Natural Phenomena Science Educational Posters & Charts
for the classroom and home schoolers.

A natural object originating in outer space is called a meteoroid while in space, a meteor or shooting star when the impact pressure of entering the Earth's atmosphere causes it to heat up and emit light, thus forming a fireball, and a meteorite when it survives an impact with the planet surface. Meteorites have also been found on the Moon and Mars.

When a number of meteors apperar to radiate from one point in the sky it is called a “meteor shower”. Most meteoroid are small fragments of cosmic debris smaller than a grain of sand, so almost all disintegrate and never hit the planet surface. Notable meteor showers are the Perseid in mid-August and the Leonid in November (33 year cycle - anticipated in 2032).

• meteorite chart poster

Earthquakes

When the plates of the Earth's crust move and collide with each other the forces create vibrations. These vibrations are commonly known as earthquakes. Earthquakes occur around the globe almost non-stop. Some are barely detectable and others create such destructive vibrations that whole cities can be shaken down to little more than rubble. Although volcanic eruptions and atomic explosions can cause earthquakes, most occur along plate boundaries where techonic forces build up.

• more Earth Processes posters

Petrified wood, fossilized remains of terrestrial vegetation, is a three dimensional representation of the original organic material.

For wood to petrify it becomes buried under sediment and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. As mineral-laden water flows through the sediment it deposits minerals in the plant's cells. As stone forms it replaces the slowly decaying plant lignin and cellulose.

The colors of petrified wood are from the specific mineral deposited: carbon = black, cobalt, chromium and copper = green/blue, iron oxides = red, brown, and yellow, magneses = pink/orange, maganese oxides = blackish/yellow.

Petrified forests can be found world wide, perhaps best known in the U.S. is Arizona's Petrified Forest National Parks. Petrified wood is the provincial stone of Alberta and also the state gem of Washington.

Geyser: A hot spring that erupts periodically, sending jets of water and/or steam into the air.

Hot Spring: Water warmed by geothermal energy that seeps to the Earth's surface to form a small pond. ...

Glaciers

In the regions closest to the poles, or regions so high in elevation that snowfall accumulation exceeds the amount that melts off over long periods of time, glaciers can be formed. As the snow compacts into ice, the weight causes it to begin moving down a mountain, carving huge valleys and sculpting mountains. Motion and change are what glaciers are all about. Glaciers have been responsible for shaping most of the Earth's surface, either by direct carving from the ice flow or from the water runoff caused by glacial melting. As the glacier carves and breaks down rock, it can relocate massive amounts of rock over large areas. Glaciers typicaly move slowly, but great land transformations over a short geological time period (such as 100 years) have been recorded.

• more Earth Processes posters
• Antarctica posters

Iceberg: A large floating chunk of ice, usually broken off from a glacier and carried out to sea on ocean currents, Typically, around 90% of the volume of an iceberg is under water, so the visible ice above the furface doesn't reveal much about the size and shape of the whole thing this has led to the expression “tip of the iceberg.”

Hidden Depths, Poster

Glacier: A large, slow-moving river of ice formed by multi-year snow accumulating on sloping terrain. Glaciers move very gradually downslope or outward, carving out valleys along the way. The runoff water creates rivers that further erode the landscape.

Fjord: A deep, steep-walled inlet of the sea formed by a glacier. May also be known as an inlet or sound.

• color blue posters

Rainbow, Photographic Print

A rainbow, the optical and meteorological phenomenon of a spectrum of light that appears in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere, take the form of a multicolored arc, with red on the outer part of the arch and violet on the inner section of the arch.

Sossusvlei Sand Photographic Print / Nambia

Sand Dunes

A hill of sand built by aeolian processes (winds eroding, transporting, and depositing materials).

A “dune field” is an area covered by extensive sand dunes, very large dune fields are called ergs.

The valley between dunes is called a slack, the windward side of the dune is longer than the “slip face” or leeward side of the dune.

• more Africa posters
• Deserts of the World posters

Volcanoes

Deep inside the Earth, heat and pressure cause solid rock to melt into a liquid known as magma. In some areas around the globe this magma has risen to the surface and erupted, creating volcanoes. Volcanoes are generaly classified into three types: Shield Volcanoes, Composite Cone Volcanoes and Cinder Cones.

Shield volcanoes are broad, domed mountains formed from highly liquid magma flowing and cooling slowly to form rock. As one eruption cools another eruption flows over it, building layers of cooled lava flows. These volcanoes erupt primarily liquid magma, or lava, as it is called once it reaches the Earth's surface.

Composite cone volcanoes are more explosive in nature. The lava fragments are cooled in the air, forming pyroclastic material. The next eruption might be more liquid, thus it has alternating layers of pyroclastic material and lava flows. This type of volcano has much steeper sides.

Cinder cones are primarily built up with pyroclastic material around a central vent. This is common in larger volcanoes.

• more Earth Processes posters
• more mountain posters
• geology posters

Waterfalls are places where flowing water abruptly drops in elevation as it flows over a steep area or a cliff.

Notable waterfalls are Angel Falls in Venzuela, Victoria Falls in Africa and Niagara Falls between the US and Canada.

• more national parks posters