Province of Albay
Mayon Volcano

Location: Albay Province 
300 km South East of Manila 
(13°15.4'N - 123°41.1'E)

Physical Characteristics:

• Height: 2,460 m asl 
• Base Circumference: 62.8 km (reckoned from 10-km radius) encompassing the towns of Camalig, Malilipot and Sto. Domingo 
• Type of Volcano: Stratovolcano or Composite Volcano, composed of a sequence of pyroclastic and lava flows 
• Areas: 314.1 km² (estimated from 62.8 km base circumference) 
• Composition of Lava: Andesitic

Historical Eruptions:

Number of Recorded Eruptions: 47 since 1616
Latest Eruption: June 2001 (Strombolian & Vulcanian types) 
Most Destructive Eruption: 01 February 1814; 1,200 people perished due to lahars

Eruption Types: 

• Strombolian - quiet emission of lava (e.g. 1978, 1st phase of 1984 eruption) 
• Vulcanian - violent explosions and eruptions of pyroclastic flows (e.g. 1st phase of 1968 eruption, 2nd phase of 1984 eruption) 
• Plinian - extremely violent explosions with continuous sustained ejection of pyroclasts (e.g. 1814 eruption)

Precursors to Eruptions:

1. Increase in seismicity level (Background: 0-10 volcanic quakes per day) 
2. Ground tilt due to magma intrusion 
3. Change in color of steam emission from white to gray due to entrained ash 
4. Increase in the volume of steam emission 
5. Crater glow due to presence of magma at or near the crater 
6. Rumbling sounds because of gas explosion 
7. Rockfalls and landslides caused by the rising magma and unstable rocks at or near the summit 
8. Fissuring due to pressure exerted by the rising magma (rarely observed)

Phenomena Associated with Eruptions: 

1. Airfall tephra (ballistic fragments, ashfalls) 
2. Pyroclastic flows 
3. Lava flows 
4. Lahars

Monitoring Techniques:

Monitoring Methods 

1. Geophysical Method
   • Seismic monitoring - telemetered to Ligñon Hill Observatory
2. Geodetic Methods
   • Electronic Distance Measurement
   • Precise Leveling
   • Tilt Measurements (wet and dry) 
3. Visual Observations
4. Geochemical methods - 
   • Gas chemistry - monitoring of sulfur dioxide emission using
   • Correlation Spectrometer (COSPEC)
5. Water Well Monitoring

Monitoring Stations 

1. Mayon Rest House Observatory (MRHO) - 3.8 km NW of the summit 
2. Sta. Misericordia Volcano Observatory (SMO) - 8.5 km E of the summit 
3. Ligñon Hill Observatory (LHO) - 12 km SSE of the summit

Hazard Zones:

1. Permanent Danger Zone - 6 km radius 
2. High Danger Zone - 6 km from the summit extended to 11 km in the SE sector 
3. Moderate Danger Zone - 8 km from the summit extended to 15 km in the SE sector

Towns Within the 15 kilometer of Mayon's Summit Crater
(As of May 1, 2000)

Source: Philippine Volcanology and Seismology