volcanoes year 7. 4. volcanic landforms 1.landforms from lava and ash: – shield volcanoes (from...
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VOLCANOES
YEAR 7
4. VOLCANIC LANDFORMS
1. Landforms from Lava and Ash:– Shield volcanoes (from hot spots)– Cinder cone volcanoes– Composite volcanoes – Lava plateaus (instead mountain)– Caldera (huge hole left after collapsing a
volcanic mountain)– Soils from lava and ash (good for plants)
SHIELD VOLCANO
CINDER CONE VOLCANO
COMPOSITE VOLCANO
LAVA PLATEAUS
CALDERA
2. Landforms from Magma:– Volcanic necks (giant tooth stick in the
ground). It forms when magma hardens in a volcano’s pipe.
– Dike (magma that forces itself across rock layers hardens into this structure)
– Sill (when magma squeezes between horizontal layers of rock)
–Batholiths (mass of rock formed when a large body of magma cools inside the crust)–Dome Mountains (other smaller bodies of
hardened magma can create dome mountains)
3. Geothermal Activity:– Hot spring forms when groundwater heated by a
nearby body of magma rises to the surface and collects in a natural pool.
– Geyser is a fountain of water and steam that erupts from the ground (when rising hot water and steam become trapped underground in a narrow crack)
5. VOLCANOES IN THE SOLAR SYSTEM
• Earth is not the only body in the solar system to show signs of volcanic activity.
• Pictures taken by space probes show evidence of past volcanic activity on Mercury, Venus and Mars (rocky planets)
• On Mars there are large volcanoes and lava flows. The largest mountain in the solar system is the Olympus Mons volcano (25km height).