Weekly Ocean News

DATASTREME OCEAN WEEK EIGHT: 19-23 March 2007

Ocean in the News:

(Thurs.) NOAA's involvement in International Polar Year is highlighted -- The NOAA Magazine has highlighted current research and support efforts made by NOAA personnel as part of the national involvement with the International Polar Year (IPY) 2007-2009 that officially started on 1 March and represents a two-year research effort by the international scientific community to understand the environment of polar regions and their effect upon climate. [NOAA Magazine]
(Thurs.) New snapper species discovered --Researchers with the Conservation International and the Environmental Defense report that a new species of snapper, which had previously been mistaken as a popular game fish, was discovered among the reefs of the Abrolhos region of the South Atlantic Ocean. [Conservation International]
(Thurs.) An improved CryoSat-2 satellite is under development -- The European Space Agency is building a new satellite, CryoSat-2, that will replace the original CryoSat satellite lost during launch in 2005. This new satellite, with some significant improvements, is to be built in three years and will be used to assess the changes in sea ice cover in polar regions. [ESA]
(Tues.) National marine sanctuary program seen to be making significant gains -- A recently issued "2006 State of the Sanctuaries Report" indicates that the NOAA National Marine Sanctuary Program made significant gains during 2006, including the establishment of the world's largest Northwestern Hawaiian Islands Marine National Monument and the shifting of shipping lanes to protect whales off the New England coast. [NOAA News]
(Tues.) Major earthquake did not create a large tsunami for a reason -- Seismologists at Washington University in St. Louis and in Australia, Japan and Tonga explained that a magnitude 8.0 earthquake in Tonga on 3 May 2006 generated a minimal tsunami because the nature of the slab-tear earthquake is different from the shallow-thrust earthquakes that usually produce the larger tsunamis. [Washington University in St. Louis]
(Tues.) The small ones could help forecast the big ones -- Scientists at Stanford University and the University of Tokyo have found that small tremors and temblors along the fault zones surrounding the Pacific Ocean basin are generated by slow-moving earthquakes and could foreshadow catastrophic seismic events such as magnitude 8 or greater earthquakes and major tsunamis along the Pacific Rim. [EurekAlert!]
(Tues.) Impact from two tropical cyclones seen from space -- Two images made a week apart by the MODIS sensor onboard NASA's Terra satellite of the northern coast of Western Australia graphically shows some of the impact that land-falling Tropical Cyclones George and Jacob had on the region. Torrential rains from these cyclones (equivalent to hurricanes) flooded the DeGrey River, which can be distinguished easily on the later image. The semi-arid region also experienced rapid and widespread plant growth that can also be seen. [NASA Earth Observatory]
A review of winter 2006-2007 -- Scientists at the NOAA National Climatic Data Center recently announced that based upon their preliminary analysis of the weather data collected to date on the just concluded meteorological winter season (the three months extending from December 2006 through February 2007) the national average winter temperature (33.6 degrees Fahrenheit) was slightly above the 20th century average national winter temperature (33.0 degrees Fahrenheit). Those states along the Eastern Seaboard and along the US-Canadian border had above average winter temperatures, while the southern Plains and southern Rockies had below average temperatures for the three-month meteorological winter of 2006-2007. States in the central Plains and the Midwest had above average winter precipitation, with Kansas and Nebraska experiencing their second wettest December-February period since 1895. Those states across the Southeast, the Eastern Seaboard and to the west of the Rockies experienced a dry winter, with Tennessee and Alabama experiencing much below average precipitation. The global average temperature was the highest on record for this three-month interval. The scientists noted that recent El Niño conditions appear to have contributed to these record temperatures. [NOAA News]
Another tropical cyclone hits Madagascar -- An image obtained from the MODIS instrument onboard NASA's Aqua satellite shows Tropical Cyclone Indlala off the coast of Madagascar late last week. This tropical cyclone, the Indian Ocean's counterpart of a hurricane, reached category 4 status on the Saffir-Simpson intensity scale and marks the fourth land-falling tropical cyclone in the last four months. [Editor's note: Since this low pressure system is in the Southern Hemisphere, the circulation as indicated by the clouds in the spiral bands are in a clockwise direction, opposite those in the Northern Hemisphere. EJH] [NASA Earth Observatory] A wider view is also provided for perspective. [NOAA OSEI]
Ice cover changes rapidly on Lake Erie -- Two images made within a span of four days by the MODIS sensor onboard NASA's Aqua satellite shows the transformation from an essentially ice-covered Lake Erie to a lake that had few ice floes. Only four days prior to the first image of an ice covered lake, the lake had also been relatively open. [NASA Earth Observatory]
Great Lakes cleanup plan may get Congressional attention -- Members of the US House of Representatives and the Senate from the Great Lakes States have outlined a proposal that would allocate $20 billion to improve water quality, restore fish and wildlife and guard against invasive species that could inflict economic pain on the region. [US Water News Online]
Large cold water eddies studied off Australia -- Oceanographers have been studying a huge "monster" cold water eddy in the South Pacific off the Australian coast near Sydney. This cold water eddy has a profound influence on the ecosystem of the Tasman Sea. [CSIRO]
Antarctic glaciers have been threatened by warmer ocean -- Scientists from University of Edinburgh and University College London have identified four Antarctic glaciers that could continue to melt rapidly as global ocean temperatures rise. These researchers claim that these four glaciers could pose a threat to future sea level rises. [EurekAlert!]
A "cascade of climate change" could occur with decline of Arctic sea ice -- A study at the University of Colorado-Boulder based upon analysis of approximately 28 years of satellite observations of sea ice cover warns that within several decades, a dwindling areal extent of Arctic sea ice could reach a tipping point that could trigger a "cascade of climate change" that could extend into midlatitudes. [EurekAlert!]
Pollution from Eurasia dirties the Arctic -- French researchers report that air pollution from Europe and Russia has spread across the Arctic basin in the form of a brown haze that has contributed to the documented warming of the region. [ENN] In a separate study, researchers at Scripps Institution of Oceanography have found that soot and other particulates from Asia comprise approximately three-quarters of the black carbon transported to polar latitudes. These researchers claim that this black carbon is a significant factor in Pacific Ocean climate. [Scripps Institution of Oceanography]
Ocean sampling expedition nets vast amounts of microbial data -- A team of scientists participating in the Sorcerer II Global Ocean Sampling expedition in the Sargasso Sea have collected an enormous amount of microbial sequence data as part of a metagenomic study. [EurekAlert!]
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: Loss of Louisiana's Coast

According to the Louisiana Coastal Wetlands Conservation and Restoration Task Force, Louisiana has been losing its coastal wetlands (bayous, marshes, and swamps) to the waters of the Gulf of Mexico at an alarming rate of about 65 to 100 square km (25 to 38 square mi) per year for the past several decades. This loss adversely affects fisheries in the Gulf of Mexico and makes the coastal zone more vulnerable to storm surges such as that produced by Hurricane Katrina in August 2005. Since the early 1930s, the state's coastal wetlands have shrunk by an area equivalent to the state of Delaware. According to USGS estimates, an additional 1800 square km (700 square mi) could be lost by mid-century. The price tag for reversing this trend, restoring some marshes, and protecting the remaining 15,000 square km (5800 square mi) of wetlands could top $14 billion and take decades to complete. Many people argue that the value of Louisiana's coastal wetlands is well worth the expense.

As much as 75% of the fish and other marine life in the northern Gulf of Mexico depend on Louisiana's coastal wetlands. The wetlands are a nursery for commercially important shellfish such as shrimp, crawfish, blue crab, and oysters. It is a food source for larger fish including yellow fin tuna, red snapper, and swordfish. In 2003, about three-quarters of the nation's fish and shellfish catch by weight came from Louisiana's waters. In addition, the wetlands are a stopover for millions of birds migrating between North and Central/South America. Furthermore, wetlands and associated barrier islands protect the ports, buildings, and other coastal zone structures from storm surges. Wetlands are particularly important in buffering the levees surrounding New Orleans, much of which is below sea level.

Many factors contribute to the loss of Louisiana's coastal wetlands. Thousands of kilometers of pipelines transporting oil and natural gas through the marshes plus the extensive network of navigation channels allow saltwater to intrude the wetlands. Increased salinity of the originally fresh or brackish waters kill wetland grasses, shrubs, and other vegetation that anchor soil in place. The canals also allow tidal currents to flow farther inland, accelerating erosion of wetland soils. The most important factor, however, is the consequence of flood control structures (levees) constructed along the banks of the Mississippi River. Levees constrict the flow of the river so that waters and suspended sediment discharge rapidly into the Gulf. Deprived of a continuous input of sediments and vegetation-supporting nutrients, existing sediments compact, wetlands subside and Gulf waters invade the wetlands. With the anticipated continued rise in sea level due to global climate change (discussed in Chapter 12 of your textbook), erosion of Louisiana's coastal wetland may accelerate in the future.

Plans to reverse the loss of Louisiana's coastal wetlands (the Coast 2005 plan and the Louisiana Coastal Area plan) seek to restore the structure and function of coastal wetlands. One proposal is to breach some levees along the lower Mississippi. This partial diversion of the Mississippi would increase the supply of sediments to the wetlands. Closing or installing locks on some navigation canals would reduce saltwater intrusion. In addition, dredged sediment would be used to re-build wetlands and restore barrier islands.

Concept of the Week: Questions

The most important factor contributing to erosion of Louisiana's coastal wetlands is [(saltwater intrusion)(levees along the banks of the Mississippi River)].
Global climate change that is accompanied by a rise in sea level is likely to [(accelerate)(have no effect on)] the rate of erosion of Louisiana's coastal wetlands.

Historical Events:

19 March 1866...The immigrant ship Monarch of the Seas sank in Liverpool killing 738 people.
20 March 2000...A large iceberg measuring approximately 170 mi by 25 mi calved off Antarctica's Ross Ice Shelf near Roosevelt Island. The iceberg was approximately 2.5 times the size of New York's Long Island. (Accord's Weather Guide Calendar)
22 March 1778...Captain James Cook of the British Royal Navy sighted Cape Flattery, in present day Washington State.
22 March 1999...Tropical Cyclone Vance produced Australia's highest measured wind speed of 166 mph at Learmonth, West Australia. Gusts reaching 185 mph were estimated in the eyewall in the Exmouth Gulf. All homes in the village of Exmouth were either damaged or destroyed. (Accord's Weather Guide Calendar)
24 March 1955...The first seagoing oil drill rig (for drilling in over 100 feet of water) was placed in service by the U.S. company C.G. Glasscock Drilling Co. The rig was able to drive piles with a force of 827 tons and pull a pile with the force of 942 tons. (Today in Science History)
24 March 1989...The tanker Exxon Valdez grounded on a reef in Prince William Sound, AK, spilling 10.1 million gallons of crude oil, resulting in the worst oil spill in U.S. history. Coast Guard units responded and prevented the entire cargo from spilling, cleaned up the oil which did spill, and conducted an investigation into the causes of the accident. The spill provided the impetus for the passage of the Oil Protection Act in 1990. (US Coast Guard Historians Office)
25 March 2000...A rouge wave near Shelter Cove, CA swept a lady from a Canadian school group into the ocean. Four members of the group tried to rescue her, but were overcome by the waves and currents. A fishing vessel and the US Coast Guard rescued two of the rescuers. (Accord's Weather Guide Calendar)