Weekly Ocean News

WEEKLY OCEAN NEWS

WEEK FOUR: 28 September-2 October 2009

Ocean in the News

(Wednesday) Deadly earthquake strikes Malaysia -- A magnitude 7.6 earthquake struck near Padang in Sumatra, Indonesia. Estimates of the death toll were at least 75 with hundreds more injured and thousands possibly trapped in collapsed buildings. A tsunami watch was immediately issued but soon cancelled as reports were for a wave of only about one foot. The region was the victim of the horrendous 2004 tsunami. [CNN]
Update - the death toll from the Samoan tsunami (see below) has reached 111.
(Wednesday) Deadly earthquake leads to tsunami warning -- A magnitude 8.0 earthquake approximately 7 miles under the floor of the South Pacific Ocean near the American Samoa Islands Wednesday morning (local time) was responsible for as many as 17 deaths. This earthquake produced a tsunami wave in the Pago Pago harbor. Three tsunami waves radiated out across the Pacific Ocean, with the largest having a height of five feet. The Pacific Tsunami Center in Hawaii and the Japanese Meteorological Agency issued tsunami watches and warnings for coastal areas around the Pacific immediately following the earthquake, but after several hours, these watches and warnings were canceled. [CNN]
Eye on the tropics --- Some active weather was reported across the tropical North Atlantic and Pacific Oceans this past week:
- In the North Atlantic basin, a tropical depression, identified as Tropical Depression 8 formed off the western coast of Africa late last week. However, this depression was short-lived, weakening within a day. A satellite image of Tropical Depression 8 can be seen on the NASA Hurricane Page.
- In the eastern North Pacific, Tropical Storm Nora, the fourteenth named tropical cyclone of 2009 in that basin, formed nearly 1000 miles off southwestern Mexico at the midpoint of last week. After traveling to the northwest, it weakened and dissipated at the end of the week. Additional information and satellite imagery for Tropical Storm Nora can be seen on the NASA Hurricane Page.
- In the western North Pacific basin, Tropical Storm Ketsana developed as a tropical depression at the end of last week over the waters east of the Philippines. This system became a tropical storm before reaching the Philippines, where heavy rain caused historic and deadly flooding on this island nation. (USA Today) As of Sunday afternoon (local time), Tropical Storm Ketsana was traveling westward across the South China Sea toward Viet Nam. The NASA Hurricane Page has additional information and satellite images on this system. (Editor's note: When this page was first posted last Friday, this tropical cyclone was a tropical depression, identified as Tropical Depression 17W. EJH)
  Farther to the east, a new tropical depression, identified as Tropical Depression 18E, formed on late Sunday (local time) over the tropical western Pacific east of the Northern Mariannas.
  Earlier last week, the once powerful Typhoon Choi-Wan (category 5 typhoon on the Saffir-Simpson Scale) weakened over the western North Pacific waters east of Japan to a tropical storm at the start of last week. Remnants of this former typhoon had become an extratropical storm as it moved across the North Pacific. See NASA Hurricane Page for satellite images and additional information on Typhoon Choi-Wan.
Ocean observing system for California coast receives funding -- NOAA officials recently announced that the Southern California Coastal Ocean Observing System, located at the Scripps Institution of Oceanography in San Diego, CA has received $1.7 million to support ocean observing efforts in Southern California as part of NOAA’s Integrated Ocean Observing System. [NOAA News]
Hydrographic survey vessel to be repaired -- NOAA's Office of Marine and Aviation Operations has announced that a commercial shipbuilding company in Portland, OR has been contracted to perform major repairs along with upgrades to the NOAA hydrographic survey vessel Rainier, a 231-ft ship that has conducted surveying along the US Pacific Coast for more than four decades. [NOAA News]
A disaster response center to be built along Gulf Coast -- NOAA officials recently announced that a building company from Charleston, SC has been awarded a contract to build NOAA’s Gulf of Mexico Disaster Response Center in Mobile, AL, which will serve as the regional home for the agency's office that will respond to oil spills and hazardous material releases into the coastal marine environment. [NOAA News]
Landmark partnership agreement made for a major marine protected area -- Officials from the US, including those from NOAA, and the Republic of Kiribati recently announced a historic alliance involving the development of a "sister site" relationship between the Papahnaumokukea Marine National Monument in the Northwestern Hawaiian Islands and the Phoenix Islands Protected Area in the Republic of Kiribati. This arrangement is designed to enhance the management and protection of what would be the world's largest marine protected area. [NOAA News]
A rare giant squid is caught -- A giant squid was caught in waters of the Gulf of Mexico off the Louisiana in late July by NOAA’s Fisheries Service scientists during a two month scientific study of the Gulf conducted by NOAA and the US Interior Department. [NOAA News]
Coastal restoration project completed -- A multi-year restoration project was recently completed by NOAA and the U.S. Fish and Wildlife Service along with state and local partners to restore the salt marsh and coastal shoreline along New York State's Hempstead Harbor following the release of hazardous waste. [NOAA News]
Increased numbers of Atlantic hurricanes, with little change in intensity -- Researchers from Clemson University and Mississippi State University who studied a 158-year record of tropical cyclones over the North Atlantic claim that while the number of tropical storms and hurricanes have been increasing, they found little evidence that the strengths of individual tropical cyclones have increased or that of the chances of these systems striking the US. [Clemson University]
Monitoring the recent ups and downs of global temperatures -- Scientists at NOAA's National Climate Data Center and the Lawrence Berkeley National Laboratory have been examining the variations in global temperatures over the last century in an attempt to explain the occurrence of recent reversals in the general increase global temperatures, where the temperature actually decreases over a span of years of up to a decade duration. Attention has been paid to the role that oceans have upon the global temperatures, where the Pacific Decadal Oscillation was cited as an example. [NASA Global Climate Change]
Human activity causing world's major deltas to sink -- Researchers from the University of Colorado at Boulder and their colleagues from other research institutions in the US, the United Kingdom and Japan used data collected from NASA's Shuttle Radar Topography Mission on the Space Shuttle to study 33 of the world's major deltas. They found that nearly three-quarters of these deltas were sinking due to human activity and a large fraction of these experienced recent severe flooding from rivers and storms over the oceans, putting millions of residents of these low-lying areas at risk. [EurekAlert!]
Humans urged to "set safe boundaries to the damage" -- Twenty-eight of the world’s most eminent environmental scientists recently published an article in which they urged humans to take immediate action to define boundaries between levels of human-caused change deemed "safe" from those considered "unsafe" and then to stay within those boundaries to reduce a variety of consequences due to possible irreversible climate change. [EurekAlert!] [Coral Reef Studies]
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, 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, including 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

28 September 1542...Portuguese explorer Juan Rodríguez Cabrillo sailed into present-day San Diego (CA) Bay during the course of his explorations of the northwest shores of Mexico on behalf of Spain. His landing at Point Loma Head apparently was the first known European encounter with California. Before dying on the Channel Islands off the Santa Barbara coast in January 1543, he had explored much of the California coast. (The History Channel)
28 September 1850...An Act of Congress (9 Stat. L., 500, 504) provided for the systematic coloring and numbering of all buoys for, prior to this time, they had been painted red, white, or black, without any special system. The act "prescribed that buoys should be colored and numbered so that in entering from seaward red buoys with even numbers should be on the starboard or right hand side; black buoys with odd numbers on the port or left hand side; buoys with red and black horizontal stripes should indicate shoals with channel on either side; and buoys in channel ways should be colored with black and white perpendicular stripes." (US Coast Guard Historians Office)
29 September 1959...Hurricane Gracie made landfall near Beaufort, SC with sustained winds of 97 mph and a peak gust of 138 mph. Ten people were killed in South Carolina and Georgia. As the weakening storm moved through Virginia on the 30th, the storm spawned an F3 tornado at Ivy, VA, which killed 11 people. On the same day, a storm produced 28 inches of snow in Colorado Springs, CO. (David Ludlum)
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)