Weekly Ocean News

DATASTREME OCEAN WEEK TEN: 31 March-4 April 2008

Ocean in the News:

(Thurs.) "Nautical Charts" is unveiled as multimedia educational tool -- NOAA's National Ocean Service recently unveiled a multimedia educational program for third through fifth grade called Nautical Charts that is designed to teach youngsters about charting and navigation. [NOAA News]
(Thurs.) Giant ocean eddy found off Australia -- An oceanographer with Australia's Commonwealth Scientific and Industrial Research Organisation has used satellite data and imagery to monitor the evolution of a giant 300-km wide eddy of cold water off the New South Wales coast for six months. [CSIRO]
(Thurs.) Research ship is retired -- The 90-foot NOAA hydrographic vessel Rude was recently decommissioned and retired from the NOAA fleet of ships at Norfolk, VA after 41 years of service. [NOAA News]
(Tues.) Pollutants studied in ice-free Arctic regions -- Researchers from NOAA’s Pacific Marine Environmental Laboratory and colleagues are participating in a program called the International Chemistry Experiment in the Arctic Lower Troposphere (ICEALOT), which is part of a larger international program being conducted during the International Polar Year called POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport). The ICEALOT science team is onboard the Woods Hole Oceanographic Institute's Research Vessel Knorr, taking air samples off the U.S. Atlantic coast, before heading for the Greenland, Barents and Norwegian Seas. [NOAA News]
(Tues.) Young arctic ice found -- Images obtained from NASA satellites indicate that the polar sea ice found in the Arctic Ocean near the end of the winter season appears to be younger than during previous winters. This current winter follows the 2007 summer in which the ice had reached a record minimum areal coverage. [NASA Earth Observatory]
(Tues.) Ice shelf disintegration monitored from space -- In late February, images made by the MODIS sensors on NASA's Terra and Aqua satellites shows the rapid disintegration of the Wilkins Ice Shelf on the Antarctic Peninsula. [NASA Earth Observatory] Additional detail was provided by the images obtained from the Taiwanese Formosat-2 satellite. [NASA Earth Observatory] Researchers at the National Snow and Ice Data Center warn that the collapse of the Wilkins Ice Shelf appears to be associated with climate change in an area of the continent experiencing rapid increases in temperature. [EurekAlert!]
Eye on the Tropics -- Tropical cyclone (hurricane) activity continued across the tropical waters of the South Indian Ocean last week, during austral autumn. Tropical Cyclone Pancho formed at the start of last week over eastern sections of the South Indian Ocean. This cyclone, which intensified to become a Category 2 cyclone on the Saffir-Simpson Scale, traveled to the south-southeast, approaching the western coast of Australia on this past Saturday, before dissipating. A satellite image from the Japanese MTSAT satellite late last week shows a well-formed eye surrounded by the characteristic bands of clouds surrounding Pancho. [NOAA OSEI] A visible image obtained from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite shows the clouds surrounding a weakening Tropical Cyclone Pancho late last week. [NASA Hurricane Page]
In the western sections of the South Indian Ocean, Tropical Cyclone Lola dissipated east of Madagascar at the start of last week. An infrared image obtained from the Atmospheric Infrared Sounder (AIRS) on board NASA's Aqua satellite shows the temperatures of the tops of the clouds surrounding Tropical Cyclone Lola. [NASA Hurricane Page]
April is Tsunami Awareness Month in Hawaii -- The State of Hawaii and the National Weather Service Office in Honolulu have declared April as Tsunami Awareness Month in the Aloha State. The National Weather Service Office is also hosting the International Tsunami Information Center in conjunction with the Intergovernmental Oceanographic Commission of UNESCO. [International Tsunami Information Center]
An ice seal considered for endangered species protection -- The NOAA Fisheries Service will consider providing protection through the Endangered Species Act for the "ribbon seal", an ice seal species found in Alaska's Bering Sea. [NOAA News]
Ancient lava flows studied under ocean floor -- Researchers from the University of Cambridge and the University of Liverpool, along with several industrial research groups in the United Kingdom, have been studying the large volume of rock that had been molten more than 55 million years ago and then solidified under the edges of the Atlantic Ocean. This rock may have been associated with volcanic activity in the North Atlantic when Greenland split from northern Europe that released massive volumes of greenhouse gases, which may have led to a rapid increase in global temperatures. [University of Cambridge]
Evolution of life delayed by low quantities of key chemicals -- Biogeochemists from the University of California, Riverside and Arizona State University who tracked the biogeochemical signatures preserved in ancient sedimentary rocks claim that low levels of oxygen and molybdenum in ancient oceans approximately 2.5 billion years ago appear to have delayed the evolution of life by two billion years. [EurekAlert!]
Global and US Hazards/Climate Extremes -- A review and analysis of the global impacts of various weather-related events, including drought, floods, and storms during the current month. [NCDC]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Solving the Mystery of Seamount Ecosystems

The United States Commission on Ocean Policy reports that less than 5% of the ocean floor has been explored. This is beginning to change as scientists and engineers develop and apply new technologies to investigate deep ocean waters and the sea bottom (refer to Chapter A in your DataStreme Ocean textbook). Consider, for example, the effort to obtain a better understanding of seamount ecosystems.

A seamount is a submarine mountain of volcanic origin (now extinct) that rises more than 1000 m (3300 ft) above the ocean floor. Usually a seamount summit is 1000 to 2000 m (3300 to 6600 ft) below sea level. They occur as isolated peaks, chains (e.g., Emperor Seamounts in the North Pacific; New England chain in the North Atlantic), or clusters. The term "seamount" was first applied in 1936 to the Davidson Seamount located off the coast of Southern California. Scientists estimate that perhaps 30,000 dot the ocean floor with as many as two-thirds located on the Pacific Ocean bottom. However, fewer than one thousand seamounts have been named and only a handful of seamounts has received detailed scientific study.

In recent years, discovery of unique life forms on seamounts has spurred scientific interest in seamount ecosystems. Many nations, including the United States, Australia, and New Zealand, are supporting scientific cruises to observe and collect specimens from seamount ecosystems. Seamount ecosystems are unusually productive and are home to unique species. Some seamount surveys have found that certain seamount species are endemic, that is, they live on only one seamount or a few nearby peaks. For example, up to one-third of all species living on some seamounts off New Caledonia are endemic while up to half of the invertebrates and fish on the Nazca seamount off Chile are endemic. In the northeast Pacific, large-scale eddies may transport larval fish from coastal environments to isolated seamounts located out at sea. Furthermore, some scientists argue that seamounts may function as stepping stones that allow for migration of species over lengthy periods--perhaps over millions of years. In addition, some seamounts may serve as aids to navigation for fish that migrate over long distances. For example, hammerhead sharks may use the magnetic field surrounding seamounts to find their way.

The recent effort to survey and explore seamount ecosystems has reached new urgency with the realization of the devastating impact of commercial fish trawlers on those ecosystems. In some cases, trawling has striped off most marine life (e.g., coral gardens) from the surface of seamounts leaving behind mostly bare rock. Typically, trawled seamounts have only half the biomass and considerably fewer species than undisturbed seamounts. Scientists anticipate that a better understanding of seamount ecosystems will help make the case for their conservation and inform the most effective strategies for their protection. Australia is one of the first nations to protect seamount ecosystems, establishing the Tasmanian Seamount Marine Reserve in 1999. The reserve covers 370 square km (140 square mi) and includes more than a dozen seamounts.

Concept of the Week: Questions

Seamounts are extinct submarine volcanoes that occur primarily in the [(Atlantic) (Pacific) (Southern)] Ocean.
Commercial fish trawling has [(little if any) (a devastating)] impact on seamount ecosystems.

Historical Events:

31 March 1932...The United States signed the Whaling Convention at Geneva with 21 other countries. (USCG Historian's Office)
31 March 1995...Coast Guard Communication Area Master Station Atlantic sent a final message by Morse code and then signed off, officially ending more than 100 years of telegraph communications. (USCG Historian's Office)
31 March 2000...The water temperature of Lake Erie at Buffalo, NY was 39 degrees Fahrenheit on the last day of March, tying the maximum temperature for the date with that of 1998. Ice was present in 61 of 74 years on the 31^st, but this was third year in a row with open water. (Accord's Weather Guide Calendar)
1 April 1873...The British White Star steamship Atlantic sank off Nova Scotia killing 547 after striking an underwater rock near Meagher's Island while on a voyage from Liverpool, England to New York City. Only 413 people survived. (Wikipedia)
1 April 1946...The Scotch Cap Lighthouse on Unimak Island in Alaska's Aleutian Islands was shaken by two earthquakes in a 27 minute span, then obliterated by a tsunami wave. The entire five-man crew was killed and the lighthouse antenna (105 ft above sea level) was washed away. Some debris was found 115 ft above sea level. The tsunami that propagated across the Pacific Ocean was responsible for more than 165 fatalities and over $26 million in damage. Many of the casualties were on the Hawaiian Islands, especially in Hilo on the Big Island. This tsunami was responsible for the development of the current Pacific Tsunami Warning System. (University of Washington) (Accord's Weather Guide Calendar) (US Coast Guard Historian's Office)
2 April 1513...Spanish explorer Juan Ponce de Leon came ashore on the Florida coast near present-day St. Augustine and claimed the territory for the Spanish crown. He is reported to be the first known European to set foot in Florida. (The History Channel)
2 April 1958...One of the most destructive coastal storms in years battered New England (31 March-3 April). Some beaches between Portland, ME and Cape Cod, MA were eroded by approximately 50 ft. Miles of sea walls and bulkheads were either breached or demolished. Many beachfront cottages in Massachusetts, New Hampshire and Maine were sandblasted. (Accord's Weather Guide Calendar)
2 April 1926....Baden-Baden, a rotor ship invented by Anton Flettner left Hamburg, Germany on a transatlantic crossing, arriving in New York on 29 May 1926. The ship used two 9-ft diameter, 50-ft high cylinders, mounted vertically on the deck at the bow and the stern for propulsion, utilizing the aerodynamic power of the Magnus Effect, which builds air pressure behind a rotating cylinder. (Today in Science History)
3 April 1797...Captain Thomas Truxtun, USN, devised and issued the first known American signal book using numerary system, encompassing 10 numeral pennants, made of combinations of red, white, blue, and yellow bunting, with flags for repeaters. This signal book contained approximately 300 signals. Fog signals were made by gunfire. Night signals were made by lanterns and gunfire. (Naval Historical Center)
4 April 1581...The famous English navigator, Francis Drake, completed his circumnavigation of the world (1577 to 1580) and was knighted by Queen Elizabeth I. (Wikipedia).
6 April 1894...President Grover Cleveland authorized enforcement of the Paris Award concerning the preservation of fur seals in Alaska. (USCG Historian's Office)
6 April 1909...The American explorer, Commander Robert E. Peary, USN, along with assistant Matthew Henson, and four Eskimos reported reaching the geographic North Pole; however, navigational errors may have meant that they were a few miles away from the exact pole. (Naval Historical Center) (The History Channel)
6 April 1913...USRC Seneca, a derelict destroyer (whose mission was to locate and destroy abandoned wrecks that were still afloat and a menace to navigation), inaugurated the Revenue Cutter Service's participation in the International Ice Patrol. (USCG Historian's Office)