Here's why:

* Explosive volcanic eruptions are characterized by high-energy releases, often driven by the interaction of magma with water or the rapid release of gases trapped within the magma. This creates a powerful explosion that blasts out volcanic material.

* Water is a key ingredient in many explosive eruptions. It can come from:

* Groundwater interacting with hot magma.

* Surface water (lakes, rivers) being heated by volcanic activity.

* Water contained within the magma itself.

* Other substances typically present in explosive volcanic eruptions:

* Volcanic ash (pulverized rock and minerals)

* Volcanic gases (sulfur dioxide, carbon dioxide, water vapor)

* Lava bombs (large, ejected pieces of molten rock)

* Pyroclastic flows (fast-moving currents of hot gas and volcanic debris)

In summary: While water is a common ingredient in explosive volcanic eruptions, the absence of water would be unusual.