Stories tagged Chemical Reactions

Jul
06
2014

Indication of massive injury on Allosaurus foot bones: ; University of Wyoming Geological Museum, Laramie, WY.
Indication of massive injury on Allosaurus foot bones: ; University of Wyoming Geological Museum, Laramie, WY.Courtesy Mark Ryan
British paleontologist Phil Manning from Manchester University has been using 21st century technology to study prehistoric injuries on dinosaur bones.

Cathartes aura: archosaurian descendent of Allosaurus.
Cathartes aura: archosaurian descendent of Allosaurus.Courtesy Mark Ryan
Manning and his team of researchers employed a particle accelerator called a synchrotron rapid scanning X-ray fluorescence (SRS-XRF) to analyze and compare the chemical compositions of both healed and healthy bone of a 150 million-year-old Allosaurus fragilis, and those of a modern turkey vulture (Cathartes aura). Both animals are members of a group known as archosaurs that includes pterosaurs, and alligators and other crocodilians. The SRS-XRF directed intense beams of light ten billion times brighter than our sun onto areas of fossilized dinosaur bone that showed signs of injuries (pathologies) and healing that had occurred while the creature was alive. The same instrument was used previously to analyze the remains of both Archaeopteryx and Green River Formation fossils, revealing organic traces not detectible in visible light.

In the current study. thin sections made from the toe bones of Allosaurus fragilis unearthed from the Cleveland-Lloyd quarry in Utah were prepared at a Temple University facility in Pennsylvania, and then sent to the Stanford Synchrotron Radiation Lightsource in California for scanning. The Allosaurus sample was also analyzed at the Diamond Light Source (DLS) in Oxford, England.

During the analysis, a suite of trace-metal enzymes - copper, zinc, and strontium- all integral to the process of healing bone were detected. Copper plays a role in the strengthening the structure of collagen, zinc aids in ossification (the creation of new bone material), while strontium inhibits the break-down of bone cells. Enzymes composed from the same three elements are used for growth and repair in our own bones.
Normally when a bone suffers some kind of trauma, such as a fracture, the body repairs it by rebuilding new bone in much the same way it did when the skeleton first formed. Manning's fossil bone sections exhibited chemical ghosts of these essential elements in elevated amounts in the injured bone section than seen in the healthy bone surrounding it.

Allosaurus: ; University of Wyoming Geological Museum, Laramie, WY.
Allosaurus: ; University of Wyoming Geological Museum, Laramie, WY.Courtesy Mark Ryan
“It seems dinosaurs evolved a splendid suite of defense mechanisms to help regulate the healing and repair of injuries," Manning said. "It is quite possible you've got a reptilian-style repair mechanism combined with elevated metabolism, like that you'd find in alligators and birds respectively. So you've got a double whammy in a good way. If you suffer massive trauma, you've got the perfect set-up to survive it."

The SRS-XRF provides scientists with a superior method in analyzing and comparing the chemical processes involved with bone-building and healing that weren't discernible in the older histological examination methods used in studying thin sections, and could lead to further knowledge of how not only dinosaur bones - but our own - grow and repair themselves.

“The chemistry of life leaves clues throughout our bodies in the course of our lives that can help us diagnose, treat and heal a multitude of modern-day ailments. It’s remarkable that the very same chemistry that initiates the healing of bone in humans also seems to have followed a similar pathway in dinosaurs,” Manning said.

The study was published in a recent issue of the Journal of the Royal Society Interface.

SOURCES and LINKS
Science News story
Mother Nature Network story
Planet Earth Online story
Phil Manning research profile

Jun
24
2014

A boy and his dye - Alex Rudine at Portland State University
A boy and his dye - Alex Rudine at Portland State UniversityCourtesy OMSI
Dye-sensitized solar cell ready to be tested
Dye-sensitized solar cell ready to be testedCourtesy OMSI
Did you know that you can make small solar cells out of things like berries, tea, and doughnuts – yum! Berries and teas have dyes (organic molecules that absorb light) that give them color. Instead of using berries, there are researchers synthesizing dyes to use in solar cells. These solar cells are called dye-sensitized solar cells - DSSC for short. DSSCs convert sunlight energy into electrical energy. They work like this. Love that Scottish accent!

Most commercial solar panels are made with silicon because silicon absorbs much of the light spectrum in sunlight. Silicon solar cells absorb a wider range of the light spectrum than DSSCs currently do. The best silicon solar cells are about 20% efficient. The best DSSCs are about 11% efficient. Why use dyes instead of silicon to make solar cells? Dyes are much cheaper and less resource intensive to make. Most silicon cells are made from purified single-crystal silicon. About 40% of the crystal is lost as it is sliced into thin wafers.

I recently met scientists at Portland State University (PSU) in Portland, Oregon who are working on making dye-sensitized solar cells more efficient. Alex Rudine has been manipulating porphyrin dyes to get them to absorb more of the light spectrum. The advantage of using porphyrins is that they absorb light well and their structure is versatile and relatively easy to manipulate.

In a DSSC, as sunlight hits the dye, an electron is excited and moves to an electron acceptor. An electron flows from the electron donor to fill the hole, creating an electrical current. One of the challenges of DSSCs is that a wet solution of iodide is the typical medium for the electron donor. There are labs working on synthesizing a solid state medium. Carl Wamser’s lab at PSU in Portland, Oregon is one of those. They have synthesized a porphyrin with a nanofiber structure with a very high surface area. A high surface area means there are more places where the energy conversion can happen.

One of the things limiting more wide-spread use of solar energy is the higher set-up costs of solar panels compared to fossils fuels. If researchers can develop a commercially successful DSSC, it would be a cheaper, more sustainable source of solar energy. Unlike burning fossil fuels which releases heat-trapping gases, solar is a clean energy source that doesn’t contribute to global warming. Enough sunlight falls on the Earth in one hour that if we could collect it, we could power for one year all the machines on Earth. That’s an amazing amount of potential clean energy we could tap into.

Researchers at PSU also have a pretty cool experiment running that combines silicon photovoltaic panels with green roofs. Click here to find out more.

Sources and Links

To read this article click here:
Walter, Michael G. and Carl C. Wamser. Synthesis and characterization of electropolymerized nanostructured aminophenylporphyrin films. Journal of Physical Chemistry C 2010: 114, 7563 -7574.

To read this article click here:
Walter, Michael G., Alexander B. Rudine, and Carl C. Wamser. Porphyrins and phthalocyanines in solar photovoltaic cells. Journal of Porphyrins and Phthalocyanines 2010; 14: 759 -792.

Mar
20
2014

NanoDays is a nationwide festival of educational programs about nanoscale science and engineering and its potential impact on the future.

Most events will be taking place between March 29 - April 6, 2014.
NanoDays 2008-2014 map
NanoDays 2008-2014 mapCourtesy NISE Network

NanoDays events are organized by participants in the Nanoscale Informal Science Education Network (NISE Network) and take place at more than 250 science and children's museums, research centers and universities across the country from Puerto Rico to Hawaii. NanoDays engages people of all ages in learning about this emerging field of science, which holds the promise of developing revolutionary materials and technologies.

To read more about NanoDays visit:
http://www.whatisnano.org/nanodays

To see a full list of organizations hosting 2014 events visit:
http://www.nisenet.org/nanodays/participants-2014

2014 Events in Saint Paul and Minneapolis, MN: http://www.smm.org/nanodays

To learn more about nanotechnology, science, and engineering, visit:
www.whatisnano.org

To see other nano stories on Science Buzz tagged #nano visit:
http://www.sciencebuzz.org/buzz_tags/nano

Nov
19
2013

Blue Jeans closeup.jpg: Blue Jeans closeup
Blue Jeans closeup.jpg: Blue Jeans closeupCourtesy Wikimedia Commons - author: Mark Michaelis

During the textile manufacturing process, excess dyes are sometimes discharged as wastewater resulting in water pollution downstream. In recent years, particular attention has focused on water pollution in China resulting from indigo dyes used to create the distinctive blue color of denim blue jeans.

Some nanoscientists are looking at ways to help remove potentially harmful dyes chemicals from water.

Scientists at Colombia’s Universidad Industrial de Santander and Cornell University have come up with a cheap and simple process using natural fibers embedded with nano particles to quickly remove dye from water.

The research takes advantage of nano-sized cavities found in cellulose; plant fibers can be immersed in a solution of sodium permanganate and then treated with ultrasound causing manganese oxide molecules grow in the tiny cellulose cavities. The treated fibers are able to quickly break down and remove the dye from the water.

More about this topic:

  • Cornell University study on fibers and dyes visit:
    http://www.news.cornell.edu/stories/2013/09/treated-fibers-clean-dye-pol...
  • GreenPeace report "Toxic Threads" visit:
    http://www.greenpeace.org/international/en/publications/Campaign-reports...
  • Popular Science article on indigo dye and water pollutionvisit:
    http://www.popsci.com/blog-network/techtiles/problem-indigo?src=SOC&dom=fb
  • China's famed Pearl River under denim threat
    http://www.cnn.com/2010/WORLD/asiapcf/04/26/china.denim.water.pollution/
  • To learn more about nanotechnology, science, and engineering, visit:
    www.whatisnano.org

    To see other nano stories on Science Buzz tagged #nano visit:
    http://www.sciencebuzz.org/buzz_tags/nano

    Oct
    14
    2013

    Typical Paleozoic fossils from Minnesota: This year's National Fossil Day theme is Paleozoic fossils. Minnesota Paleozoic rocks hold an abundance of such fossils dating from the Late Cambrian though the Late Ordovician Periods.
    Typical Paleozoic fossils from Minnesota: This year's National Fossil Day theme is Paleozoic fossils. Minnesota Paleozoic rocks hold an abundance of such fossils dating from the Late Cambrian though the Late Ordovician Periods.Courtesy Mark Ryan
    It's Earth Science Week and this year's celebration centers around maps and mapping and their importance in geology and other earth sciences. Then on Saturday, October 19th from 1-4pm, the Science Museum of Minnesota is celebrating National Fossil Day with some special fossil-related exhibits throughout the museum. This year's theme is Paleozoic life, which is exactly the types of fossils commonly found in the southern half of Minnesota. Unfortunately, the official National Fossil Day website is closed due to the US government shutdown that continues, but that shouldn't stop anyone from celebrating fossils. Join us Saturday for some fossil fun.

    LINKS
    OneGeology mapping webite
    Minnesota Geological Survey maps
    Fossil hunting in Lilydale (closed indefinitely due to a spring 2013 tragedy)
    Collecting fossils in Minnesota

    Sep
    28
    2013

    A lake carrier heads out on Lake Superior from Duluth: As with the world's oceans, researchers have now detected plastic pollution in all the Great Lakes.
    A lake carrier heads out on Lake Superior from Duluth: As with the world's oceans, researchers have now detected plastic pollution in all the Great Lakes.Courtesy Mark Ryan
    Over the past couple years, Science Buzz has posted several stories (here and here) about the humongous patches of garbage and plastic debris found floating in the world's oceans. It's a serious problem and one that should raise red flags for anyone concerned with the Earth's environment. But even more troubling is the recent news that plastic particles have now been found in all five of the Great Lakes lining the border of the USA and Canada. Unlike the large globs of plastic clogging areas of the ocean, the plastics polluting the Great Lakes are microscopic particles detectable only in a microscope. But they're no less disturbing.

    A team of researchers led by Dr. Sherri “Sam” Mason, professor of chemistry at SUNY-Fredonia has been gathering water samples and reported finding high concentrations of plastic particles in the chain of freshwater lakes. One of the researchers involved is environmental chemist Lorena Rios-Mendoza from University of Wisconsin-Superior. Both she and Mason have studied the Great Trash Island (aka Trashlantis) in the Pacific Ocean but has now turned their attention to the Great Lakes.

    Most of the plastic found in the water is visible only under a microscope, but has been found in all five of the Great Lakes, both in the water column, and in lake sediment. The amount of micro-plastic varies between lakes with Lake Erie - the shallowest and smallest by water volume - containing the largest ratio and Lake Superior - the largest and most voluminous - a much smaller ratio. But it doesn't matter; the point is that we're polluting some of our important sources of fresh water with plastic.

    It's thought that cosmetics with could one of the sources, since the industry relies heavily on using micro-beads in its products. These tiny plastic particles used on our faces, skin, and teeth, eventually get washed off into the water supply where they're too small to get filtered out. But cosmetics certainly aren't the only source. Plastic refuse obliterates the shoreline in Haiti
    Plastic refuse obliterates the shoreline in HaitiCourtesy tedxgp2
    Think of the ungodly amount of plastic material we use and discard every year. Surprisingly, only about five percent of the bags, bottles, cups, electronics, etc. get recycled; most plastic trash ends up in landfills where it slowly degrades and eventually finds its way into the world's favorite garbage dump: the oceans.

    “We have no idea how long some of these plastics stay in the ocean, could be more than 40 years,” Rios-Mendoza said. She also worries if organic toxins in the water can attach themselves to the tiny plastic particles, and end up in the food chain. In this regard, Rios-Mendoza has been sampling Great Lake fish to see if such toxic particles are present in their guts.

    It's important to remember that only 3 percent of the world's water is freshwater and the five Great Lakes - Superior, Huron, Michigan, Ontario, and Erie - together contain 20 percent of that freshwater. That's a large portion of a relatively scarce and essential life ingredient. Last fall, I posted an interesting graphic that illustrates nicely Earth's total water supply versus fresh water and puts things in perspective.

    Lake Superior: Plastic pollutants have now invaded the upper Great Lake.
    Lake Superior: Plastic pollutants have now invaded the upper Great Lake.Courtesy Mark Ryan
    Rios-Mendoza and Mason have been collaborating with a research and education group called 5Gyres Institute that monitors and studies garbage patches found in five subtropical gyres in the world's oceans. Rio-Mendoza presented a preliminary study of their work on the Great Lakes at a recent meeting of the American Chemical Society. The team's future studies involve pinpointing the sources of plastic pollution and acquiring a better understanding of how plastics degrade in the environment.

    "We all need to become aware of how much plastic we use in our lives and avoid using single-use products. Don’t buy water in plastic bottles or cosmetic products with micro beads. Bring re-usable bags to the store with you. Simple things like this make a big difference, but it’s also important to keep talking about this issue and raising awareness about how it affects the Great Lakes and the world’s oceans.” --- Dr. Sherri Mason“

    By the way, here in Minnesota, and situated at the western tip of Lake Superior, the city of Duluth was recently proclaimed to have the best tasting drinking water in the state. By best-tasting, I'm assuming they mean it has no taste whatsoever since water is described as a colorless, tasteless liquid. Whatever the case, I always thought Duluth's drinking water was the best while growing up there (my grandparents lived in a Twin Cities' suburb and I never liked the taste of their softener-treated water).
    In another water-related story, it's estimated that life on Earth can survive for at least another 1.75 billion years until we move out of the habitable zone and our oceans (and other water sources) will evaporate in the increased heat. So it's probably best that we take care of what water we have - it needs to sustain us for a long time.

    SOURCE and LINKS
    National Geographic story
    Red Orbit story
    The World's Largest Dump
    The Great Pacific garbage patch
    Star Tribune story on Duluth's water

    Jan
    24
    2013

    Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.
    Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.Courtesy Jeremie63
    Chemists from the University of Massachusetts Amherst have developed a way to quickly and accurately detect and identify metastatic cancer cells in living tissue, in much the same way that your nose can detect and identify certain odors.

    The smell of a rose, for example, is a unique pattern of molecules, which activates a certain set of receptors in your nose. When these specific receptors are triggered, your brain immediately recognizes it as a rose.

    Similarly, each type of cancer has a unique pattern to the proteins that make up its cells. The Amherst chemists just needed a "nose" to recognize these patterns. What they came up with was an array of gold nanoparticle sensors, coupled with green fluorescent proteins (GFP). The researchers took healthy tissue and tumor samples from mice, and trained the nanoparticle-GFP sensors to recognize the bad cells, and for the GFP to fluoresce in the presence of metastatic tissues.

    This method is really sensitive to subtle differences, it's quick (can detect cancer cells within minutes), it can differentiate between types of cancers, and is minimally invasive. The researchers haven't tested this method on human tissue samples yet, but it holds some exciting potential.

    Jul
    18
    2012

    Sprayable Battery: Move over spray-tan, there's a new aerosol in town.
    Sprayable Battery: Move over spray-tan, there's a new aerosol in town.Courtesy Alex Walker
    Researchers from Rice University have rethought the battery. Typically, batteries are made up of 5 layers: a positive and negative electrode, each with a metal current collector, and a polymer separator. These layers are manufactured in sheets and then rolled into cylinders. Rice researchers realized that each of these layers were available, or could be created, in sprayable form. They used lithium titanium oxide and lithium cobalt oxide for the anode and cathode, existing metallic paints and carbon nanotube mixtures for the current collectors, and a chemical hodge-podge with a very lengthy name for the separator layer. The result is an ultra thin (a fraction of a millimeter thick) lithium ion battery.
    In their first experiment, researchers sprayed each consecutive layer onto nine bathroom tiles, topped with a solar cell. The resulting batteries were able to power 40 LEDs for six hours.
    In its current state, this method is too toxic to be used outside a controlled environment, but with a little tweaking, a safe alternative will be found. At that point, any surface could be a battery!

    Jul
    13
    2012

    Evolution timeline from 1882: This caricature of Darwin's theory appeared in the 1882 Punch Almanac. The recent evolution timeline created by Kyrk and Sezen is a bit of an improvement.
    Evolution timeline from 1882: This caricature of Darwin's theory appeared in the 1882 Punch Almanac. The recent evolution timeline created by Kyrk and Sezen is a bit of an improvement.Courtesy Public domain via Wikipedia
    This cool evolution timeline is really fascinating and fun to mess around with. I'm guessing Charles Darwin would agree it's a vast improvement over the one that appeared in Punch Almanac in1882 when he was still alive (see image at right). This new one was created by John Kyrk, a biology-trained artist in San Francisco in collaboration with Dr. Uzay Sezen, a plant biologist from the University of Georgia. The timeline is available in several languages and would be very useful in a classroom setting when studying evolution and paleontology.

    The site is interactive and follows the evolution of our universe from the Big Bang to the present. You start it by clicking and sliding the red pyramid on the right. As you scroll across the timeline, various events in the history of the Universe, Solar System and ultimately, the Earth show up on the screen. All along, links also appear that either explain concepts or show examples of them. In the upper left hand corner is a menu linking you to several corollary Flash animations by Kyrk explaining cell biology and how RNA, DNA, cells, water, and other basic elements of life (including viruses) operate. Kyrk thinks animated illustrations are very useful in teaching and remembering ideas and concepts.

    All the phases of Earth’s formation and development are covered in the evolution timeline, including the Late Heavy Bombardment, Snowball Earth, Cambrian Explosion, stromatolites, photosynthesis and iron formation. Once life begins to rise up, your computer screen will run amok with Earth’s diverse species populations from the one-celled animals, trilobites and fish to amphibians, reptiles, dinosaurs and mammals – the whole shooting match. All the major extinction events are shown, too.

    The site also contains a link to this YouTube video version of someone else working the timeline so you can just sit back and watch how it happens, But I recommend working the interactive page yourself. A lot more happens and is available than the video allows you to see. Note that you’ll need Flash for it to run on your computer.

    I wonder how Darwin would have reacted if he were able to see his theory illustrated in this way?

    SOURCES
    Evolution Timeline

    Feb
    19
    2012

    The Blue Heron: the Large Lakes Observatory's research vessel is owned by the University of Minnesota-Duluth.
    The Blue Heron: the Large Lakes Observatory's research vessel is owned by the University of Minnesota-Duluth.Courtesy Mark Ryan
    Last October, I attended the Geological Society of America’s annual meeting held here in Minneapolis. The convention presented plenty of opportunities to hear the latest ideas in geology, paleontology, and planetary science but the highlight for me was being able to join a GSA field trip on Lake Superior aboard the research vessel, the Blue Heron.

    Blue Heron interior: Mid-deck area includes monitoring station, right, and one of two dry labs, background left, serving as a snack table during our trip.
    Blue Heron interior: Mid-deck area includes monitoring station, right, and one of two dry labs, background left, serving as a snack table during our trip.Courtesy Mark Ryan
    The 86-foot vessel is owned by the University of Minnesota-Duluth (UMD) and operated by the Large Lakes Observatory (LLO), an organization created in 1994 for investigating the geochemical and geophysical properties of large lakes, and their global impact. To accomplish this research, the LLO required a worthy vessel for limnological research, and the Blue Heron was purchased just three years later.

    The vessel docks at the Corps of Engineers Vessel Yard on Park Point (aka Minnesota Point), a natural sand bar separating Duluth’s harbor basin from Lake Superior. The ten-mile spit was created by the lake’s wave action on material deposited by the St. Louis river, and is supposedly the largest freshwater sand bar in the world. Field trip leaders Doug Ricketts, the marine superintendent at LLO, and Charlie Matsch, professor emeritus of geology at UMD, greeted arriving participants and divided us into two groups. While one group spent the morning on Lake Superior, the other visited geological highlights in the Duluth area with professor Matsch. In the afternoon the groups switched places.

    I joined the morning shift on the lake with a dozen geologists made up of GSA attendees from Minnesota, Wisconsin, and City University of New York. Besides Doug Ricketts and the ship’s five crew members, regents professor Tom Johnson, and the director of the LLO, professor Steve Colman, were also on hand to help demonstrate and explain the Blue Heron’s research capabilities.Lakebound through the harbor: As we head toward Lake Superior, regents professor Tom Johnson, left, and  director of the LLO, professor Steve Colman, discuss the morning agenda with one of the field trip passengers. The yellow tow fish used for profiling the lake bottom sets on the deck in the background.
    Lakebound through the harbor: As we head toward Lake Superior, regents professor Tom Johnson, left, and director of the LLO, professor Steve Colman, discuss the morning agenda with one of the field trip passengers. The yellow tow fish used for profiling the lake bottom sets on the deck in the background.Courtesy Mark Ryan

    Safety first: Blue Heron chief mate, John Simenson, goes over some of the vessel's safety rules.
    Safety first: Blue Heron chief mate, John Simenson, goes over some of the vessel's safety rules.Courtesy Mark Ryan
    We shoved off right on schedule, heading across the harbor toward the Superior entrance on the Wisconsin end of the sand bar. The crew spent this time going over the ship’s safety rules - how to descend ladders, which alarms meant what, how to communicate with the bridge - that sort of thing. We then made a quick tour of the facilities. The Blue Heron is equipped with a wet lab on the open deck and two dry labs inside, and all sorts of data gathering equipment for geophysical, geochemical, and biological sampling. These include multibeam sonar for profiling the lake bottom and sub-bottom, several coring instruments for collecting sediment samples, and water samplers able to collect at various depth levels in the water column while also measuring such things as temperature, depth, pH levels, and conductivity. There’s gear for tracking lake currents, and plankton nets and a trawl for gathering biological data. Inside, both above and below deck, computers record, display and analyze the gathered data. Many of the off-ship instruments can be monitored and controlled on-board from computer consoles.

    Out on the big lake: Lake Superior is the deepest and largest of the Great Lakes, and contains ten percent of the world's fresh surface water.
    Out on the big lake: Lake Superior is the deepest and largest of the Great Lakes, and contains ten percent of the world's fresh surface water.Courtesy Mark Ryan
    The R/V Blue Heron is outfitted to carry five crew members and six researchers and can stay on the lake, around the clock, for 21 days between port calls. It’s used mainly on Lake Superior, the largest and least studied of the Great Lakes. Shipboard amenities are sparse (there’s no television or DVD) but include eleven bunks, a full galley for food preparation, dining table, shower, and of course, the "head", or as you landlubbers like to call it, the toilet. Internet service is sometimes available when the vessel is near shore.

    Yellow fish deployed: The EdgeTech CHIRP/sidescan sonar is submerged and towed behind the Blue Heron for gathering bottom data.
    Yellow fish deployed: The EdgeTech CHIRP/sidescan sonar is submerged and towed behind the Blue Heron for gathering bottom data.Courtesy Mark Ryan
    Upon entering Lake Superior, the crew set to work demonstrating some of the vessel’s science gear, which is pretty much the same kind of instrumentation used in oceanographic research. Just beyond the Superior entrance, the EchoTech CHIRP/sidescan sonar tow fish was lowered from the Blue Heron’s stern. This bright yellow instrument is towed underwater behind the vessel as it makes several passes over the lake bed, and able to gather hydrographic and bathymetric data. One function is to send out an intermittent, low frequency “chirp” pulse that can penetrate the sub-bottom and record changes in its geophysical properties. The sonar data is processed using on-deck computers.The first demonstration was a scan of the underwater channel of the Nemadji River, a Wisconsin tributary to the lake. The mouth of the Nemadji has been drowned by a process called post-glacial rebound or more scientifically, differential isostatic rebound. During the last ice age, a mile thick sheet of ice covered the region and placed enormous pressure on the earth’s crust, depressing it downward. As the glaciers retreated, that enormous weight was gradually removed, and the lake basin began to rebound (a process still going on today). But the northern and eastern ends of Lake Superior basin are rebounding at a faster rate, tilting the water southward and to the west and subsequently flooding those areas of the shoreline.

    CHIRP/sidescan sonar monitors: Left display shows a sidescan view of the bottom.  Right monitor reveals CHIRP sub-bottom profile of drowned channel of the Nemadji river.
    CHIRP/sidescan sonar monitors: Left display shows a sidescan view of the bottom. Right monitor reveals CHIRP sub-bottom profile of drowned channel of the Nemadji river.Courtesy Mark Ryan
    As the submerged tow fish was doing its stuff, we all gathered at a couple workstations in the lower deck dry lab to watch as images appeared on the computer screens. In one, you could plainly see the distinct profile of the Nemadji’s drowned riverbanks. Lower deck dry lab: Marine superintendent Doug Ricketts explains the R/V Blue Heron's data gathering capabilities to field trip participants.
    Lower deck dry lab: Marine superintendent Doug Ricketts explains the R/V Blue Heron's data gathering capabilities to field trip participants.Courtesy Mark Ryan
    The other monitor displayed bathymetric information being picked up by the duel frequency sidescan sonar. Printouts of the lakebed topography, created from a mosaic of stitched-together scans, were laid out on a worktable with several charts and maps.

    Yellow tow fish retrieval: Blue Heron marine technician Jason Agnich (left) and seaman Peter Norick haul in the EdgeTech sidescan sonar tow fish.
    Yellow tow fish retrieval: Blue Heron marine technician Jason Agnich (left) and seaman Peter Norick haul in the EdgeTech sidescan sonar tow fish.Courtesy Mark Ryan
    For the next demonstrations, the Blue Heron moved out several miles onto the big lake. We’d all been warned of the lake’s fickle weather, and told to bring proper attire, just in case. Having been raised in Duluth, I was well acquainted with Superior’s moodiness, especially in autumn, so I brought along rain gear, a jacket, and an extra sweatshirt, expecting the worst. But I was most comfortable in jeans and a t-shirt. Cloud cover was sporadic, and while the water temperature was only around 49 degrees, the air temperature hovered in the mid to upper 70s during the entire excursion. We couldn’t have hoped for a nicer day; a perfect Duluth day, as we used to call them.

    While some of the group watched the crew prepare for the next presentation, others enjoyed lunch (sandwich, chips, fruit and a cookie) at the galley dining table. During my lunch break Tom Johnson told me the story of how the university came to own the research vessel. In her previous life, the Blue Heron was known as the Fairtry a commercial fishing trawler that fished the Grand Banks in the northwest Atlantic (like the Andrea Gail in The Perfect Storm). UMD purchased it in 1997 and Tom sailed it from Portland, Maine, through the St. Lawrence Seaway and across the Great Lakes to Duluth. Despite some minor engine problems at the start, he said it was a fantastic two-and-a-half week trip. Over the next winter, the Fairtry was converted into a limnological research vessel and re-christened the Blue Heron.

    Water sampling carousel: GSA field trip participants listen as LLO's Doug Ricketts, center, goes over some of the geophysical and geochemical data gathered by the Blue Heron's water sampling carousel.
    Water sampling carousel: GSA field trip participants listen as LLO's Doug Ricketts, center, goes over some of the geophysical and geochemical data gathered by the Blue Heron's water sampling carousel.Courtesy Mark Ryan
    Meanwhile, out on the back deck, the crew was ready to launch the next instrument, a carousel of canisters called Niskin bottles used for sampling the water column. Topside control: Marine tech Jason monitors the submerged water sampling carousel, which can be controlled to collect water samples at different levels, as well as additional water quality data.
    Topside control: Marine tech Jason monitors the submerged water sampling carousel, which can be controlled to collect water samples at different levels, as well as additional water quality data.Courtesy Mark Ryan
    This device is lowered into the lake and controlled remotely from the deck, and can collect samples at various depths into any one of its dozen canisters. It can also measure temperature, conductivity, pH balance, transparency, dissolved oxygen levels and other tests. After deployment, marine technician, Jason Agnich, sat at a computer workstation just inside the hatch, and easily controlled the carousel with a joystick while monitoring its progress on a couple electronic displays.

    Gravity corer: Marine technician Jason Agnich helps launch the gravity corer, retrieves the sample, and lays it out on the wet lab workbench for study.
    Gravity corer: Marine technician Jason Agnich helps launch the gravity corer, retrieves the sample, and lays it out on the wet lab workbench for study.Courtesy Mark Ryan
    We moved a little farther down lake where two coring instruments, a spider-framed multi-corer, and an arrow-like gravity corer were put into action. The first can collect several shallow core samples by lowering it by winch to the lakebed, while the latter is dropped like a giant dart deep into the sub-bottom sediment for one large core.

    Sediment sample examination: Tom Johnson, left, and Steve Colman examine one of the sediment samples collected by the Blue Heron's multi-corer from the bottom of Lake Superior.
    Sediment sample examination: Tom Johnson, left, and Steve Colman examine one of the sediment samples collected by the Blue Heron's multi-corer from the bottom of Lake Superior.Courtesy Mark Ryan
    After each was raised back to the surface, the collected core samples were removed from their tubing and laid out on the wet lab table for study. We all huddled around the workbench as each core was cut open with a knife so participants could take a closer look. The sediment cores were composed of a densely packed fine-grained mucky silt as brown as milk chocolate, and appeared more appropriate for a scatological study than a geological one, to me anyway. But that didn’t stop some of us from taking home a small plastic bag of it as a souvenir.

    View of the Blue Heron's wet lab: Lake bottom sediment samples are examined on the workbench.
    View of the Blue Heron's wet lab: Lake bottom sediment samples are examined on the workbench.Courtesy Mark Ryan
    View from the Blue Heron: As the research vessel heads back to port, autumn colors brighten up Duluth's distant hillside.
    View from the Blue Heron: As the research vessel heads back to port, autumn colors brighten up Duluth's distant hillside.Courtesy Mark Ryan
    As we made our way back toward the harbor, I stood at the starboard rail and took in the beautiful autumn colors lighting up the lake’s distant North Shore. We were three, maybe four miles offshore but I was able to pick out my old stomping grounds in Duluth’s east end. The old neighborhood – like much of the city - was built up on terraces formed by past shoreline configurations of prehistoric Lake Superior. Duluth’s Skyline Parkway, a boulevard that skirts the hilltop across the length of the city was built on an old gravel beach line of Glacial Lake Duluth when the water surface was nearly five hundred feet above its present level. The bridge over the mouth of the Lester River was just barely discernible from where I stood but it was easy to spot the large swath of dark pine forest that encompassed Lester Park and Amity creek (the western branch of Lester river) where my friends and I used to hang out. It’s also where Charlie Matsch would guide our group later in the afternoon. He brought us there to examine the Deeps, my favorite old swimming hole carved out of the massive basalt flows that extruded from what’s now the center of Lake Superior during the Mid-continental rifting event that took place nearly a billion years ago.

    Harbor bound: The Blue Heron heads back to port through the Duluth canal.
    Harbor bound: The Blue Heron heads back to port through the Duluth canal.Courtesy Mark Ryan
    We returned to port through the Duluth entrance, and as we entered the canal captain Mike King announced our arrival with a blast of the Blue Heron’s air horn. Duluth’s landmark Aerial-Lift Bridge, already raised for our return entry, responded in kind with a shrill loud blast of its own. Tourists lining the pier called out and waved as we passed the old lighthouse and rolled toward the harbor. We all waved back and I have to say it was kind of a thrill, for me anyway, after having participated in the same ritual, oh probably a hundred times in the past but always from the pier not from a vessel.

    Return to harbor: The Blue Heron heads back to port after passing under Duluth's landmark Aerial-Lift Bridge.
    Return to harbor: The Blue Heron heads back to port after passing under Duluth's landmark Aerial-Lift Bridge.Courtesy Mark Ryan
    The Blue Heron swung in through the harbor, and soon we were back at port where we started at the Corps of Engineers Vessel Yard. Charlie Matsch was there to greet us and take for the second leg of the field trip.

    Charlie took us first up the hillside to the rocky knob near the landmark memorial Enger Tower where he showed us some interesting exposures of gabbro, an intrusive rock common to the geological formation known as the Duluth Complex. Much of the bluffs west of downtown Duluth are composed of this dark, course-grained mafic rock. Now, I admit I enjoy a geological outcrop as much as the next guy (especially when a real geologist is explaining it), but it was the sweeping view from the hilltop that drew my attention. The Blue Heron: cuts through Duluth's harbor for another excursion on Lake Superior.
    The Blue Heron: cuts through Duluth's harbor for another excursion on Lake Superior.Courtesy Mark Ryan
    The lake and harbor and much of the St. Louis river bay stretched out below us in an array of vivid blues contrasting with the bright reds and golds of autumn. On one side of the harbor, bridges, railroads, and structures of industry jutted out on Rice's Point toward Wisconsin, paralleled on the other side by the slender ribbon of Park Point. As I took in this grand vista, a small, barely discernible bluish blur of movement caught my eye. There, cutting through the harbor, the Blue Heron headed southward toward the Superior entrance for another run on the great lake.

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