Volcanoes affect the hydrosphere in many ways, such as promoting rainfall. After a volcano erupts, condensation forms around the dust particles it expells, causing rain. This in turn promotes growth of plants in the biosphere.
An eruption can cause glaciers to melt, which flow into rivers and feed the biosphere. Another volcanic effect occurs when sulfuric acid from the eruption combines with rain in the hydrosphere. When this acid rain reaches the surface of the Earth, it pulls minerals from the soil, which not only deprives the soil of valuable nutrients but increases the acidity of the water and affects those animals that can live in it.
The hydrosphere is the part of the Earth that contains all the Earth's water, from oceans and lakes to rivers, streams and water vapor. The hydrosphere extends up to the troposphere in the atmosphere where rain falls. The other major spheres are the geosphere, which makes up the rocks and mantle, the biosphere, which includes all life, and the atmosphere, or air. All of these spheres are affected by volcanoes; however, not all interactions caused by eruptions involve every sphere. For instance, eruptions release carbon dioxide into the atmosphere that plants in the biosphere use in photosynthesis. The hydrosphere is not directly involved in this reaction.