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U.K. Center Provides National Focus For Océanographie Sciences And Technology • Research and training at new Southampton Oceanography Centre explore functioning of Earth and its oceans Michael Freemantle, C&EN London
f you had stood on the quay at Empress Dock in Southampton, England, 60 years ago, you would have seen vessels discharging banana cargoes from Central America and the West Indies. You might also have seen the world's great trans-Atlantic passenger liners being tugged into or out of the nearby Ocean Dock. Since its heyday in the 1930s, the port's trans-Atlantic passenger trade has dwindled and bananas are no longer unloaded at Empress Dock. Today, you are likely to see the Siena Normandy, a ferry that crosses the English Channel twice a day to Cherbourg, France, arriving at or departing from the ferry terminal adjacent to the dock. And you might possibly see a research vessel berthed on the quay alongside one of Southampton's newest and proudest additions, an international oceanography center. Southampton's Empress Dock was opened by Queen Victoria on July 26, 1890. The Southampton Oceanography Centre at Empress Dock was officially opened by Prince Philip, Duke of Edinburgh, on April 17, 1996. The historic link is appropriate. Southampton has been a thriving international port since the 8th century, following the arrival of the Saxons. Henry V, king of England, sailed from the port for the Battle of Agincourt in France in 1415. The Pilgrim Fathers left Southampton for the New World aboard the Mayflower and the Speedwell in 1620. And on April 10, 1912, the liner Titanic left Southampton on its tragic maiden voyage.
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Southampton Oceanography Centre (above) in conjunction with several royal research ships, such as RRS Discovery (right), carries out research on ocean circulation and ocean and seafloor processes.
"Southampton abounds in merchants, sailors, and mariners who flock from distant parts to that town with an immense quantity of cargoes, galleys, and ships plying with merchandize to the port," according to the charter given by Henry VI to the town in 1447. And now the thriving international port also hopes to be the home of a thriving international center abounding in marine scientists and technologists plying their professional océanographie skills in teaching and research. Construction and development of the Southampton Oceanography Centre (SOC) cost about $76 million. It is Britain's largest single investment in marine science since the Challenger expedition of 1872-76, which heralded the start of modern oceanography. Scientists on board the Challenger mapped SEPTEMBER 2,1996 C&EN 23
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The use of advanced ocean technology is an important driving force at the center, explains Hamilton. SOC's existing océanographie equipment and facilities include a range of laboratories, temperature-controlled areas, pressure test facilities, a research aquarium, and seafloor survey systems. Much of the equipment designed to work deep in the ocean was built by engineers from the former Institute of Océanographie Sciences Deacon Laboratory (IOSDL). The U.K. National Océanographie Library and associated information services are also housed at the center. One example of SOC's océanographie equipment is the seafloor survey system known as TOBI (Towed Ocean Bottom Instrument). The vehicle is used to explore the deep ocean and can operate to depths of 6,000 meters. "TOBI can do a variety of things," says Hamilton. "It resolves in fine detail the topography near the bottom of the ocean and can sense changes in the magnetic field near to the seabed. It also carries chemical sensors on board that monitor hydrothermal vents." The Ocean Technology Division at SOC, which is responsible for developing and operating novel instruments and vehicle systems, is also developing a range of océanographie sensors. Research focuses on methods of combining chemical and biological sensors with physical, geotechnical, and geophysical sensors. The sensors have a range of applications including coastal and environmental management—for example, the monitoring and management of waste. Offshore uses include exploration for oil, gas, and mineral resources. The division's chemical sensors incorporate ultraviolet, fluorescence, electrochemical, optical, and fiber-optic techniques. The division also is responsible for managing NERC's multi-million-dollar Autosub research program. Autosub is a remotely operated underwater vehicle that is being developed to simultaneously collect multiple sets of chemical, biological, physical, and geophysical océanographie data over thousands of kilometers to depths of 6,000 meters. Such autonomous underwater vehicles will become the "satellites of the oceans," according to SOC. "These truly robotic vehicles will rove the oceans, diving from sea surHamilton: synergy by pooling resources face to seabed, measuring temperature,
the ocean floor and the distribution of deëp-sea sediments and minerals, collected geological and biological samples, and determined horizontal and vertical temperature profiles in the Atlantic, Pacific, and Indian Oceans. Today at SOC, scientists are involved in research that ranges around the world, from the ocean's surface to its depths. Projects include climate-related research, using chlorofluorocarbons (CFCs) as ocean tracers, probing chemical and physical processes occurring on the seafloor, and environmental studies. Southampton is also now home port of the "Royal Research Ships" of the U.K.'s Natural Environment Research Council (NERC): RRS Discovery, RRS Charles Darwin, and RRS Challenger. This fleet of research vessels, previously based in Barry, South Wales, is equipped specifically for deep-sea oceanography and marine geology. The fleet serves the needs of the academic community in universities and research institutes throughout the U.K. "The idea of the new center is to develop a synergy, the whole greater than the sum of the parts, by pooling resources," says Norman Hamilton, professor of geology at the University of Southampton and deputy director of the center. "The center's mission is to understand the functioning of the Earth and its oceans as a physical, biological, geological, and chemical system on a global scale," he explains. SOC has on-site some 1,000 research scientists, lecturing and support staff, and students. The annual operating costs are about $40 million, says Hamilton.
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salinity, and several other physical parameters," says Hamilton. "And every time one pops up to the surface, it will transmit data back, via satellite, to SOC. A vehicle will be able to spend many hundreds of hours at sea, away from the mother ship." The James Rennêll Division for Ocean Circulation at SOC, formerly a center of IOSDL, uses satellite observations, modeling methods, and computer simulation techniques to study ocean circulation on a global scale. The division is also the focus for the British contribution to the billion-dollar World Ocean Circulation Experiment (WOCE). The experiment, which is part of the World Climate Research Program, aims to develop improved models of ocean circulation for use in climate prediction. WOCE was set up by the World Meteorological Organization to look at ocean circulation in relation to climate changes that result from both natural and anthropogenic causes, says Denise Smythe-Wright, head of tracer chemistry at SOC. "It is a very big international program," she says. The first phase of the experiment, which involves more than 20 countries, began in 1990. According to the 1996 WOCE project status report, the analysis, interpretation, modeling, and synthesis phase of the experiment will continue until 2002. The use of chemical tracers, such as CFCs, to study the dynamics of the ocean is a major component of the WOCE program says Smythe-Wright. "SOC's tracer chemistry group was set up primarily to look at the spread of materials throughout the ocean," she
Smythe-Wnght: CFCs used for tracer studies
Southampton center integrates diverse efforts The Southampton Oceanography Centre (SOC) became operational in October 1995, 10 years after a report from the U.K. House of Lords Select Committee on Science & Technology called for greater collaboration in the country between research institutes and universities, in particular the Institute of Océanographie Sciences Deacon Laboratory (IOSDL) and the University of Southampton. Plans for the center were put to the British government in 1988, and the site at Empress Dock in Southampton was acquired in 1989. "The concept was to put a research institute into a higher education campus setting," says Norman Hamilton, professor of geology at the university and deputy director of the center. "The center is a joint venture between the University of Southampton and the Natural Environment Research Council [NERC]." NERC is one of seven research councils in the U.K. responsible for administering government funding for science. "The center has two funding streams," Hamilton tells C&EN. NERC provides the main funding stream and the university— which receives funding from the U.K's Higher Education Funding Council—provides the other stream, he says. At a single site, SOC brings together IOSDL, funded by NERC; Southampton University's oceanography and geology departments; and the marine technology and underwater acoustics group in the university's faculty of engineering and applied science. These university departments and group were previously located at the university's main campus in Highfield, a section of Southampton. IOSDL, formerly based in Wormley, in the county of Surrey, was Britain's premier institution for physical, chemical, geological, geophysical, and biological research in the deep ocean. Its research activities have been placed in four multidisciplinary NERC-funded divisions at SOC: the Ocean Technology Division, the James Rennell Division for Ocean Circulation, the George Deacon Division for Ocean Processes, and the Challenger Division for Seafloor Processes.
tells C&EN. "The program realized er of waters that have formed in tj\e that anthropogenic substances that southern ocean." have gotten into the ocean could be The group was able to use tracer used to trace the movement of water data to identify and "age" a Brazil masses around the ocean. eddy transported across the South At"Ocean water is in distinct density lantic to the Cape Basin near the coast layers," she explains. "New water is of Africa. This was the first observation formed at the poles and spreads of such an eddy so far east, according throughout the oceans. We determine to the team. The CFC-tracer data sugwhen water was ventilated—that is, gested that the eddy was more than when it was in contact with the atmo- four years old. sphere—and how it mixes and Smythe-Wright's group is not only circulates." using CFCs to trace the circulation of The CFC-tracing technique relies on water around the ocean, but also is the varying ratios of CFC use over re- looking at the oceanic sink of new halocent decades to give an age to seawa- carbons, such as CFC replacements, ter. For example, between the 1950s and their degradation products. "In adand the late 1970s, the ratio of CFC-11 dition, we are studying the natural pro(CC13F) to CFC-12 (CC12F2) in the atmo- duction of halocarbons such as methyl chloride, methyl bromide, and methyl sphere gradually increased. "CFCs are anthropogenic and there- iodide from marine biota, such as fore unique because they are the plankton, and relating this production to ocean processes," only tracers we have she says. which have an associated time frame/' Smythe-Wright's says Smythe-Wright. group is one of sev"CFCs are soluble in eral in SOC's George seawater. So the atmoDeacon Division for spheric concentrations Ocean Processes that are mirrored in the are endeavoring to surface seawater withunderstand the ways in about one month. the ocean works as We can look at CFC an interactive physiconcentrations in any cal-biogeochemical water sample around system. the world and comResearch on the pare the ratios with atprocesses and fluxes mospheric growth associated with the curves. This tells us Thomson: deep-sea redox reactionsseabed is carried out when the water was by SOC's Challenger last in contact with the atmosphere." Division for Seafloor Processes. The diIn a recent investigation, Smythe- vision consists of research groups Wright used CFC-113 (C2C13F3) to working on sedimentary processes, biCFC-11 and CFC-113 to CFC-12 ratios ological processes, crustal processes to examine the circulation of the abys- and mineral resources, and chemical sal water mass in the Argentine Basin, changes and fluxes. known as the Antarctic Bottom Water. Research geochemist John Thomson During a cruise on the RRS Discovery, explains that the group working on Smythe-Wright and her team collected chemical changes and fluxes is investimore than 900 water samples from 91 gating the rates and kinds of chemical stations in the South Atlantic Ocean. processes that control the distribution The group obtained profiles not only of metals in sediments. Applications infor CFCs but also for salinity, nitrates, clude the assessment of environmental silicates, and phosphates [/. Geophys. impacts in deep water and the evaluaRes., 101, 885 (1996)]. "Different water tion of deep-sea mineral deposits. masses have different signatures for "We have recently been working on these tracers," says Smythe-Wright. deep-sea sediments looking at the geo"The South Atlantic Ocean has a high chemical effects of changes in accumudiatom population. When these die, lation rate," Thomson tells C&EN. their siliceous skeletons dissolve, giv- "Sediments in the deep sea accumulate ing relatively high values for silicates. fairly slowly, but during glacial periods We can therefore use silicates as a trac- there is an enhanced accumulation. SEPTEMBER 2,1996 C&EN
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SCIENCE/TECHNOLOGY Presently, we are in an interglacial period with high sea levels, warm climates, and lower accumulation rates. "In many parts of the world ocean, there's a very delicate balance between the organic carbon supplied from the surface of the ocean and the oxygen content of deep-sea sediments," Thomson continues. He explains that sediments can be divided into an oxygencontaining zone, a deeper zone where there is no oxygen, and a reduction zone. They are known respectively as oxic, postoxic, and anoxic zones. "There is a redox discontinuity at the oxicpostoxic boundary," says Thomson. "We have found that there is a redox ladder of different elements across this boundary." As a result, redox-sensitive elements migrate through the sediments. "Elements such as iron and manganese diffuse upward from the sediments and are precipitated as oxyhydroxides," says Thomson. "Other elements that are present in seawater in large quantities, like molybdenum, vanadium, and uranium, diffuse into the sediments. These three elements are quite conservative in seawater. They are not removed from the water in oxic conditions. In anoxic conditions, however, the elements become concentrated in the sediments and are even precipitated out of the water column." Thomson and colleagues have shown that sediments laid down in the latter part of the last glacial period in the deep northeast Atlantic, southwest of the British Isles, exhibit enhanced concentrations of several redox-sensitive elements including manganese, molybdenum, iron, arsenic, phosphorus, selenium, vanadium, cadmium, and uranium [Earth Planet. Set. Lett., 139, 365 (1996)]. The group collected the sediment samples during a cruise of the RRS Charles Darwin. The solid sediments were separated from their interstitial pore water by centrifugation and filtration on board the ship. Iron(II), manganese(II), nitrates, phosphates, and silicates in the water were determined on board by injection-flow colorimetric methods. "The way in which an element partitions in pore waters is quite delicate," says Thomson. "So you can get a much better indication of what reactions are going on by looking at the pore waters. Pore water analysis generally has to be 26
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The vents are thought to occur every 50 km or so along the crest of the midocean ridge, according to Hamilton and SOC's other deputy director, Colin Summerhayes [Geoscientist, 6, 8 (1996)]. The hydrothermal fluids are known to form by the heating of cold seawater as it percolates down through cracks in the oceanic crust. "These fluids are anoxic," says Thomson. "They are full of sulfur, as hydrogen sulfide, and iron. As soon as they mix with the cold oxic bottom waters, they precipitate." The dense clouds of suspended sulfide particles and oxides formed by their reaction with seawater produce the so-called black smokers. Hydrothermal vents have been identified in a ridge beneath the Atlantic Ocean called the Mid-Atlantic Ridge. Until 1993, three active high-temperature sites—the Trans-Atlantic Geotraverse site, Snake Pit, and Lucky Strike— had been located on the ridge. In 1994, an international group of scientists, including scientists now at SOC, reported the discovery of the Broken Spur Vent Field on the ridge [Earth Planet. Set. Lett., 125,119 (1994)]. The vent field, comprising three discrete black smoker sources of fluid in excess of 350 °C and two weathered sulfide mounds, was discovered during a cruise of the RRS Charles Darwin. The scientists used TOBI, towed at between 200 and 300 meters above the seafloor, to survey the ridge for vents. Another vehicle—which contained a unique system of geophysical and geochemical sensors, water bottles, and pumps called Bridget—was used to identify, map, and sample the plumes. Research in the University of Southampton's department of geology, which is located at SOC, is also concerned with processes that occur on the ocean floor, including the development of hot springs. "The major areas of geochemical and metallogenic studies here at the moment focus on the origin of igneous rocks; that is, rocks formed by magmatic processes, welling out of the deep of the Earth," explains Robert P. Foster, senior lecturer in geology at the university. "Very large volumes of rock and much of Earth's crust developed on the ocean floor with the upwelling of midoceanic ridges, and the lateral migration of igneous rocks produced there." Foster explains that current processFoster: understanding seafloor processes es at midoceanic ridges can be related
done on the ship because sample speciation does not survive transport back to the laboratory." The group working on biological seafloor processes is aiming to use the analysis of the sediments that carpet the seabed to make climate predictions. These sediments are Earth's largest sink for natural and anthropogenic carbon. The debris from marine organisms acts as a record of environmental change reflecting past climates. "The sinking organic matter has to run the gauntlet of organisms who prey on it and burrow into it," says group member Tony Rice. With the help of European Union funding, the group is collaborating with scientists from nine European countries to investigate how communities of organisms on the ocean bed affect these deposits. The study site is in an abyssal plain about 250 miles southwest of Ireland's Bantry Bay, according to Rice. "We want to use this site to understand how sedimentary records are affected by biological and chemical activity on the seafloor. This information is vital if we are to date reliably past environmental upheavals and predict future climatic change." The Crustal Processes & Mineral Resources group of the Challenger Division for Seafloor Processes is engaged in research on hydrothermal vents, also known as hot springs, on ocean ridges. These vents are hot, mineral-rich fluids that spew from underwater volcanic systems to form new mineral deposits. They support unique forms of life known as aphotic fauna.
to ancient mineral deposits. "We see analogies for this very young environment going back at least 2.7 billion years where we see major accumulations of metal sulfides, which are a major source of copper and zinc around the world," he tells C&EN. "If you think of what we are seeing at the midoceanic ridges now, in 100 million or 200 million years' time, they may form the continental crust." Foster believes that bringing together geologists and oceanographers onto a single site at SOC will prove increasingly beneficial for the study of oceanic and continental crustal processes. "To understand ancient processes, for example, we now have an ideal opportunity with our colleagues in oceanography to look at presentday processes and relate them back to ancient crusts. We can now physically see hot springs erupting off the seafloor, we can see chemical sedimentation and the nature of these chemicals, and we can see how these metal sulfides physically accumulate. We can then relate these observations back to ancient crusts, in southern Spain, for example, to understand in detail how those minerals accumulate." This type of research can have important economic benefits, suggests Foster. "There is a great deal still to be learned about the chemical and physical processes occurring on the seafloor," he says. "Understanding how and where metals accumulate is important for our future development." The point is reinforced by Hamilton. "If we are to understand and properly exploit our planef s natural resources— for example oil, natural gas, sands, gravels, and metals produced from hydrothermal vents—then we need to understand how the oceans work," he says. SOC research activities focus not only on processes deep in the global ocean, but also on coastal and shelf sea processes. Scientists in the university's department of oceanography are studying, for example, the circulation and fluxes of tidal and residual waters in shelf seas and estuaries, sediment transport processes, and the biogeochemical cycling of nutrients and trace metals in coastal systems. "We have a number of projects that collectively represent a major effort to improve understanding of the processes which affect the fluxes and distributions of metals in coastal and shelf sea
environments," says marine chemist J. Dennis Burton, professor in the oceanography department. "My own research interests center on biogeochemical cycles of trace elements, particularly metals in estuarine and shelf environments." Burton, working with department colleague Peter J. Statham and several research fellows, has measured dissolved and particulate cadmium, cobalt, copper, iron, manganese, nickel, lead, and zinc in environments such as the North Sea and the English Channel, and developed models for the distribution of these metals in these seas. "Our present effort is directed to the development of a water quality model that includes the nonconservative processes which are important for most metals," Burton tells C&EN. Several scientists in the department are working on the development of electrochemical sensors, used on research vessels and submersibles, for measuring metals, carbon dioxide, dissolved organic carbon, dissolved oxygen, pH, and salinity. The department has also developed various remote-sensing instruments. Remotely sensed image data from satellites and aircraft are used to measure the distribution of chlorophyll, sea surface temperature, suspended sediment motion, and pollutants. Many of the projects in the department "involve collaboration with other laboratories in the U.K. and in Europe," notes Burton. For example, one of the department's projects concerns the development and use of artificial reefs from prime and recycled materi-
Croudace: studying sediment histories
als for increasing biodiversity and fisheries and coastal· zone management. The work is part of an international program covering studies in Italy, India, and Hong Kong, and involves collaboration with an artificial reef research network of 36 European Union laboratories. SOC also has a geosciences advisory unit that offers in-depth studies of environmental radioactivity and environmental geochemistry for clients in the nuclear and petroleum industries and local district councils. "We started about eight years ago looking at environmental radioactivity in the southern part of England," says geochemist Ian W. Croudace, who heads the unit and is a member of the university's geology department. "Initially we investigated the effects of fallout from Chernobyl. Funding from a local authority consortium allowed us to buy a large amount of state-of-theart counting equipment. "Most of our interests relate to the terrestrial and coastal environment rather than the marine environment," Croudace tells C&EN. "We investigate what happens to elements discharged from nuclear reactors and nonnuclear industries like the Esso oil refinery at Fawley." The Fawley oil refinery is the largest in the U.K. and one of the most complex in Europe, according to Croudace. The plant is located on Southampton Water, a coastal plain estuary that stretches from Southampton to the Isle of Wight and the English Channel. In one study, reported last year, Croudace and coworker Andrew B. Cundy investigated the pollution history of sediment cores retrieved from the Fawley area of Southampton Water. These cores reveal a clear record of anthropogenic inputs, according to Croudace and Cundy. The researchers found that "the main source of pollution is from the oil refinery at Fawley, developed from 1949 to 1951 onward, discharging hydrocarbon pollution and elevated copper concentrations" [Environ. Sci. Technol, 29,1288 (1995)]. They add, however, that "effluent quality improvements over the last two decades have led to marked reduction in these discharges." The Southampton Oceanography Centre is engaged not only in research in the marine and earth sciences and the development of marine technology, it is also very active in undergraduate SEPTEMBER 2,1996 C&EN 27
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and postgraduate training of students in the marine and earth sciences. "The university offers a wide range of first degrees in geology and oceanography/' says Hamilton. "We arrange for all our students to come here. Postgraduate students are here permanently. Undergraduates spend some of their time at the main campus in Highfield, which is where the university is based, but they have their practical classes in the laboratories at the center. We gradually introduce them to the center so that by the time they get to their third year, they spend the whole of their time here." As the center approaches the end of
its first year of operation, Hamilton is pleased with its achievements. "The two communities, from the university and the Institute of Océanographie Sciences, have settled in and are learning to work together. Our students have benefited greatly from being at the new center." Hamilton is upbeat about the future. "There is a tremendous amount of expertise here ranging from studies in the local estuaries right out to the deep oceans," he says. "The research and training opportunities we provide here will help to educate those young minds who are going to lead us into the sustainable development of our planet in the 21st century." Π
Synthetic strategy yields large porphyrin arrays in one step Michael Freemantle, C&EN London hemists in New Zealand have developed a building-block strategy for constructing large porphyrin arrays from porphyrin monomers in one step. The methodology could eventually lead to the design and construction of photovoltaic cells that use large arrays of synthetic porphyrins. Senior lecturer in organic chemistry David L. Officer, lecturer in inorganic chemistry Anthony K. Burrell, and doctoral student David C. W. Reid at Massey University, Palmerston North, have used the strategy for the one-step construction of porphyrin pentamers and a nonamer [Chem. Commun., 1996, 1657]. Porphyrin molecules, composed of four pyrrole rings, have near-planar structures. These macrocyclic compounds are usually found in nature in the form of metal complexes. For example, the chlorophylls—the green pigments used by plants in photosynthesis—are magnesium porphyrin complexes. Plant cells use photosynthetic antenna arrays of up to 300 chlorophyll molecules for harvesting light. "A photovoltaic cell could be envisioned as operating in an analogous fashion, effecting the capture of light using large arrays of synthetic porphyrins," suggests the New Zealand team. The team points out that conventional strategies to synthesize large porphyrin arrays often involve many sequential steps, separation of mixtures, and exten-
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sive chromatographic purification— invariably resulting in low overall yields. "The critical feature of our work is
the success of a Wittig reaction which enables a porphyrin phosphonium salt to react with almost any aldehyde, one of the commonest groups on organic molecules," Officer tells C&EN. The reaction, named after the Ger man chemist Georg Wittig, who won the Nobel Prize for Chemistry in 1979, is used in organic synthesis to prepare alkenes from organophosphorus zwitterions—known as ylides—and alde hydes or ketones. "It is the products of the Wittig reac tions which become our building blocks and allow the rapid array synthesis," says Officer. "By placing an aldehyde group on our building block we can make one new porphyrin ring." To prepare the pentameric porphy rin, the group started with the nickel derivative of the porphyrin aldehyde building block synthesized from the tetra-m-xylyl derivative of the porphy rin phosphonium salt and benzene-1,4dicarboxaldehyde. Condensation of the porphyrin aldehyde with pyrrole yield ed a star-shaped porphyrin pentamer.
Eight porphyrins surround nonamer's central porphyrin
