DATASTREME OCEAN WEEK TEN: 12-16 April 2010

Items of Interest:

• Prepare for National Lab Day --
The Digital Learning Network at NASA Langley Research Center is hosting a series of live webcasts during April aimed at encouraging K-12 teachers to promote hands-on science education in their classrooms. This series of webcasts are in preparation for National Lab Day scheduled for Wednesday, 12 May 2010. [NASA Langley]
• New geosynchronous weather satellite makes its first image of Earth --
Officials with NOAA and NASA recently released the first full-disk visible image of Earth made by sensors onboard NOAA's GOES-15 (Geostationary Operational Environmental Satellite) launched one-month earlier. [NOAA News] [NASA GOES-P Mission]

Ocean in the News:

• Eye on the Tropics ---
The transition season from summer and winter in the Southern Hemisphere has meant little tropical cyclone activity over the tropical waters of the world's oceans. Tropical Storm Robyn weakened and dissipated over the South Indian Ocean early last week. For more information on Tropical Storm Robyn, together with satellite images, consult the NASA Hurricane Page.
• Hurricane forecast update --
Last week, the hurricane forecast team from Colorado State University headed by Phil Klotzbach released its April update of their forecast of the 2010 North Atlantic hurricane season that officially begins on 1 June 2010. Because of record warm waters in the equatorial Atlantic and the weakening of the current El Niño event, the team foresees a more active seasonal than average. In this update, the forecasters call for 15 named tropical cyclones (hurricanes and tropical storms), with eight potentially becoming hurricanes. As many as four could become severe, reaching category 3 or higher on the Saffir-Simpson Scale. They also anticipate a higher than average probability of a major Atlantic hurricane making landfall somewhere along the coast of the coterminous US. [USA Today] [The Tropical Meteorology Project]
• Winter visitors "haul out" on North Carolina's beaches --
As many as nine young gray seal pups were seen to "haul out" and rest along the beaches of North Carolina's Outer Banks in March as they traveled southward along the coast in the Labrador Current in search of food. [Field Trip Earth] [Editor's note: Special thanks goes to Terri Kirby Hathaway, LIT Leader and Marine Education Specialist for the North Carolina Sea Grant Program in Manteo, NC, for forwarding this article. EJH]
• Effects of spring runoff into the Adriatic seen from space --
An image obtained last week from the MODIS sensor on NASA's Aqua satellite shows the color contrast due to sediments from runoff from spring rainshowers and melting snow in Italy's Apennine Mountains spreading out across the Adriatic Sea. [NASA Earth Observatory]
• New robotic underwater vehicle is ocean-powered --
Researchers from NASA's Jet Propulsion Laboratory, the U.S. Navy and the Scripps Institution of Oceanography have successfully demonstrated the Sounding Oceanographic Lagrangrian Observer Thermal RECharging (SOLO-TREC) autonomous underwater vehicle, the first robotic submarine vehicle to be powered entirely by natural, renewable thermal energy extracted from the ocean. [NASA JPL]
• Hawaii's submarine canyons are teeming with marine life --
In an extensive study conducted of the submarine canyons off the coast of the Hawaiian Islands, researchers from Hawaii Pacific University and the University of Hawaii at Manoa have found that these submarine canyons have especially abundant and unique communities of large marine animals such as fish, shrimp, crabs, sea cucumbers, and sea urchins, including more than 40 species not observed around the waters of the Aloha State. [EurekAlert!]
• Two aquatic invaders transfer toxic substances into Great Lakes fish --
Fishery biologists at the University of Michigan, Grand Valley State University and the University of Saskatchewan have determined that the zebra mussel and the round goby, two invaders of the Great Lakes, appear to play a major role in introducing toxic polychlorinated biphenyls (PCBs) into the aquatic food chain in the Great Lakes, contaminating Saginaw Bay walleyes. [University of Michigan News Service]
• More reliable wind power grid proposed --
Researchers from the University of Delaware and Stony Brook University have proposed a wind power grid that would use the power output from a series of five-megawatt wind turbines to be built offshore of the US East Coast. This grid would provide more consistent electricity production from a string of wind generators strategically located over the western North Atlantic where winds are more persistent and would provide more reliable wind power. [EurekAlert!]
• Keeping track of Antarctic ice from space --
Satellite images of ice shelves and glacial ice on the Antarctic Peninsula were recently released:
• A series of three images obtained from the MODIS instruments on NASA's Aqua and Terra satellites from March 2002 to late February 2005 shows the Larsen B Ice Shelf on the Antarctic Peninsula that collapsed and shattered in 2002, with fragments that lingered until 2005. [NASA Earth Observatory]
• Two images made in April 2002 and February 2003 from sensors on NASA’s Landsat 7 satellite show the retreat of the Crane Glacier on the Antarctic Peninsula at and after the collapse of Larsen B Ice Shelf. [NASA Earth Observatory]
• Familiar pattern discovered in long-term climate record --
A geologist at the University of California-Santa Barbara who analyzed ocean cores from 57 sites around the world has concluded that the climate record for the last 1.2 million years that she extracted has a pattern that connects with the rhythmic changes in the Earth's orbital cycle involving changes in orbital eccentricity, axial tilt and precession of the equinoxes. [EurekAlert!]
• Studying ancient seafloor "supervolcanoes" --
In fall 2009, an international team of scientists participating in Integrated Ocean Drilling Program's Expedition 324 have been exploring the origin of the 145 million-year-old Shatsky Rise volcanic mountain chain on the ocean floor more than 900 miles east of Japan. The supervolcanoes in this submarine mountain chain approximately two miles below the sea surface spewed large amounts of gases and particles into the atmosphere, as well as re-paving the ocean floor and changing the oceanic circulation. [Texas A&M University]
• 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: Solving the Mystery of Seamount Ecosystems

The United States Commission on Ocean Policy reports that less than 5% of the ocean floor has been explored. This is beginning to change as scientists and engineers develop and apply new technologies to investigate deep ocean waters and the sea bottom (refer to Chapter 13 in your DataStreme Ocean textbook). Consider, for example, the effort to obtain a better understanding of seamount ecosystems.

A seamount is a submarine mountain of volcanic origin (now extinct) that rises more than 1000 m (3300 ft) above the ocean floor. Usually a seamount summit is 1000 to 2000 m (3300 to 6600 ft) below sea level. They occur as isolated peaks, chains (e.g., Emperor Seamounts in the North Pacific; New England chain in the North Atlantic), or clusters. The term "seamount" was first applied in 1936 to the Davidson Seamount located off the coast of Southern California. Scientists estimate that perhaps 30,000 dot the ocean floor with as many as two-thirds located on the Pacific Ocean bottom. However, fewer than one thousand seamounts have been named and only a handful of seamounts has received detailed scientific study.

In recent years, discovery of unique life forms on seamounts has spurred scientific interest in seamount ecosystems. Many nations, including the United States, Australia, and New Zealand, are supporting scientific cruises to observe and collect specimens from seamount ecosystems. Seamount ecosystems are unusually productive and are home to unique species. Some seamount surveys have found that certain seamount species are endemic, that is, they live on only one seamount or a few nearby peaks. For example, up to one-third of all species living on some seamounts off New Caledonia are endemic while up to half of the invertebrates and fish on the Nazca seamount off Chile are endemic. In the northeast Pacific, large-scale eddies may transport larval fish from coastal environments to isolated seamounts located out at sea. Furthermore, some scientists argue that seamounts may function as stepping stones that allow for migration of species over lengthy periods--perhaps over millions of years. In addition, some seamounts may serve as aids to navigation for fish that migrate over long distances. For example, hammerhead sharks may use the magnetic field surrounding seamounts to find their way.

The recent effort to survey and explore seamount ecosystems has reached new urgency with the realization of the devastating impact of commercial fish trawlers on those ecosystems. In some cases, trawling has striped off most marine life (e.g., coral gardens) from the surface of seamounts leaving behind mostly bare rock. Typically, trawled seamounts have only half the biomass and considerably fewer species than undisturbed seamounts. Scientists anticipate that a better understanding of seamount ecosystems will help make the case for their conservation and inform the most effective strategies for their protection. Australia is one of the first nations to protect seamount ecosystems, establishing the Tasmanian Seamount Marine Reserve in 1999. The reserve covers 370 square km (140 square mi) and includes more than a dozen seamounts.

Concept of the Week: Questions

1. Seamounts are extinct submarine volcanoes that occur primarily in the [(Atlantic) (Pacific)(Southern)] Ocean.
2. Commercial fish trawling has [(little if any)(a devastating)] impact on seamount ecosystems.

Historical Events:

• 13 April 1960...The Navy's first navigation satellite, Transit-1B, was placed into orbit from Cape Canaveral, FL and demonstrated the ability to launch another satellite. The Transit system was designed to meet Navy's need for accurately locating ballistic missile submarines and other ships. (Naval Historical Center) (Today in Science History)
• 14 April 1543...Bartolomé Ferrelo returned to Spain after assuming command of the ill-fated expedition of the Spanish navigator Juan Rodríguez Cabrillo (who died on San Miguel Island in California's Channel Islands). The expedition was the first known entry by Europeans into San Francisco Bay in the New World.
• 14-15 April 1912...The British steamer RMS Titanic sank following its collision with an iceberg in the North Atlantic off Newfoundland on its maiden voyage from South Hampton to New York. The collision occurred at about 11:45 PM on 14 April and the ship, which was considered unsinkable, sank in 2.5 hours during the early morning hours of the 15^th. Reports showed 1517 people out of 2207 onboard lost their lives in this accident. Because of this disaster, certification and life saving devices were improved and an International Ice Patrol was established to monitor the iceberg hazards in the North Atlantic. The U.S. Coast Guard continues to conduct much of the effort. (US Coast Guard Historian's Office) A 21-year old telegraph operator at the Marconi radio station in New York City, David Sarnoff who became a pioneer in radio and television broadcasting, received and transmitted the distress calls from the Titanic. (Today in Science History)
• 16 April 1851...The famous "Lighthouse Storm" (a "nor'easter") raged near Boston Harbor. Whole gales and gigantic waves destroyed the 116-ft Minot Ledge Light at Cohasset, MA with the loss of its two keepers still inside. The lighthouse was the first one built in the United States that was exposed to the full force of the ocean. The storm coupled with a spring tide resulted in massive flooding, great shipping losses and coastal erosion. Streets in Boston were flooded to the Custom House. (David Ludlum) (US Coast Guard Historians Office) (Accord's Weather Guide Calendar)
• 16 April 1854...A furious storm that produced two feet of snow at New Brunswick, NJ also caused approximately 18 shipwrecks along the New Jersey coast. The immigrant ship Powhattan beached 100 yards from the shore. With rescue impossible, 340 people onboard lost their lives. "The shrieks of the drowning creatures were melancholy indeed." (Accord's Weather Guide Calendar)
• 16 April 1992...The Katina P ran aground off Maputo, Mozambique, causing 60,000 tons of crude oil to spill into the ocean. (Wikipedia)
• 17 April 1492...Spain and the Italian explorer Christopher Columbus signed a contract for him to sail to Asia to obtain spices. (Wikipedia)
• 17 April 1524...Giovanni Verrazano, a Florentine navigator, onboard the frigate La Dauphine "discovered" New York Bay. (Wikipedia)
• 18 April 1906...An early morning magnitude 7.8 earthquake along with a subsequent fire devastated much of San Francisco, CA, resulting in one of the worst natural disasters to hit a major US city. As many as 6000 people may have died because of this disaster. The earthquake was along the San Andreas Fault, with an epicenter thought to have been near Mussel Rock along the coast at suburban Daly City. [A series of articles commemorating the 100th anniversary of the San Francisco earthquake has been posted. San Francisco Chronicle]
• 18 April 1848...U.S. Navy expedition to explore the Dead Sea and the River Jordan, commanded by LT William F. Lynch, reached the Dead Sea. (Naval Historical Center)

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Prepared by AMS DS Ocean Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2010, The American Meteorological Society.