DATASTREME OCEAN WEEK FOUR: 14-18 February 2011

Ocean in the News

• Eye on the tropics ---
During the last week:
• In South Indian Ocean Tropical Cyclone Bingiza formed at end of last week east of Madagascar. This system traveled southward at the start of the weekend before turning west toward Madagascar by late Saturday. At this time, Bingiza intensified rapidly to a category 3 tropical cyclone on the Saffir-Simpson Scale and could still reach Madagascar. For more information on Cyclone Bingiza, together with satellite images, consult the NASA Hurricane Page.
  Tropical Storm 14S formed over the waters of the eastern South Indian Ocean approximately west of 600 miles of Learmonth, Australia at the end of last week. However, this tropical storm was relatively short-lived. The NASA Hurricane Page has additional information on Tropical Storm 14 S.
• In South Pacific basin, Tropical Cyclone Zaka formed at the beginning of last week near Raoul (or Sunday) Island in the Kermadec Islands northeast of New Zealand. This tropical storm moved to the south-southwest toward New Zealand's North Island, but dissipated rapidly. For additional information on this system, see the NASA Hurricane Page.
• New marine renewable energy website is launched --
NOAA's Office of Ocean and Coastal Resource Management recently unveiled a new website that is designed to provide legal and licensing information to a wide group of parties who are interested in developing Ocean Thermal Energy Conversion (OTEC) capability in the United States. [NOAA News]
• Major increase in US quota for yellowtail flounder requested --
Based upon legislation recently signed by President Obama, NOAA officials are proceeding with negotiations with their Canadian counterparts designed to increase the Georges Bank yellowtail flounder quota for US commercial fishing interests in 2011. [NOAA News]
• Public comment invited on national aquaculture policies --
Last week, the US Department of Commerce and NOAA released two drafts of national aquaculture policies for public comment within the next 60 days. These policies support sustainable marine aquaculture designed to increase the US supply of healthy seafood, create jobs in coastal and other communities, spur innovation in technology, and help restore depleted species and marine habitats. [NOAA News]
• Historic US Coast Survey map that helped Lincoln's Civil War strategy is highlighted --
As part of the observance of the 150th anniversary of the American Civil War, NOAA's Central Library has added another map to its special collection of Civil War maps and charts called "Charting a More Perfect Union" that is available for public display. This map, entitled "Map showing the distribution of the slave population of the southern states and the United States," was created in September 1861 by the US Coast Survey, NOAA's predecessor, and may have been used by President Abraham Lincoln to coordinate military operations with his emancipation policies. [NOAA News]
• NOAA administrator makes remarks on scientific integrity --
Dr. Jane Lubchenco, under secretary of commerce for oceans and atmosphere and NOAA administrator delivered an address early last week on scientific integrity and the NOAA Code of Scientific Conduct to a meeting of the Union of Concerned Scientists. [NOAA News]
• Gulf restoration keynote address made by NOAA administrator --
Last week, Dr. Jane Lubchenco, under secretary of commerce for oceans and atmosphere and NOAA administrator, delivered the keynote address at the Center for American Progress, Washington, DC entitled "Beyond Recovery: Moving the Gulf Toward a Sustainable Future." [NOAA News]
• Moby Dick era whaling shipwreck discovered --
Maritime heritage archaeologists associated with NOAA's Office of National Marine Sanctuaries recently announced that they found the wreckage of the nineteenth century Nantucket whale ship, Two Brothers, on a reef off French Frigate Shoals in the remote Papahanaumokuakea Marine National Monument. This lost whaling shipwreck, located in North Pacific Ocean waters approximately nearly 600 miles northwest of Honolulu, is of the same era as the whale ship that inspired Herman Melville to write his famous book Moby-Dick. [NOAA News]
• Record low January Arctic sea ice extent seen from space --
An image obtained from data collected by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on NASA’s Aqua satellite shows the extent of sea ice across the Arctic Ocean during January. According to the U.S. National Snow and Ice Data Center, the Arctic sea ice was at its lowest extent ever recorded for January since 1979 when satellite records began. [NASA Earth Observatory]
• New Great Lakes basin water availability assessment made --
The US Geological Survey recently released a new basin-wide water availability assessment for the Great Lakes Basin that indicated that while water is regionally abundant across the basin, local water shortages may occur. [USGS Newsroom]
• Oregon State's fleet of offshore gliders to expand --
Oceanographers at Oregon State University are ready to expand their fleet of autonomous underwater vehicles to 21 within the next year because of funding from the National Science Foundation's Ocean Observatories Initiative. These gliders will be used as part of the university's ocean research program that will address issues ranging from climate change to "dead zones" and hypoxia. [Oregon State University]
• Weaker trade winds seen across tropical Atlantic --
Researchers at the University of Hawaii at Manoa have found that the prevailing trade winds across the tropical Atlantic basin have weakened, based upon their analysis of wind-wave height data collected by ship crews in an effort to correct what they claimed was 60 years of biased raw wind data over the oceans caused by a change in the placement of ship anemometers. The weakening of the near surface trade winds have changed the temperature and rainfall patterns over the tropical ocean basins. [University of Hawaii at Manoa]
• Tracking behavior of leatherback turtles in South Pacific --
A team of scientists led by a Stanford University marine biologist has conducted a five-year study involving the tagging and the tracking of endangered leatherback turtles as the travel into the South Pacific Ocean in an attempt to understand and predict the turtles' movements in the ever-changing environment of the open ocean, with the goal of reducing the impact of fishing on the turtle population. [Stanford University News]
• Decline in polar bear litter sizes may be linked to loss of sea ice --
Using data that was collected beginning in the 1990s, University of Alberta researchers claim to have linked the reproductive ecology of polar bears in Hudson Bay with declining litter sizes and loss of sea ice. [University of Alberta Express News]
• Analyzing seafloor biomass patterns --
Researchers from the United Kingdom's National Oceanography Centre and Texas A&M University have created maps of the global seafloor invertebrate biomass from data collected from the Census of Marine Life. They have used these maps to study the role that deep-sea ecosystems have upon the global carbon cycle. [National Oceanography Centre]
• Endangered North Atlantic right whales found by hydrophones --
Employing undersea hydrophones as listening devices, scientists from Oregon State University have documented the presence of endangered North Atlantic right whales in a region east of Greenland, where they were thought to be extinct after years of being hunted. [Oregon State University]
• Field campaign starts to study West Coast winter storms and "atmospheric rivers" --
NOAA and NASA scientists are participating in the Winter Storms and Pacific Atmospheric Rivers (WISPAR) field campaign that began last Friday to improve understanding of how atmospheric rivers form and behave, especially in the transport of large amounts of water vapor across the North Pacific and into western North America. They have been using one of NASA's instrumented Global Hawk aircraft to collect data and to evaluate the study operational use of unmanned aircraft for investigating these rivers of humid air. [NOAA News] [NASA JPL]
• 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

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

Historical Events

• 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 (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)
• 18 February 1828...More than 100 vessels were destroyed in a storm at Gibraltar.
• 18 February 1846...A General Order was issued by the Secretary of the US Department of Navy "on Port and Starboard," in which the term "port" replaced "larboard." (Naval Historical Center)
• 19 February 1473...Nicolaus Copernicus, the father of modern astronomy, was born in Torun in north central Poland. He was the first modern European scientist to propose that the Earth and other planets revolve around the Sun. (The History Channel)
• 19 February 1845...The Lighthouse Establishment was transferred to the Revenue Marine Bureau. Metal buoys were first put into service. They were riveted iron barrels that replaced the older wooden stave construction. (USCG Historian's Office)
• 19 February 1972...A vicious coastal storm dumped 10 to 20 inches of snow over interior sections of the mid-Atlantic and Northeast states and caused some of the worst coastal damage of the century in New England. Storm surges up to 4.5 ft and winds gusting over 80 mph along coastal Rhode Island, Massachusetts, New Hampshire, and Maine resulted in extensive property damage and tremendous beach erosion. Twenty-seven houses were destroyed and 3000 damaged in Massachusetts alone. (Intellicast)
• 19 February 1977...Using the research submersible Alvin, deep-ocean researchers John B. Corliss and John M. Elmond found an extraordinary oasis of life on the Pacific Ocean floor off the Galapagos Islands, including new types of worms, clams and crabs around geothermal hot water vents. These organisms appeared to depend upon bacteria oxidizing hydrogen sulfide contained in the volcanic gases spewing out of the hot springs. (Today in Science History)
• 20 February 1823...English Captain James Weddell and the brig Jane reached 74º 15' S, or 940 mi (1520 km) from the South Pole. His voyage reached farther south than anyone had ventured until the 1850s, as it was 214 mi south of the latitude that Captain James Cook had sailed.
• 20 February 1835...While in Chile, Charles Darwin experienced a strong earthquake and shortly thereafter saw evidence of uplift in the region. From measurements, he determined that the land rose several feet, and later hypothesized that coral reefs in the Pacific could develop along margins of subsiding landmasses. (Today in Science History)
• 20 February 1856...The John Rutledge, an American steamer that sailed from Liverpool, England for New York, hit an iceberg in the North Atlantic. Most of the 155 people onboard were lost.

Return to DataStreme Ocean Website

Prepared by DS Ocean Central Staff and Edward J. Hopkins, Ph.D.,
email hopkins@meteor.wisc.edu
© Copyright, 2011, The American Meteorological Society.