Many people use the terms "ocean" and "sea" interchangeably when speaking about the ocean, but there is a difference between the two terms when speaking of geography (the study of the Earth's surface).

Seas are smaller than oceans and are usually located where the land and ocean meet. Typically, seas are partially enclosed by land.

For more information:
Office of Coast Survey
A History of Charting America's Waters, NOAA 200th
Anniversary Web Site

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The origins of the phrase 'Seven Seas' can be traced to ancient times.

In various cultures at different times in history, the Seven Seas has referred to bodies of water along trade routes, regional bodies of water, or exotic and far-away bodies of water.

In Greek literature (which is where the phrase entered Western literature), the Seven Seas were the Aegean, Adriatic, Mediterranean, Black, Red, and Caspian seas, with the Persian Gulf thrown in as a "sea."

In Medieval European literature, the phrase referred to the North Sea, Baltic, Atlantic, Mediterranean, Black, Red, and Arabian seas.

After Europeans 'discovered' North America, the concept of the Seven Seas changed again. Mariners then referred to the Seven Seas as the Arctic, the Atlantic, the Indian, the Pacific, the Mediterranean, the Caribbean, and the Gulf of Mexico.

Not many people use this phrase today, but you could say that the modern Seven Seas include the Arctic, North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, and Southern Oceans.

However, our oceans are more commonly geographically divided into the Atlantic, Pacific, Indian, Arctic, and Southern (Antarctic) Oceans.

For more information:
How many oceans are there?
NOAA Nautical Charts
A History of Charting America's Waters, NOAA 200th Anniversary Web Site

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The National Geodetic Survey is celebrating the 15th anniversary of the Continuously Operating Reference Station (CORS) program. This program helps scientists and others monitor our ever changing planet by providing highly accurate positioning information....

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There are over 1,700 marine protected areas (MPAs) in the United States established by federal, state, and territorial governments. These areas cover 34 percent of U.S. marine waters and vary widely in their purpose, legal authorities, managing agencies, and level of protection.

Although MPAs are found in every region of the United States, the West Coast, including California, Oregon, and Washington, has the highest number of MPAs.  However, the region with the largest area of MPAs is the Pacific Islands. This is because of the designation of the Papahānaumokuākea Marine National Monument, which is one of the largest marine conservation areas in the world.

For more information:
MPAs: Evolving Efforts to Manage Marine Resources, NOAA 200th Anniversary Web Site
Marine Protected Areas Center
Marine Protected Areas Virtual Library
Office of Ocean and Coastal Resource Management
MPA Case Studies
Diving Deeper: Marine Protected Areas

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The Center for Operational Oceanographic Products and Services (CO-OPS) is primarily responsible for predicting and measuring water levels and currents and disseminating this information. CO-OPS collects, analyzes, and distributes such data to maintain safe maritime navigation and waterborne commerce.

While CO-OPS computes tidal predictions for more than 3,000 water-level stations around the United States, the publication of full daily predictions is limited to fewer stations. Stations with full daily predictions are called “reference stations” and remaining stations are called “subordinate stations.” You can calculate tidal predictions for subordinate stations by applying specific differences to the times and heights of tides of the specified reference stations.

To access tidal predictions for 2009, as well as 2008 – 2004, visit the CO-OPS Water Level Tidal Predictions Web page. For more information:
Water Level Tidal Predictions, Center for Operational Oceanographic Products and Services
Tides and Water Levels, NOS Education
Changing Technology for Real-Time Tide Measurements, NOAA 200th Anniversary Web Site

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To be classified as an iceberg, the height of the ice must be greater than 16 feet (five meters) above sea level and the thickness must be 98-164 feet (30-50 meters) and the ice must cover an area of at least 5,382 square feet (500 square meters).

There are smaller pieces of ice known as “bergy bits” and “growlers.” Bergy bits and growlers can originate from glaciers or shelf ice, and may also be the result of a large iceberg that has broken up. A bergy bit is a medium to large fragment of ice. Its height is generally greater than three feet (one meter) but less than 16 feet (five meters) above sea level and its area is normally about 1,076-3,229 square feet (100-300 square meters). Growlers are smaller fragments of ice and are roughly the size of a truck or grand piano. They extend less than three feet (one meter) above the sea surface and occupy an area of about 215 square feet (20 square meters).

Icebergs are also classified by shape, most commonly being either tabular or non-tabular. Tabular icebergs have steep sides and a flat top. Non-tabular icebergs have different shapes, with domes and spires.

Icebergs are monitored worldwide by the U.S. National Ice Center (NIC). NIC produces analyses and forecasts of Arctic, Antarctic, Great Lakes, and Chesapeake Bay ice conditions. NIC is the only organization that names and tracks all Antarctic Icebergs.

For more information:
U.S. National Ice Center

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Experts from NOAA joined a group of eighty scientists, managers, and industry representatives from California, Oregon, and Washington at the first West Coast Regional Harmful Algal Bloom (HAB) Summit in Portland, Oregon, February 10-12. At the meeting, the representatives endorsed a regional harmful algal bloom (HAB) monitoring, alert and response network and forecasting system....

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Underwater volcanoes at spreading ridges and convergent plate boundaries produce hot springs known as hydrothermal vents.

Scientists first discovered hydrothermal vents in 1977 while exploring an oceanic spreading ridge near the Galapagos Islands. To their amazement, the scientists also found that the hydrothermal vents were surrounded by large numbers of organisms that had never been seen before. These biological communities depend upon chemical processes that result from the interaction of seawater and hot magma associated with underwater volcanoes.

Hydrothermal vents are the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centers or subduction zones (places on Earth where two tectonic plates move away or towards one another). The cold seawater is heated by hot magma and reemerges to form the vents. Seawater in hydrothermal vents may reach temperatures of over 340°C (700°F).

Hot seawater in hydrothermal vents does not boil because of the extreme pressure at the depths where the vents are formed.


For more information:
Loihi Submarine Volcano: A Unique, Natural Extremophile Laboratory, NOAA Office of Oceanic and Atmospheric Research
Hydrothermal Vents Program, NOAA Pacific Marine Environmental Laboratory

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"Extremophiles" are microorganisms with the ability to thrive in extreme environments such as hydrothermal vents.
Since they live in “extreme environments” (under high pressure and temperature), they can tell us under which range of conditions life is possible.

The unique enzymes used by these organisms, called "extremozymes," enable these organisms to function in such forbidding environments. These creatures hold great promise for genetically based medications and industrial chemicals and processes.

It's important to note that these organisms are 'extreme' only from a human perspective. While oxygen, for example, is a necessity for life as we know it, some organisms flourish in environments with no oxygen at all.

 



For more information:
Novel Microorganisms from the cold dark sea, NOAA Ocean Explorer
Loihi Submarine Volcano: A unique, natural extremophile laboratory, NOAA Office of Oceanic and Atmospheric Research
Hydrothermal Vents Program, NOAA Pacific Marine Environmental Laboratory

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At 3:31 PM on January 15, 2009, U.S. Airways Flight 1549, an Airbus A320 commercial passenger plane, made an emergency water landing on the Hudson River, on the West Side of Manhattan in New York City. The National Ocean Service was at the ready, supporting passenger rescue, assessing risk of contamination to the environment, and helping to survey the cold and icy river for the wreckage of the plane....

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