c) Increase in the volume of steam emission
d) Crater glow due to presence of magma at or near the crater
e) Rumbling sounds because of gas explosion
f) Rock falls and landslides caused by the rising magma and unstable
Rocks at or near the summit
g) Fissuring due to pressure exerted by the rising magma (rarely observed)
Phenomena Associated with Eruptions:
Air fall tephra (ballistic fragments, ashfalls)
Pyroclastic flows
Lava flows
Lahars
MONITORING TECHNIQUES:
Monitoring Methods:
A. Geophysical Method
Seismic monitoring - telemetered to Lignon Hill Observatory
B. Geodetic Methods
Electronic Distance Measurement
Precise leveling
Tilt measurements (wet and dry)
C. Visual Observations
D. Geochemical methods
Gas chemistry - monitoring of sulfur dioxide emission using Correlation
Spectrometer (COSPEC)
E. Water Well Monitoring
Monitoring Stations:
Mayon Rest House Observatory (MRHO) - 3.8 km NW of the summit
Sta. Misericordia Volcano Observatory (SMO) - 8.5 km E of the summit
Lignon Hill Observatory (LHO) - 12 km SSE of the summit
HAZARD ZONES:
Permanent Danger Zone - 6 km radius
High Danger Zone - 6 km from the summit extended to 11 km in the SE sector
Moderate Danger Zone - 8 km from the summit extended to 15 km in the SE sector
MUNICIPALITIES WITHIN 15 KM OF MAYON 'S SUMMIT CRATER:
Mayon Volcano, Philippines
Photos by Robert Gardner
Mayon Volcano reaches 2,460 meters and is the central feature of the Albay Province, of which Legazpi City is the capital, about 300-km southeast of Manila . It must be one of the most beautiful volcanic cones anywhere in the world and is visible for miles around in the otherwise flat landscape of the region. The volcano is still active and has erupted in 2000 and 2001. There is a research station () located about one-third of the way up that is accessible by road and is the jump-off for climbers. See also and other . Here are six photos I took from several locations around the volcano.
The 2,462-meter Mayon, about 340 kilometers southeast of Manila in Albay province, is famous among local and foreign tourists for its near-perfect conical shape despite dozens of eruptions in the past three centuries.
The eruption of Feb. 24 was Mayon's 47th since its first recorded upheaval in 1616.
Mayon's last major eruption was in February 1993, when 70 people died and more than 50,000 people were evacuated.
Its deadliest eruption was in 1911 when it buried the entire town of Cagsawa under ash and killed more than 1,300 people.
February 23, 2000 12:00 mn: Lava starts to flow....many believe that the image of the Blessed Virgin Mary is formed as the lava flows down ....