Αποτελέσματα Αναζήτησης
Throughout Earth’s history volcanoes have erupted enormous amounts of molten rock onto the Earth’s surface. Today there are about 500 currently active. right: Erta Ale lava lake, Ethiopia; Grand Spring, Yellowstone, USA; Sarychev Peak Volcano, Russia; Lava flows from Kilauea, Hawaii. Ash, steam & gas.
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.
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...
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.
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. Characteristics of Lava. Fresh lava is very hot. It can reach temperatures as high as 2,200° F (1,200° C).
As the rising magma nears the Earth's sur-face, pressure decreases, which causes the gases in the magma to expand. This expansion propels the magma through openings in the Earth's surface: a vol-canic eruption occurs. Once magma is erupted, it is called lava.
