Category : Natural History

Natural History / Natural History - 9 years ago

What is a nautical chart?

NOAA's Office of Coast Survey, part of the National Ocean Service, is the nation's nautical chartmaker. A nautical chart is one of the most fundamental tools available to the mariner. It is a map that depicts the configuration of the shoreline...

Natural History / Natural History - 9 years ago

Why is the ocean salty?

Some areas of the ocean are saltier than others. This image shows methane mussels living at the edge of a underwater brine pool in a cavern at a depth of 650 feet in the Gulf of Mexico. The pool of brine in the foreground is nearly four times as...

Natural History / Natural History - 9 years ago

What is a marine protected area?

The majority of marine protected areas in the United States are multiple-use sites, meaning fishing, boating, surfing, diving, and other recreational activities are allowed. Marine protected areas (MPAs) in the U.S. come in a variety of forms...

Natural History / Natural History - 9 years ago

Why do Harmful Algal Blooms occur?

Satellite image of Lake Erie showing a mild harmful algal blom in the southwestern portion of the lake. Harmful algal blooms (HABs) occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while produc...

Natural History / Natural History - 9 years ago

What is a red tide?

VIDEO: Learn about "red tides" and human health in this video from the U.S. Integrated Ocean Observing System®. Harmful algal blooms, or HABs, occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control...

Natural History / Natural History - 9 years ago

What is a sonar?

A three-minute video about multibeam and side scan sonar, including a visualization that shows how sonar data is used to make products like nautical charts. | Download: Soundscapes (75 MB) Sonar, short for Sound Navigation and Ranging, is he...

Natural History / Natural History - 9 years ago

What is hydrography?

By mapping out water depth, the shape of the seafloor and coastline, the location of possible obstructions, and physical features of water bodies, hydrography helps keep our maritime transportation system moving safely and efficiently. Download...