Why do volcanoes erupt?How do waterfalls form?
1. A volcanic eruption is when magma in the earth’s crust pushes out of the ground.The earth’s interior is so hot that rock exists in liquid form, called magma.Normally, the underground pressure is very high, the magma is tightly encased in the earth’s crust, it is not easy to get out of the ground.But in places where the crust is more tenuous, where the pressure is lower underground than it is around, the gas and water in the magma are likely to separate out, increasing the magma’s activity and pushing it out of the ground.When magma bursts out of the ground, the gases and water vapor in the magma quickly separate and expand in volume, which is what happens when a volcano erupts.2. How is the waterfall formed?There are many reasons for the formation of the waterfall, mainly the following: due to the movement of the earth’s crust, resulting in a very steep rock wall, the river through here, naturally rushing down;Volcanic water left at the top of the volcano into a lake, the lake overflow;Lava from volcanoes or landslides caused by earthquakes blocked rivers, creating natural dykes that raised water levels and allowed it to overflow.In the riverbed of a river, hard rocks are not easy to be eroded, while soft rocks are easy to be eroded, resulting in the difference between the height and height of the bottom of the river. In ancient glaciers, “U” shaped valleys were later occupied by rivers, and the water flowed through the valleys with great difference in depth.In coastal areas where rivers flow into the ocean, if the coast is damaged quickly, the bottom of the river, which was high out of the sea, “hangs” above the shore;In limestone areas where the river flows, the terrain changes sharply, or the river flows out of steep cliffs.