Is a volcanic dome non explosive?

Answer 1

Sometimes they are and sometimes they are not. The processes that form volcanic domes are non-explosive, but they can produce explosive eruptions. There are two different types of volcanic dome.

The first is a lava dome. These form when very viscous lava is extruded onto the surface. Normally, highly viscous magma is gas-rich, and it is this gas that drives an explosive eruption. The formation of a lava dome can potentially mean two different things. In some cases a lava dome is a sign that a volcano is running out of gas and no longer has the potential to explode in the near future. In other cases a dome may just be the tip of a larger body of magma. The gas in this tip has escaped, allowing it to flow out and form a plug to the gas-rich magma beneath it. Pressure can built beneath this plug until the remained of the magma erupts explosively.

The second type is a cryptodome. A cryptodome forms forms when viscous magma collects at a shallow depth beneath the surface and essentially inflates the ground above it. This in and of itself is not an explosive process, but can readily lead to an explosive eruption.

Answer 2

In some cases, though not all, a lava dome may act as a plug for a larger, gas-rich mass of magma. The gas is kept dissolved in the magma under immense pressure. If the lava dome fails, pressure is suddenly released on the gas-rich magma. The effect is rather like opening a can of soda that has just been shaken; the gas comes out out of solution and expands violently, generating an explosion.

Answer 3

It already exploded.

Answer 4

Yes