Source: Produced for Teachers' Domain
Earth's rocky surface is covered with natural features formed by weathering, erosion, and deposition. Although these forces are typically associated with destruction, they have also created many of the world's natural wonders. This still collage produced for Teachers' Domain contains images of natural wonders produced by these powerful forces.
Throughout northern Europe, Canada, and North America, glaciers have played an important role in shaping the landscape. In mountainous regions subject to glaciation, the erosive force of glacial movement widens and deepens the V-shaped river valleys that guide the flow of the glaciers. When the ice thaws, a U-shaped valley is revealed. The transformed landscape is often marked with stray boulders known as glacial erratics, which have been deposited far from their source, and deep grooves, or striations, in exposed bedrock.
The vibrant colors and preserved state of the logs and stumps suggest that a forest stood only yesterday. But it was millions of years ago that these trees were petrified, or converted into stone, through a series of natural processes. During this petrification, silica-rich groundwater filled decaying plant tissue with mineral particles. Scientists believe the silica came either from sand from an advancing desert, or from volcanic ash that buried the forest for thousands of years.
Mineral hot springs deposits
Geothermal features, including hot springs, geysers, and mud pots, appear at places on Earth's surface that are heated by underground magma chambers. Because minerals dissolve more readily in hot water than cold, hot springs often contain high mineral concentrations. When groundwater reaches the surface and cools, some of these minerals may be deposited out of solution. Stepped terraces, like those at Yellowstone's Mammoth Springs, are made of travertine, a mineral deposit that is usually white when deposited, but may be red, brown, or yellow if iron compounds or other minerals are present.
The shores of the Dead Sea, bordered by Jordan and Israel, mark the world's lowest surface elevation: more than 400 meters (1,300 feet) below sea level. Mountain-fed rivers and streams transport the dissolved mineral salts for which this large landlocked lake is known. While most inland bodies of water have outlets that lead to the sea, no rivers drain the Dead Sea, so the salt accumulates. Because it is typically very hot there, water evaporates quickly and in great volume, enhancing the salt concentration. This makes it possible for visitors to float effortlessly in the Dead Sea.
Most waterfalls form over many years along streambeds composed of layers of hard, erosion-resistant rock and soft, easily eroded rock. Water gradually erodes the soft rock it passes over, leaving the more resistant rock. Where breaks in elevation occur along the residual hard rock formation, water may either gently cascade down a series of rock steps or plunge vertically to a pool below.
Academic standards correlations on Teachers' Domain use the Achievement Standards Network (ASN) database of state and national standards, provided to NSDL projects courtesy of JES & Co.
We assign reference terms to each statement within a standards document and to each media resource, and correlations are based upon matches of these terms for a given grade band. If a particular standards document of interest to you is not displayed yet, it most likely has not yet been processed by ASN or by Teachers' Domain. We will be adding social studies and arts correlations over the coming year, and also will be increasing the specificity of alignment.