They form because of the movement of tectonic plates. Tectonic plates are pieces of earths crust and uppermost mantle together referred to as the lithosphere. The plates are around 100 km, 62 mi thick and consist of two types of material, oceanic crust and continental crust. Divergent boundaries occur when two plates pull apart, letting the magma through the gap. Convegent boudaries occur when to plates come together, when the continential crust and the ocianic crust come together.
Mount Ngauruhoe
Mount Ngauruhoeis located in the central north island. Mount Ngauruhoe last erupted In 1977 and is still active to this day.
I caused no major damage to the are surrounding the volcanoe but it spat out lava for a few hours and eneded later on that day.
Kīlauea in Hawaii cause major damage to both the people and the island of Fiji when it last erupted on january the 3rd 1983.
