Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK FOUR: 11-15 February 2013

For Your Information

New director for NOAA's National Weather Service selected -- Late last week, Dr. Louis W. Uccellini, the current director of the National Weather Service's National Centers for Environmental Prediction (NCEP), was selected as the new director of NOAA's National Weather Service. In addition, he will be the assistant NOAA administrator for weather services, effective this past weekend. As NCEP director he was responsible for the overall planning and operation of such centers as the National Hurricane Center, the Ocean Prediction Center and the Climate Prediction Center. [NOAA News] (Editor's Note: Dr. Uccellini has long been a supporter of the AMS Education Program. In addition, while at the University of Wisconsin-Madison, he was an instructor to this reporter. Congratulations and many thanks! EJH )
Reconstructing past oceanic conditions from marine sediment cores -- If you would like information on how scientists can reconstruct past environmental conditions in the oceans from the analysis of the physical, chemical and geological data in deep-sea sediment cores, please read this week's Supplemental Information...In Greater Depth.

Ocean in the News

Eye on the tropics --- The weather across the tropical ocean basins of the Southern Hemisphere was relatively quiet last week as austral summer continued. At the start of the week, Tropical Cyclone Felleng, which had briefly been a strong category 4 cyclone on the Saffir-Simpson Scale the previous week, dissipated over the South Indian Ocean to the southeast of Madagascar. Consult the NASA Hurricane Page for additional information and satellite imagery on Cyclone Felleng.
In the western South Pacific, Tropical Storm Haley formed on this past Sunday approximately 500 miles to the south of Bora Bora in the Society Islands of French Polynesia. This tropical storm was traveling toward the east-southeast and could dissipate by early this week.
Florida Keys marine reserve yield more and larger fish -- A research report recently released by NOAA indicates that the "no-take" protections issued for the Tortugas Ecological Reserve in NOAA's Florida Keys National Marine Sanctuary has been beneficial as populations of commercially important fish species such as red grouper have increased in this reserve. The reports also found that commercial and recreational fishery interests in the Florida Keys also have benefited. [NOAA News]
Exploring the PORTS® program -- A podcast produced by NOAA's National Ocean Service explores Physical Oceanographic Real-Time System (PORTS®), a responsible for providing real-time oceanographic data and other navigation products to mariners in an effort to promote safe and efficient navigation within US waters. [NOAA National Ocean Service]
A "La Nada" phase appears to persist across the Pacific -- Scientists with the Ocean Surface Topography Team at NASA's Jet Propulsion Laboratory report that images of sea surface heights across the Pacific generated from data collected by NASA's Jason-2 satellite indicate the equatorial Pacific remains locked in a neutral state for the tenth consecutive month. They term this neutral phase as a "La Nada" state, as opposed to the cold phase La Niña events of recent years and the warm phase El Niño events. A neutral state tends to make long-range climate forecasting more difficult due to their greater unpredictably. This La Nada phase could persist for a while. [NASA JPL] Forecasters with NOAA's Climate Prediction Center also indicate that ENSO-neutral conditions continue and should persist through Northern Hemisphere spring. (ENSO represents El Niño/Southern Oscillation). [NOAA Climate Prediction Center]
New way found to identify which El Niño events have largest impact on nation's winter weather -- Research conducted by scientists at the NOAA Pacific Marine Environmental Laboratory and the University of Washington has created a new way to identify which El Niño events would have biggest impact on US winter weather that would involve the monitoring changes in outgoing long-wave radiation (OLR). They considered all El Niño events identified by sea surface temperatures since 1979 and found those events that also showed a marked dip in OLR from deep convective clouds as found from satellite imagery appeared more likely to play havoc with winter weather across the country. Those events with a smaller OLR dip did not. [NOAA News]
Two of Great Lakes at record low water levels -- The "Detroit News" recently reported that at the end of January, the US Army Corps of Engineers claimed that Lakes Huron and Michigan had reached all-time low lake levels, breaking the previous record set in 1964. While the drought across the nation's midsection played a role in the record low levels, higher lake evaporation rates and a lack of winter ice have also contributed to these historic levels. [Detroit News]
Salmon may use Earth's magnetic field as navigational aid -- Researchers at Oregon State University and their colleagues have found that migrating sockeye salmon appear to use changes in the intensity of the Earth's geomagnetic field to successfully locate the river of where they were born for spawning after swimming as much as 4000 miles out into the open ocean. The researchers base their conclusions on 56 years of fisheries data on the return of salmon to the Fraser River in British Columbia. [Oregon State University]
Growth of toxic algae linked to nitrogen from pollution and natural sources -- Researchers from San Francisco State University report that nitrogen entering the oceans from natural sources and human activity has increased the growth of a group of tiny, toxic phytoplankton species known to be harmful to marine life and human health. One of the species can cause the human illness Amnesic Shellfish Poisoning. [San Francisco State University News]
Studying the world's saltiest pond -- Using time lapse photography and other data, geologists from Brown University have discovered how Don Juan Pond in Antarctica's McMurdo Dry Valleys has become the most saline natural body of water known on Earth. They report that salty soil and the saline water not only absorbs water vapor from the atmosphere due to hygroscopic attraction but also melts snow causing an influx of fresh water to maintain the pond. The high salinity keeps this water body from freezing. The researchers claim that this process may have similarities with water flow on Mars. [Brown University]
Tropical rainfall patterns in Central America have varied over last two millennia -- Researchers from the University of Pittsburgh have found that the climate patterns they reconstructed from lake sediments in a Nicaraguan lake indicate drought cycles across Central America interrupted by wet spells over the last 2000 years, which included the Little Ice Age and the Medieval Climate Anomaly. They found that over this time the Atlantic and Pacific Oceans have had fluctuating influences on the rainfall. The researchers found that the North Atlantic Oscillation has had an impact on rainfall during recent times, but the El Niño/La Niña Southern Oscillation pattern appeared to be important. [University of Pittsburgh News]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, drought, floods, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
Global and US Hazards/Climate Extremes -- A review and analysis of the global impacts of various weather-related events, to include 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 crew members 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)
16 February 1832...The HMS Beagle with Charles Darwin onboard reached St-Pauls (1 degrees N, 29 degrees W).
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)