Exploration, Antarctica

When it became apparent that several European nations were actively exploring Antarctica, a French medical doctor by the name of Jean-Baptiste Etiene Auguste Charcot (1867-1936) decided that France should not be excluded from this enterprise. Therefore, he raised funds for the construction of a ship he named Le Francais. In August 1903 he set sail for the Antarctic Peninsula and proceeded to map its west coast and offshore islands. Contrary to most of his predecessors, Charcot decided to winter over in a sheltered bay on Booth Island (65°05 S, 064°00 W), where he and his... 

In principle, numerous reports have detailed the possibility to modify an enzyme to carry out a different type of reaction than that of its attributed function, and the possibility to modify the cofactor of the enzyme has been well explored [8,10]. Recently, the possibility to directly observe reactions, normally not catalyzed by an enzyme when choosing a modified substrate, has been reported under the concept of catalytic promiscuity [9], a phenomenon that is believed to be involved in the appearance of new enzyme functions during the course of evolution [23]. A recent example of catalytic promiscuity of possible interest for novel biotransformations concerns the discovery that mutation of the nucleophilic serine residue in the active site of Candida antarctica lipase B produces a mutant (SerlOSAla) capable of efficiently catalyzing the Michael addition of acetyl acetone to methyl vinyl ketone [24]. The oxyanion hole is believed to be complex and activate the carbonyl group of the electrophile, while the histidine nucleophile takes care of generating the acetyl acetonate anion by deprotonation of the carbon (Figure 3.5). 

In conventional synthetic transformations, enzymes are normally used in aqueous or organic solvent at moderate temperatures to preserve the activity of enzymes. Consequently, some of these reactions require longer reaction times. In view of the newer developments wherein enzymes can be immobilized on solid supports [183], they are amenable to relatively higher temperature reaction with adequate pH control. The application of MW irradiation has been explored with two enzyme systems namely Pseudomonas lipase dispersed in Hyflo Super Cell and commercially available SP 435 Novozym (Candida antarctica lipase grafted on an acrylic resin). 

For many years, cosmochemistry depended on the chance discovery of meteorites - either witnessed falls and serendipitous finds, or the dogged determination of a few private collectors who systematically searched for them. That changed in 1969, when Japanese explorers in Antarctica led by Masaru Yoshida stumbled onto meteorites exposed on bare ice. American geologist William Cassidy immediately recognized an opportunity, and with support from the National Science Foundation he mounted a joint expedition with the Japanese to the Allan Hills region of Antarctica in 1977 to recover meteorites. This was the first of many expeditions, sponsored by the National Science Foundation and headed first by Cassidy and later by Ralph Harvey, that have returned to Antarctica every year to collect meteorites (Fig. 1.11). The Japanese have operated a parallel field program in... 

Why were McClintock and Baker exploring the oceans off Antarctica ... 

On July 21, 1998 the United States Board on Geographic Names recognized Drs. McClintock and Baker by naming geographic features after them on the north (McClintock Point) and south (Baker Point) sides of Explorers Cove, New Harbor, McMurdo Sound, Antarctica. This honor was bestowed upon them to recognize their extensive contributions to Antarctic marine biology and chemical ecology. 

As the exploration of the biosphere has continued, environments on Earth have been discovered that are quite different from and alien to human-like life. Nevertheless, where an environment has been found to contain a chemical disequilibrium, if liquid water is also present and the temperature does not exceed the upper limit for covalent bonding of core biomolecules, life is present. Active life has been found in deep-ocean thermal vents at temperatures in excess of 112°C. Life has been found in Antarctica where liquid water exists only transiently. It has been found 5 km below Earth s surface in mine shafts, and in the effluents of mining operations at Rio Tinto, Spain, that are as acidic as dilute sulfuric acid. Several of those environments are summarized in Table 3.1. 

In 1911 the geologist Sir Douglas Mawson led an expedition to explore the unknown region of Antarctica west of Cape Adare on the Ross Sea. Mawson set off east of Cape Denison with fellow explorers Xavier Mertz and Belgrave Ninnis. Having completed only 320 miles, Belgrave Ninnis... 

The natural balance of the environment has been seriously affected by man in many parts of the planet. However, there is universal consensus that the fate of Antarctica has to be different and that its natural resources, scientific values and beauty must be preserved. Although most inner zones of the Antarctic continent remain unexplored and have minimum human presence, the coastal zone has been thoroughly navigated, with permanent human settlements since the beginning of the twentieth century. The coast of the Antarctic Peninsula, in particular, has been one of the most extensively explored zones, attracting an important human presence. The closeness of the peninsula to South America, its less severe climate and its icefree accessibility in summer account for the numerous research stations and the commercial exploitation of the marine resources. The remnants of human activity such as abandoned stations, field dumps of fuel, rubbish dumps, etc., are still visible. 

The XV ATCM (1989, Paris) represented a real turning point for the protection of the Antarctic environment. The parties, in Recommendation XV. 1 prompted their governments to undertake as a priority objective the further elaboration, maintenance and effective implementation of a comprehensive system for the protection of the Antarctic environment and its dependent and associated ecosystems aimed at ensuring that human activity does not have an adverse impact on the Antarctic environment and its dependent or associated ecosystems or compromise the scientific, aesthetic or wilderness values of Antarctica . The parties asked that a Special Antarctic Treaty Consultative Meeting be held in 1990 to explore and discuss proposals relating to the comprehensive protection of the Antarctic environment. 

Long-term trends observed by recent measurements cover a few decades, at most. For much longer periods, the supposition of a quasi-stationarity of the atmosphere makes it likely that a longer trend will not continue indefinitely, but that eventually a new steady state is reached or the trend reverses. In recent years it has become possible to investigate the abundance of trace substances and their variations in past epochs by the exploration of deep ice cores from the great ice sheets of Greenland and Antarctica. These provide a record of atmospheric conditions dating back at least 70,000 years. 

Captain James Cook was the first person to circumnavigate Antarctica between 1772 and 1775 during his three voyages of exploration into the Pacific Ocean (Beaglehole 1955,1961,1962,1967 Bellec2000). On January 30, 1774, Captain Cook reached a point near the coast of West Antarctica at 71°10 S, 106°54 W. 

These voyages exposed the crews of his ships to frightful conditions caused by severe cold, violent storms, and dangerous pack ice along the coast. As a result of these hardships and based on what he had seen. Captain Cook reported that any land that may exist close to the geographic south pole was not worth the effort to explore (Stonehouse 2(X)2). In the years that followed Captain Cook s voyages, the ocean around Antarctica was frequented by a multitude of European and American whalers and seal hunters who were primarily interested in making a profit from the sale of whale oil and seal skins (Stonehouse 2002 Victor 1964). 

Even as Bellingshausen was returning from his expedition to Antarctica, a British seal hunter of Scottish ancestry by the name of James Weddell (1787-1834) entered upon the stage of Antarctic exploration. Weddell in Fig. 1.2 retired from the British Navy in... 

On the return trip to Erance, d Urville was surprised to encounter an American warship that was part of a fleet commanded by Lieutenant Charles Wilkes (1798-1877) who was leading the United States Exploring Expedition from 1838 to 1842 to the southern ocean. On December 26 of 1839 four ships in Wilkes fleet headed south toward the coast of Antarctica. Wilkes in Fig. 1.4 sailed along the coast of East Antarctica including the part that is now called Wilkes Land (69°00 S, 120°00 E). Only two of the six ships that started this voyage returned to New York in August of 1842. 

Fig. 1.3 Jules C. Dumont d Urville (1790-1842) was a French naval officer and navigator who led the French Naval Expedition to Antarctica from 1837 to 1840. He was an experienced explorer who had worked in the eastern Mediterranean Sea followed by two expeditions to map the coasts of Australia and New Zealand and to map variations of the magnetic field in the South Pacific euid the Southern Ocean. He used two ships (Astrolabe and Zelee) in eui attempt to find the magnetic pole in Antarctica Although he failed to achieve that objective, he named Adelie Land along the coast of East Antarctica after his wife and discovered two large islands off the coast of the Antarctic Peninsula (Photo by the Scott Polar Research Institute, University of Cambridge, used here with permission)...

On the day when the sailing ship Astrolabe of Dumont d Urville encountered the Porpoise of Wilkes fleet on the high sea off the coast of East Antarctica, the crews of both ships hoisted full complements of sails and passed without saluting each other in contrast to Bellingshausen and Palmer who preceded them as Antarctic explorers. 

The magnetic field of the Earth and the location of the magnetic poles were of great interest to the seafaring nations of the nineteenth century because the magnetic compass was used to steer ships across the oceans that contained few points of reference. For this reason, several Antarctic explorers of the nineteenth century attempted to map the magnetic field of the Earth and to determine the position of the magnetic pole in Antarctica (e.g., Dumont d Urville and Charles Wilkes). 

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