Category : Natural History

Natural History / Natural History - 8 months ago

What is a meteotsunami?

Storm clouds loom over Lake Superior. When conditions are right, meteotsunamis may occur in many bodies of water around the world, including the Great Lakes. Some meteotsunamis have been observed to reach heights of 6 feet or more. Meteotsunamis a...

Natural History / Natural History - 8 months ago

What is a watershed?

While some watersheds are relatively small, others encompass thousands of square miles and may contain streams, rivers, lakes, reservoirs, and underlying groundwater that are hundreds of miles inland. Shown here: an aerial view of Drakes Bay, par...

Natural History / Natural History - 11 months ago

What is a current survey?

Did you know? An Operational Forecast System provides a nowcast and forecast (up to 48 hours) of water levels, currents, salinity, water temperatures, and winds for a given area. These systems are located in coastal waters and the Great Lakes in...

Natural History / Natural History - 11 months ago

What is a backscatter?

VIDEO: How does backscatter help us understand the sea floor? Here's what you need to know in less than a minute. Transcript Backscatter is the reflection of a signal (such as sound waves or light) back in the direction from where it originat...

Natural History / Natural History - 11 months ago

What is a ghost forest?

A ghost forest on Capers Island, South Carolina. As sea level rises, more and more saltwater encroaches on the land. Along the world’s coasts and estuaries, invading seawater advances and overtakes the fresh water that deciduous trees rely upo...

Natural History / Natural History - 1 year ago

What is eutrophication?

This NASA Earth Observatory image shows the region where the Mississippi River meets the Gulf of Mexico. It illustrates how sediment is moved from the land to the sea. The Mississippi River carries millions of tons of nutrient-rich sediment into...

Natural History / Natural History - 1 year ago

What is high tide flooding?

As relative sea level increases, it no longer takes a strong storm or a hurricane to cause coastal flooding. Flooding now occurs with high tides in many locations due to climate-related sea level rise, land subsidence, and the loss of natural barrie...

Natural History / Natural History - 1 year ago

How does sand form?

The giant bumphead parrotfish is an amazing fish that can live to be 40 years old, growing up to four feet long and 100 pounds. They use their large head bumps to literally bump heads during competitive displays, when large numbers of fish aggreg...

Natural History / Natural History - 1 year ago

What is a Rossby wave?

Rossby waves naturally occur in rotating fluids. Within the Earth's ocean and atmosphere, these planetary waves play a significant role in shaping weather. This animation from NASA's Goddard Space Flight Center shows both long and short atmosphe...

Natural History / Natural History - 1 year ago

What are the Totten Beacons?

The rusty remnants of a Totten Beacon (foreground) located near American Shoal lighthouse. Photo credit: M. Lawrence. Main beacon pile centered among three significantly shorter support posts. Photo credit: M. Lawrence. In 1513, Span...

Natural History / Natural History - 1 year ago

What is a tide gauge?

The rise and fall of the tides play an important role in the natural world and can have a marked effect on maritime-related activities. The image aboves shows the NOAA San Francisco Tide Station, in operation for more than 150 years. A tide ga...

Natural History / Natural History - 1 year ago

What are brain corals?

Brain coral in the Dry Tortugas, Florida. The cerebral-looking organisms known as brain corals do not have brains, but they can grow six feet tall and live for up to 900 years! Found in the Caribbean, Atlantic, and Pacific Oceans, brain corals...