Tsunami Philippines

Tsunami in the Philippines are extremely rare. 

The last measurable tsunami in the Pilippines affected the northern and the eastern seaboards on March 11, 2011. In that event, tsunami waves of around half a meter, resulting from a relatively shallow and very large 8.9 magnitude earthquake off the coast off Miyagi prefecture, Honshu, Japan, arrived in the early evening and caused a little or no damage, and no loss of life.

Prior to March 2011, the last recorded tsunami in the Philippines, that actually caused loss of life, occurred in the Verde Island Passage (between Batangas & Mindoro Island, affecting Puerto Galera) in the early morning of November 15, 1994, originating from a 7.1 magnitude (Richter) earthquake, 11KM West of the Baco Islands, according to the Philippine Institute of Volcanology and Seismology. The tsunami waves, resulting from the 7.1 magnitude earthquake, were measured at 6 meters in many areas when they reached land, but up to 8.5 meters in a few locations (primarily the Baco Islands) where the bathymetry was favorable; the tsunami waves reached up to 250 meters inland in areas that faced the earthquake epicenter. The death toll was 41 people. 

References: http://www.pgyc.org/tsunami-earthquake.php

1976 Moro Gulf earthquake

The 1976 Moro Gulf earthquake and tsunami took place on August 16, 1976, at 16:11 UTC (on August 17, 1976), near the islands of Mindanao and Sulu, in the Philippines. Its magnitude was calculated as being as high as 8.0 on the moment magnitude scale. The epicenter was in the Celebes Sea between the islands of Mindanao and Borneo. The Pacific Tsunami Warning Center's preliminary magnitude was given as 8.0 on the Richter scale and as 7.9 by other sources. There were many aftershocks following the main earthquake. A major aftershock on August 17 (local date) had a magnitude of 6.8. It was followed by at least fifteen smaller aftershocks.

 

Tsunami damage at Lebak, Mindanao 

Effects:
The initial earthquake was widespread and was felt as far as the central Philippine islands of the Visayas. A massive tsunami devastated 700 kilometers of coastline bordering the Moro Gulf in the North Celebes Sea, resulting in destruction and death in the coastal communities of the Sulu Archipelago and southern Mindanao, including Zamboanga City and Pagadian City. At least 5000 people died during the earthquake and tsunami, with thousands more remaining missing.[4] Some reports say that as many as 8,000 people lost their lives in total, with ninety percent of all deaths the result of the following tsunami.

Initially over 8,000 people were officially counted as killed or missing, 10,000 injured, and 90,000 homeless, making the 1976 Moro Earthquake and Tsunami one of the most devastating disasters in the history of the Philippine Islands. After the initial earthquake the people were unaware of the need to move to higher ground; when the tsunami hit it sucked most of the victims out to sea. Based on the investigation on the affected region it was confirmed that the waves reached up to 4 to 5 metres (13 to 16 ft) when they hit the areas. There were reports of weak tsunami activity as far as Japan, as well as Indonesian Hydrographic Office reports of unusual wave activity affecting the islands of Sulawesi (Celebes Island) and Borneo.

In Zamboanga City, 14 buildings were partially damaged. Zamboanga City was spared from serious damage of the tsunami triggered by this earthquake because the Basilan Island and the Santa Cruz Islands served as a buffer and deflected waves.

Warnings:
The Pacific Tsunami Warning Center (PTWC) in Honolulu issued a Tsunami Watch for the Pacific and queried tide gauge stations in Okinawa, Yap and Malakal. Based on negative reports from these stations, the watch was cancelled. Unfortunately, minutes after the earthquake, a large local tsunami struck the region. There was no time to issue a local warning.

Aid response:
The Philippine Government sent out aid and support as soon as news reached Manila. Later a team of US and Filipino geologists and officials surveyed the disaster zone with the help of the Philippine Air Force. The objective of the survey was to obtain measurements of the tsunami wave heights, extent of inundation and gather additional information on the earthquake and the tsunami and its effects in the region.

Aftermath:
The earthquake occurred at night, when offices and schools in Cotabato, Zamboanga and other cities were unoccupied, therefore the loss of life was greatly reduced. Pagadian, on the other hand, was the only city hardest hit by the tsunami that followed. Although the earthquake had a large magnitude, surprisingly, it produced little ground deformation on land areas. However, there was extensive earthquake damage to buildings, bridges and roads in Mindanao and particularly in the city of Cotabato.

Reference: http://www.ringsurf.com/online/2412-tsunamis_through_history.html

         

The most known volcanoes in the Philippines are Mount Pinatubo, Mount Mayon and the Taal volcano. They are all located on the Northern island Luzon. Mount Mayon is a splendid example of a strato volcano. Mount Mayon rises up 2462 meters above sea level.

          Mayon Volcano is an active volcano in the province of Albay, on the island of Luzon in the Philippines. Renowned as the "perfect cone" because of its almost symmetric conical shape, the mountain was declared a national park and a protected landscape on July 20, 1938, the first in the country. It was reclassified a Natural Park and renamed Mayon Volcano Natural Park in the year 2000. Local folklore refers to the volcano being named after the legendary heroine Daragang Magayon.

Mayon is a classic stratovolcano(composite) type of volcano capped by a small central summit crater. The cone is considered the world's most perfectly formed volcano for its symmetry,[6] which was formed through layers of pyroclastic and lava flows from past eruptions and erosion. The upper slopes of the basaltic-andesitic volcano are steep averaging 35–40 degrees. Like other volcanoes located around the Pacific Ocean, Mayon is part of the Pacific Ring of Fire. It is located on the eastern side of Luzon, near the Philippine Trench which is the convergent boundary where the Philippine Sea Plate is driven under the Philippine Mobile Belt. When a continental plate or belt of continental fragments meets an oceanic plate, the lighter continental material overrides the oceanic plate, forcing it down into the Earth's mantle. Magma may be forced through weaknesses in the continental crust caused by the collision of the tectonic plates. One such exit point is Mayon.

Recorded eruptions:

*1814 eruption: 

*1881–1882 eruption: 

*1897 eruption: 

*1984 and 1993 eruptions: 

*2009–2010 eruption: 

*2013 phreatic eruption:

*2014 renewed activity: On 12 August 2014 a new 30m-50m high lava dome appeared in the summit crater. This event was preceded by inflations of the volcano (measured by precise leveling, tilt data, and GPS), and increases in sulphur dioxide gas emissions.

On 14 September 2014, rockfall events at the southeastern rim of the crater and heightened seismic activity caused PHIVOLCS to increase the alert level for Mayon from 2 to 3, which indicates relatively high unrest and that magma is at the crater and that hazardous eruption is possible within weeks.[60] The rock falls, and visible incandescence of the crater from molten lava and hot volcanic gas indicated a possible incipient breaching of the growing summit lava dome.

On 15 September 2014, NASA's Moderate-Resolution Imaging Spectroradiometer (MODIS) detected thermal anomalies near Mayon's summit, consistent with magma at the surface.

On 16 September 2014, provincial governor Joey Salceda said that the government would begin to "fast-track the preparation to evacuate 12,000 families in the 6-8 km extended danger zone", and soldiers would enforce the no-go areas.

On 18 September 2014, PHIVOLCS reported 142 VT earthquake events and 251 rockfall events during the past day. White steam plumes drifted to the south-southwest and rain clouds covered the summit. Sulfur dioxide (SO2) emission was measured at an 757 tonnes/day on 17 September 2014, after it had peaked at 2,360 tonnes/day on 6 September 2014. Ground deformation (precise leveling and tilt meters) during the 3rd week of August 2014 recorded edifice inflation.

Reference: http://en.wikipedia.org/wiki/Mayon_Volcano#cite_note-PhivolcsBulletin20-31 (Read all the info on the Recorded Eruptions). 

Monitoring Mayon:

Mayon Volcano is the most active volcano in the Philippines, and its activity is regularly monitored by PHIVOLCS from their provincial headquarters on Ligñon Hill, about 12 kilometres (7.5 mi) SSE from the summit. Three telemetric units are installed on Mayon's slopes, which send information to the seven seismometers in different locations around the volcano. These instruments relay data to the Ligñon Hill observatory and the PHIVOLCS central headquarters on the University of the Philippines Diliman campus. PHIVOLCS also deploys electronic distance meters (EDMs), precise leveling benchmarks, and portable fly spectrometers to monitor the volcano's daily activity.

Mayon Danger and Safe Zones, Evacuation Centers - Schadow1 Expeditions

Transmission of Warning:

At the five most active volcanoes being monitored by PHIVOLCS--Mayon, Bulusan, Taal, Hibok-Hibok, and Canlaon--eruption warnings are usually passed through the appropriate DCC. When one of these volcanoes manifests abnormal behavior, PHIVOLCS interprets its changing behavior and decides whether or not to send warnings and, if so, when. As soon as PHIVOLCS decides to issue a warning, it notifies the Office of the President and the national and local DCCs, through Volcano Bulletins and advisories that explain the condition of the volcano and recommended actions. The DCCs, in turn, transmit the warning to those at risk and respond in various other ways. Although transmission of warnings is officially the responsibility of the DCCs, PHIVOLCS observatory personnel help deliver warnings to nearby inhabitants. Later, PHIVOLCS' main office might release information to the media to clarify and explain the volcano's condition.

This warning procedure was modified in the case of Pinatubo. Warning messages were formulated at PHIVOLCS' main office and transmitted simultaneously through the DCC hierarchy, major national and local newspapers, radio and television stations, nongovernmental organizations (NGOs), and directly to the endangered inhabitants.

Multipath warning transmission has been found to create confusion, duplication, and administrative problems in some situations. This is why, at other monitored Philippine volcanoes, warnings and evacuation advice are passed, as much as possible, through the concerned DCCs. The effectiveness of the modified transmission procedure adopted at Pinatubo was assessed by use of two indicators: (1) consistency between the warning message released by the source (PHIVOLCS) and the message received by the recipients and (2) the time gap between issuance from the source and receipt by the target public.

Reference: http://pubs.usgs.gov/pinatubo/tayag/ 

MAYON VOLCANO BULLETIN 03 March 2015 8:00 A.M.

Mayon Volcano’s seismic monitoring network recorded three (3) volcanic earthquakes during the past 24 hours. Weak to moderate emission of white steam plumes that crept downslope and drifted towards west-northwest and northwest was observed. No crater glow was observed last night. Sulfur dioxide (SO2) emitted at the crater averaged 134 tonnes/day last 24 February 2015 was still below the baseline level during normal periods. Data from the ground deformation survey on January 20-31, 2015 indicated a deflation of the edifice relative to the November 27-29, 2014 survey, although the edifice remains inflated relative to baseline measurements beginning 2010. Data from continuous tilt monitoring indicate that magma has stalled deep beneath the northern flanks of the volcano, although the edifice is still inflated or swollen compared to baseline levels.

Mayon Volcano’s alert status is currently at Alert Level 2. This means the volcano is at a moderate level of magmatic unrest. Although the volcano is currently exhibiting low-level of seismic activity, ground deformation data indicate that eruptible magma had already accumulated the previous year beneath the edifice. Current conditions may still change and eventually lead to hazardous eruption. The public is still reminded to avoid entry into the 6-km Permanent Danger Zone or PDZ due to perennial hazards of rockfalls, avalanche, ash puffs and sudden steam-driven or phreatic eruptions at the summit area. Furthermore, people living in valleys and active river channels are cautioned to remain vigilant against sediment-laden streamflows and lahars in the event of prolonged and heavy rainfall. PHIVOLCS-DOST is closely monitoring Mayon Volcano’s activity and any new development will be immediately posted to all concerned.

Reference: http://www.phivolcs.dost.gov.ph/index.php?option=com_content&view=article&id=4328:mayon-volcano-bulletin-03-march-2015-800-am-&catid=70:latest-volcano-bulletin&Itemid=500008

Seismic Hazard analysis in the Philippines using earthquake occurrence data:

  The seismic hazard in the Philippines is evaluated from historical earthquake data using a new computer program called the Seismic Hazard Mapping Program (H-MaP). The seismic hazard is given in terms of the expected peak ground acceleration and the expected acceleration response spectrum. Regions of high seismic hazard are identified. These include Central Luzon which suffered heavy damage during the July 16, 1990 earthquake. The design levels of the seismic force of the Philippines are compared with those of the Japan and are found to be considerably lower. Long period structures are found to be more vulnerable to damage. The collection of strong ground motion records from Philippine earthquakes is necessary for more realistic design level for the Philippines. From the seismic hazard maps, a seismic zoning map based on the expected maximum accelerations is proposed. 

This figure shows a tectonic model of the northern Philippine island arc, based on seismicity, earthquake focal mechanisms, GPS measurements, and satellite imagery. The island arc lithosphere is modeled as a series of elastic blocks, which accommodate large-scale tectonic motions between the Philippine Sea Plate (PHSP) and the Sundaland Block of Eurasia (SUND). The major plate motion is accommodated by deformation along a series of arc-bounding and intra-arc faults that accumulate elastic strain between major earthquakes






  The 7.2 magnitude earthquake on 15 October 2013 was the strongest to hit the Philippines' Bohol island province in nearly 25 years, and occurred on a previously unknown fault line. Municipalities in the northwest of Bohol were hardest hit. The total number of affected people has been adjusted to 1.3 million from an initial estimate of 3.2 million as 2 million people from Cebu were first included, but later assessments identified that the island was not affected by the earthquake. According to government assessments and figures from early January, the earthquake damaged in total 79,217 houses out of which 13,402 were destroyed. The Bohol Earthquake Action Plan (BEAP) was issued on 25 Oct, requesting $46.8 million. A revised version was launched in January, reducing the requested amount to $33.8 million in line with the outstanding needs. (OCHA, 6 Feb 2014)

Highlights

 The priority remaining needs are shelter, early recovery and support to health services.

 This revised action plan seeks US$33.8 million over a six-month period from October 2013 to April 2014.1 The current funding gap is $19 million.

 WASH facilities are still needed in evacuation camps, schools and health facilities.

 Accurate information on IDPs to effectively allocate funds and develop a comprehensive resettlement strategy will soon be finalized.

13 new projects in the revised action plan that include local partners.

Philippines:BoholEarthquakeActionPlan(Revised)January2014:http://reliefweb.int/sites/reliefweb.int/files/resources/Bohol%20Earthquake%20Action%20Plan%20%28BEAP%29%20Revision%20FINAL.pdf

Reference: http://www.iitk.ac.in/nicee/wcee/article/10_vol10_6031.pdf

The Philippine Sea plate is tectonically unusual in that almost all the boundaries are convergent. The Pacific plate is subducting beneath the Philippine Sea plate to the east while the west/northwestern part of the Philippine Sea plate is subducting beneath the continental Eurasian plate. The areas surrounding the Philippine Sea plate are very active, producing numerous local earthquakes, tsunamis, and volcanic activity. 

The evolution of the Philippine Sea plate originated lower than the equator about 55Ma ago and was followed by several tectonic events resulting in its present day location. Ultimately it was a change in the movement, to a westward motion, of the Pacific plate that converted the N-S transform fault on the Philippine Sea plate to the subduction zone currently present along the boundary between these two plates.

When the Philippine plate reaches a depth greater than 100km, the water it contains lowers the fusion point of the surrounding rocks, which creates magma. This magma is hotter and less dense than the rocks around and therefore starts to migrate towards the surface, where it eventually generates volcanism typical of subduction. The chain of volcanoes is more or less always at the same distance (around 300km) from the trench, which is the surface limit between the Philippine and the Eurasian plates.

Block-diagram showing a cross-section of the subduction zone beneath the Philippines. The Philippine tectonic plate (on the right) dives under the Eurasian plate (on the left).

MINERAL RESOURCES

The richness of the Philippines in terms of mineral resources is being attributed to its location at the western fringes of the so-called Pacific Ring of Fire – a ground found to be super loaded with mineral deposits.   Globally, Philippines are ranked 5th as most mineralized country in the world. 

The Philippines is situated along the Circum-Pacific Rim of Fire, where the processes of volcanism and plate convergence caused the deposition of minerals, both metallic and non-metallic.  In fact, the large reserves of various kinds of minerals beneath our ground has put the country in the world mineral map as 5th mineral country in the world, 3rd in gold reserves, 4th in copper, and 5th in nickel.

Around 9 million hectares, or 30% of the country’s total land area of 30 million hectares, are believed to contain important metallic mineral deposits; while 5 million hectares are also known to be potential sites for non-metallic mineral reserves.

The country’s offshore areas, which cover around 2.2 million square kilometers, also contain placer minerals, including gold, magnetite and chromite-bearing sands, aggregate resources like sand and gravel, decorative stones, and polymetallic sulfide deposits.

In all, the country’s estimated mineral reserves are placed at about 14.5 billion metric tons of metallic minerals and about 67.66 billion metric tons of non-metallic minerals.

The most prolific copper and gold producers in the Philippines are found in the Baguio and Mankayan districts, province of Benguet; although the Surigao-Davao districts are also contributing much to Philippine gold production. Major producers of nickel are in Palawan and Surigao.

For more info about Philippine mineral resorces:  click  http://www.mgb.gov.ph

Geography of The Philippines

Geography of The Philippines

The Philippines is a tropical country in Pacific Ocean, blessed with beautiful natural landscapes - and active volcanoes and extreme weather patterns.

The Philippines, consisting of some 7,107 islands, is located in the western Pacific Ocean. Taiwan lies to its north, and Vietnam to the west.
It is the 73rd-largest country in the world by surface area, but with a population of some 98 million people, making it the seventh most populous country in Asia, and the 12th most populous in the world.
Its capital, Manila, is the second largest city in the country after Quezon City (the former capital) - and home to most of the country's educational and political institutions.

Natural Disasters

Typhoon Haiyan is one of the deadliest natural disasters ever to hit the Philippines. But it’s far from the only one - the Southeast Asian country is located in an area that has been struck by a number of major storms.

The Philippines has suffered from an inexhaustible number of deadly typhoons, earthquakes, volcano eruptions and other natural disasters. This is due to its location along the Ring of Fire, or typhoon belt – a large Pacific Ocean region where many of Earth’s volcanic eruptions and earthquakes occur.
Annually, approximately 80 typhoons develop above tropical waters, of which 19 enter the Philippine region and six to nine make landfall, according to the Joint Typhoon Warning Center (JTWC).

The Philippines is in fact the country most exposed to tropical storms in the world. Violent tropical storms, such as the latest Haiyan typhoon, can generate 10 times as much energy as the Hiroshima atomic bomb.

Here is a list of earthquakes, volcanic eruptions, typhoons, cyclones and other natural disasters the Philippines has had to cope with during the past decade - leaving thousands of people dead and the country's infrastructure and economy in tatters.

Bohol earthquake, October 2013
Typhoon Bopha, November-December 2012
Pantukan landslide, January 2012
Tropical Storm Washi, December 2011
Typhoon Fengshen, June 2008
Cyclone Durian, November 2006
Guinsaugon landslide, February 2006

Tropical Depression Winnie, November 2004