The Omnibus Public Land Management Act of 2009 signed into law by President Barack Obama on March 30 contains several provisions related to ocean and coastal research, monitoring, and conservation--central responsibilities of NOS. We have a rundown of the highlights....

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Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 0 degrees Celsius (32 degrees Fahrenheit), but seawater freezes at about -1.9 degrees Celsius (28.4 degrees Fahrenheit) because of the salt in it. When seawater freezes, however, the ice contains very little salt because only the water part freezes. It can be melted down to use as drinking water.

At least 15 percent of the ocean is covered by sea ice some part of the year. On average, sea ice covers almost about 25 million square kilometers (10 million square miles) of the Earth.

Sea water becomes more and more dense as it becomes colder, right down to its freezing point. Fresh water, on the hand, is most dense while still at 4 degrees Celsius (39.2 degrees Fahrenheit), well above the freezing point. The average temperature of all ocean water is about 3.5 degrees Celsius (38.3 degrees Fahrenheit).

For more information:
National Ice Center
NOAA's Arctic Theme Page
National Weather Service National Centers for Environmental Prediction: Sea Ice (sea ice data)
Salinity Data, National Oceanographic Data Center ...

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Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height. But as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters. While tsunamis are often referred to as tidal waves, this name is discouraged by oceanographers because tides have little to do with these giant waves.

The largest tsunami on record rushed past Ishigaki Island, Japan, in 1971. It was an incredible 84.7 meters (278 feet) high. While it caused little damage, the giant wall of water relocated a 750-ton block of coral 2.4 kilometers (1.5 miles) inland.

For more information:
NOAA Deep-ocean Assesment and Reporting of Tsunamis (DART)
Map and Real-time DART Data
NOAA Tsunami Program
National Geophysical Data Center
NOAA Enhances Its Ability to Provide Tsunami Warnings (NOAA 200th Anniversary Web site) ...

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Each year, three times as much rubbish is dumped into the world's oceans as the weight of fish caught.

Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health. Our oceans and waterways are polluted with a wide variety of marine debris ranging from soda cans and plastic bags to derelict fishing gear and abandoned vessels. 

Marine debris is defined as any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment or the Great Lakes.

Today, there is no place on Earth immune to this problem. A majority of the trash and debris that covers our beaches comes from storm drains and sewers, as well as from shoreline and recreational activities such as picnicking and beachgoing. Abandoned or discarded fishing gear is also a major problem because this trash can can entangle, injure, maim, and drown marine wildlife and damage property.

For more information:
NOAA Marine Debris Program
Coastal Management & Marine Debris, Office of Ocean & Coastal Resource Management


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The Kuroshio Current, in the Pacific off the east coast of Taiwan extending northward off the east coast of Japan, is the ocean's largest current. It can travel between 40-121 kilometers per day (25-75 miles per day) at speeds between 1.6-4.8 kilometers per hour (about 1-3 miles per hour) and extends some 1,006 meters ( 3,300 feet) deep.

Ocean currents are driven by wind, temperature changes, and tides

Oceanic currents are driven by three main factors:

1. The rise and fall of the tides. Tides create a current in the oceans, near the shore, and in bays and estuaries along the coast. These are called "tidal currents." Tidal currents are the only type of currents that change in a very regular pattern and can be predicted for future dates.

2. Wind. Winds drive currents that are at or near the ocean's surface. These currents are generally measured in meters per second or in knots (1 knot = 1.85 kilometers per hour or 1.15 miles per hour). Winds drive currents near coastal areas on a localized scale and in the open ocean on a global scale.

3. Thermohaline circulation. This is a process driven by density differences in water due to temperature (thermo) and salinity (haline) variations in different parts of the ocean. Currents driven by thermohaline circulation occur at both deep and shallow ocean levels and move much slower than tidal or surface currents.

Currents affect the Earth's climate by driving warm water from the Equator and cold water from the poles around the Earth. The warm Gulf Stream, for instance, brings milder winter weather to Bergen, Norway, than to New York, much further south. It keeps the Norwegian coast an incredible 6.1 degrees Celsius (43 degrees Fahrenheit) warmer than other places equally far north.

Most ocean currents flow in one direction all the time. In the northern Indian Ocean, though, they change direction twice a year, driven by the monsoon winds. From November to March, the currents are blown towards Africa by the cool, dry north-east monsoon winds. In May, the winds blow in the opposite direction, driving the water towards India.

For more information:
Observations of the Gulf Stream, NOAA Ocean Explorer
NOAA CoastWatch
Tides & Currents: Center for Operational Oceanographic Products and Services
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From March 23 through April 3, NOS scientists will embark on a scientific mission to study the coral reefs and fish habitats off the coast of Vieques, Puerto Rico....

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Human-made products are not completely biodegradable. These products will take a long time, possibly hundreds of years, to degrade. Some products such as glass never degrade. To determine how long it will take for debris to degrade depends on several factors such as material type, size, thickness, and environmental conditions (e.g., amount of exposure to sunlight or location - on the beach or floating at sea).

While photodegradable plastics (plastics capable of being broken down by light) may break down from its first state (or created state), these plastics never completely degrade, but actually divide into tiny pieces called microplastics. Microplastics are the multi-colored pieces of plastic that can be found in a handful of sand on the beach or in the ocean. Scientists are still investigating the impact of microplastics on our ocean and marine life.

For more information:
NOAA Marine Debris Program
Diving Deeper Podcast, Episode 3 (Feb. 23, 2009) - What is marine debris?


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When it comes to eating, the ocean provides much more than just seafood. Many of the foods and products found in your local grocery store contain ingredients from the ocean.

For example, peanut butter and toothpaste both contain carrageenan. Carrageenan is a generic term for compounds extracted from species of red algae. Boiling the algae extracts the carrageean, which in turn is used to make peanut butter more spreadable. Carrageenan also gives toothpaste its consistency and is used in other cosmetics, pharmaceuticals, and industrial products.

For more information:
International Year of the Ocean – Ocean Exploration Fact Sheet

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Want to learn about estuaries and the threats that endanger them AND have some fun? Check out NOS’s new educational online game: "WaterLife: Where Rivers Meet the Sea."...

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Reef-building corals cannot tolerate water temperatures below 64° Fahrenheit (18° Celsius). Many grow optimally in water temperatures between 73° and 84° Fahrenheit (23°–29°Celsius), but some can tolerate temperatures as high as 104° Fahrenheit (40° Celsius) for short periods.

Most reef-building corals also require very saline (salty) water ranging from 32 to 42 parts per thousand.

The water must also be clear so that a maximum amount of light penetrates it. This is because most reef-building corals contain photosynthetic algae, called zooxanthellae, which live in their tissues. The corals and algae have a unique relationship. The coral provides the algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, zooxanthellae supply the coral with food. The algae need light in order to produce food via photosynthesis.

For more information:
Corals Tutorial, NOS Education
Coral Reef Biology, NOAA's Coral Reef Information System

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