Mayon Volcano

Mayon Volcano
Mt.Mayon tam3rd.jpg
Mayon Volcano as viewed from Lingñon Hill in Daraga, Albay
Elevation 2,463 metres (8,081 ft)
Location Albay, Philippines
Prominence 2,447 metres (8,028 ft)
Type Stratovolcano
Last eruption 2006
Listing Ultra
The volcano is in the Philippines

Mayon Volcano is an active stratovolcano in the province of Albay, in the Bicol Region, on the island of Luzon, in the Philippines.

Renowned as the "Perfect Cone" because of its almost perfectly conical shape, Mayon is situated 15 kilometres northwest of Legazpi City.

Mayon is a continuing nominee as one of the New 7 Wonders of Nature.[1]

Contents

Geomorphology

Mayon is a stratovolcano or composite volcano. The current cone was formed through pyroclastic and lava flows from past eruptions. Mayon is the most active of the active volcanoes in the Philippines, having erupted over 47 times in the past 400 years.

It is located on a convergent boundary between the Eurasian and the Philippine Plate. Where a continental plate meets an oceanic plate, the lighter continental plate overrides the oceanic plate, forcing it down. Magma, formed where the rock melts, may be forced through the earth's crust. One such exit point for the magma, is Mayon.

Like other volcanoes located around the rim of the Pacific Ocean, Mayon is part of the "Pacific Ring of Fire".

Location and formation

Mayon Volcano in Albay showing its distance from the Albay Gulf

Mayon Volcano is the main landmark of Albay Province, Philippines. It is ten kilometres (6 mi) from the Gulf of Albay,[2] in the municipalities of Legazpi City, Daraga, Camilig, Guinobatan, Ligao City, Tabaco City, Malilipot, and Santo Domingo (clockwise from Legazpi). It rises 2462 m (8,077 ft) above the gulf.[3]

Mayon Volcano is the Philippines' most active volcano and is considered to be the world's most perfectly formed volcano[2] for its symmetrical cone. It is a basaltic-andesitic volcano.[3] The upper slopes of the volcano are steep averaging 35-40 degrees and are capped by a small summit crater. Its sides are layers of lava and other volcanic material.

Recorded eruptions

Mayon Volcano on 23 September 1984

Mayon has had forty-seven eruptions in recorded history.[4] The first recorded eruption was in 1616, the latest ceased on 1st October 2006, although a devastating lahar followed on 30 November 2006.

The most destructive eruption of Mayon occurred on February 1, 1814. Lava flowed but not as much compared to the 1766 eruption. Instead, the volcano was belching dark ash and eventually bombarding the town with tephra that buried the town of Cagsawa—only the bell tower of the town's church remained above the new surface. Trees were burned; rivers were certainly damaged. Proximate areas were also devastated by the eruption with ash accumulating to 9 m (30 ft) in depth. 2,200 Albay locals perished in what is considered to be the most lethal eruption in Mayon's history.[2]

Mayon Volcano's longest uninterrupted eruption occurred on June 23, 1897 which lasted for seven days of raining fire. Lava once again flowed down to civilization. Seven miles eastward, the village of Bacacay was buried 15 m (50 ft) beneath the lava. In Libog, 100 people were declared dead—incinerated by steam and falling debris or hot rocks. Other villages like San Roque, Misericordia and Santo Niño became deathtraps. Ash was carried in black clouds as far as 160 km (100 mi) from the catastrophic event. More than 400 persons were killed.[2]

Samuel Kneeland, a professor and a geologist had observed the volcanic activity five months before the eruption. Kneeland was amazed with the beauty of Mayon:

“ At night the scene was truly magnificent and unique. At the date of my visit the volcano had poured out...a stream of lava on the Legaspi side from the very summit. The viscid mass bubbled quietly but grandly, and overran the border of the crater, descending several hundred feet in a glowing wave, like red-hot iron. Gradually, fading as the upper surface cooled, it changed to a thousand sparkling rills among the crevices, and, as it passed beyond the line of complete vision behind the woods near the base, the fires twinkled like stars, or the scintillions of a dying conflagration. More than half of the mountain height was thus illuminated. ”
[2]
Mayon Volcano overlooks a peaceful pastoral scene approximately five months before the volcano's violent eruption in September 1984.

No casualties were recorded from the 1984 eruption after more than 73,000 people were evacuated from the danger zones as recommended by scientists of the Philippine Institute of Volcanology and Seismology.[5]

Pyroclastic flows killed 77 people, mainly farmers, in Mayon’s fatal eruption of 1993.

2006 activity

Mayon erupted again from July to October 2006, with no apparent loss of life during the actual eruption period.

On July 18, 2006: The number and size of incandescent rockfalls from the active lava dome, as well as sulfur oxide emissions, increased, according to the Philippines Institute of Volcanology and Seismology (Phivolcs), which warned that pyroclastic flows or an explosive eruption could occur any time.

On August 7, 2006: The Philippine government ordered the evacuation of about 20,000 people living near the volcano, stating that an eruption was feared soon[6]. Volcanologists have detected 21 low-frequency volcanic earthquakes since early Sunday morning.[7]

On August 8, 2006: The government expected to move some 34,276 people to 31 state-run shelters and warned that the mountain could explode at any time. [8] [9]

Mayon Volcano as seen from space.

On August 9, 2006: Volcanologists warned that Mount Mayon could explode at any time but that the gravitational pull of a full moon could provide the final push. A full moon coincided with at least three of Mayon’s nearly 50 explosions over the last four centuries, including the two most recent in 2000 and 2001. Nearly 40,000 people have been moved from an 8 km (5 mi) danger zone on the southeast flank of the volcano, which has been quaking and spitting plumes of ash since July.[4]

On August 10, 2006: Scientists in the Philippines renewed warnings of a major explosion at the Mount Mayon volcano, describing a sudden period of quiet as "ominous". A drop in gas emissions and earthquakes sparked fears that the crater had plugged itself, increasing the likelihood of an explosive eruption. [10]

On August 11, 2006: Scientists said ground surveys showed Mayon was still "swollen" and registered a high number of volcanic earthquakes, emitted large amounts of sulfur dioxide gas and continued to eject lava down its slope nearly four weeks after it came to life in a "quiet" eruption on July 14.[11] Phivolcs maintained threat level at Alert Level 4 for the next month due to the continued extrusion of lava, ash explosions, steam and smoke plumes, seismic activity, and threat of further eruption.

On September 11, 2006 Phivolcs downgraded threat level to Alert Level 3. "After the ash explosion of 01 September, a general decline in the overall activity of Mayon has been established. The decrease in key parameters such as seismicity, gas (Sulfur Dioxide) emission rates and ground inflation all indicate a waning condition. The slowdown in the eruptive activity is also evident from the decrease in intensity of crater glow and the diminishing volume of lava being extruded from the summit". [12]

On October 03, 2006 Phivolcs downgraded threat level to Alert Level 2. "All monitored key parameters such as earthquake levels, ground deformation and gas outputs further declined. In addition, lava extrusion apparently ceased on 01 October 2006 as reported by Ligñon Hill Observatory. The above observations indicate the absence of an intruding new mass of magma." [13]

On October 25, 2006 Phivolcs downgraded threat level to Alert Level 1 (no hazardous eruption imminent). [14]

Phivolcs did not issue any further alerts or updates for Mayon in November or December 2006, or in 2007.

Devastating Aftermath

On November 30, 2006: Typhoon Durian caused mudslides of volcanic ash and boulders from the slopes of Mayon Volcano, killing an estimated 1,000 and covering a large portion of the village of Padang (an outer suburb of Legazpi City) in mud up to the houses' roofs.[15] [16]

The number of dead was estimated at around 1000, about half the death toll of the 1814 eruption. The precise figure may never be known since many people were buried under the lahars, and entire villages disappeared.

Parts of Daraga were also devastated, including the Cagsawa area, where the ruins from the eruption of 1814 were partially buried once again. Large areas of Guinobatan were destroyed, particularly Maipon.

Students from Aquinas University in Barangay Rawis of Legazpi City were among those killed as mudslides engulfed their dormitory. Central Legazpi escaped the mudslide but suffered from severe flooding and power cuts.

Current eruptive activity

On 10 August 2008 Phivolcs issued the following news statement:

At 9:12 A.M. today, Mayon Volcano manifested mild ash explosion that reached an approximate height of 200 m above the summit crater before drifting east-northeast. The ash-ejection was recorded as explosion-type earthquake which lasted for one minute by the seismic network deployed around the volcano.Immediately after the explosion, visual observation becomes hampered by the thick clouds. During the past weeks, seismic activity had slightly increased and crater glow had slightly intensified. Precise leveling surveys conducted at Mayon from May 10 – 22, 2008 compared to February 17 – March 2, 2008 survey also showed inflation of the volcanic edifice.

The above observations show that Mayon Volcano is undergoing an episode of increased activity probably related to magma movement and post eruptive behavior of the volcano. Although no major eruption is indicated, steam and ash explosions may occur in the following days.

In view of the above, PHIVOLCS reiterates that Mayon Volcano’s status remains at Alert Level 1. [17]

See also

References

  1. ↑ "Mayon Volcano". News7Wonders. Retrieved on 2008-05-08.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Davis, Lee (1992). Natural disasters: from the Black Plague to the eruption of Mt. Pinatubo. New York, NY: Facts on File Inc.. pp. 300-301. 
  3. ↑ 3.0 3.1 "Mayon Volcano, Philippines". Philippines Department of Tourism. Volcano.und.edu.
  4. ↑ 4.0 4.1 "Full moon fear for Mayon volcano", BBC News (2006-8-6). Retrieved on 2008-08-29. 
  5. ↑ USGS
  6. ↑ BBC: Philippine volcano 'set to erupt'.
  7. ↑ National Geographic: Photo in the News: Philippine Volcano Threatens Eruption
  8. ↑ Manila Standard: 34,000 flee Mayon area; Manila Bulletin: Mayon volcano records 3 additional ash explosions
  9. ↑ Mayon volcano's lava lights up the clouds near Legazpi City
  10. ↑ 'Ominous quiet' at Mayon volcano BBC News.
  11. ↑ Relief goods arrive amid wait for Mayon’s big bang Associated Press
  12. ↑ Mayon Volcano Bulletin
  13. ↑ Mayon Volcano Bulletin
  14. ↑ Mayon Volcano Bulletin
  15. ↑ Typhoon sends red-hot boulders into villages - CNN.com
  16. ↑ http://news.yahoo.com/s/ap//ap_on_re_as/asia_storm
  17. ↑ [1]

External links