Weekly Ocean News

Weekly Ocean News

WEEK FOUR: 20-24 February 2017

For Your Information

Worldwide GLOBE at Night 2017 Campaign is underway -- The second in the series of GLOBE at Night citizen-science campaigns for 2017 will continue through Monday, 27 February. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of a constellation (Orion in both the Northern and Southern Hemispheres) with the seven magnitude/star charts of progressively fainter stars. Activity guides are also available. The GLOBE at night program is intended to raise public awareness of the impact of light pollution. The next series in the 2017 campaign is scheduled for 20-29 March 2017. [GLOBE at Night]
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 --- Organized tropical cyclone (a low pressure system such as a tropical storm or hurricane that forms over tropical oceans) activity during the last week was limited to Tropical Cyclone Dineo that formed over the waters of the South Indian basin. Cyclone Dineo, which intensified to what would be a category 1 hurricane on the Saffir-Simpson scale, developed last Monday in the Mozambique Channel, between Mozambique and Madagascar. During the next several days, Dineo strengthened as it slowly traveled toward the west-southwest. By Wednesday Dineo had strengthened to a category 1 tropical cyclone as maximum sustained surface winds reached 80 mph, as the central eye of this system was just off the coast of Mozambique. As Cyclone Dineo made landfall along the African coast, it weakened and became disorganized as it became a remnant low. Consult the NASA Hurricane Page for satellite images and additional information on Cyclone Dineo.
Follow the underwater exploration of deep water regions around Samoa live and online -- The public is invited to follow live and online scientists onboard the NOAA Ship Okeanos Explorer who will be exploring the deepwater areas of the western Pacific Ocean surrounding American Samoa and Samoa during the next two weeks, running through 2 March as part of the 2017 American Samoa Expedition: Suesuega o le Moana o Amerika Samoa. NOAA's Deep Discoverer Remotely Operated Vehicle (ROV) will make descents to depths of 6000 meters and return live video from the camera mounted on this submersible. The primary emphasis will be in the Rose Atoll Marine National Monument, National Marine Sanctuary of American Samoa, and National Park of American Samoa. [NOAA Media Release] or [NOAA National Marine Sanctuaries News]
Meeting of US Coral Reef Task Force to be held this week -- The US Coral Reef Task Force is scheduled to hold its 37th biannual meeting in Washington, DC this Tuesday through Thursday (21-23 February), with public sessions on Thursday. The US Coral Reef Task Force includes leaders of 12 Federal agencies, seven US States, Territories, Commonwealths, and three Freely Associated States to lead national efforts to preserve and protect coral reef ecosystems. This week's meeting, to be co-chaired by NOAA in the Department of Commerce and the Department of the Interior, is intended to emphasize the importance of coral reef conservation and highlight conservation strategies and successes. An enhanced vision will promote how the task force can meet the challenges facing coral reefs, and the communities and economies that depend on them. [NOAA News]
Coastal managers along Gulf of Mexico receive sea level rise tools -- During this past January staff from NOAA's Centers for Coastal Ocean Science and their partner organizations (Louisiana State University, the University of South Carolina, and the Gulf of Mexico Sentinel Site Cooperative) held a workshop in Alabama that demonstrated and transferred sea level rise tools and data to regional coastal managers. More than 40 representatives from federal, state and local agencies along with non-governmental organizations participated in the training sessions, receiving hands-on training focusing on how future changes in storm surge flooding could affect coastal wetlands. [NOAA Centers for Coastal Ocean Science News]
Severe erosion documented along West Coast during 2015-16 El Niño -- In a study released during this past week, US Geological Survey (USGS) scientists and their colleagues investigated 29 beaches along the US West Coast running from Washington state south to southern California for winter beach erosion during the 2015-16 winter, which featured one of the most powerful El Niño events in more than a century. The scientists surveyed the beaches, making 3-D surface maps and cross-shore profiles using aerial lidar (light detection and ranging), GPS topographic surveys, and direct measurements of sand levels, combined with wave and water level data at each beach, collectively spanning 1997-2016. Of the 29 beaches surveyed, the researchers found that winter beach erosion was 76 percent above normal, by far the highest ever recorded, and most beaches in California eroded beyond historical extremes. If severe El Niño events were to become more common in the future, this coastal region will become increasingly vulnerable to coastal hazards, independently of projected sea level rise. [USGS News]
International effort aims to map world's oceans by 2030 -- A global, non-profit mapping effort, known as GEBCO—the General Bathymetric Chart of the Oceans, is currently underway that will map the ocean floor by 2030. Currently, more than 85 percent of the ocean floor remains unmapped. A volunteer collaboration of scientists and institutions around the world is producing data sets and data products about the sea floor, including gridded bathymetric data sets, a world map and Gazetteer of Undersea Feature Names. This mapping effort is expected to affect many earth systems topics ranging from climate research and weather prediction to mineral resource exploration and fisheries. A seven-minute video is available that contains interviews with researchers talking about the importance of creating a global seafloor bathymetric map while attending the Forum for Future Ocean Floor Mapping in Monaco in June 2016. [Lamont-Doherty Earth Observatory News]
Data collected from under large Greenland glacier by ocean sensors -- Five ocean sensors deployed under the Petermann Glacier in North Greenland by an oceanographer from the University of Delaware and colleagues from the British Antarctic Survey and Oregon State University in 2015 have provided these researchers with underwater temperature, salinity and tidal motion data to as deep as 2300 feet below the glacier. These ocean sensors are connected to a surface weather station on the glacier. The Petermann Glacier, the second largest floating ice shelf in the Northern Hemisphere, connects the Greenland ice sheet with the Arctic Ocean. The researchers found that the floating ice shelf is tied to the ocean below the ice shelf and to Nares Strait. [University of Delaware News]
Extreme ocean waves caught by high-resolution modeling -- Scientists at the US Department of Energy's Lawrence Berkeley National Laboratory recently reported on their development of higher resolution ocean wave models with 25-km resolution that better capture the high ocean waves associated with strong tropical cyclones such as tropical storms and hurricanes. These new models may allow forecasters to better estimate wind-generated wave action from these tropical cyclones and how the extreme waves upon coastal communities, shipping and offshore oil platforms. [Lawrence Berkeley National Laboratory News]
"The Blob" of warm water in North Pacific appears to have boosted ozone levels in US West -- According to research conducted by scientists from the University of Washington Bothell, "The Blob", a nickname given by the Washington state climatologist to a large patch of abnormally warm sea water that lingered off the North American West Coast from late 2013 into 2016 appears to be responsible for creating an atmospheric flow pattern conducive to elevated levels of low-level ozone concentrations along the Western States. The researchers took air samples from the peak of Oregon's Mount Bachelor and found that a strong offshore atmospheric flow pattern developed across the US West because of the presence of "The Blob" reduced air quality due to increased ozone levels above Washington, Oregon, northern California and western Utah. [University of Washington News]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA's National Weather Service, FAA and FEMA on current environmental events that may pose as hazards such as tropical weather, fire weather, marine weather, severe weather, drought and floods. [NOAA/NWS Daily Briefing]
Earthweek -- Diary of the Planet [earthweek.com]

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

(Place your responses on the Chapter Progress Response Form provided in the Study Guide.)

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

20 February 1823...English Captain James Weddell and the brig Jane reached 74 deg 15 min 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.
21 February 1835...The HMS Beagle, along with Charles Darwin left Valdivia, Chile.
21 February 1907...During an exceptionally heavy gale, the British-owned mail ship Berlin hit dangerous shoals and broke up while attempting to navigate around the Hook of Holland in the English Channel. Only 14 on board survived, while 127 were killed or drowned.
22 February 1773...Extreme cold swept down the length of the Eastern Seaboard. A ship off the coast of Saint Augustine, FL reported a snowstorm severe enough to cause the loss of the ship and most of her crew. (National Weather Service files)
22 February 1901...A mail steamboat struck a rock and broke apart while attempting to enter the Golden Gate near San Francisco, CA during heavy fog, drowning 128 people. (National Weather Service files)
22-26 February 1995...Cyclone Bobby slammed into the Western Australia coast causing widespread flooding. Some areas reported up to 12 in. of rain from the storm. (The Weather Doctor)
23 February 1802...A great snowstorm raged along the New England coast producing 48 inches of snow north of Boston and 54 inches of snow at Epping, NH. Three large (indiamen) ships from Salem were wrecked along Cape Cod by strong winds. (David Ludlum) (Intellicast)
23-24 February 1995...Cyclone Bobby slammed into the Western Australia coast causing widespread flooding. Some areas reported as much as 12 inches of rain from the storm. On the 24th
Tropical Cyclone Bobby had 1-min sustained winds of 148 mph and a pressure of 930 millibars. (National Weather Service files)
24 February 1881...De Lesseps' Company began work on the Panama Canal
25 February 1977...An oil tanker explosion west of Honolulu spilled 31 million gallons of oil into the Pacific Ocean.
26 February 1935...Robert Watson-Watt demonstrated RADAR (Radio Detection and Ranging) for the first time, using the BBC shortwave radio transmitter to successfully detect the distance and direction of a flying bomber during the so-called Daventry Experiment.
26 February 1938...The first passenger ship was equipped with radar.