instruments. Location of said instruments shall be determined by a Civil/Structural Engineer.

For proposed buildings, the Civil/Structural Engineer shall include the layout, installation requirements, and location of the instrument in the structural plan submitted for building permit purposes. The actual installation of the instruments shall be under the supervision of the

Certified Civil/Structural Engineer verified and confirmed by the Building Official.

For existing buildings, the installation and operation of these instruments shall form part of the requirements of the Annual Certificate of Inspection issued by the Building Official.

Owners of existing buildings with already installed Earthquake Recording Instrumentation (ERI) shall be notified by the Building Official to comply with these guidelines accordingly, in case the specifications of the ERI installed do not conform as prescribed in these guidelines. However, the jurisdiction of the annual inspection shall be limited only on reporting the existence of the seismic instruments in a building, detailed installation number, latest certification of the local building official and a narrative physical condition as it was found by the

Building Official.

For newly constructed buildings, the installation of these instruments shall form part of the requirements for Certificate of Occupancy issued by the Building Official, indicating there on Earthquake Instrument Notification Procedures in

Compliance to these guidelines and rules. 

3. Additional Requisite Information of Buildings to be Instrumented

It is necessary to establish a baseline data to make effective use of the records to
be collected from the accelerograph installed in the building. The following
information are required:
  • Blueprint of the as-built plans of the buildings;
  • Structural design calculations/computations;
  • Dynamic analysis (mode shapes and frequencies), as used in the design calculations, if available, forced vibration test results, and ambient vibration test results; and,
  • Comprehensive sub-surface soil exploration and investigation report.

1. The following are the minimum specifications for Earthquake Recording Instruments (ERI) to be used for buildings listed in Table 1:

 a. Accelerogaph

      • Seismic qualified as tested by recognized international testing laboratory
      • Stores seismic activity information as gathered by the attached accelerometer
      • Equipped with fault detection
      • Provides real-time alarm information (either audio, visual or both) during an earthquake event.
      • Equipped with internal battery back-up power to ensure continuous operation during a power fluctuation.
      • Where applicable, it may include:
      • Minimum design life: 10 years and should be demonstrated and certified to have a 40,000-hour (minimum) mean time between failures
      • Minimum of three components (vertical, longitudinal and ransverse)
      • Natural Frequency: Above 50 Hz
      • Damping: Approximately 60-70 percent critical
      • Sensitivity: 2g
      • Bandwidth: DC to 100 Hz
      • Environment: IP 67
b. Recording
      • Sampling Frequency : Minimum of 100 samples per second
      • Time: From at least 20 seconds before the ground shaking begins until 30 seconds after the last triggering level motion
      • RMS Noise: System noise shall be less than 40 µg measured over 0-30 Hz.
      • Media : Memory Card
      • Continuous Recording : capable of continuous recording
      • AD Converter : 16 bits
c. Timing
      • Interval: Half a second or less
      • Accuracy: Plus or minus 0.2 second per 100 seconds
      • Type : GPS or NTP Server
d. Triggering (As applicable)
      • Method: Pendulum or other device using earthquake motion as an exciting force
      • Level: Accelerograph: 0.5 to 100 gals nominal velocitimeter: 5 µm/s to 1 mm/s
      • Time: Full operation of accelerograph/velocity in not over 0.1 second after activitation.
e. Power
      • Battery maintained by charger
f. Communication
      • Ethernet: 10 base –T or 100 base-TX
      • Protocol: TCP/IP FTP/SFTP
2. Records. To maintain continuous recording of data, a media for recording must be used at all times. 3. Battery Inspection. The accelerograph shall be tested with any charge device disconnected from an electric power source.


Sunday, October 4, 2020

Magnitude 5.6 earthquake

PHIVOLCS Earthquake Bulletins of latest seismic events in the Philippines are listed below. The event parameters (hypocenter, time and magnitude) are determined using incoming data from the Philippine Seismic Network. Philippine Standard Time (PST) is eight hours ahead of Coordinated Universal Time (UTC). (PST = UTC + 8H) UTC is the time standard for which the world regulates clocks and time. Earthquakes in this list with their date and time in blue have reported and recorded intensities. Intensity ratings are based on the PHIVOLCS Earthquake Intensity Scale.

Located at 13.66°N, 120.55°E - 033 km S 78° E of Looc (Occidental Mindoro), 05 Oct 2020 - 02:16:53 AM

Reported Intensities; Intensity IV - Looc, Lubang, Mamburao, Paluan, Abra de Ilog and Sablayan, Occidental Mindoro; Calapan City, San Teodoro and Baco Oriental Mindoro;

Tingloy and Calatagan, Batangas;

Intensity III - Tagaytay City; Alfonso, Cavite; Pinamalayan, Oriental Mindoro; San Pascual, Bauan, Mabini, Padre Garcia and Alitagtag, Batangas;

Intensity II - Amadeo and Mendez, Cavite; Bansud, Socorro and Victoria, Oriental Mindoro; Calintaan and Magsaysay, Occidental Mindoro; Makati City;

Quezon City; Mandaluyong City; Malabon City; Muntinlupa City; Pasig City; Taguig City; Biñan, Laguna

Intensity I - Tanuan, Batangas; Mariveles, Bataan;

Instrumental Intensity:

Intensity V - Calatagan, Batangas

Intensity IV - Puerto Galera, Oriental Mindoro;

Intensity III - San Jose, Occidental Mindoro; Roxas, Oriental Mindoro; Tagaytay City; Nasugbu, Batangas

Intensity II - Bacoor City; Carmona, Maragondon and Indang Cavite; Las Piñas City; Muntinlupa City; Calumpit and Plaridel, Bulacan; Dolores, Quezon;

Intensity I - Marikina City; Quezon City; San Juan City; Gumaca and Mauban, Quezon; Marilao and San Rafael, Bulacan; Talisay,Batangas; Gumaca, Lucban

and Mauban, Quezon; Marilao and San Rafael, Bulacan; Guagua, Pampanga;

The Origin is Tectonic with 120 km Depth of Focus 

What to do after an earthquake

  • Expect aftershocks hours, days, or weeks after the main quake.
  • Aftershocks can cause building damage and falling debris that could injure you.
  • Avoid open flames in damaged buildings.
  • Earthquakes can damage gas lines, so don’t use lighters or matches.
  • If you live near the coast, stay away from the beach.
  • Earthquakes can cause dangerous tsunamis and flooding.
  • Drive carefully and plan alternative routes.
  • Structural damage and traffic light outages may make it difficult to get to your destination.

Wednesday, September 9, 2020

Magnitude 5.9 earthquake Sept 9


PHIVOLCS Building Located at: C.P. Garcia Avenue, U.P.- Diliman, Quezon City, PHILIPPINES, with Tel.: 8426-1468  Fax: 8927-1087

PHIVOLCS Earthquake Bulletins of latest seismic events in the Philippines are listed below. The event parameters (hypocenter, time and magnitude) are determined using incoming data from the Philippine Seismic Network. Philippine Standard Time (PST) is eight hours ahead of Coordinated Universal Time (UTC). (PST = UTC + 8H) UTC is the time standard for which the world regulates clocks and time. Earthquakes in this list with their date and time in blue have reported and recorded intensities. Intensity ratings are based on the PHIVOLCS Earthquake Intensity Scale.

  • Date/Time: 09 Sep 2020 - 03:18:37 PM
  • Location:04.01°N, 126.68°E - 207 km S 40° E of Sarangani (Davao Occidental)
  • Depth of Focus (Km): 010
  • Origin: TECTONIC
  • Magnitude :Mw 5.9

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