Mayon Volcano

Mayon Volcano lies in the eastern portion of the province of Albay and is about 300 km. southeast of Manila. Well known for its beauty and near perfect cone, this active volcano is one of the tourist attractions of the country.

Mayon reaches up to around 2,462 m. above sea level and covers an area of 250 sq. km. Its base circumference is 62.8 km. encompassing the towns of Camalig, Malilipot and Sto. Domingo.

Mayon is classified as a stratovolcano or composite cone. It consists of deposits formed basically by four major types of volcanic activity: airfall deposition, pyroclastic flows, rain triggered debris flows and lava flows. Airfalls and pyroclastic flow deposits are composed of unconsolidated materials, varying in size from ash to ssmall boulders. These deposits result from the eruption of fragmented rocks from the crater and are transported downslope under the influence of gravity, explosion blast and the prevailing wind.

Considered as the most active volcano in the Philippines, Mayon Volcano has had at least 43 eruptions since 1616. Its most violent and devastating outburst occurred on February 1, 1814. Nearby towns of Camalig, Cagsawa and Budiao were severely damaged, half of Guinobatan was ruined and at least 1,200 people perished in this eruption.

The eruptions of Mayon are usually "Vulcanian" or explosive in nature. They are characterized by the emission of fine ash and ash-laden gases forming huge "cauliflower" clouds. The symmetry of the volcano indicates that the eruptions have always occured at the central vent and that these have never been violent enough to destroy Mayon's form.

Mayon, though sometimes destructive, is also productive. Its fertile slopes and surrounding plains, coupled by abundant rainfall through the year, have made Albay a rich agricultural region with the bulk of its population found in towns bordering the volcano such as Camalig, Guinobatan, Daraga, Legaspi, Sto. Domingo, Ligao and Malilipot. The region is suited for growing abaca and coconut, two of Bicol's major crops, as well as palay and vegetables.

Taal Volcano

Taal Volcano, one of the world's lowest volcanoes, is an island located near the center of Taal Lake in Batangas Province. Its highest point, 311m . Above sea level, is on the eastern rim of the main crater.

Covering an area of 23 sq. km., the Volcano Island is surrounded by a fresh body of water, about two meters above sea level and 127 sq. km. in area. Taal Lake is known to have originated from the collapse of pre-historic volcanic centers. The underwater topography suggests the presence of about 35 different submerged volcanic landforms.

Taal Volcano is a tuff cone. The rock formation consists of moderately consolidated ash beds with varying amounts of coarser fragments. Composed of at least 35 cones coalesced by several eruptions, Taal has about 47 craters or depressions formed either by direct explosive eruptions or by collapse or ground subsience.

The 35 identified cones were formed by different type of volcanic processes: base surges (rapidly moving mixtures of volcanic debris and steam), airfalls and effusion of lava. Twenty-six of these cones are tuff cones, five are cinder cones and four are maars (shallow to deep circular depressions of volcanic origin).

The Main Crater occupies the central portion of the Volcano Island. Twelve of Taal Volcano's eruptions occured at this crater from 1749 to 1911. There are five other major eruption centers, namely: Binintiang Malaki, Binintiang Munti, Pira-0piraso, Calauit and Mt. Tabaro Eruption Site.

To date, Taal Volcano, has had 33 recorded eruption since its first known outburst in 1572. Its most catastrophic eruptions occured in 1754 and 1911. In 1754, the towns of Sala, Lipa, Tanauan, and Taal, then on the borders of Lake Taal, were destroyed and were subsequently relocated to their present sites. The 1911 eruption completely devastated the whole Volcano Island and claimed a toll of 1,034 lives. Ashes spewed out by the volcano reached as far as Manila and covered an area of 2,000 sq. km.

Based on Taal Volcano's morphological features, it can be deduced that most of its eruptions were either Phreatic or Phreatomagmatic. Ground water and mobile magma may have either separately or jointly played the pricipal role in determining the nature of Taal eruptions. The 1968 and 1969 activities were, however, characterized as Strombolian with lava fountaining from several active vents and the effussion of molten rocks at the base of crater.

Despite the hazards posed by the volcano, Taal Volcano Island has been attracting migrants because of its fertile soil and rich fishing grounds. Lake Taal is known for several varieties of milkfish, carps, maliputo and tawilis.

The island had a population of more than 5,000 in 1990.

Butusan Volcano

Butusan Volcano is located at the south central part of Sorsogon Province. It covers a surface area roughly 400 sq. km. and towers to about 1559 m. above sea level. The volcano forms part of the Bicol Volcanic Chain which stretches from Camarines Norte in the north to Sorsogon in the south. The chain, sometimes called volcanic belt, is composed of active and geologically young volcanoes most probably related to the Philippine Trench.

Bulusan is clasified as a composite volcano and is made up of lava flows and domes. It is flanked by several cones namely: Mt. Homahan, Mt. Binactan, Mt. Batuan, Mt. Juban, Mt. Calaunan, Mt. Tabon-Tabon, Mt. Calungalan and Mt. Jormajan. Beside the active volcano is an old ridge called Sharp Peak which is 1215 m. high and 1.8 km. to the northeast. Between Bulusan and Jormajan is theNatakop lava dome.

The earliest recorded eruption of Bulusan Volcano occured in 1852. This was followed by periods of eruptive activity in 1886, then 1892, and in 1894. Another 22 years elapsed before Bulusan showed signs of restiveness. On January 16, 1916, the volcano ejected mud and ash for five days, thereby triggering landslides. The volcano's eruptive activity from Oct. 1918 to March 1919 was characterized by dust emissions and lava outpourings.

Bulusan's series of 17 eruptions during May 1919 to May 1922 were of short duration ranging from 15 to 30 minutes each. Other eruptions were recorded in June 1928 and Dec. 25, 1933 and then the volcano rested for 45 years. On June 28, 1978, it suddenly ejected ashladen steam clouds which formed in a dark column of smoke 1500 m. high. Andesitic baalt ash was ejected and blown by winds to as far as Barcelona in the northeast about 15 km. from the volcano.

The eruptions which followed in 1979, 1980, 1981 and 1983 were all pheatric and as mild as the previous ones.

A total of 60 barangays within the territorial jurisdiction of six municipalities (Barcelona, Bulusan, Casiguran, Gubat, Irosin and Juban) are covered by the Bulusan Volcano hazard zones established by PHIVOLCS. These barangays lie within 4-10 km. from the summit of Bulusan Volcano.

Canlaon Volcano

Canlaon Volcano, a large stratovolcano, is located in the north central portion of Negros Island. It forms a natural boundary between the provinces of Negros Occidental and Negros Oriental.

Canlaon has a maximum elevation of 2435 m and a basal diameter of 30 km. It is a part of the volcanic arc related to subduction along the Negros Trench, which includes Mt. Silay in the north, Mt. Mandalagon and Mt. Cuernos de Negros in the south.

Canlaon consists of a multitude of craters and parasitic cones aligned linearly, with an older caldera in its central portion. Most of the older cratershave formed lakes or lagoons. The volcanic edifice has been built by airfall deposits, lava agglutinates and lava flows, pyroclastic flows and lahar.

The earliest record of Canlaon's eruption dates back to 1866. Since then, it has had at least 15 eruption periods, the latest occuring this year (1988).

Recorded eruptions have so far been mild, consisting of ash and steam explosion sometimes coupled with lava flows and pyroclastics. Occurrence of older deposits, however, suggests that pre-historic eruptions have been more violent.

Though a large segment of the volcano is considered a forest reservation, settlers have already encroached on the area. Several sugarcane haciendas are located on Canlaon's slopes. Vegetable and rice form secondary agricultural products.

JOLO ISLAND

LOCATION : Southwestern Mindanao/Sulu Archipelago
Latitude
: 5 degrees 57.57' N
Longitude
: 121 degrees 10.44' E
HEIGHT FROM SL : 811 m. maximum
TYPE OF VOLCANO : Compound, mostly cinder cones and maars
KNOWN ERUPTIONS : Mt. Dakula - 1641
Lake Seit - 1897
TYPE OF ACTIVITY :
MAIN ROCK TYPE : Basalt

Numerous cinder cones, tuff cones and maars make up the island province of Jolo. In 1641, Magisa reported that on Jan. 4, a small island "opposite the bar of the main river of Jolo" erupted and sent a shower of ash to as far as Zamboanga. However, a survey of Jolo and adjoining islands indicated that Mt. Dakula near Lake Panamo appears to be the most recent of all the cones in the province.

A submarine volcanic activity was also reported on September 21, 1897. The presence of a still active solfatara at Lake Seit, makes this maar the probable center of this activity.

MOUNT MATUTUM

LOCATION : Southern Mindanao/Cotabato
Latitude
: 6 degrees 21' N
Longitude
: 125 degrees 06.5' E
HEIGHT FROM SL : 2293 m.
TYPE OF VOLCANO : Strato-volcano
KNOWN ERUPTIONS : 1911
TYPE OF ACTIVITY :
MAIN ROCK TYPES : Andesite

About 70 km. south-southwest of Mt. Apo is a well preserved 2,293 m high cone named Matutum (which in the local dialect means "has fired or burnt out"). At the top is a 120-m deep and 320-m wide crater, breached by three gorges and covered with dense growth.

An unconfirmed report states that Matutum was smoking on March 7 , 1911. However, several authors believe that the volcano is dormant.

Mount Musuan of Calayo

Location : Bukidnon
Latitude
: 7 52'N
Longitude
: 125 04'E
Height from S.L. : 646
Type of Volcano : Essentially a tuff cone
Known Eruptions : 1886 or 1887
Type of Activity :
Main Rock Type :

Musuan or Calayao volcano is an isolated tuff cone amidst a relatively flat, agriculturally rich terrain. It is vegetated from foot to summit with cogon grasses. Some trees thrive sparingly in its northeastern side. Its peak is flat and nearly circular with a diameter of 10-15 m.

Jesuit Father, Eusebio Barado who traveled across the island of Mindanao from Misamis to Cotobato in 1891, reported Calayo's eruption some four years ago, and its emission of sulfurous vapors which burned everything around it.

Musuan Volcano came into limelight when a swarm of fairly strong earthquakes rocked Valencia, Bukidnon, a municipality 4.5 km north of the volcano, from November 13 to 16, 1976. The event followed three major earthquakes that hit the Mindanao region (Cotobato Earthquakes of August 16 and 17, Magnitude 7, 9 and 6,8 respectively, and Surigao Earthquake of November 7, Magnitude 6,8), giving the impression that the swarm resulted from crustal or magmatic movement in the volcano, following what could be considered as part of the crustal readjustment process in the region.

In the investigation conducted on November 21-30, 19 local tremors of varying magnitudes were recorded (A temporary seismograph was installed 4.5 km from the volcano during the period). Of these, 4 were perceptible. All the tremors resembled deep volcanic earthquakes with S-P measured at about 1.0 sec.

MOUNT RAGANG

Location : Northern Mindanao/Lanao and Cotobato
Latitude
: 7 41.2'N
Longtitude
: 124" 31.8'E
Height from S.L. : 2815 m
Type of Volcano : Strato-volcano
Known Eruption : 1756, 1834, 1840, 1856, 1858,
1865, 1871, 1873, 1915, 1916
Type of Activity : Explosive with lava flow
Main Rock Type :

This volcano occupies the northeast end of a series of relatively young volcanic cones in the boundary of the provinces of Lanao and Cotobato. The eruptive vent is rimmed by three peaks with a deep hollow at the center. From the southeast of this crater, a flow of jagged lava radiates to about one km. All around the cones and craters, product of past eruptions are scattered in the order of their size: boulder near the cones and the cinders, lapilli, and ashes farther away. The numerous jets of sulfurous vapors from vents in the crater and along one of the cones serve as evidence of the volcano's past activity. A thick column of steam rising from the fissure was reported in 1916 by Capt. G.O. Fort, P.C. The scorched and burnt trees at the southeastern sector seem to indicate a strong blast of hot gases in the quite recent past, probably that of the 1915 eruption.

Other eruptions of Ragang took place in 1834, on January 20-April 5, 1840, on November 1, 1856, on February 18, 1858, in 1865, shortly before December 8, 1871 and on January 16-April 1873.

Showers from the volcano, particularly during the 1840 eruption,were reported to have reached as far as 95 km west and 480 km northwest of Mindanao.

MOUNT HIBOK-HIBOK

LOCATION : Northern Mindanao/Camiguin
Latitude
: 9 12'N
Longtitude
: 124 40.5'E
HEIGHT FROM S.L. : Hibok-Hibok-1330 m; Vulcan -
TYPE OF VOLCANO : Compound volcano appropriately a dome.
KNOWN ERUPTIONS : Hibok-Hibok - 1827, 1862, 1897,
1902, 1948-1953
Vulcan - 1871, 1874
TYPE OF ACTIVITY : Pelean, Dome building with nuee ardente.
MAIN ROCK TYPE : Olivine-bearing andesite & dacite

Hibok-Hibok volcano, also called Catarman, has a summit formed of loose ejectamenta. It has several craterlets at or near its crest, some representing shallow lakes. The present crateral area at the northeast slope facing Mambajao was mined for sulfur before the volcano's activity in 1948. Rock is normal andesite with augite, little hypersthene and olivine. Plagioclase is oligoclase with little labradorite. Some lavas contain horn blende.

The first recorded eruption of Hibok-Hibok ocurred in 1827. This was followed by similar activity in 1862. Both eruptions caused destruction to arable lands.

In January 1871, earthquakes and subterranean rumbling sounds disturbed the north end of Camiguin island. Landslides and fissuring destroyed trees and plantations. When the swarm of earthquake ceased in April of the same year, an explosion followed accompanied by a shower of rocks, dust, and ashes. Destruction was complete within a radius of 3 km from the new vent. The eruption continued for a week, and a volcanic dome called Vulcan began to form 3.5 km from the general area of Hibok-Hibok. After four years of activity, the adventive lava dome reached a height of 457 m with a base nearly 1.5 km in diameter.

Vulcan is quiet at present and appears to have been unaffected by the activity of the adjacent Hibok-Hibok. Vulcan's activity has been limited to emission of small amounts of steam from crevices at the top of the dome.

In 1897, the area occupied by the present dome of Hibok-Hibok emitted white sulfurous vapors which ruined agricultural lands. Solfataric activity continued up to 1902 when a thunder storm occurred around the volcano and a new solfataric vent formed opposite the crest. Frequent subterranean sounds were noted during the activity which lasted for 8 to 10 days.

The last activity of Hibok-Hibok started in August 1948, with a series of earth tremors. The landslides and earthquakes were climaxed by the crateral outburst in September 1953, Hibok-Hibok has been in more or less continous activity punctuated by eruptive phases.

In every few years of activity, Hibok-Hibok seems to follow a cycle of behavior consisting of :

  1. A short period of smoke emission from the crater and avalanche of volcanic materials with or without accompanying tremors;
  2. Explosions or steam blasts with emission of heavy clouds of steam, ashes and other fragmentary volcanic materials
  3. Disorging of incandescent materials and emission of ash and smoke in large quantities; and
  4. Decrease in amount of smoke and other ejecta from the crater.
The whole cycle covers a period of 9 to 14 months.

Cold and hot mud flows, or lahars, had developed, especially after heavy rains, so that now they pose another hazard to inhabitants living near the drainage channels of the volcano.




Home | Pinatubo's Two Faces | Pre-Eruption Manifestation | Chronological Account | Aftermath | Facts and Trivia | Glossary | Map