Weekly Ocean News

WEEKLY OCEAN NEWS

WEEK FOUR: 30 September-4 October 2013

For Your Information

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.
Summary of new climate change report made available to policymakers -- Last Friday, the 36-page "Climate Change 2013: The Physical Science Basis Summary for Policymakers" of the Working Group I contribution to the IPCC Fifth Assessment Report (WGI AR5) was approved and released by the Twelfth Session of Working Group I (WGI-12) that was held in Stockholm, Sweden. This first part of the highly anticipated Fifth Assessment Report (AR5) from the United Nations Intergovernmental Panel on Climate Change (IPCC) will be followed by the remainder of the report that is scheduled to be released on Monday of this week. The 259 IPCC scientists from 39 countries emphasized that confidence about the human fingerprint on climate change has grown to 95 percent. [IPCC Working Group I]
Global patterns of carbon dioxide monitored from space -- A global map was generated showing the concentrations of atmospheric carbon dioxide in the mid-troposphere (altitudes around 18,000 feet) as obtained from data collected in May 2013 by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite. The map shows a global pattern that reduced concentrations in the Southern Hemisphere near the end of that hemisphere's growing season and higher levels in the Northern Hemisphere, where the growing season was commencing. May 2013 represented the month with the highest concentration of carbon dioxide near the Earth's surface as monitored by NOAA's Mauna Loa Observatory. [NASA Earth Observatory]

Ocean in the News

Eye on the tropics --- The weather across the tropical ocean basins of the Northern Hemisphere became relatively quiet during the last week even though the surface waters in this hemisphere remain relatively warm. No named tropical cyclones (low pressure systems that form over tropical ocean waters, with near surface maximum sustained winds of at least 39 mph that intensify to tropical storm- or hurricane-force status) developed in the North Atlantic and the eastern North Pacific basins. However, Tropical Depression 11 formed early Sunday morning nearly 1000 miles to the east-northeast of the northern Leeward Islands. Forecasts indicate that this system could intensify and become Tropical Storm Jerry on Monday.
In the western North Pacific basin, Tropical Storm Pabuk gradually curved toward the north and then northeast as it traveled across the waters to the east of China and then Japan. By early last week this tropical storm intensified into a typhoon and then by midweek it reached a typhoon-2 status on the Saffir-Simpson Scale. Near the end of the week, Typhoon Pabuk had weakened and lost its tropical characteristics, becoming a midlatitude system off the Japanese coast. Information on Typhoon Pabuk is available from the NASA Hurricane Page.
Late in the week, a tropical storm formed from a tropical depression over the South China Sea to the west of the Philippine island of Luzon. This tropical storm that was identified as Wutip intensified to become a category-2 typhoon as it traveled to the west toward the northern coast of Vietnam over the weekend. Current forecasts indicate that Typhoon Wutip should make landfall along the Vietnam coast on Monday (local time). Wutip should weaken quickly once making landfall. Heavy rain associated with this typhoon could result in flooding in sections of Vietnam, Laos and Thailand, where recent heavy rain had fallen earlier this month. The NASA Hurricane Page has additional information and satellite images pertaining to Typhoon Wutip.
Five-year NOAA research and development plan announced -- Early last week, NOAA officials released an online accessible document describing its five-year research and development plan that is designed to guide NOAA scientists in their effort to observe and predict changes in the global ocean-atmosphere system and to alert and protect society from the negative impacts of these changes. [NOAA News]
Deep sea ecosystem recovery from Deepwater Horizon spill could take decades -- A team of NOAA and university scientists recently published the first comprehensive analysis of the impacts placed upon the deep sea soft-sediment ecosystem in the section of the Gulf of Mexico surrounding the Deepwater Horizon well head that blew out in 2010 and subsequently produced a large oil spill into Gulf waters. The researchers found that the ecosystem will likely take decades to recover from the spill. [NOAA News]
Bottom feeding techniques of humpback whales revealed -- Researchers from NOAA and their colleagues studied the feeding techniques employed by tagged humpback whales in the bottom waters in the Stellwagen Bank National Marine Sanctuary that is located off the Massachusetts coast. The team found that the humpback whales employed three distinct feeding approaches that were previously unknown: simple side-rolls, side-roll inversions, and repetitive scooping. [NOAA National Marine Sanctuaries News]
Changing winds could cause growth in Antarctic sea ice -- A scientist at the University of Washington claims that approximately 80 percent of the observed growth in the Antarctic sea ice during recent decades can be explained by changes in the atmospheric circulation around Antarctica, while 20 percent may be attributed to changes in oceanic circulation. The atmospheric circulation, primarily associated with the changes in the polar vortex, could push sea ice away from the continent, leading to the creation of open waters where new ice can easily form. The changes in the polar vortex could be associated with reduction in stratospheric ozone over Antarctica. The Antarctic sea ice has expanded while Arctic sea ice has been shrinking to record small areal extent. [Climate Central]
Late Cretaceous Period may have been ice-free -- Researchers from the University of Missouri who studied fossilized shells planktic and benthic foraminifera recovered from Tanzania report that this fossil record indicates that the Earth's atmosphere during the Late Cretaceous Period (at least 90 million years ago) had carbon dioxide levels that were up to 1000 ppm and no continental ice sheets appeared to be present. The carbon dioxide concentration during the late Cretaceous was more than the current concentration that is close to 400 ppm. [Research at Mizzou (University of Missouri)]
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

30 September 1932...Tropical cyclone rainfall of 4.38 inches at Tehachapi in southern California over 7 hours caused flash floods on Agua Caliente and Tehachapi Creeks resulting in 15 deaths. (The Weather Doctor)
30 September 1954...The USS Nautilus, the world's first nuclear-powered submarine, is commissioned by the U.S. Navy. In addition to breaking numerous submarine travel records to that time, the Nautilus made the first voyage under the Arctic sea ice at the geographic North Pole in August 1958, passing from the Pacific to Atlantic Ocean basins. The Nautilus was decommissioned on 3 March 1980 and is currently on display at the Submarine Force Museum in Groton, CT. (The History Channel)
30 September 1997...Omega Navigation Station Hawaii ceased operation, coinciding with the end of worldwide Omega transmissions. (USCG Historian's Office)
1 October 1844...U.S. Naval Observatory headed by LT Matthew Fontaine Maury occupied its first permanent quarters. (Naval Historical Center)
1 October 1846...The British naturalist Charles Darwin, ten years after his voyage on the Beagle, began his study of barnacles, which was to appear in four volumes on living and fossil Cirripedes (barnacles). For his observations, he had a single lens microscope made to his own design. (Today in Science History)
1 October 1976...Hurricane Liza brought heavy rains and winds to Brazos Santiago, Mexico, causing a dam to break on the Cajoncito River, which killed 630 people as a wall of water crashed into the town of La Paz. (The Weather Doctor)
1 October 1893...The second great hurricane of the 1893 season hit the Mississippi Delta Region drowning more than 1000 people. (David Ludlum)
2 October 1836...The British naturalist Charles Darwin returned to Falmouth, England, aboard the HMS Beagle, ending a five-year surveying expedition of the southern Atlantic and Pacific Oceans, that included visits to Brazil, the Galapagos Islands, and New Zealand. The information and experience obtained from this voyage led Darwin to develop his historic work on the theory of evolution and the 1859 publication entitled, The Origin of Species by Means of Natural Selection. (The History Channel)
2 October 1867...A hurricane struck Galveston, TX with a storm tide that caused $1 million damage. (Intellicast)
2 October 1882...A major hurricane struck the Louisiana Delta with 100-mph winds and 12-ft storm tide which inundated the bayous resulting in 1500 deaths. (Intellicast)
2 October 1898...A hurricane struck the Weather Bureau (now National Weather Service) hurricane observation post at Carolina Beach, North Carolina and swept away the office's outhouse. The storm became known as the "Privy Hurricane". (Northern Indiana NWSFO)
3 October 1841...The "October Gale," the worst of record for Nantucket, MA, caught the Cape Cod fishing fleet at sea. Forty ships were driven ashore on Cape Cod, and 57 men perished from the town of Truro alone. Heavy snow fell inland, with 18 inches reported near Middletown, CT and 3 inches at Concord, MA. (David Ludlum)
4 October 1582...The Gregorian Calendar was implemented by Pope Gregory XIII to correct for an increasing discrepancy between the leap year corrections of the Julian Calendar and the actual length of the year marked by the Earth's orbit of the sun. In Italy, Poland, Portugal, and Spain, 4 October of this year was followed directly by 15 October, skipping over 10 days. (Wikipedia)
4 October 1869...A great storm struck New England. The storm reportedly was predicted twelve months in advance by a British officer named Saxby. Heavy rains and flooding plagued all of New England, with strong winds and high tides along the coast of New Hampshire and Maine. Canton, CT was deluged with 12.35 inches of rain. (David Ludlum)
5 October 1972...Heavy rains, mostly the remnants of Tropical Storm Joanne, fell across much of Arizona. It was believed to be the first time in Arizona weather history that a tropical storm entered the state with its circulation still intact. The center was over Flagstaff early on the 7th. (3rd-7th) (The Weather Channel)
5-7 October 1999...A storm southeast of New Zealand caused surf to reach heights of 12 ft along the south shores of all the Hawaiian Islands, flooding some roads and parking lots. The lobby of the Kihei Beach Resort on Maui and three ground floor units were flooded. (Accord Weather Guide Calendar)