Why does a building on solid bedrock resist better to an earthquake than a building on sediment or reclaimed land? Why does a building with base isolation resist better to an earthquake than a building without base isolation? Why does a building with full bracing resist better to an earthquake than a building with no bracing? Impacts of Volcanic Hazards What are the principal signals of a volcanic unrest? How can we forecast volcanic eruptions?
Tsunamis Where is a tsunami most likely to happen? Can Singapore be affected by a tsunami? Can animals sense an impending tsunami? What should we do during a tsunami? Why do trees seem to resist more to tsunamis than houses? Why does a boat at sea experience a tsunami differently from a boat near the shore? Volcanoes All About Volcanoes What is the difference between magma and lava? Is lava always liquid? What does a magma chamber look like?
Climate Sea Levels Why will sea level rise not be the same everywhere? How can we date corals? Geology and Tectonics Geology How do we know the age of the seafloor? Why is the seafloor so recent and the continental crust so old? Where do we find the oldest continental rocks and the oldest seafloor?
What are the different types of rocks? What is a fossil and what are they used for? What are hydrothermal vents, and why do we find them along mid-ocean ridges? Seismology What is a seismic wave? What is the difference between body waves and surface waves, and between P-waves and S-waves?
Why can't S-waves travel through liquids? How far can seismic waves reach? Why do P-waves travel faster than S-waves? Why is the interior of the Earth hot? Both the temperature and mineral content of magma affect how easily it flows. The viscosity thickness of the magma that erupts from a volcano affects the shape of the volcano. Volcanoes with steep slopes tend to form from very viscous magma, while flatter volcanoes form from magma that flows easily.
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They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource. If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media. When this molten rock is still located within the Earth, it is known as magma. It is composed of molten or semi-molten rock, volatiles, solids and sometimes crystals that are found beneath the surface of the Earth.
This vicious rock usually collects in a magma chamber beneath a volcano, or solidify underground to form an intrusion. Where it forms beneath a volcano, it can then be injected into cracks in rocks or issue out of volcanoes in eruptions.
Magma is also known to exist on other terrestrial planets in the Solar System i. In addition to stable lava tubes being observed on Mercury, the Moon and Mars, powerful volcanoes have been observed on Io that are capable of sending lava jets km miles into space. When magma reaches the surface and erupts from a volcano, it officially becomes lava. There are actually different kinds of lava depending on its thickness or viscosity. Whereas the thinnest lava can flow downhill for many kilometers thus creating a gentle slope , thicker lavas will pile up around a volcanic vent and hardly flow at all.
The term lava is usually used instead of lava flow. This describes a moving outpouring of lava, which occurs when a non-explosive effusive eruption takes place. Once a flow has stopped moving, the lava solidifies to form igneous rock.
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