Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK FOUR: 13-17 February 2012

Ocean in the News

Eye on the tropics --- During the last week several tropical cyclones were found across the South Pacific and South Indian basins:
- In the South Pacific basin, Cyclone Jasmine became a major category 4 cyclone on the Saffir-Simpson Scale by late in the week with maximum sustained surface winds to over 130 mph as it moved toward the east-southeast near New Caledonia. This intense cyclone was expected to weaken and dissipate over open waters to the southwest of Tonga late by the start of this week. For additional information and satellite imagery on Cyclone Jasmine, consult the NASA Hurricane Page. Another tropical cyclone, identified as Tropical Storm Cyril moved across the waters of the South Pacific near Tongatapu, the main island of Tonga. However, this system weakened as it traveled to the southeast and dissipated before the midpoint of last week. See the NASA Hurricane Page for satellite images and additional information on this tropical storm.
- In the South Indian basin, Cyclone Giovanna developed late in the week south of Diego Garcia. Traveling to the southwest toward Madagascar, Giovanna intensified into a major category 4 cyclone on the Saffir-Simpson Scale by early Saturday as maximum sustained surface winds reached 140 mph. By late in the weekend, this major cyclone had weakened only slightly as it was projected to approach Madagascar, bringing strong winds and heavy rain. The NASA Hurricane Page has additional information on Cyclone Giovanna.
Winter flounder catch limits in Gulf of Maine are increased -- NOAA's Fisheries Service announced last week that the agency was increasing to 1.1 million pounds the limits on the amount of Gulf of Maine winter flounder that commercial fishing vessels can catch for the current fishing season, which runs through the end of April. This doubling of the previous limits was based upon new scientific information indicating that overfishing is no longer occurring on this fish stock. [NOAA News]
Arctic oil spill response mapping tool to be completed -- NOAA and the Bureau of Safety and Environmental Enforcement (BSEE) recently announced a partnership designed to enhance an interactive online mapping tool called Environmental Response Management Application (ERMA®) for the Arctic region that would be available by summer 2012. This tool would help responders at federal through local levels, the media and the public prepare for and respond to possible oil spills in the Arctic basin. This new version for the Arctic is based on the version of ERMA® initially used by federal responders in the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. [NOAA News]
La Niña advisory continues -- Scientists with the NOAA's Climate Prediction Center recently noted that below average sea surface temperatures continued across the equatorial Pacific Ocean east of the International Dateline through January 2012, which indicated the continued presence of a mature La Niña event, or an anomalous atmospheric and ocean circulation regime characterized in part by relatively cold waters in the waters of the eastern Pacific along the Equator to the west of the South American coast. This event affects the atmospheric and oceanic elsewhere around the planet. These forecasters continued their La Niña advisory as the foresee that this weak-to-moderate La Niña event would persist for the next month before weakening to El Niño/Southern Oscillation (ENSO)-neutral conditions during the three-months running from March through May 2012. [NOAA's Climate Prediction Center]
Instrumentation onboard new environmental satellite close to being commissioned -- The team of scientists and engineers from NASA and NOAA are continuing to checking and commissioning the set of five instruments on the nation's newest polar-orbiting satellite, the Suomi National Polar-orbiting Partnership (NPP) satellite designed to monitor atmospheric conditions. One of these instruments that has been sending data back to Earth is the Cross-track Infrared Sounder (CrIS) that will produce high resolution, three-dimensional temperature, atmospheric pressure, and moisture profiles to be used in NOAA's weather prediction computer models and climate models designed to monitor El Niño and La Niña conditions. Commissioning of all instruments should be completed by late March, when NOAA assumes operational control of this satellite. [NOAA News]
Decline of wild salmon populations masked by hatchery fish counts -- Scientists from the University of California-Santa Cruz, the US Fish and Wildlife Service, Lawrence Livermore National Laboratory, NOAA's National Marine Fisheries Service and UCLA report that only 10 percent of the fall-run of Chinook salmon spawning in a California river were naturally produced wild salmon, which indicates that the numbers of hatchery-raised fish mask the decline in wild fish returning to sustain a natural population in the river. [University of California, Santa Cruz]
"Google Earth" used to verify Mediterranean aquaculture data -- Researchers at the University of British Columbia's Fisheries Centre have been using satellite images from Google Earth, the popular virtual globe, mapping and geographical information program to estimate the amount of fish cultivated by fish farms in the Mediterranean basin. The researchers claim that their technique can be used to verify aquaculture data supplied by governments and other large institutions. [University of British Columbia]
Despite low solar activity, imbalance in Earth's energy budget remains -- A science team led by the director of NASA's Goddard Institute for Space Studies, James Hansen, recently reported that their updated calculations of the planetary energy budget show that more energy was absorbed by the Earth surface than the amount of energy returned to space between 2005 and 2010, a time of unusually low solar activity when the amount of incident solar radiation on the planet declined slightly. The researchers claim that this energy imbalance was due to greenhouse gases generated by human activity serving as the primary force driving increased global temperatures rather than changes in solar activity. An improvement in calculations of the Earth's energy budget came from satellites as well as from the fleet of Argo floats that have been deployed in the global ocean basins to measure ocean temperatures downward several thousand meters from the surface. [NASA Goddard Institute for Space Studies]
New Japanese satellite radar instrument shipped to US -- A new Dual-frequency Precipitation Radar (DPR) instrument designed and built by the Japan Aerospace Exploration Agency (JAXA) and Japan's National Institute of Information and Communications Technology has been shipped to NASA's Goddard Space Flight Center. This instrument, to be placed on the NASA's Core Observatory for the Global Precipitation Measurement (GPM) mission satellite, is designed to make three-dimensional measurements of the shapes, sizes and other physical characteristics of both raindrops and snowflakes. The instrument, along with a companion instrument should open a new generation of space-based observations of global precipitation, a key element of the Earth's climate. This satellite is scheduled to be launched in 2014. [NASA Global Precipitation Measurement Mission]
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.

REPORT FROM THE FIELD -- Jeff Chapman, a member of the DataStreme Oceans LIT from southern Minnesota-western Wisconsin, reported on a recent annual vacation that his family made to southwestern Florida. He forwarded a link at http://dolphinexplorerchronicles.typepad.com/ that documents the behavior of dolphins in the Gulf of Mexico waters around the 10,000 islands off the southwestern Florida coast. He noted that in 2007, his son Jayson initially spotted and named one of the dolphins "Jayson." In their return trip in 2011, they found that "Jayson" has been spotted socializing with "Seymour," a dolphin that has a tangle of monofilament fishing line that was threatening the loss of its tail.

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

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)
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)