Weekly Ocean News

DATASTREME OCEAN WEEK FOUR: 11-15 February 2008

Ocean in the News

(Thurs.) Oregon coast coho to receive federal protection -- Last week, officials with NOAA’s Fisheries Service announced that Oregon coast coho would be listed as a threatened species under the federal Endangered Species Act, which would give the species federal protection. [NOAA News]
(Thurs.) Seismic fault system studied in waters off Japan -- Scientists from ten nations have collected samples from the Nankai Trough fault zone in the waters off Japan's Kii Peninsula as part of the third expedition of the Integrated Ocean Drilling Program’s Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), which was recently completed. [EurekAlert!]
(Thurs.) Overall effects of warming trend could be masked in oceans by winds -- Scientists at the United Kingdom's University of Liverpool and at Duke University in the US claim that based upon a 50-year record of North Atlantic temperatures, variations in the large-scale wind patterns, such as the North Atlantic Oscillation, could be masking the overall effect of increases in global temperatures within the waters of the North Atlantic Ocean because of a complex pattern of heat storage within that basin. [EurekAlert!]
(Thurs.) Reconstructed proteins serve as proxy paleoclimatic indicator -- Researchers from the University of Florida and their colleagues in the private sector have reconstructed proteins from ancient bacteria that can be used to determine a planetary temperature record extending back into the Precambrian period, which indicates a general planetary cooling from 3.5 billion to 500 million years ago. [EurekAlert!]
(Tues.) NOAA celebrates multiculturalism -- NOAA celebrates Black History Month 2008 by honoring "Carter G. Woodson and the Origin of Multiculturalism." Dr. Woodson was an author of several books on multiculturalism in America during the early 20th century. [NOAA]
(Tues.) A critical habitat for threatened coral is proposed -- NOAA is seeking public comment through early May 2008 on its proposed designation of a critical marine habitat in Florida, Puerto Rico and the US Virgin Islands for protection the threatened elkhorn and staghorn coral under the 2006 Endangered Species Act. [NOAA News]
(Tues.) Coral reefs could be protected by an ocean "thermostat" -- Scientists at the National Center for Atmospheric Research (NCAR) and Australian Institute of Marine Science report that natural processes may be acting to serve as an ocean "thermostat", which would help regulate sea surface temperatures especially in regions of the western Pacific Ocean with a certain temperature range, thereby helping protect some coral reefs from major damage caused by global climate change. [UCAR/NCAR]
(Tues.) New glider taken for a test -- Researchers from the Woods Hole Oceanographic Institution and a local Massachusetts company recently completed the first test of their environmentally powered robotic vehicle or "glider" that uses heat energy extracted from the ocean for propulsion. [EurekAlert!]
(Tues.) Climate "tipping points" are identified -- An international team of scientists from the United Kingdom, the US and Germany has identified nine key components in the earth's climate system that could pass their "tipping points" or critical thresholds during this century that would have long-term climatic consequences, along with the estimated time that a major transition would occur. [EurekAlert!] The cited "tipping elements" or components in the climate system that could be affected by anthropogenic forcing include Arctic sea ice, ice sheets in Greenland and West Antarctica, the boreal forest, the Amazon rainforest, El Niño Southern Oscillation (ENSO), monsoonal regimes in India and Africa and the Atlantic thermohaline circulation. [EurekAlert!]
(Tues.) Antarctic expedition reveals climatic importance of the Southern Ocean -- An international team of scientists participating in an Antarctic scientific expedition onboard the Alfred Wegener Institute's research vessel Polarstern recently reported on their preliminary findings concerning the role that the Southern Ocean has upon the past, present and future climate, including how the large quantities of plankton in surface waters affect the global carbon cycle. [EurekAlert!]
Eye on the tropics -- As austral summer continues, tropical cyclones (low pressure systems originating in the tropics) remained active across the western South Pacific and South Indian Ocean basins:
- In the western South Pacific, Tropical Cyclone Gene finally dissipated near the midpoint of last week. This tropical cyclone became a major system, reaching category 3 status on the Saffir-Simpson Intensity Scale, causing damage and death in Fiji and Vanuatu. An image from the Japanese MTSAT satellite early last week shows the characteristic swirl of clouds surrounding Gene, along with the relatively clear central eye, a signature of many tropical cyclones. [NOAA OSEI] Shortly thereafter, an image generated from data collected by the scatterometer sensor on the QuikSCAT satellite shows the winds surrounding the Gene, forming a clockwise circulation around a Southern Hemisphere low pressure system with a traditional nearly calm eye. [NASA Earth Observatory]
- In the South Indian Ocean basin, the sixteenth tropical cyclone of the season for that basin developed as Tropical Cyclone Hondo early last week east of Diego Garcia. Hondo became a major Category-4 tropical cyclone on the Saffir-Simpson Intensity Scale. As of late Sunday, Hondo was traveling to the south-southeast across the Indian Ocean. An image made from the data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite shows the clouds circulating around Tropical Cyclone at about the time when this system reached category-4 status. [NASA Earth Observatory]
  Farther to the east, Tropical Cyclone 17S, also developed late last week, but remained relatively weak, reaching the intensity equivalent of a marginal tropical storm in the North Atlantic basin. It was beginning to dissipate as it moved eastward to the northwest of Australia over the weekend.
  The eighteenth tropical cyclone of the season, Tropical Cyclone Ivan, developed late last week over the waters of the South Indian Ocean west of Diego Garcia and reached category 1 status. It was moving to the southeast during the weekend. An image obtained from the METEOSAT satellite shows last week's three systems, Tropical Cyclones Hondo, Ivan and 17S. [NOAA OSEI]
Summer thaw begins in Antarctica -- Comparison between images obtained nearly one week apart in late January 2008 by the MODIS sensor on NASA's Terra satellite shows the melting of fast ice around the tip of the Antarctic Peninsula as summer is underway across the Southern Hemisphere. [NASA Earth Observatory]
Advisory council membership applications sought for a national marine sanctuary -- NOAA’s Thunder Bay National Marine Sanctuary in northern Lake Huron is seeking applications for its advisory council, which encourages public participation in sanctuary management along with providing advice to the sanctuary's superintendent. [NOAA News]
Winds could be a major player in large fluctuations in fisheries -- Using data collected for more than fifty years as part of the California Cooperative Oceanic Fisheries Investigations program, researchers at Scripps Institution of Oceanography claim that changes in the near-surface wind patterns over the eastern North Pacific due to changes in the climate appear to be a major contributing factor in the mid-20th century collapse of the sardine population in ocean waters off the California coast. [Scripps Institution of Oceanography]
International cooperation on mariculture program -- Researchers at Stevens Institute of Technology in New Jersey recently received a grant from the United States Agency for International Development (USAID) that is intended to enhance a collaborative effort with Egyptian and Israeli scientists in the development of a land-based integrated mariculture system in Egypt and Israel for a variety of marine products involving the recycling of fish stock excretions. [EurekAlert!]
Another NOAA Weather Radio transmitter hits the airwaves -- A new NOAA Weather Radio-All Hazards transmitter was recently installed at Mt. Baldy near Salmon, ID that insures increased access to current weather information and forecasts across southeast central Idaho from the National Weather Service Forecast Office in Missoula, MT. Currently, over 850 NOAA Weather Radio transmitters are in operation across the US, its territories, possessions and adjacent coastal waters. [NOAA News]
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: Variations in Marine Sediment Thickness

Sediments are particles of organic or inorganic origin that accumulate in loose form in depositional environments such as lake or ocean bottoms. Marine sediments, the central focus of this week's investigations, have a variety of sources and exhibit a wide range of composition, size, and shape. Marine sediments settle to the ocean floor as unconsolidated accumulations but ultimately may be converted to solid sedimentary rock via compaction and cementation. The pattern of variations in marine sediment thickness on the ocean floor confirms some basic understandings regarding marine geological processes.

Go to the DataStreme Ocean Website and under "Geological," click on "Sediment Thickness." This map of marine sediment thickness in the ocean basins was compiled by the National Geophysical Data Center (NGDC), Marine Geology and Geophysics Division primarily based on existing maps, ocean drilling, and seismic reflection profiles. Sediment thickness is color-coded in meters from violet (thinnest) to red (thickest). Many factors account for the variation in the thickness of marine sediment deposits including type and location of sediment sources, sediment transport mechanisms, and the age of the underlying crust.

According to the map, sediment thickness generally increases with distance from near the central portion of an ocean basin to the continental margin. This pattern may be explained by the principal sediment source and/or the age of the underlying crust. Rivers and streams that empty into the ocean slow and diverge, releasing the bulk of their suspended sediment load in coastal environments (e.g., bays, estuaries, deltas) and onto the continental shelf. Ocean currents transport sediment along the coast. In some areas of the continental shelf, massive amounts of sediment accumulate, become unstable, and flow down the continental slope to the base of the continental rise and beyond. However, only the finer fraction of river-borne sediment is swept into the deep ocean waters. Thickening of marine sediments in the direction of the continental margin may also reflect the aging of oceanic crust with distance away from divergent (spreading) plate boundaries where new oceanic crust forms. The older the crust the longer is the period that sediment rains down on the ocean bottom and the thicker is the blanket of accumulated sediment.

The map indicates that the thickness of marine sediment deposits is greater in the continental margin along the Atlantic coast of North America than along the Pacific coast. The Atlantic coast of North America is a passive margin; that is, the continental margin is not affected significantly by tectonic processes (no plate boundary) and the principal geological processes consist of sedimentation along with erosion by ocean waves and currents. In fact, passive margins and relatively thick marine sediment deposits occur on both sides of the Atlantic. (Passive margins also occur around the Arctic Ocean and surrounding Antarctica.) On the other hand, the Pacific coast of North America is an active margin; that is, the continental margin is associated with plate boundaries and is subject to deformation by tectonic stresses. Active continental margins are relatively narrow so that sediment delivered to the coast by rivers and streams flows directly into deeper water or trenches—preventing thick accumulations of marine sediments from building in the continental margin.

Concept of the Week: Questions

The thickness of marine sediment deposits is greater in the [(continental margins)(deep-ocean basins)].
The thickness of marine sediment deposits generally is greater in [(active)(passive)]continental margins.

Historical Events

11 February 1809...The American inventor, Robert Fulton patented his steamboat, the Clermont, for the first time, although he had made the first successful steamboat trip up the Hudson River from New York City to Albany, NY in 1807. (Wikipedia) (Today in Science)
11 February 1862...The Secretary of the Navy directed the formation of an organization to evaluate new inventions and technical development, which eventually led to the National Academy of Science. (Naval Historical Center)
11 February 1971...The US and the USSR, along with other nations, signed the multilateral Seabed Treaty outlawing the emplacement of nuclear weapons (or "weapons of mass destruction") on the ocean floor in international waters, or beyond a 12-mile coastal zone. (Wikipedia)
12 February 1907...A collision of the steamer Larchmont and a large schooner, the Harris Knowlton, during a blizzard resulted in the deaths of 332 people. Only nine survivors were rescued. The incident occurred off Rhode Island's Block Island and was the worst disaster in New England maritime history. (RMS Titanic History)
12 February 1997...A combination of heavy surf and high winds contributed to the overturning of a U.S. Coast Guard motor life boat (MLB 44363) on a search and rescue mission when responding to a distress call from the sailing vessel Gale Runner in the stormy North Pacific Ocean off Washington State's Quillayute River Bar. Three of four crewmembers lost their lives in the first fatal sinking of this type of ship in its 35-year history. (Accord's Weather Guide Calendar) (USCG Historian's Office)
13 February 1784...Ice floes blocked the Mississippi River at New Orleans, then passed into the Gulf of Mexico. The only other time this occurred was during the "Great Arctic Outbreak" of 1899. (David Ludlum)
13 February 1969...The National Transportation Safety Board issued its "Study of Recreational Boat Accidents, Boating Safety Programs, and Preventive Recommendations". (USCG Historian's Office)
13 February 1997...Ocean swells generated by a storm well to the northwest of the Hawaiian Islands generated surf with heights to 20 feet and some sets to 25 feet along the northern shores of the islands. A professional surfer was killed by 25-foot surf at Alligator Rock on Oahu's North Shore. Lifeguards aided more than thirty people. (Accord's Weather Guide Calendar)
14 February 1779...The famous British scientific navigator, Captain James Cook, Royal Navy, was killed by natives of the Sandwich Islands on the Kona coast of what is now the state of Hawaii's Big Island. His geographic discoveries and three scientific expeditions of the Pacific made him the most famous navigator since Magellan. (Wikipedia) (Today in Science History)
14 February 1840...Officers from the USS Vincennes made the first landing in Antarctica on floating ice. (Naval Historical Center)
14 February 1903...An Act of Congress (31 Stat. L., 826, 827) that created the Department of Commerce and Labor provided for the transfer of the Lighthouse Service from the Treasury Department. This allowed the Secretary of Commerce and Labor to succeed to the authority vested in the Secretary of the Treasury under the existing legislation. (USCG Historian's Office)
14 February 1912...The first diesel-powered submarine was commissioned in Groton, CT. (Wikipedia)
14 February 1954...A waterspout was observed two miles east of Baranof, AK, an unusual occurrence for Alaska, particularly in winter. Just prior to the formation of the waterspout, a "terrific wind from the south out of a bay inside Warm Springs Bay" lifted water 20 feet and looked "as if it were boiling". (Accord's Weather Guide Calendar)
15 February 1912...Fram reached latitude 78º 41' S, farthest south ever by ship. Therefore, the "Fram" became the first ship to have sailed the farthest north and the farthest south.
15 February 1954...An ocean exploration depth record of 13,287 feet (over 2,000 fathoms, or over 2-1/2 miles) was attained when Georges Houot and Pierre Willm reached the Atlantic Ocean floor off Dakar, Senegal. (Today in Science History)
15 February 1982...An intense cyclone (low pressure system) off the Atlantic coast of Newfoundland capsized the Ocean Ranger, a drilling rig, killing 84 persons, and sank a Soviet freighter resulting in 33 more deaths. The cyclone produced 80-mph winds that whipped the water into waves fifty feet high. (David Ludlum)
15 February 1998...A "rogue" wave from the Pacific Ocean swept into the harbor at Port Arena, CA. This wave continued through a harbor parking lot, depositing sand, debris and logs, as well as moving thirty parked vehicles. No injuries were sustained. (Accord's Weather Guide Calendar)
16 February 1832...The HMS Beagle with Charles Darwin onboard reached St-Pauls (1ºN, 29ºW).
16 February 1993...The Haitian passenger ferry Neptune sank, sending 1,215 Haitians to their deaths. Coast Guard units participated in the search and rescue operation but found no survivors. They then assisted in recovering the bodies of the victims. (USCG Historian's Office)
17 February 1836...The HMS Beagle and Charles Darwin left Tasmania.
17 February 1867...The first ship passed through the Suez Canal. (Wikipedia)