Radiometric dating from hawaiian volcanoes
The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
These solid particles become pyroclasts or volcanic ash.
gas emission from Lake Nyos in Cameroon killed more than 1700 people and 3000 cattle.
The gases can also have an effect on the atmosphere and climate.
it makes bubbles just like in a bottle of carbonated beverage when the pressure is reduced).
When a gas bubble forms, it will also continue to grow in size as pressure is reduced and more of the gas comes out of solution. If the liquid part of the magma has a low viscosity, then the gas can expand relatively easily.
Volcanic Eruptions In general, magmas that are generated deep within the Earth begin to rise because they are less dense than the surrounding solid rocks.
As they rise they may encounter a depth or pressure where the dissolved gas no longer can be held in solution in the magma, and the gas begins to form a separate phase (i.e.
(Note that solids, even though they appear solid have a viscosity, but it very high, measured as trillions time the viscosity of water).
Viscosity is an important property in determining the eruptive behavior of magmas.
This type of eruption is called a If the eruption column collapses a pyroclastic flow will occur, wherein gas and tephra rush down the flanks of the volcano at high speed.