Lava is salty materials.As soon as it jump out of the weak parts of the earth,volcanoes are formed.Volcanoes can erupt many materials. There are about 2000 known extinct volcanoes on earth; and there are 523 known active volcanoes.455 of them are on land and 68 of them are under the sea.They are distributed unevenly. The combination of volcano ash and rainstorm can form mudslide which can destroy roads,bridges,flood the nearby countrysides and cities,making many people homeless. However,volcanoes are also beneficial for us.There are often many hot springs near the volcanoes because the heat generated by lava makes the underground water hot.
There is a "liquid zone" that measures 100 to150 kilometers under the earth crust, where there exists the liquated silicate materials that contain gas in high temperature and pressure, which is called lava. As soon as it jumps out of the weak parts of the earth, volcanoes are formed. Volcanoes can erupt many materials.
Salt material, that magma. Once it is out of the lot from the weak surface crust to form the volcano. Volcanic eruptions can emit a variety of substances. Known on Earth, "extinct" about 2000; ha...
盐物质,即岩浆。它一旦从地壳薄弱的地段冲出地表,就形成了火山。火山爆发能喷出多种物质。 Once magma or lava rushes out of the weakest / thinnest part of the earth's crust, it carries various kinds of substances and forms a volcano . 在地球...