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Lava generally flows slowly, so it is usually easy to escape. The lava also stays to the lowest lying areas it can get to, making the paths they take fairly predictable.
Pyroclastic flows move very quickly, often exceeding 100 mph, making them nearly impossible to escape. Their momentum and their lower density compared with lava also means that they do not necessarily follow topography. They have been known to surge across valleys and over ridges with deadly results.
Wiki User
∙ 7y ago
Wiki User
∙ 7y agoPyroclastic flows move very fast, leaving almost no opportunity to get out of the way in time. While they are not always as hot as lava flows, they are still unsurvivably hot. They also carry a tremendous amount of force, capable of leveling most buildings. Lava flows are usually much slower-moving, giving people time to evacuate. So while lava flows can be very destructive, deaths from them are relatively rare.
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What are the similarities in a lava flow and a pyroclastic flow?
A lava flow is simply a flow of liquid rock down a slope that usually results from an effusive eruption. A pyroclastic flow is an avalanche-like flow of hot ash, rock and gas that moves down a volcano during an explosive eruption, The move much faster than lava flows and are far more dangerous.
What are the most common volcanic hazards?
In addition to suffocating ash and flowing lava, pyroclastic flows are probably the most dangerous feature of some volcanoes. Pyroclastic flows are currents of extremely hot gases and rocks that flow down and away from the slopes of volcanoes. They travel at speeds has high as 450 mph, and the temperature of the gas and rock can reach more than 1800° F (1000° C).
Which is faster a lava flow pyroclastic flow or lahar?
Pyroclastic flows move much faster than lava flows and carry much more momentum. This means there is little time tog et out of the way, and that they can pass over barriers that would stop or deflect lava flows. They can also carry more material. A single pyroclastic flow can bury an area to several meters thick in a matter of seconds.
Why does pyroclastic flow travel faster than a lava flow?
Lava is a very viscous liquid, meaning it will resist flowing rather like syrup. Lava flows are often slowed even more as they form a crust of solid rock. A pyroclastic flow is a different matter; it is a dense cloud of hot ash, rock, and gas, behaving more like an avalanche than a flowing liquid. Pyroclastic flows are not slowed by viscous forces.
Why does a pyroclastic flow travel more quickly than a lava flow?
A lava flow flows as a viscous liquid, rather like molasses only thicker. A pyroclastic flow is a mixture of ash, gas, and rock fragments and is not significantly affected by viscous forces that would slow it down. It moves like an avalanche or thunderstorm downburst rather than a liquid.
What is more deadly lava or pyroclastic flow?
Pyroclastic flow.
What are the similarities in a lava flow and a pyroclastic flow?
A lava flow is simply a flow of liquid rock down a slope that usually results from an effusive eruption. A pyroclastic flow is an avalanche-like flow of hot ash, rock and gas that moves down a volcano during an explosive eruption, The move much faster than lava flows and are far more dangerous.
What are the most common volcanic hazards?
In addition to suffocating ash and flowing lava, pyroclastic flows are probably the most dangerous feature of some volcanoes. Pyroclastic flows are currents of extremely hot gases and rocks that flow down and away from the slopes of volcanoes. They travel at speeds has high as 450 mph, and the temperature of the gas and rock can reach more than 1800° F (1000° C).
Which is faster a lava flow pyroclastic flow or lahar?
Pyroclastic flows move much faster than lava flows and carry much more momentum. This means there is little time tog et out of the way, and that they can pass over barriers that would stop or deflect lava flows. They can also carry more material. A single pyroclastic flow can bury an area to several meters thick in a matter of seconds.
Why does pyroclastic flow travel faster than a lava flow?
Lava is a very viscous liquid, meaning it will resist flowing rather like syrup. Lava flows are often slowed even more as they form a crust of solid rock. A pyroclastic flow is a different matter; it is a dense cloud of hot ash, rock, and gas, behaving more like an avalanche than a flowing liquid. Pyroclastic flows are not slowed by viscous forces.
Why does a pyroclastic flow travel more quickly than a lava flow?
A lava flow flows as a viscous liquid, rather like molasses only thicker. A pyroclastic flow is a mixture of ash, gas, and rock fragments and is not significantly affected by viscous forces that would slow it down. It moves like an avalanche or thunderstorm downburst rather than a liquid.
What volcano is more dangerous land or water?
Land based volcanoes are more dangerous to people. More important is the type of lava, based on viscosity. Highly viscous lavas tend to cause explosive eruptions, like Mt. Saint Helens, while low viscosity lava tends to flow after eruption, without the ash and pyroclastic effects associated with highly viscous lavas.
What type of flow does mt st helens have?
Mount St. Helens has produced lava flows in the past. However, the famous eruption in 1980 produced something much more dangerous: pyroclastic flows. These are avalanche-like currents of hot ash, rock, and gas that race out of a volcano. The initial pyroclastic flow from the lateral blast may have briefly been supersonic.
Why is a pyroclastic flow more dangerous than an earthquake?
An earthquake create a hazard of collapsing buildings and falling objects, which are the greatest threats. So it is quite possible to survive. A pyroclastic flow produces searing temperaturesthat can be well over 1,000 degrees Fahrenheit. You can survive the collapse of a building, but you cannot survive a pyroclastic flow.
Is a non-explosive volcanic eruption more likely to produce lava or pyroclastic material?
Lava because pyroclastic material explodes from a volcano, Lava just runs down the surface of the volcano nonexplosive or explosive.
What is the viscosity of magma in a pyroclastic flow?
In a pyroclastic flow, the magma would almost always be considered high-velocity. The velocity and strength of the magma is a result of its chemical composition.
What damage doese volcanoe cause?
What usually causes the most damage is the pyroclastic debris and the ash. The ash isn't normal fire ash (tephra) more than 10 cm of volcanic ash can collapse a building. The next most devastating factor is the pyroclastic flow (lahar), gases through fumaroles and lastly the lava is least devastating. (Anyone can out run a lava flow... backwards)
