MAYON VOLCANO

Alert Level	Monitoring Network
Hazard Map	Volcano Observatory

LOCATION:  

       ALBAY PROVINCE, 300 km SE 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:                    

            No. of Recorded Eruptions:  47 since 1616        
            Latest Eruption:  24 June & 26 July 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 continous sustained ejection of pyroclasts
                                       (e.g. 1814 eruption)       

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

            Phenomena Associated with Eruptions:                
                        Airfall 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 inthe SE sector

MUNICIPALITIES WITHIN 15 KM OF MAYON 'S SUMMIT CRATER: