Stratovolcano or composite cone- Formed from many alternating eruptions of ash and lava. Beautifully symmetrical cones.
16. What is a hot spot?
A hot spot occurs near the crust where very hot solid rock rises through the mantle (a mantle plume) and forms magma near the surface of the Earth. Hot spots form volcanoes in both oceanic plates and continental plates.
Fill in the blank with the correct answer. Use the following words to complete the blanks. Dust, Lava Tube, Mantle Plume, Ash, Caldera, Pyroclastic Flow, Blocks.
17. A large rough edged, angular pyroclast that is ejected during a volcanic eruption is called a block .
18. A caldera is a bowl-shaped depression caused by a volcanic eruption in which the top of the volcano collapses.
19. The smallest of the pyroclasts are called dust . They may stay in the atmosphere for years.
20. A lava tube forms when the surface of the lava cools and hardens, while the molten interior flows through and drains away.
21. Ash is the second smallest pyroclast. This material along with lava builds stratovolcanoes larger with repeated eruptions.
22. A mantle plume is very hot, solid rock that rises through the mantle and will become magma as it reaches the surface of the Earth. They form hot spots.
23. A pyroclastic flow is a very hot, twirling mixture of ash, gases, and small pieces of pumice and other pyroclasts that are heavier than air and move down a volcano at high rates of speed.