Mauna Loa diagram in Hawaii Source: https://theextinctionprotocol.wordpress.com/2012/10/25/hawaiis-big-kilauea-and-mauna-loa-volcanoes-may-share-underground-magma-chamber/
Pyroclastic Flows are fluidized masses of rock fragments and gases that move rapidly in response to gravity. It forms when an eruption column collapses. They move extremely fast as they can also extend to 50 km from their source. They are even really hot as they can become 1075 degrees. The effects they cause is incinerate,burn and asphyxiate people.
Picture of pyroclastic flow from a volcano
Magma is a molten and semi-molten rock mixture found under the surface of the earth. When magma is ejected by a volcano or other vent and the material it makes its called lava. Magma is extremely hot as its usually between 700 degrees and 1,300 degrees. This makes it able to create new landforms. Magma can engulf into a low density of area. The most dangerous kind of magma is rhyolitic as it has a high viscosity.
Which is more Deadly?
Top Five deadliest volcanic eruptions
Tambora, Indonesia Year:1815, Deaths,92,000 Cause: Starvation
Krakatau, Indonesia, Year:1883, Deaths:36,417 Cause:Tsunami
Mount Pelee, Martinique Year:1902 Deaths: 29,025 Cause: pyroclastic flow
Ruiz, Colombia, Year:1985, Deaths:25,000 Cause: Mud flow
Mount Unzen, Japan, Year:1792, Deaths: 25,000, Cause: Volcano Collapse
As shown in the list pyroclastic flow has caused more deaths in the past than Magma by the pyroclastic flow from Mount Pelee causing the third most deaths from a volcanic eruption ever.
Picture of Mount Pele. Source: Getty Images
In conclusion if the Largest volcano in the world Mauna Loa were to erupt again after 32 years the pyroclastic flow would be the Hazard everyone would be afraid of the most because of its ability to cover whole city's and its almost impossible to avoid due to its extreme speeds.