Αποτελέσματα Αναζήτησης
19 Οκτ 2023 · A volcano is an opening in a planet or moon’s crust through which molten rock, hot gases, and other materials erupt. Volcanoes often form a hill or mountain as layers of rock and ash build up from repeated eruptions. Volcanoes are classified as active, dormant, or extinct.
WHAT IS A VOLCANO? Volcanoes are openings in the Earth’s rocky Core crust which allow hot molten (melted) rock, ash and gas to escape from below the surface. Volcanoes form when parts of the Earth’s solid mantle melts to form pockets of hot liquid rock called magma. This magma collects in large pools deep underground known as magma chambers.
During a volcanic eruption, hot melted rock called magma escapes from a vent, or opening, in Earth’s surface, or crust. Magma released from a volcano is known as lava. Fresh lava ranges from 1,300 to 2,200 °F (700 to 1,200 ° C) in temperature. It glows red as it flows out of the volcano’s opening.
29 Απρ 2024 · The 1985 eruption of Nevado del Ruiz, Colombia, caused small lahars of rock, ash, and melted snow to flow down into the surrounding river valleys. The lahars gained momentum and size as they traveled the riverbeds, ultimately destroying more than 5,000 homes and killing more than 23,000 people.
The eruption released an avalanche of hot ash, gas, steam, and rocks that mowed down giant trees up to 15 miles (24 kilometers) away. When magma finds a way to escape from beneath the earth's...
Lava is hot, liquefied rock that flows from a volcano or other opening in the surface of Earth. When the liquid rock is still underground it is known as magma. Igneous rock is formed when lava cools and hardens.
In some volcanic eruptions, the molten rock—called magma when it is underground and lava when it reaches the surface—flows slowly out of the vent. In more violent eruptions, lava shoots straight up, and rock fragments are ejected in a great cloud of ash-laden gas that rises high into the air.
