Archive for October 20th, 2009

Keeping a Close Eye on Underwater Weather..

Tuesday, October 20th, 2009

Hey everyone,

Our assignment this semester involves the monitoring of Ru27's CTD (conductivity, temperature, density).  Throughout the summer, Ru27 experienced little threat in terms of bottom water temperatures compared to what we have seen recently.  The temperature at the bottom of RU27's flight depth averaged roughly around 16 degrees near the end of the summer, but it began to get much cooler as the Fall semester continued.  As October approached, bottom water temperatures around 120 m. hovered around 13.5 degrees C and, at one point, reached just below 13 degrees C.  At this point, RU27's battery capacity needs to be scrutinized as the temperatures change throughout the remainder of her flight.  The contour plots below show how the temperature within the water column has changed since mid-September.  Two important things to notice is the constant change in the thermocline and how the bottom water temperatures have changed within a month.

First Week of Fall SemesterWeek 4 of Fall Semester

On October 15th (Thursday), we attempted to change the inflection depth to 80 meters, which was something we have never done before with RU27.  Our group spoke with Dave and he mentioned that this was due to the increasing biology growth.  The idea was to slow the barnacle growth by staying in much cooler waters and also to stay below the picnocline.  Above the thermocline and picnocline is where all the nutrients will be because they can't get below that large change in water structure. Therefore, changing the inflection depth to 80 meters would stunt biology growth since they cannot get access to the nutrient-rich part of the water column.  The only concern of changing the inflection depth to 80 meters was the possibility of Ru27 aborting her mission.  Unfortunately, the test did not work out as planned and a pressure sensor on the CTD was damaged in the process.  However, we still continue to search for the best flight pattern for Ru27 in order to avoid further biology growth and possible battery harm. We will continue to communicate with Dave and also update CTD plots throughout the semester.

Cheers,

Colin and Abe

Who? What? When? Where? Histories of Atlantic Crossings

Tuesday, October 20th, 2009

This week we've been trying to get down to the real essentials of the crossings that we researched, so we can provide the really crucial and important information when we input more of their tracts into Google Earth (next week!) Here are some things we have so far!

~Katie, Erin, and Dan

Joshua Slocum

· Born February 20, 1844, in Annapolis County, Nova Scotia, by the Bay of Fundy.

· Obtained his first command on the California coast in 1869, and sailed for 13 years out of San Francisco to China, Australia, the Spice Islands, and Japan.

· In 1892, a friend, Captain Eben Pierce, offers Slocum a ship that "wants some repairs" Slocum goes to Fairhaven, MA to find that the "ship" is a rotting old oyster sloop propped up in a field. It is the Spray.

· Slocum departs from Boston Harbor, MA on his famous circumnavigation on April 24, 1895, at the age of 51, in the rebuilt 37-foot sloop Spray.

· Slocum returns, sailing into Newport, RI, on June 27, 1898 in his tiny sloop Spray and after single-handedly sailing around the world , a passage of 46,000 miles. This historic achievement made him the patron saint of small-boat voyagers, navigators and adventurers all over the world.

· Sailing Alone Around The World published in book form in 1900 by The Century Company. It describes his experiences on this adventurous voyage and became an instant best seller. It has been translated into many languages, and is still in print today.

· On November 14th of 1909, at the age of 65, he set out on another lone voyage to South America leaving from Vineyard Haven on Martha's Vineyard, but was never heard from again.

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Ferdinand Magellan

· Ferdinand Magellan was born in 1480 in Sabrosa, Portugal

· Magellan took part in his first sea voyage in 1505 when Portugal sent him to India to help install Francisco de Almeida as the Portuguese viceroy

· Magellan believed that the Spice Islands could be reached by sailing west through the New World. He proposed this idea to Manuel I, the Portuguese king, but was rejected. On March 22, 1518, Charles I was persuaded by Magellan and granted him a large sum of money to find a route to the Spice Islands by sailing west, thereby giving Spain control of the area, since it would in effect be "west" of the dividing line through the Atlantic

Magellan set sail going west toward the Spice Islands in September 1519 with five ships (the Conception, the San Antonio, the Santiago, the Trinidad, and the Victoria) and 270 men.

· After months of sailing across the Atlantic Ocean, the fleet anchored at what is today Rio de Janeiro to restock its supplies on December 13, 1519. From there, they moved down the coast of South America looking for a way into the Pacific

· On March 28, they landed in the Philippines and befriended a tribal king, Rajah Humabon of Cebu Island. After spending time with the king, Magellan and his crew were persuaded into helping the tribe kill their enemy Lapu-Lapu on Mactan Island. On April 21, 1521, Magellan took part in the Battle of Mactan and was killed by Lapu-Lapu's army.

· After Magellan's death, Sebastian del Cano had the Conception burned (so it could not be used against them by the locals) and took over the two remaining ships and 117 crewmembers. To ensure that one ship would make it back to Spain, one ship, the Trinidad, headed east, and the Victoria continued west. The Trinidad was seized by the Portuguese on its journey, but on September 6, 1522 the Victoria and only 18 surviving crew members returned to Spain, completing the first circumnavigation of the earth.

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The Challenger Mission

· The H.M.S. Challenger, commanded by Captain George Nares, embarked from Portsmouth, England on December 21, 1872 and changed the course of scientific history. Physicists, chemists, and biologists collaborated with expert navigators to map the sea

· During the 4 year journey, the voyages circumnavigated the globe, sounded the ocean bottom to a depth of 26,850 feet, found many new species, and provided collections for scores of biologists.

· The result was the Report Of The Scientific Results of the Exploring Voyage of H.M.S. Challenger during the years 1873-76 which, among many other discoveries, catalogued over 4,000 previously unknown species. John Murray, who supervised the publication, described the report as "the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries"

· The Challenger was equipped with 144 miles of sounding rope and 12.5 miles of piano wire for sampling gear.

· Challenger returned to Spithead, Hampshire on 24 May 1876, having spent 713 days at sea out of the intervening 1,606. On her 68,890-nautical-mile (127,580 km) journey, she conducted 492 deep sea soundings, 133 bottom dredges, 151 open water trawls, 263 serial water temperature observations, and discovered about 4,700 new species of marine life

· The Challenger expedition produced 50 volumes, most of which described the organisms collected from both deep and shallow water. Much of what we understood about world ocean biogeography for the next 75 years stemmed from analyses of collections made on this journey

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