asteroid: A rocky object in orbit around the sun. Most asteroids orbit in a region that falls between the orbits of Mars and Jupiter. Astronomers refer to this region as the asteroid belt.
earthquake: A sudden and sometimes violent shaking of the ground, sometimes causing great destruction, as a result of movements within Earth’s crust or of volcanic action.
eruption: (in geoscience) The sudden bursting or spraying of hot material from deep inside a planet or moon and out through its surface. Volcanic eruptions on Earth usually send hot lava, hot gases or ash into the air and across surrounding land. In colder parts of the solar system, eruptions often involve liquid water spraying out through cracks in an icy crust. This happens on Enceladus, a moon of Saturn that is covered in ice.
Ring of Fire: An area around the Pacific Ocean’s edge where plate tectonics processes cause relatively frequent earthquakes and volcanic eruptions.
tsunami: One or many long, high sea waves caused by an earthquake, submarine landslide or other disturbance.
volcano: A place on Earth’s crust that opens, allowing magma and gases to spew out from underground reservoirs of molten material. The magma rises through a system of pipes or channels, sometimes spending time in chambers where it bubbles with gas and undergoes chemical transformations. This plumbing system can become more complex over time. This can result in a change, over time, to the chemical composition of the lava as well. The surface around a volcano’s opening can grow into a mound or cone shape as successive eruptions send more lava onto the surface, where it cools into hard rock.
wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion.
