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.
Pahoehoe lava, which has a low viscosity and flows more easily, is less likely to form a pyroclastic flow compared to a'a lava, which is more viscous and tends to fragment into pyroclastic material when flowing.
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.
Mauna Loa is a shield volcano, which typically erupts effusively with flowing lava rather than explosively with pyroclastic flows. Pyroclastic flows are more commonly associated with stratovolcanoes.
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).
Lascar volcano typically erupts with dacitic lava, which has a higher silica content compared to other types of lava such as basaltic lava. Dacitic lava is more viscous and tends to flow more slowly, resulting in explosive eruptions characterized by ash clouds and pyroclastic flows.
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.
A mafic lava flow will move faster than a felsic lava flow due to its lower viscosity. However, felsic magma tends to erupt explosively, producing fast-moving pyroclastic flows instead of lava flows.
Lava because pyroclastic material explodes from a volcano, Lava just runs down the surface of the volcano nonexplosive or explosive.
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.
This statement is incorrect. Plinian and Pelean eruptions are types of explosive volcanic eruptions that do not typically produce lava flows. Instead, they involve the violent ejection of ash, rock fragments, and gases into the atmosphere. Lava flows are more commonly associated with effusive eruptions, such as those of Hawaiian volcanoes.
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.