What is an immediate consequence of volcanic eruptions on land?

The formation of new land is a direct and immediate consequence of volcanic eruptions. When a volcano erupts, it expels molten rock, ash, and gases. This material can accumulate around the volcano and eventually solidify, leading to the creation of new landforms, such as volcanic islands or even expansion of the surrounding landmass.

For example, when a submarine volcano erupts, the lava cools and solidifies underwater, leading to the emergence of new islands above sea level. Over time, repeated eruptions can build up significant land, altering the geography of the area. This process is a fundamental aspect of plate tectonics and demonstrates the dynamic nature of the Earth's surface.

While loss of biodiversity and destruction of man-made structures can certainly be significant outcomes of volcanic activity, they do not occur in a direct and immediate way related to the formation of land itself. Creation of new rivers is typically a secondary consequence that might result from volcanic activity but is not an immediate effect.