Firstly: The earth has Eight tectonic plates under the ground and when they move and rub together it makes an earthquake and eruptions and that is very dangerous but mostly when one get on top of another. More than 80% of the earth's surface comes from volcanoes. Innumerable (It means very numerous) volcanic eruptions formed the sea. There are more than 500 active volcanoes in the world. More than half of these volcanoes are part of the Ring of fire a region that encircles the Pacific Ocean.
Secondly: In an eruption, gases and rock shoot up through the opening and spill over or fill the air with lava parts and pieces . Eruptions can cause lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. The Most Deadly eruptions have occurred in indonesia with tens of thousands of lives lost to starvation and a tsunami as a result of the eruption, ash flows, and mudflows. A volcano is A mountain that opens downward to a pool of molten rock below the surface of the earth, when pressure builds up, eruptions occur.
Thirdly: In the North Island once had trees covering it but they were destroyed by one of New Zealand's big eruption and then it buried lake Taupo. Mount Ruapehu, active volcano and highest peak 9,176 feet 2,797 ml on North Island, New Zealand, in Tongariro National Park. Mount Ruapehu is situated on the Taupo Plateau, which rises 2,000 to 3,000 feet about 600 to 900 m above sea level. Also Mount Wellington is a 135 metre volcanic peak located in the Auckland volcanic field of Auckland, New Zealand. It is the youngest on shore volcano of the Auckland volcanic field, having been formed by an eruption around 10,000 years ago. It is the largest of Auckland's scoria cones(Scoria cones means there are veins on the volcano that are filed with magama). Mt Wellington is not expected to erupt again.
In Conclusion: The earth has eight tectonic plates under the ground and when they move and rub together it makes an earthquake and eruptions and that is very dangerous but mostly when one get on top of another, In an eruption, gases and rock shoot up through the opening and spill over or fill the air with lava fragments and also Eruptions can cause lava flows, hot ash flows, mudslides, avalanches, falling ash and floods, Mount Ruapehu, active volcano and highest peak 9,176 feet 2,797 ml on North Island, New Zealand, in Tongariro National Park.