These deposits can be remobilised by rainwater and generate lahars
(mud flows) by themselves and or by incorporating existing erodible material on channel banks," Phivolcs warned in an advisory.
Remember that lahars
and sediment-laden streams are both dangerous," Phivolcs director Renato Solidum told reporters after confirming that lahar
was flowing from one lava channel on Mayon's slopes.
These deposits can be remobilized by rainwater and generate lahars
by themselves and or by incorporating existing erodible material on channel banks," Phivolcs said.
The public is strongly advised to be vigilant and desist from entering the eight (8) kilometer-radius danger zone, and to be additionally vigilant against pyroclastic density currents, lahars
and sediment-laden streamflows along channels draining the edifice,' it said.
act like concrete, flowing when carried by water but becoming solid when deposited on land.
They probably resulted from settling clouds of dry ash followed by denser lahars
, deadly flows of water-saturated ash and rock, Sheridan adds.
They focus instead on lahars
, wet concrete-like slurries of water and sediment that can travel up to 60 mph.
Major volcanic hazards include lahars
, landslides, and flank collapse.
Like concrete cascading down a cement truck chute, lahars
could even entomb the streets of Orting.
can travel at more than 50 miles an hour, contain up to 90 per cent solid debris, and will entomb everything in their path.
Forests may be completely destroyed and buried by (1) lava flows, pyroclastic flows and ash falls (geological nomenclature follows Bates and Jackson, 1984 and Scarth, 1994) from active volcanoes or (2) lahars
, mudflows, debris flows, earth flows and landslides from either active volcanoes or unstable terrain on the slopes of inactive volcanoes.
One of the worst causes of destruction after an eruption, lahars
can be truly devastating.