DATASTREME OCEAN WEEK EIGHT: 21-25 March 2005

• Nation's ocean policy to be discussed -- The NOAA Administrator and Commerce Department Undersecretary for Ocean, Conrad Lautenbacher will address the "Managing Our Nation's Fisheries" conference this week. The mission of this conference is to lay the foundation for implementing the Ocean Action Plan. [NOAA News]
• No tsunami from Japanese earthquake--A strong earthquake with a magnitude of 7 centered off the west coast of the Japanese island of Kyushu on Sunday morning killed one person, injured at least 250 others and caused damage in the Fukuoka prefecture. Since the earthquake originated at least 5 miles below the ocean floor, initial fears were that a tsunami would propagate across the Pacific. However, a tsunami was not reported. [BBC]
• Tropical storm brings death to the Philippines -- Tropical Storm Roke moved across the central Philippines late last week capsizing several boats and causing the deaths of at least three people, while 13 others remained missing. Typically, the Philippines are experiencing the dry season during March, as most tropical cyclones (typhoons and tropical storms) affect the islands during the wet season from June through October. [USA Today]
• Confrontation at sea averted -- The British Coast Guard had to intervene to end a confrontation that was developing between Greenpeace protesters and crews from British trawlers over the fear that dolphins were being killed during the fishing for sea bass. [ENN]
• Sonar could have caused orcas to flee -- The National Marine Fisheries Service recently released a report indicating that the use of sonar by a US Navy destroyer in Washington State inland waters near the San Juan Islands appears to have been responsible for the abnormal behavior of a pod of orca or killer whales. [ENN]
• Movement of massive iceberg monitored -- Radar images obtained from the European Space Agency's Envisat satellite indicate that iceberg B-15A, the world's largest floating object, was once again drifting across the McMurdo Sound, but could pass very close to the Drygalski ice tongue. [ESA]
• New hurricane probability map unveiled -- The National Hurricane Center recently reported that it will post a new type of hurricane probability map during the upcoming North Atlantic hurricane season on its website that is intended to provide the public with a better sense of the probability of the probability of the track of a tropical weather system. These maps would also attempt to project the approaching system's size and strength. [USA Today]
• A rise in sea level foreseen for this century -- A team of numerical climate modelers at the National Center for Atmospheric Research recently reported that their models indicate that global sea level could rise another 4 inches during this century from thermal expansion due to higher global temperatures even if concentrations of several greenhouse gases remained at current levels. [EurekAlert!]
• Blueprint for rescuing American coral reefs unveiled -- Marine ecologists from the US and Australia urged the nation to take immediate action to save the fragile coral reefs in Hawaii and Florida that are threatened. [EurekAlert!]
• Silver found in North Pacific waters -- Researchers from the University of California, Santa Cruz found high levels of silver in water collected two years ago from the North Pacific that were fifty times higher than the natural background level. While below levels considered toxic to marine life, the silver contamination appears to be from atmospheric depositions of aerosols from coal burning in Asia. [EurekAlert!]
• How fish remain motionless at different levels discovered -- Scientists at the University of Liverpool have discovered how fish have evolved a gas-filled swim bladder over the last 400 million years that have permitted them to float motionless at different depths in the oceans. [EurekAlert!]
• Tsunami helps provide glimpse of ancient temples --Last December's destructive tsunami that was responsible for the deaths of nearly 170,000 people in coastal areas surrounding the Indian Ocean also revealed some ancient cities and other submerged ruins. When the water rushed out before the tsunami hit, ancient submerged temples were momentarily exposed along the coast of India, while the wave also removed beach sand from other buried sites. [CNN]
• British researchers begin tsunami research -- Scientists at three British universities have received grants to conduct research on the structural, topographical and seismological aspects of the recent Indian Ocean tsunami. [EurekAlert!]
• Another Indonesian earthquake could pose new perils in tsunami region -- Scientists from the University of Ulster in Northern Island recently warned that stresses in the earth's crust from the recent massive earthquake off Indonesia that produced last December's devastating tsunami could place increased pressure on surrounding earthquake zones, leading to possibly more earthquakes and tsunamis. They also call for implementation of a Circum Indian Ocean Tsunami Warning System. [EurekAlert!]
• "Ocean Floor" lab creates methane-hydrates-- Scientists at the Brookhaven National Laboratory have replicated the high-pressure and low-temperature conditions found on the ocean floor in their laboratories to create and study methane hydrates, an abundant source of natural gas typically trapped in sediments on the ocean floor. [Brookhaven National Laboratory]
• 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

Louisiana is losing its coastal wetlands (bayous, marshes, and swamps) to the waters of the Gulf of Mexico at an alarming rate of about 65 square km (25 square mi) per year. 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 the low-lying city of New Orleans.)

Many factors contribute to the erosion 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 sediments and vegetation-supporting nutrients, 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 DataStreme Ocean textbook), erosion of Louisiana's coastal wetland may accelerate in the future.

The plan to reverse the loss of Louisiana's coastal wetlands calls for breaching some levees along the lower Mississippi. This partial diversion of the Mississippi would supply more sediment 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

1. The most important factor contributing to erosion of Louisiana's coastal wetlands is [(saltwater intrusion)(levees along the banks of the Mississippi River)].
2. 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.

• 22 March 1778...Captain James Cook 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)
• 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)
• 26 March 1845...Joseph Francis of New York City patented a corrugated sheet-iron lifeboat. (Today in Science)
• 26 March 1946...The International Ice Patrol resumed after being suspended during World War II. (US Coast Guard Historians Office)
• 27 March 1513...Spanish explorer Juan Ponce de Leon sighted Florida (and the continent of North America) for the first time, mistaking it for another island. (Wikipedia)
• 27 March 1827...At the age of 18, Charles Darwin submitted his first report of an original scientific discovery to the Plinian Society in Edinburgh, Scotland. Darwin had made several discoveries about the biology of tiny marine organisms found along the Scottish coast. (Today in Science)
• 27 March 1899...The first international radio transmission between England and France was achieved by the Italian inventor G. Marconi.
• 27 March 1930...The US radio broadcast was made from a ship at sea.
• 27 March 1964...The most powerful earthquake in US history, the Good Friday Earthquake, rocked south central Alaska, killing 125 people and causing$311 million in property, especially to the city of Anchorage. The earthquake, which had a magnitude of 9.2, caused some landmasses to be thrust upward locally as high as 80 feet, while elsewhere land sank as much as 8 feet. This earthquake and submarine landslides also created a tsunami that also produced extensive coastal damage. A landslide at Valdez Inlet in Alaska generated a tsunami that reached a height of 220 feet in the inlet. Tsunami damage reached Crescent City in northern California. Tens of thousands of aftershocks indicated that the region of faulting extended about 600 miles. The Alaska Tsunami Warning Center was established because of this disaster, with a mission to warn Alaskan communities of the threat from tsunamis. [See the 1964 Prince William Sound Tsunami page from the University of Washington.]
• 27 March 1980...Waves to 20 feet and winds to 58 mph in the North Sea southwest of Stavanger, Norway led to the collapse of an oil rig accommodation platform. The deaths of 123 of the 212 people on the platform was the world's worst drilling catastrophe. (Accord's Weather Guide Calendar)

Return to DataStreme Ocean Homepage

URL: DS Ocean/news.html

Prepared by AMS DS Ocean Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2005, The American Meteorological Society.