Alluvial Fan - National Geographic Society
2023年10月19日 · An alluvial fan is a triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt. This sediment is called alluvium . Alluvial fans are usually …
Floodplain - National Geographic Society
2023年10月19日 · The formation of a crevasse splay is very similar to the formation of an alluvial fan. The thickest layer of sediment is nearest the breach, while the thinnest and youngest …
Delta - Education | National Geographic Society
2023年11月15日 · Deltas with this triangular or fan shape are called arcuate (arc-like) deltas. The Nile River forms an arcuate delta as it empties into the Mediterranean Sea. Stronger waves …
Alluvial fans can be tiny, with an apron of just a few centimeters spreading out from the trickle of a drainpipe. They can also be enormous. Over time, water flowing down the Koshi River in …
A Desert Created by Water - Education
2024年4月29日 · Analyze and explain the relationships between physical processes and the location of land features (e.g., river valleys, canyons, deltas, glaciated lakes and moraines, …
Mesa - Education | National Geographic Society
2023年10月19日 · A mesa is a flat-topped mountain or hill.It is a wide, flat, elevated landform with steep sides. Mesa is a Spanish word that means table. Spanish explorers of the American …
Education | National Geographic Society
Engage with National Geographic Explorers and transform learning experiences through live events, free maps, videos, interactives, and other resources.
Desert - Education | National Geographic Society
At the foot of these formations, water drops its burden of gravel, sand, and other sediment, forming deposits called alluvial fans. Many deserts have no drainage to a river, lake, or ocean. …
Overbank Deposits - Education
2023年10月19日 · The resulting sediment-heavy water breaks through and is deposited onto the floodplain in a large fan shape, called a crevasse splay. Crevasse splays are often the …
Karst - Education | National Geographic Society
2024年7月3日 · Karst is an area of land made up of limestone. Limestone, also known as chalk or calcium carbonate, is a soft rock that dissolves in water. As rainwater seeps into the rock, it …