http://www.english.hadhramaut.info Lava build-up on Philippine volcano [The Source: /english.aljazeera.ne - 17/12/2009] Scientists monitoring the Mount Mayon volcano in the Philippines say pressure appears to be building in at least two new lava domes in the volcano's crater, indicating a major eruption is imminent. The volcano, the most-active in the Philippines, has been spewing torrents of molten lava and clouds of ash for several days, triggering an evacuation of tens of thousands of residents living in the area.Mayon has been ejecting lava and clouds of ash for several days [Reuters] Government officials have said the evacuees may have to spend up to four months crammed into crowded shelters before they can return home."We saw the formation of two lava domes at the crater of Mayon during an aerial survey yesterday," government volcanologist July Sabit told the AFP news agency on Thursday."This indicates pressure is building up from the inside and the rising magma had accumulated at the mouth to form the domes," he said."If this continues, it is likely that part of the domes will collapse, causing pyroclastic flows or amajor eruption."Pyroclastic flows are fast-moving torrents of rock and superheated gases ejected during a volcanic eruption.Travelling at speeds of up to 700kmh, such flows are invariably deadly for anyone caught in their path.As a precautionary measure, the military and police have evacuated an estimated 50,000 residents, mostly from farming villages in Mayon's fertile foothills.The provincial governor has declared a "state of imminent disaster" in order for special disaster funds to be released to pay for the evacuation and help those who have been moved. 'Ring of fire' Officials have declared a state of "imminent disaster" around the volcano [Reuters] Mayon is the most active of 22 volcanoes in the Philippines, having erupted more than 50 times in the last four centuries.The last time the volcano erupted was in 2006.Mayon's most destructive eruption came in 1841 when lava flows buried the town of Cagsawa and killed more than 1,200 people.The country lies on the volatile "Ring of Fire", a belt of volcanoes circling the Pacific Ocean that is also prone to earthquakes.In June 1991 the Philippines was the scene of the world's most violent eruption of the last century when 800 people were killed around Mount Pinatubo north of Manila.The eruption spewed out ash that spread around the globe and caused volcanic mudflows that buried whole towns.