Volcanic eruptions are an awe-inspiring natural phenomenon. They emit plumes of hot gas and ash high into the air, and often result in lava flowing out of the volcano. What happens to this molten rock once it’s released from the volcano?
You’ve probably seen movies about volcanoes, where scientists blow air into a volcano to cool the lava before it flows out of the ground. However, most eruptions aren’t that simple.
First, lava doesn’t just “flow” out of the ground in a single giant blob. Instead, it’s broken up into small pieces called lahars. Lava is very heavy, and the wind can carry small pieces across the landscape.
Once lava starts flowing, it can’t stop. Even when it reaches the ocean, it keeps going and can eventually form new islands.
The rate at which lava flows depends on a number of factors. The type of volcanic eruption, the amount of molten rock, and the composition of the material in the lava play important roles. Lava flows can be slow, or they can move very quickly, depending on what’s happening in the volcano.
If the lava is relatively cool, it may flow slowly. But when the lava is hotter, it flows more quickly.
Because lava flows into the sea, it cools quickly. This can be an advantage, because lava flows are much harder to work with than lava that’s still hot.
A good example of a lava flow is Mount St. Helens. A big explosion in 1980 caused the volcano to erupt. The resulting lava was superheated, and lava quickly flowed down the volcano.
Mount St. Helens is still a live volcano, and lava from it still flows.
Hot lava doesn’t evaporate like cold water. In fact, hot lava will get denser as it cools. As it cools, the density of the lava increases, and its viscosity (thickness) decreases. When the lava cools, its volume shrinks, and the material becomes denser. The result is that the liquid lava becomes more dense than the surrounding rocks.
Hot lava is so much more dense that when it flows from the volcano, the lava begins to sink into the ground. This sinking occurs because the surrounding rocks have become cooler than the molten lava, and the lava has been cooled enough that it is now less viscous and is sinking into the cooler rocks.
When a volcano erupts, molten rock called magma is shot out into the air. Magma is very hot and can easily cause burns if it comes into contact with skin. At the same time, gas and ash are expelled from the volcano. Gas and ash can be dangerous when they escape from the volcano and form a cloud, called an eruption cloud. The gas and ash in an eruption cloud can cause respiratory problems for people nearby.
Hot lava is a dangerous element that can cause a lot of harm if not handled properly. It is important to be aware of the dangers it poses and to take the necessary precautions when traveling near an active volcano.
