Category : Natural History

Natural History / Natural History - 4 years ago

What is a hurricane?

VIDEO: What is a hurricane? Here's what you need to know in less than a minute. Transcript A tropical cyclone is a rotating low-pressure weather system that has organized thunderstorms but no fronts (a boundary separating two air masses of d...

Natural History / Natural History - 5 years ago

Was Moby Dick a real whale?

Illustrations from Moby-Dick, published in 1851 and authored by Herman Melville. Moby-Dick; or, The Whale, the allegorical novel about Captain Ahab’s search to kill a great white whale, was based on real-life events. Born in 1819, author Herma...

Natural History / Natural History - 5 years ago

Why do we name tropical storms?

Hurricane Ike (2008), the third costliest storm in United States history. Until the early 1950s, tropical storms and hurricanes were tracked by year and the order in which they occurred during that year. Over time, it was learned that the use...

Natural History / Natural History - 5 years ago

What is a seiche?

This animation shows a standing wave (black) depicted as a sum of two propagating waves traveling in opposite directions (blue and red). Similar in motion to a seesaw, a seiche is a standing wave in which the largest vertical oscillations are at e...

Natural History / Natural History - 5 years ago

What is a fish ladder?

Fish ladder near the south shore of Long Island, where recorded Alewive migration was occurring. The survival of many fish species depends on migrations up and down rivers. Among anadromous fish such as salmon, shad, and sturgeon, downstream m...

Natural History / Natural History - 5 years ago

What is a bivalve mollusk?

A roughfile clam from the Flower Garden Bank National Marine Sanctuary—just one of many different bivalve mollusk species. Like fish, bivalve mollusks breathe through their gills. As filter feeders, bivalves gather food through their gills. So...

Natural History / Natural History - 5 years ago

What is ocean acidification?

What is ocean acidification? Watch our video for a quick overview. For more than 200 years, or since the industrial revolution, the concentration of carbon dioxide (CO2) in the atmosphere has increased due to the burning of fossil fuels and l...

Natural History / Natural History - 5 years ago

What is a Plimsoll line?

Plimsoll mark on the hull of a floating ship. The Plimsoll line is a reference mark located on a ship’s hull that indicates the maximum depth to which the vessel may be safely immersed when loaded with cargo. This depth varies with a ship’s di...

Natural History / Natural History - 5 years ago

What is LIDAR?

LIDAR data is often collected by air, such as with this NOAA survey aircraft (right) over Bixby Bridge in Big Sur, Calif. Here, LIDAR data reveals a top-down (top left) and profile view of Bixby Bridge. NOAA scientists use LIDAR-generated product...

Natural History / Natural History - 5 years ago

What is the mariner's 1-2-3 rule?

Illustration of the Mariner-s 1-2-3 rule. The Mariner's 1-2-3 rule, also referred to as the Danger Rule, is an important guideline mariners follow to keep out of a tropical storm or hurricane's path. It refers to the rounded long-term National...