Tag: Tides and Currents

Natural History / Natural History - 3 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 - 6 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 - 6 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 - 7 months 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 - 11 months 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 is a catcher beach?

A classic example of a catcher beach along the shores of Hawaii. This map shows debris concentrations from an aerial survey done in Alaska in 2012. The map points to two known catcher areas, along Kruzof Island and Gore Point. Not to be...

Natural History / Natural History - 1 year ago

What is a King Tide?

A king tide viewed from south of Pier 96 in San Francisco, California, in February, 2016. Credit: Dave Rauenbuehler A King Tide is a non-scientific term people often use to describe exceptionally high tides. Tides are long-period waves that ro...

Natural History / Natural History - 1 year ago

What are the Roaring Forties?

A research vessel braves the strong westerly winds of the Roaring Forties during an expedition to measure levels of dissolved carbon dioxide in the surface of the ocean. During the Age of Sail (circa 15th  to 19th centuries), these strong prev...

Natural History / Natural History - 1 year ago

What are the doldrums?

This NASA satellite image shows the Inter-Tropical Convergence Zone, known to sailors around the world as the doldrums. Known to sailors around the world as the doldrums, the Inter-Tropical Convergence Zone, (ITCZ, pronounced and sometimes ref...

Natural History / Natural History - 2 years ago

What is a NOAA tide table?

This image shows daily tide predictions for Eastport, Maine, for January-February 1867. This page is from the first edition of a national annual tide table publication created in 1866 by the U.S. Coast Survey, a predecessor of NOAA. A tide tab...