Weekly Ocean News

WEEKLY OCEAN NEWS

DATASTREME OCEAN WEEK SIX: 9-13 OCTOBER 2006

Ocean in the News

(Thurs.) Shipwreck discovered in new national marine monument -- Marine archaeologists with the NOAA Maritime Heritage Program recently announced their finding of the wreckage of the three-masted British cargo ship Dunnottar Castle in the newly designated Northwestern Hawaiian Islands National Marine Monument. This ship was lost in July 1886. [NOAA News]
(Thurs.) Decreased levels of toxins found in mollusks -- The NOAA National Centers for Coastal Ocean Science recently released a new report that indicates that toxic organic compounds appear to be continuing to decrease in mussels and oysters collected from 240 sites around the nation. [NOAA News]
(Thurs.) Satellite data helps in assessment of coral reef health -- Data collected from NASA satellites are being used to help scientists make a comprehensive assessment of the health of coral reefs in NOAA's Florida Keys National Marine Sanctuary. [NASA GSFC]
(Thurs.) A new interocean canal proposed by Nicaragua -- The President of Nicaragua wants to build a canal similar to the current Panama Canal that would link the Atlantic and Pacific Oceans across his country for an estimated cost of $18 billion. [ENN]
(Thurs.) Satellite shows marine clouds hugging Pacific Northwest coast -- A satellite image obtained from the MODIS instrument onboard NASA's Aqua satellite shows an extensive layer of stratus and stratocumulus clouds in the marine atmospheric boundary layer along the Pacific Northwest coast. [NASA Earth Observatory]
(Thurs.) Global network of Marine Protected Areas sought for coral conservation -- Researchers for the Institut de Recherche Pour le Développement urge the development of a global network of Marine Protected Areas that would preserve the biodiversity of the threatened coral reefs by designing the network based upon certain size and distance criteria. [Institut de Recherche Pour le Développement] [Note that this is a pdf file]
(Tues.) New radar on an airplane should provide 3-D hurricane wind data -- NOAA has contracted with a Texas company to build and test a tail Doppler radar system for its Gulfstream-IV hurricane surveillance aircraft that would provide three-dimensional wind data from the core of hurricanes which the aircraft would penetrate on missions. [NOAA News]
(Tues.) El Niño event could continue through spring -- Researchers at the Climate Prediction Center said that the El Niño pattern that has developed could continue through both Northern Hemisphere winter and the spring of 2007. These researchers felt that this anomalous atmospheric and ocean circulation patterns most often associated with a warming in the eastern equatorial Pacific Ocean would be weak to moderate, but less intense than the major El Niño event of 1997-98. [USA Today] NASA scientists have been collecting data from their Aqua and Jason satellites that tend to confirm their NOAA colleagues' assessment of the onset of weak El Niño event. [NASA Life on Earth] [NASA Earth Observatory]
(Tues.) A new algal bloom forecast system is operational for the Texas Gulf Coast -- The director of NOAA's Coastal Services Center announced at the recent Gulf of Mexico Alliance meeting that a new harmful algal bloom forecast system is currently operational along the Texas Gulf Coast, providing users with weekly forecasts of blooms and their potential impacts on the environment. [NOAA News]
(Tues.) Climate change during Ice Age linked to changes in ocean salinity -- Researchers from the US and Great Britain report that their comparison of the climate records extracted from the Greenland ice sheet and the oceanic temperature and salinity records reconstructed from 45,000 to 60,000 year old deep-sea sediment cores indicate that repeated sudden changes in temperature over Greenland and tropical rainfall patterns during the last Ice Age can be linked to rapid changes in the salinity, or oceanic salt concentration, in the North Atlantic, possibly associated with ocean circulation. , in an [EurekAlert!]
(Tues.) Phytoplankton swirls around New Zealand -- An image recently obtained from the MODIS (Moderate Resolution Imaging Spectroradiometer) onboard NASA's Aqua satellite shows swirls of chlorophyll-pigmented phytoplankton that are tracing the turbulent patterns in the oceanic circulation off the New Zealand coasts. [NASA Earth Observatory]
(Tues.) Early humans traveled along coastal waters -- A University of Oregon professor reports that ancient humans roughly 10,000 years ago possessed sufficiently sophisticated maritime capabilities so as to travel along coastal waters and explore distant places such as the Americas and Southeast Asia. [BBC News]
(Tues.) Marine life is threatened by sewage and coastal destruction -- The United Nations Environment Programme recently released a report entitled "State of the Marine Environment" in which sewage is blamed as a growing threat to the world ocean, putting marine life and their habitat at increased risk. In addition, concern was also voiced over increased damage to coastal ecosystems by increased human activity. [ENN]
Eye on the tropics --
- As of Sunday afternoon, no tropical cyclones were found in the North Atlantic, eastern North Pacific or the western North Pacific basins.
- Last week, Tropical Storm Bebinca weakened as it moved northward across the western Pacific, to the east of the Philippines, an island nation that has experienced several recent tropical weather systems, including Typhoon Xangsane the previous week, accompanied by flooding rain. Rains associated with Bebinca and another system resulted in flash floods that caused six deaths near Manila. [USA Today] A visible image from the Japanese MTSAT satellite shows Tropical Depression Bebinca to the south of Japan at the end of last week. [NOAA OSEI]
- The death toll from Typhoon Xangsane continued to climb across the Philippines and Viet Nam, with at least 169 people in both countries being reportedly killed by this typhoon as of the start of last week. [USA Today]
Another downward revision in a hurricane forecast -- Last week, hurricane expert Prof. Bill Gray of Colorado State University and his associate Phillip Klotzbach, reduced their previous forecast of the number of hurricanes that they expected to develop in the North Atlantic basin for the remainder of this hurricane season to six hurricanes and the number of named tropical storms to eleven. They cited the onset of an El Niño event as being responsible for their updated forecast, which would be slightly more than the long-term averages for the basin. [USA Today]
Celebrate Earth Science Week -- The National Oceanic and Atmospheric Administration, including the National Weather Service, along with NASA, the US Geological Survey and several professional scientific organizations such as the American Geological Institute have recognized this coming week (8-14 October 2006) as Earth Science Week to help the public gain a better understanding and appreciation for the earth sciences and to encourage stewardship of the Earth. This year's theme is "Be a Citizen Scientist!" and will focus on increasing scientific literacy and encouraging the public to become more observant of their environment as "citizen scientists," regardless of their careers or levels of academic achievement. Learn about what geoscientists do, how their work is important to society and what is needed to become a geoscientist. [American Geological Institute]
Online teaching tool unveiled for coral reef ecosystems -- The NOAA Coral Reef Conservation Program and the National Science Teachers Association announced at the end of last week that a web-based "science toolbox" for educators called Coral Ecosystem SciGuide has been placed online. The toolbox is designed to provide educators at all grade levels resources organized within three theme areas: coral reef biology, coral ecosystems and coral conservation. [NOAA News]
Deep sea trawling ban considered -- The United Nations General Assembly is scheduled to begin debate on a plan led by Australia that would ban deep sea bottom trawling on the high seas and impose tougher regulation of other destructive fishing practices. [ENN]
Oil and waves seen from space -- Photographs taken by astronauts on the International Space Station not only show interesting sun glint patterns in intersecting ocean waves surrounding the Bajo Nuevo Reef in the western Caribbean Sea, but also oily surfactants that have affected the surface tension of the water. [NASA Earth Observatory]
Warming of the Arctic continues -- The leader of an Arctic expedition from the Alfred Wegener Institute for Polar and Marine Research onboard the research vessel Maria S Merian recently reported that water flowing into the Arctic from the Norwegian Sea was 0.8 Celsius degrees higher in the summer of 2006 than in the previous summer. [EurekAlert!]
Decline in Arctic sea ice in 2006 noted -- Researchers from the National Snow and Ice Data Center at University of Colorado at Boulder report that rising temperatures across the Arctic basin have helped reduce the Arctic sea ice to the fourth smallest areal size on record in 29 years of satellite observations. [EurekAlert!]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Abyssal Storms

Until recently, ocean scientists thought of the deep ocean abyss as a dark, cold but serene place where small particles rained gently onto the ocean floor. However, instruments lowered to the sea floor to measure ocean motion or currents and resulting mobilization of bottom sediments detected a much more active environment. Scientists found that bottom currents and abyssal storms occasionally scour the ocean bottom, generating moving clouds of suspended sediment. A surface current of 5 knots (250 cm/sec) is considered relatively strong. A bottom current of 1 knot ( 50 cm/sec) is ripping. Although this may be called an abyssal storm, the water motion pales by comparison to wind speeds in atmospheric storms.

Abyssal currents and storms apparently derive their energy from surface ocean currents. Wind-driven surface ocean currents flow about the margins of the ocean basins as gyres centered near 30 degrees latitude. (Refer to Figure 6.6, page 131, in your DataStreme Ocean textbook.) Viewed from above, these subtropical gyres rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. For reasons given in Chapter 6 of your textbook and this week's Supplemental Information, surface currents flow faster, are narrower, and extend to greater depths on the western arm of the gyres. These are known as western boundary currents and include, for example, the Gulf Stream of the North Atlantic basin. Abyssal currents are also most vigorous on the western side of the ocean basins, moving along the base of the continental rise, which is on the order of several kilometers deep.

Abyssal storms may be linked to or may actually be eddies (rings) that occasionally break off from the main current of the Gulf Stream (and other western boundary currents). During an abyssal storm, the eddy or ring may actually reach to the bottom of the ocean where the velocity of a bottom current increases ten-fold to about 1.5 km (1 mi) per hr. While that is an unimpressive wind speed, water is much denser than air so that its erosive and sediment-transport capacity is significant even at 1.5 km per hr. At this higher speed, the suspended sediment load in the bottom current increases by a factor of ten. Abyssal storms scour the sea floor leaving behind long furrows in the sediment. After a few days to a few weeks, the current weakens or the eddy (ring) is reabsorbed into the main surface circulation and the suspended load settles to the ocean floor. In this way, abyssal storms can transport tons of sediment long distances, disrupting the orderly sequence of layers of deep-sea sediments. Scientists must take this disruption into account when interpreting the environmental significance of deep-sea sediment cores.

Concept of the Week: Questions

In the subtropical ocean gyres, boundary currents flow faster on the [(western)(eastern)] side of an ocean basin.
Currents in an abyssal storm erode, transport, and redeposit sediments that have accumulated on the [(continental shelf)(deep ocean bottom)].

Historical Events

9 October 1873...LT Charles Belknap called a meeting at the Naval Academy to establish the U.S. Naval Institute for the purpose of disseminating scientific and professional knowledge throughout the U.S. Navy. (Navy Historical Center)
9 October 1967...A cyclone of relatively small dimension with a surface width of only 31 miles, hit India's coast at Orissa and moved to the northeast along the coast for 75 miles. As many as 1000 people and 50,000 head of cattle died. A surge in the storm's wake penetrated 16 miles inland. (Accord Weather Guide Calendar)
10-16 October 1780...The most deadly Western Hemisphere hurricane on record raged across the Caribbean Sea. This "Great Hurricane of 1780" killed 22,000 people on the islands of Martinique, St. Eustatius, and Barbados. Thousands more died at sea. (The Weather Doctor)
10 October 1845...Naval School, renamed the U.S. Naval Academy, opened in Annapolis, MD with 50 midshipmen students and seven faculty. (Navy Historical Center)
10 October 1861...Fridtjof Nansen, the Norwegian explorer, oceanographer, statesman, and humanitarian was born. Nansen led a number of expeditions to the Arctic (1888, 1893, 1895-96) and oceanographic expeditions in the North Atlantic (1900, 1910-14). He wrote The Oceanography of the North Polar Basin (1902). For his relief work after World War I, he was awarded the Nobel Prize for Peace in 1922. (Today in Science History)
10 October 1913...President Woodrow Wilson with the aid of a telegraph signal sent from Washington, DC triggered the demolition of the Gamboa Dike, allowing water to fill the Culebra Cut and create Lake Gatun, at 85 ft above sea level, the largest man-made lake at that time. This act signaled the completion of construction of the Panama Canal, which would eventually open to ship traffic between the Atlantic and Pacific Oceans on 14 August 1914. (Wikipedia, Today in Science History)
11 October 1737...A deadly cyclone and storm surge of 42 ft raced up the Hooghly River in India and through the city of Calcutta destroying an estimated 40,000 boats and drowning as many as 300,000 people. (The Weather Doctor)
11 October 1846...A very intense hurricane caused great destruction in the Florida Keys. Key West was virtually destroyed with 5 feet of water reported in the city. Fort Taylor was reduced to ruins. (Intellicast)
11 October 1897...Property saved at Cape Hatteras, NC. During a severe storm, the surf threatened to wash away a fish house, with valuable nets and other gear. Surfmen saved the property and took it to a place of safety. They also assisted a lighthouse keeper to remove lenses of the beacon to a secure place. The lighthouse was in danger of being washed away by the sea. (US Coast Guard Historian's Office)
12 October 1492--Italian explorer Christopher Columbus sighted and landed on an island (possibly Watling Island) in the Bahamas during his travels westward across the Atlantic Ocean in search of an ocean route to eastern Asia. Apparently he underestimated the size of the world and assumed that he had reached East Asia after setting sail with three ships from Palos, Spain on 3 August 1492. During this expedition, which was the first known European expedition to the Americas since the 10^th century Viking colonies in Newfoundland, he sighted Cuba and landed on Hispaniola. (The History Channel)
12 October 1886...A hurricane made landfall between Sabine Pass, TX and Johnson's Bayou, LA. Waves were said to be as high as 2-story buildings. The surge extended 20 mi inland, with 150 people killed. Survivors clung to trees or floated on mattresses. Only two of 100 homes in Sabine Pass were reparable. (Accord Weather Calendar)
12 October 1954...Hurricane Hazel pounded Haiti and the island of Hispaniola with winds of 125 mph. Many villages were reported totally destroyed and more than 1000 Haitians died. (The Weather Doctor)
12 October 1965...End of Project Sealab II where teams of naval divers and scientists spent 15 days in Sealab moored 205 feet below surface near La Jolla, CA. (Navy Historical Center)
12 October 1979...The lowest observed sea-level barometric pressure (870 millibars or 25.69 inches of mercury) was recorded near Guam in the western Pacific Ocean at the center of Typhoon Tip. (The Weather Doctor)
13 October 1775...Birthday of U.S. Navy. The Continental Congress established the Continental Navy, later the U.S. Navy. (Naval Historical Center)
13 October 1884...The longitude that passes through the principal Transit Instrument at the Observatory in Greenwich, England was selected as the single universal meridian at the International Meridian Conference held in Washington, DC. A universal day was also selected. (Today in Science History)
15 October 1947...A hurricane made a hairpin turn off the Georgia coast after being seeded with dry ice. The storm passed over Savannah and tracked inland through Georgia. (Intellicast)
15 October 1954...Hurricane Hazel struck the Carolina coastline near Cape Fear, NC. The hurricane (category 4 on the Saffir-Simpson Scale) demolished every pier along a 170-mile stretch from Myrtle Beach, SC to Cedar Island, NC, and obliterated rows of beach homes. At Long Beach, 300 homes vanished; no debris remained. Hurricane Hazel also destroyed 1500 homes as it made landfall with 17-ft tides. Winds between Myrtle Beach, SC and Cape Fear, NC gusted to 150 mph. Later, the remnants of Hazel moved northward into Ontario and became the most remembered storm in Canadian history. Winds gusted to 75 mph and as much as 7.2 inches of rain fell. Eighty people died, mostly from flooding in the Toronto area (David Ludlum) (The Weather Channel) (The Weather Doctor)
15 October 1999...A waterspout (a tornado over water) moved onshore at Fort Lauderdale Beach, FL and blew out a plate glass window in a bar, injuring 8 patrons. The waterspout also overturned a vehicle and caused other significant damage on Los Olas Blvd. (Accord Weather Calendar)