VOLCANOES YEAR 7

4. VOLCANIC LANDFORMS 1.Landforms from Lava and Ash: – Shield volcanoes (from hot spots) Shield volcanoes – Cinder cone volcanoes Cinder cone volcanoes – Composite volcanoes Composite volcanoes – Lava plateaus (instead mountain) Lava plateaus – Caldera (huge hole left after collapsing a volcanic mountain) Caldera – 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).