Which term describes volcanic activity that happens through a fissure?

The term that describes volcanic activity occurring through a fissure is "fissure eruption." This process involves magma being emitted through cracks in the Earth's surface, rather than from a central vent like in typical volcanoes. Fissure eruptions typically result in the outpouring of lava over large distances and can create extensive lava fields. This is distinct from other terms like pyroclastic flow, which refers to a fast-moving current of hot gas and volcanic matter, and debris flow, which involves the rapid downhill movement of a mixture of water and sediment. Lava dome formation pertains to the buildup of viscous lava around a vent, not the fissure itself. Therefore, "fissure eruption" accurately captures the essence of volcanic activity through a fissure.