# data[].attributes.attachment_link.description
Landforms are the physical features on the surface of the Earth. They are created by natural forces such as wind, water, erosion and tectonic plate movement. Landforms are typically categorized by their physical attributes of slope, stratification, soil type, elevation and orientation.

# data[].attributes.attachment_link.description
A gorge is a steep-sided, narrow valley with a river or stream running along the bottom. Gorges are formed by the interplay of several geological processes, including erosion, tectonic processes such as vertical uplift and cavern collapse. Erosion by the resident body of water is usually the primary contributor to gorge formation.

# data[].attributes.attachment_link.readable_text
Rivers and streams cover much more of the planet than geologists previously estimated, according to a new study published in Science. In total, this new estimate shows that, excluding land with glaciers, Earth is covered by just under 300,000 square miles (773,000 square kilometers) of rivers and streams. That's more square footage than the state of Texas, and it's as much as 44 percent higher than previous counts.

The finding has implications for the study of climate change, because rivers exchange greenhouse gasses with the atmosphere, especially when humans pollute their waters.

"It was assumed until about 2006 that rivers and lakes were just a pipe transporting carbon to the ocean," John Downing, a limnologist and biogeochemist at the University of Minnesota Duluth, told Gizmodo. "But the rivers are leaking gasses into the atmosphere."

As pollutants like fertilizers and sewage seep into water supplies, gasses including methane, carbon dioxide, and nitrous oxide bubble out and drift up into the atmosphere. More river coverage could mean we're sending even more of those greenhouse gasses into the air than current calculations account for.

"Here's another reason not to spoil water," said Downing, who was not involved in the new study. "If you pollute it, you spoil fishing and swimming, but you also spoil the atmosphere."

To map out the planet's rivers and streams, University of North Carolina hydrologists George Allen and Tamlin Pavelsky analyzed thousands of images from a NASA Landsat satellite. Using software developed by Pavelsky, the duo ended up with 58 million river measurements they then used to calculate the total coverage of rivers and streams on Earth.

And they didn't just blindly trust their software. To make sure the program was reliable, the researchers employed what Allen called "a small army of undergraduates" to vigilantly monitor whether the program was measuring rivers, not roads, and if it was avoiding other mistakes along the way. "They were so enthusiastic," Pavelsky said. "They did such a great job."

Aside from their Texas-sized estimate, the researchers also found that rivers were both narrower and more sparse in human-developed areas, which surprised them. This could be because people are siphoning water for agriculture, draining swamps, and leveeing rivers, but more research will have to be done to say for sure.

Other scientists have made estimates of Earth's river and stream coverage in the past. Downing, for instance, used the distinct way rivers branch and how much water they move to estimate their global coverage. Others have used elevation and water runoff data to do it. But none have shown river morphology-a river's shape and direction-like this satellite estimate does, the researchers said.

"If you look around the world, rivers look different from place to place," Allen, who recently began a professorship at Texas A&M University, told Gizmodo. "They might be braided, or sinuous, or meandering. And for the most part, current technology doesn't take into consideration the actual morphology of rivers. This data set is the first of its kind to do this at a global scale on high resolution."

Downing was impressed by the number of data points Allen and Pavelsky considered, and found their results exciting-especially because the duo's estimate was within 15 percent of his own.

"I think it's absolutely terrific," Downing said. "They put in a massive amount of effort and confirmed the numbers we already had that were created from basic physical principles."

Having a map of Earth's river morphology may prove extremely useful when predicting floods, Downing added, or for studying the way rivers behave in the future as the Earth warms. Plus, now that this fine-tuned, river-measuring technique has some reliable results, he said it could be useful to see how river flow rates change from season to season-another good data set to have when working to keep communities safe from floods.

"Rivers are so wonderful, but they can also be dangerous," Downing said. "Water goes where it wants to go-so it's good to know where it goes and how much area it's covering."

# data[].attributes.attachment_link.title
Earth Has Many More Rivers and Streams Than We Thought, New Satellite Study Finds

# data[].attributes.attachment_link.description
Rivers and streams cover much more of the planet than geologists previously estimated, according to a new study published in Science. In total, this new estimate shows that, excluding land with glaciers, Earth is covered by just under 300,000 square miles (773,000 square kilometers) of rivers and streams. That's more square footage than the state of Texas, and it's as much as 44 percent higher than previous counts.

# data[].attributes.attachment_link.readable_text
Plateaus are sculpted by geologic forces that lift them up and the wind and rain that wear them down into mesas, buttes, and canyons. Monument Valley and the Grand Canyon, both icons of the American Southwest, were chiseled from the Colorado Plateau.

Plateaus are built over millions of years as pieces of Earth's crust smash into each other, melt, and gurgle back toward the surface. Some owe their creation to a single process; others have been subjected to more than one during different epochs of Earth's history.

The highest and biggest plateau on Earth, the Tibetan Plateau in East Asia, resulted from a collision between two tectonic plates about 55 million years ago. The land buckled up along the seam of the collision and formed the Himalaya mountain range. Farther away, the crust uplifted but didn't crumple and wrinkle, creating instead a raised, flat, and wide open expanse known as the "roof of the world."

Formation From Under the Earth's Surface

Many plateaus form as magma deep inside the Earth pushes toward the surface but fails to break through the crust. Instead, the magma lifts up the large, flat, impenetrable rock above it. Geologists believe a cushion of magma may have given the Colorado Plateau its final lift beginning about ten million years ago.

Repeated lava flows that spill out from cracks in the ground and spread out over hundreds of square miles can also slowly build up massive plateaus. The Columbia Plateau in the U.S. Pacific Northwest and the Deccan Plateau of west-central India were formed by these runny lava flows.

Plateaus also form in the ocean, such as the Mascarene Plateau in the Indian Ocean, one of the few underwater features clearly visible from space. It extends approximately 770 square miles (2,000 square kilometers) between the Seychelles and Mauritius Islands.

The Power of Wind and Water

Other plateaus are created over time as wind and rain wear away the side of an uplifted region, giving it geographic distinction from the surrounding terrain. Wind and rain eventually wear plateaus down to mesas and buttes and sculpt odd landforms like the arches and hoodoos found in southern Utah's famed national parks.

Water is the greatest erosive force on plateaus. As they course along, rivers carve valleys into the rock, washing the sediment toward the sea. Over time, these valleys become giant, majestic chasms like the Grand Canyon, which is continually carved by the Colorado River.

# data[].attributes.attachment_link.description
Plateaus are sculpted by geologic forces that lift them up and the wind and rain that wear them down into mesas, buttes, and canyons. Monument Valley and the Grand Canyon, both icons of the American Southwest, were chiseled from the Colorado Plateau.

# data[].attributes.attachment_link.description
Resort Cams contains the most extensive network of mountain webcams with numerous live views from the mountains of NC, the Smoky Mountains, and other locations in the Appalachian Mountains.

# data[].attributes.attachment_link.description
When tectonic plates smash into each other, they push the Earth's crust higher and higher, forming mountains. Some mountain ranges, like the Himalayas, are still growing. Others, like the Appalachians, saw their heyday hundreds of millions of years ago and have been weathering away ever since.

# data[].attributes.attachment_link.readable_text
What is a Mountain?

The dictionary defines a mountain as that which is 'higher and steeper than a hill'.

A mountain is a landform that rises high above the surrounding terrain in a limited area. They are made from rocks and earth.

Generally, mountains are higher than 600 metres. Those less than 600 metres are called hills.

What do Mountains look like?

Mountains usually have steep, sloping sides and sharp or slightly rounded ridges and peaks.

Mountains can be rocky and barren. Some have trees growing on their sides and very high mountains have snow on their peaks.

Some common features of mountains include the following:

the summit, or the top of a mountain;

the slope, or side of the mountain; and

a very steep valley between young mountains, known as a gorge.

Where are Mountains found?

Mountains exist on every continent and even beneath our great oceans.

Did you know?

Mountains cover one-fifth of the earth's land surface, and occur in 75 percent of the world's countries.

How are mountains formed?

Mountains are formed through varying causes, there are several distinct types of mountains.
Click here to find out more

What is a mountain range?

Mountain ranges are long chains or groups of mountains. Ranges are usually 1,000 or more miles long.

The Rocky Mountains and the Himalayan Mountains are examples of mountain ranges.

What is a mountain system?

A group of mountain ranges is called a mountain system. For example, the mountain systems of the United States include the Rockies and the Appalachians.

How many people live on mountains?

Mountains are home to approximately one-tenth of the world's people

Did you know?

More than half of the world's fresh water originates in mountains, and all the world's major rivers are fed from mountain sources.
Photos of Mountains

# data[].attributes.attachment_link.description
What is a Mountain? The dictionary defines a mountain as that which is 'higher and steeper than a hill '. A mountain is a landform that rises high above the surrounding terrain in a limited area. They are made from rocks and earth. Generally, mountains are higher than 600 metres.