Final answer:
When lava from a volcano hardens, it forms new landmasses such as islands or volcanic rock formations. The type of landform depends on the lava's viscosity, with pancake-shaped volcanoes resulting from highly viscous lava. The 'ring of fire' is a well-known area where such volcanic activities commonly occur, leading to the creation of these landforms.
Step-by-step explanation:
When lava flows from a volcano and hardens, a new landform is created, often an island or a volcanic rock formation. This is because when the molten lava cools down, it solidifies into rock. Volcanic islands are a common result when this activity occurs in the ocean, and these islands can expand over time with successive eruptions. The formation of such landforms is a clear demonstration of geothermal energy at work, similar to the eruptions seen east of Pu'u 'O'o crater in Hawaii.
Over time, these lands may develop from bare rock into more complex ecosystems as life gradually takes hold. However, the type of landform that will be observed depends on the viscosity of the lava; for example, highly viscous lava may form pancake-shaped volcanoes, as found on Venus, while less viscous lava might spread out and form broader landforms.
The study of such processes is part of geology, a field that helps explain not just the formation of new landforms, but also the continuous changes on a planet's surface due to volcanic activity. The famous "ring of fire" around the Pacific Ocean contains many examples of such dynamic geological processes.