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During April and May 2004, three
<br />members of the Department of Geology
<br />and Geophysics - Limnological Research
<br />Center (LRC) traveled to Spain to partici-
<br />pate incollaborative paleoclimate research
<br />with scientists from Spanish universities
<br />and scientific institutions.
<br />Blas Valero-Garces, aformer
<br />postdoctoral research fellow at the LRC
<br />and now a scientist with the Instituto
<br />Pirenaico de Ecologic - Consejo Superior
<br />de Investigaciones Cientificas (Pyrenean
<br />Institute of Ecology -Spanish Scientific
<br />Research Council) in Zaragoza, Spain,
<br />recently received funding to coordinate a
<br />major expedition. For many years, Blas has
<br />hoped to use the specialized LRC field
<br />equipment and expertise to retrieve
<br />sediment samples from several Spanish
<br />lakes. These lakes have been high-priority
<br />targets for research: they are thought to
<br />contain deep stacks of sediment that span
<br />long periods of time (perhaps 50,000 years)
<br />and provide a particularly clear reflection
<br />of past climate, geological processes, and
<br />human activities near the lakes.
<br />While all lake basins slowly accumulate
<br />layers of sediment over time, differences in
<br />water chemistry, inflows and outflows, lake
<br />morphometry, and other variables make
<br />some lakes (such as these) more sensitive
<br />recorders of changes in their surrounding
<br />Hotspots continued from page 3
<br />false_ Secchi disc records have shown a
<br />decrease in water clarity in only one of our
<br />study lakes. In the others, clarity has
<br />remained constant or has increased. One
<br />possible explanation for this is that better
<br />management of phosphorus has countered
<br />potential increases in phosphorus inputs
<br />that would otherwise be associated with
<br />urbanization. Examples of better manage-
<br />ment of phosphorous are the 1985 state-
<br />wide ban on phosphorus-containing
<br />detergents, improved management of
<br />septic tanks, improved. management of
<br />manure in confined animal facilities, and
<br />improved sewage treatment.
<br />Our final report to the U.S. Forest
<br />Service will include chapters on hydrologic
<br />and climatic factors and the past develop-
<br />environment over time. And unlike most
<br />Minnesota lakes, which were bulldozed by
<br />glaciers (or not formed) until major ice
<br />sheets departed approximately 12,000
<br />years ago, these Spanish lakes contain
<br />extraordinarily long land-based archives of
<br />past climate -which would yield important
<br />clues for deciphering major paleoclimatic
<br />problems.
<br />Despite these appealing qualities, the
<br />target lakes had kept most of their secrets
<br />- they are too deep, or too big (or both), to
<br />permit the use of common, low-cost
<br />sediment coring devices. And they are
<br />never ice-covered, which further limits the
<br />types of equipment that can be used to
<br />retrieve sediment samples.
<br />But Blas was familiar with the LRC's
<br />unique equipment, and knew it could be
<br />used on these lakes. These devices were
<br />originally designed by Swedish scientist
<br />Borje Kullenberg for use in the most
<br />challenging coring conditions on earth: the
<br />oceans. They were used on large ships,
<br />which have dedicated hydraulic hoists and
<br />other heavy machinery to lift the equiment,
<br />and which also provide large, stable
<br />platforms from which to deploy the coring
<br />device. The LRC Kullenberg corer was
<br />specifically designed to be disassembled,
<br />transported on a single trailer or shipped in
<br />a standard shipping container, and
<br />ment history of these watersheds, and an
<br />analysis of lake sensitivity. The report will
<br />be available in early 2005. Ultimately, we
<br />hope that regional planners and lake
<br />managers will use our findings to help
<br />them plan for the continued enjoyment of
<br />our lake resources long into the future.
<br />The two photos at right are examples of the
<br />common property types seen on the study
<br />lakes' shores: the fishing cabin and the
<br />mansion. It is not uncommon for these two
<br />types of structures to be located on adjacent
<br />lots. This demonstrates the changing nature of
<br />lake use from seasonal recreation to year-
<br />round residential.
<br />reassembled on-site. It consists of two 20-
<br />foot boats that nest inside each other on
<br />the trailer, but lie next to each other in the
<br />water (see photo on page 1). A platform is
<br />constructed across the two boats, and a
<br />tower is raised above them. The hydraulic
<br />winch, capstan, pipes, and. other equip-
<br />ment are then positioned on the platform..
<br />In this way, the capability of the ocean-
<br />proven Kullenberg system can be used on
<br />any lake that can be reached with a car or
<br />truck.
<br />In early February, LRC researchers
<br />Doug Schnurrenberger,Mcrk Shapley, and
<br />Anders Noren loaded the Kullenberg corer
<br />into a shipping container and sent it to
<br />Barcelona. Two months later, they flew to
<br />Spain and met Blas and more than thirty
<br />other Spanish researchers. Thus began the
<br />six-week expedition, which covered eight
<br />lakes via a road trip of more than two
<br />thousand miles through Spain. At each
<br />lake, they assembled the platform, re-
<br />trieved several four- to nine-meter sedi-
<br />ment cores, and then disassembled and
<br />packed everything for the next leg of the
<br />trip. In ali, the total haul was more than 210
<br />meters of core, which were shipped with all
<br />of the equipment back to the LRC for initial
<br />analyses and description. They are likely
<br />to keep Blas and company busy for many
<br />years to come.
<br />Minnegram 4
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