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The word lava comes from Italian and is probably derived from the Latin word labes, which means a fall or slide. [2] [3] An early use of the word in connection with extrusion of magma from below the surface is found in a short account of the 1737 eruption of Vesuvius, written by Francesco Serao, who described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of ...
The lavas of different volcanoes, when cooled and hardened, differ much in their appearance and composition. If a rhyolite lava-stream cools quickly, it can quickly freeze into a black glassy substance called obsidian. When filled with bubbles of gas, the same lava may form the spongy appearing pumice. Allowed to cool slowly, it forms a light ...
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. [1] Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit ...
Hike via south slope of volcano (closest area near eruption site) Mount St. Helens (known as Lawetlat'la to the indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, [1] in the Pacific Northwest region of the United States. It lies 52 miles (83 km) northeast ...
The subsidence of the crust produced a large, slightly depressed lava plateau. [2] The ancient Columbia River was forced into its present course by the northwesterly advancing lava. The lava, as it flowed over the area, first filled the stream valleys, forming dams that in turn caused impoundments or lakes. [ 2 ]
Craters of the Moon National Monument and Preserve showcases the surreal lunar-like landscape left by those long-hardened lava flows. Visitors can take in the sights on a 7-mile loop drive or hop ...
The tendency of felsic lava to be cooler than mafic lava increases the viscosity difference. The silicon ion is small and highly charged, and so it has a strong tendency to coordinate with four oxygen ions, which form a tetrahedral arrangement around the much smaller silicon ion. This is called a silica tetrahedron. In a magma that is low in ...
The volcano spread lava over 26 km 2, with 52 km 2 covered in volcanic sand. [9] The town of Parícutin, which once had a population of 733, is now completely gone, and all that remains of the town of San Juan Parangaricutiro, with a former population of 1,895, are parts of its main church which stand out among the hardened lava flow. [7] [11] [13]