Stories tagged geology

Literally dig deeper into the earth surface and discover what is lying right under your feet.

I've been checking out some of the visual material taken of yesterday's massive flooding in Duluth and thought this one was pretty interesting. The video of the raging Miller Creek in Lincoln Park was taken while it was still raining and you see can visible change in the water level by the end of it.

Amity Creek in Duluth
Amity Creek in DuluthCourtesy Mark Ryn
The recent floods in Duluth and other communities in northern Minnesota illustrate the incredible erosive power of running water. I was living in Duluth in 1972 when floods then ripped up the entire length of 6th Avenue East from top to bottom. This go-round appears to be even more devastating. I was particularly saddened to hear that the Swinging Bridge at Jay Cooke State Park has been destroyed by the force of the St. Louis River. The Lake Superior Zoo was inundated with water killing several of animals there. Several animals escaped, including the polar bear which was quickly tranquilized, recaptured, and sent to Como Zoo in St. Paul. One seal was more successful in its escape and made it out of the zoo compound to Grand Avenue where it stopped traffic. Recovery from all the damage is going take a while.

ADDITIONAL PHOTOS and INFO
KARE11 site
Duluth News Tribune
Denver Post

Last month's earthquakes in Northern Italy produced some interesting examples of soil liquefaction, a phenomenon, that occurs often during earthquakes when soil or other uncompacted ground material suddenly loses its strength and structure and begins to act like a liquid.

More about soil liquefaction.

Mount St. Helens erupting
Mount St. Helens eruptingCourtesy USGS
Preceded by a magnitude 5.1 earthquake, Washington state's Mount St. Helens explodes with a major eruption in 1980 that flattens the surrounding forest, blankets the immediate area with mud and avalanche debris, and unleashes more than 500 million tons of ash into the air that reaches as far as Oklahoma (although traces of the ash encircle the globe). Fifty-seven people lose their lives from the eruption.

USGS page

Watch 300,000 cubic meters of Swiss mountainside collapse before your very eyes.

Picture of a rock: Ripple marks from the Jurassic-aged Sundance Sea.
Picture of a rock: Ripple marks from the Jurassic-aged Sundance Sea.Courtesy Mark Ryan
I'm not sure why this showed up on Facebook today, but it's kind of interesting. It's an old story from 2008 about a poll taken of 220,000 university students in Great Britain concerning just how satisfied they were with their courses. The results surprised everyone because geology students came out as most happy with their coursework than other students, especially those poor kids slogging through photography and cinema courses. You'd think taking pictures or watching movies or reading about taking pictures or about movies you've watched would be more fun than looking at rocks. Outside. In the rain. With bugs. And wet socks. But I guess that isn't the case. You can read the story, if you want, to find out why that is. I have neither a degree in geology nor in photography but love both subjects, and really like taking pictures of rocks, so I don't care.

SOURCE
Guardian story

Pinatubo spewing ash in 1991
Pinatubo spewing ash in 1991Courtesy Public domain from USGS via Wikipedia
If you have nothing else to do this weekend, why not spend some time monitoring volcanic eruptions? Erik Klemetti at Wired Science has updated his compilation of a whole bunch of links to webcams trained on various volcanoes around the world. Some, like Hawaii's Mauna Kea and Mauna Loa weren't doing much when I looked at them, but others, like Mexico's Popocatépetl and Japan's Aso were showing some activity.

Apr
27
2012

Beaker & Brush
Beaker & BrushCourtesy Science Museum of Minnesota
A few weeks ago I attended the Beaker & Brush Discussion in St. Paul, a public event about the intersection of science and art put on by the Science Museum of Minnesota the second Tuesday of each month. April’s topic was titled "Why We Collect", a discussion about why we as a society and as individuals like to collect things. Museum staff members were on hand to relate the museum's and their personal perspectives on the nuts and bolts of collecting. The subject particularly interested me because ever since I was a kid, I’ve collected stuff. Things like rocks and fossils, silent movie posters, space memorabilia, historic Duluth material, and early paleontology ephemera – I’ve collected them all. Lately it’s been dinosaur-related postcards. I got interested in collecting those because I designed some dinosaur postcards sold here at the museum gift shop, which, you know, I think is kind of cool. I like how it connects me to the long history of dinosaur postcards, which goes back quite a while. The two oldest cards in my collection date back before 1910. Both are related to industrialist Andrew Carnegie’s namesake dinosaur, Diplodocus carnegiei, which he had spared no expense extracting from the High Plains of Wyoming for his museum in Pittsburgh. Carnegie was so proud of his collection of bones that he had several mounted casts of the great sauropod created that he presented to heads of state in many countries around the world.

Field Museum postcard: reproduction of paleo-artist Charles R. Knight's "Flying and Swimming Reptiles" mural.
Field Museum postcard: reproduction of paleo-artist Charles R. Knight's "Flying and Swimming Reptiles" mural.Courtesy Mark Ryan collection
This brings me to a recent postcard I saw on eBay from the Field Museum of Natural History. The card showed a sepia-toned reproduction of one of paleo-artist Charles R. Knight’s murals. Knight was (and still is) a highly regarded natural history artist known for his exceptional talent at bringing long-extinct animals to life in his fantastic paintings. This one showed flying and swimming reptiles in the Cretaceous sea that once extended across the middle of the North American continent. Knight created the original painting (along with 28 others) between 1926 and 1930 for the Field Museum exhibits in Chicago, where they can still be seen today. A color reproduction of the same painting portrayed in the postcard also sets beneath the mosasaur skeleton seen at the Science Museum of Minnesota. Knight, by the way, was my grandmother’s maiden name. She was born in London, as was Charles Knight’s father, so I like to think that somewhere in the past, we might share a family connection.

Reverse of Field Museum postcard: the addressee and address are significant.
Reverse of Field Museum postcard: the addressee and address are significant.Courtesy Mark Ryan Collection
But beyond that, I like Knight’s images and have several in my collection, so even though this postcard wasn’t actually of dinosaurs per se (dinosaurs didn’t fly or live in water), I considered bidding on it. But what clinched it for me was the address on back of the postcard. The reverse side, which the seller included in his listing, displayed a 1932 postmark and was addressed to Mrs. Cornelius Vanderbilt at 640 Fifth Avenue in New York City, an address with which I happened to be familiar.

Let me explain the connection.

Old quarry in Barryville, New York: stone from here was used for pavement in Manhattan.
Old quarry in Barryville, New York: stone from here was used for pavement in Manhattan.Courtesy Mark Ryan
A couple summers ago, we went to visit my son, who at the time was living in upstate New York. He and his girlfriend were living in Barryville, a small hamlet in the Catskills on the Delaware River about 100 miles northwest of New York City. They were renting a place for the summer with another couple on an old farm and quarry once owned by a man named Hickok. The site contained three residences, two for rental and another used by the property owners. It was a very quaint and idyllic setting, surrounded by woods, with the three buildings close together on the property and set before a steep wall of quarry rock where a small waterfall tumbled over one corner.

The rock in the quarry, I discovered, was primarily sandstone (or more precisely a feldspathic greywacke) of Devonian age, and the largest bedrock unit of the Catskill formation. Deposited in a delta environment during the Acadian orogeny (ancestral Appalachians Mountains) about 360 million years ago, it’s essentially the same rock that underlies the Pocono Mountains to the south in Pennsylvania. The rock unit was first quarried in Ulster County, New York and became known as bluestone because of its color at that location but the stone can come in several hues – in Barryville it’s red. Over the years, the rock has been heavily quarried as an architectural and building stone because of its durability, resistance to weathering, and how easily it splits into slabs. Today, the term “bluestone” is a commercial designation rather than geological and can include many kinds of rock used for building.

One evening the owners related to me how some of the rock quarried behind their house had been used to pave the sidewalks of New York City, and in fact back in the late 19th century, the house they lived in had been moved several yards toward the river so quarrymen could get at one very large, continuous slab of rock. Once removed, the single slab was shipped by barge over the Delaware & Hudson Canal and down to NYC for placement in front of the Vanderbilt Mansion on Fifth Avenue. The Vanderbilt name is practically synonymous with “filthy rich”, at least back then during the Gilded Age. I enjoy history and geology so the story intrigued me, and later that evening I went online to see what I could find out about the story.

William H. Vanderbilt's Twin Mansions: William H. lived in the nearer building (640 Fifth Avenue) while his two married daughters and their families lived in the 642 Fifth Avenue address which was divided into two residences.
William H. Vanderbilt's Twin Mansions: William H. lived in the nearer building (640 Fifth Avenue) while his two married daughters and their families lived in the 642 Fifth Avenue address which was divided into two residences.Courtesy Public domain
It didn’t take long at all to come across this 1881 clipping in the New York Times archives that describes, in detail, getting the massive 25-foot rock from Barryville to NYC and placed in front of the William H. Vanderbilt mansion being built on Fifth Avenue between 51st and 52nd Streets in Manhattan. If by now you guessed that the address was 640 Fifth Avenue, you’d be right (actually William H. Vanderbilt built two identical mansions at the same time on the block, one for himself - the 640 address - and another at 642 Fifth Avenue that was divided into two residences for his two daughters and their families).

The Commodore and son: Cornelius Vanderbilt, aka "The Commodore" and patriarch of the family, constantly berated his oldest son when William was growing up, referring to him as incompetent and a blockhead. It wasn't until later in life that William proved him wrong, finally convincing his critical father that he was capable of taking on the family railroad business and other interests. William subsequently inherited the bulk of his father's millions and doubled it during his own lifetime.
The Commodore and son: Cornelius Vanderbilt, aka "The Commodore" and patriarch of the family, constantly berated his oldest son when William was growing up, referring to him as incompetent and a blockhead. It wasn't until later in life that William proved him wrong, finally convincing his critical father that he was capable of taking on the family railroad business and other interests. William subsequently inherited the bulk of his father's millions and doubled it during his own lifetime.Courtesy Public domain via Wikipedia
William Vanderbilt’s father, Cornelius “The Commodore” Vanderbilt, had amassed the family fortune via shipping and railroad interests in the mid-1800s, rocketing the ultra-wealthy Vanderbilts to the very stratospheric top layer of the socio-economic heap. To put their vast wealth in perspective compare the Commodore’s $100,000,000 (an inheritance that William Vanderbilt doubled) to the guys who led the mules that pulled the canal barge transporting William’s monster sidewalk slab. They’d have to walk 15-20 miles a day, tend to the mules, and pump out the barges – all for about $3 a month! Even the other wealthy families of the time (i.e. Astors and Carnegies) paled in comparison to the House of Vanderbilt. The extended Vanderbilt clan owned several properties along Fifth Avenue but William Vanderbilt’s Triple Palaces, as they were also known, would be the finest along Vanderbilt Row.

Nine-foot Malachite Vase: The ornate Neo-classical vase made of the mineral malachite stood in the vestibule of William H. Vanderbilt's Fifth Avenue Twin Mansions. This is one of two matching urns originally created for Czar Nicholas of Russia. He presented one to Count Demidoff, and Vanderbilt purchased it from his estate in 1880. It now resides at the Metropolitan Museum of Art. Its twin can be seen at the Hermitage in St. Petersburg, Russia.
Nine-foot Malachite Vase: The ornate Neo-classical vase made of the mineral malachite stood in the vestibule of William H. Vanderbilt's Fifth Avenue Twin Mansions. This is one of two matching urns originally created for Czar Nicholas of Russia. He presented one to Count Demidoff, and Vanderbilt purchased it from his estate in 1880. It now resides at the Metropolitan Museum of Art. Its twin can be seen at the Hermitage in St. Petersburg, Russia.Courtesy Public domain
For nearly two years, six hundred laborers (including 60 sculptors and artisans from Europe) toiled on William H. Vanderbilt’s 640 residence, creating a brownstone behemoth which he filled with extreme opulence, including over 200 original pieces of art now in the Metropolitan Museum of Art. According to a book about the mansion published privately by Vanderbilt, everything inside "sparkles and flashes with gold and color...with mother-of-pearl, with marble, with jewel effects in glass...and every surface is covered, one might say weighted, with ornament." The gigantic five-story oblong pile of stone and marble contained seventy rooms - “most of them huge” - and 33 bathrooms. Many of the dozens of servants lived on site, maids on the 5th floor and attic, manservants in the sub-basement. One employee’s only job was to keep the building’s furnaces stoked with coal.

The Picture-Gallery: William H. Vanderbilt privately published a catalog detailing the art and architectural treasures found at his 640 Fifth Avenue mansion. Much of his artwork collection was later donated to the Metropolitan Museum of Art.
The Picture-Gallery: William H. Vanderbilt privately published a catalog detailing the art and architectural treasures found at his 640 Fifth Avenue mansion. Much of his artwork collection was later donated to the Metropolitan Museum of Art.Courtesy Public domain
When he died in 1885, William H. Vanderbilt was the richest man in the world (at a time when the US had no income tax!). The mansion at 640 was willed to his brother, George Vanderbilt (who also built a giant 125,000 acre estate in Ashville, North Carolina, called Biltmore), and when George died in 1914, the huge house with the pavement stone from Barryville passed down to Cornelius Vanderbilt III and his wife, Grace Wilson Vanderbilt, the postcard’s addressee.

Mrs. Cornelius Vanderbilt: born Grace Graham Wilson in 1870, she became New York's leading socialite after her marriage to Cornelius Vanderbilt III.
Mrs. Cornelius Vanderbilt: born Grace Graham Wilson in 1870, she became New York's leading socialite after her marriage to Cornelius Vanderbilt III.Courtesy Public domain
Grace Wilson Vanderbilt was the darling of European royalty, and for many years New York’s leading socialite. Her marriage to Cornelius III caused him to be disinherited by his father (Cornelius II) and ostracized by many of the other Vanderbilts. (When his father died, rather than getting $60-$70 million, Cornelius III (nicknamed Neily), inherited only half a million dollars plus income from a million dollar trust fund. His brother Alfred threw another $7 million his way to somewhat even the score). Grace’s own father, Richard T. Wilson, was a New York banker of great wealth and close friends with Andrew Carnegie, but the Vanderbilts, for whatever reason, considered her a social climber. Despite the family animosity, Grace managed to make herself the Mrs. Vanderbilt, the family’s last grand dame of the social set. (An article in the November, 1905 Munsey’s Magazine stated Grace had attained her social status by learning “the art of success scientifically, from approved models” – meaning all the European royalty she met as a young girl). During her reign, Grace hosted huge dinner parties, usually twice a week, and even larger, lavish balls for a thousand guests (I guess this is when having 33 bathrooms comes in handy). She once claimed to have entertained 37,000 guests in a single year. Neily wasn’t as interested in his wife’s social activities. As a boy he longed to be a scientist, and graduated from Yale a mechanical engineer. He was also an expert sailor and career military man. When he wasn’t yachting or soldiering he’d spend his time creating various railroad improvement devices for which he owned several patents, or co-founding businesses like the Interborough Rapid Transit Company (IRT), New York’s very first subway system.

Postcard inscription: "Dearest Grace, I can't tell you how sorry I was to miss you. I tried to telephone but you were out. Many thanks for the lovely box of candy. We are all enjoying it. You were a dear to think of us. Much love from us all. Eleanor"
Postcard inscription: "Dearest Grace, I can't tell you how sorry I was to miss you. I tried to telephone but you were out. Many thanks for the lovely box of candy. We are all enjoying it. You were a dear to think of us. Much love from us all. Eleanor"Courtesy Mark Ryan Collection
So back to the postcard. The fact it had been addressed to the Vanderbilt mansion where the big sidewalk slab from the Barryville quarry ended up was enough to make it desirable to me, so I bid on it and won it. While waiting for its arrival in the mail, I looked more closely to the card’s inscription: a social regret and thank you for a box of candy to Grace signed simply “Eleanor”. This intrigued me, and investigating it further, I eventually came to the realization that the writer was Eleanor Roosevelt.Eleanor Rooselvelt
Eleanor RooselveltCourtesy LIbrary of Congress
At the time her husband Franklin Delano Roosevelt (we share birthdays!) would have been governor of New York, and within 8 months become the president-elect of the United States. Now that was something. The card was cancelled with a St. Paul & Williston RPO postmark (railroad post office – my grandfather worked the Chicago-St. Paul leg). Eleanor could very well have been west visiting her nephew, Teddy Roosevelt, Jr. at the Field Museum. Like his father, TR - the former president - Teddy Jr. was a naturalist and explorer. Perhaps Eleanor was in Chicago to attend a memorial service for William V. Kelley who had fully financed her nephew’s 1929 Asian expeditions (Kelley-Roosevelts Expedition) for the natural history museum. Kelley had just died days before the postmark date.

Grace Vanderbilt was close friends with Alice Roosevelt, TR’s daughter, and Teddy, Jr’s half-sister, and obviously knew Eleanor, although, later, she and Neily would be vocal opponents of FDR and his New Deal recovery program, which they thought were socialistic. Sounds familiar, does it not? (Neily even called the president a traitor to his class). Of course the Great Depression had little effect on the Vanderbilts or their friends. The House of Vanderbilt’s range was widespread. Besides the Fifth Avenue mansions (and a boatload of private yachts), family members owned several summer homes in Newport, Rhode Island (e.g The Breakers, Marble House, and Grace and Neily’s Beaulieu. At Hyde Park, New York, a Vanderbilt mansion combines withFDR’s birthplace, and Eleanor Roosevelt’s getaway Val-Kill, to form the National Park Service’s Vanderbilt-Roosevelt National Historic sites. .

So, why do people collect things? According to this informative site, it can be for a number of reasons. Personally, I think I do it for several of the reasons listed: it connects me with memories of my youth or to some place I’ve visited, or just hooks me in with something that fascinates me. I know when I’m in the heat of my obsession - whatever that may be at the time, I find it difficult to part with any of my collection. Sometimes I’ll sell a lesser item to acquire something better, but that’s the exception rather than the rule. At some point my interest flags and I sell or give away most of the collection and move on to something else. But I find no matter what I collect, it often triggers an intense desire in me to find out as much as I can about it. Like this Vanderbilt postcard. Because of one silly postcard and a giant slab of sandstone, all these odd historical, geological, architectural, political, and socioeconomic connections have been brought together here. It makes for a good story anyway.

Titanic disaster in 1912: George Vanderbilt and his wife changed their plans to sail aboard the doomed vessel.
Titanic disaster in 1912: George Vanderbilt and his wife changed their plans to sail aboard the doomed vessel.Courtesy Public domain via Wikipedia
I’ll end with one last anecdote. With all the interest this month with the 100th anniversary of the sinking of the Titanic, there’s a Vanderbilt connection to it. In April of 1912, George Vanderbilt and his wife – the second owners of the 640 Fifth Avenue mansion - were in Europe and had booked passage on the maiden voyage of the Titanic. But George’s mother-in-law expressed a very strong premonition and convinced them to make other plans. Lots can go wrong on maiden voyages, she said. Lucky for them, they followed her advice and removed their luggage from the doomed liner and made the trip back on its sister ship RMS Olympic instead. George’s footman, Frederic Wheeler, however wasn’t as lucky. Wheeler remained on the Titanic and perished in the disaster.

ADDITIONAL SOURCES
Queen of the Golden Age by Cornelius Vanderbilt IV, McGraw-Hill, 1956
Beetlehead’s 640 Fifth Avenue (excellent blog)
Mrs. Cornelius Vanderbilt, Munsey’s Magazine, Nov. 1905
Vanderbilt home and info on Flickr

A large portion of the famed White Cliffs of Dover collapsed sending thousands of tons of chalk into the English Channel. The chalk cliffs, which stretch for about 8 miles along England's southern coast, are the result of deposition of "coccolith biomicrites formed from the skeletal elements of minute planktonic green algae" that were once suspended in the upper water column of an ocean during the Cretaceous Period. The soft chalky limestone is composed mainly of calcium carbonate, nodular flint seams, and marine fossils. It's suspected that the rain-soaked cliff face was loosened from recent freezing. The Daily Mail has some very cool photos of the 300-foot rockfall. And here's a link to Discovering Fossils with info about the geology of the cliffs and fossils that can be found there. This informative website is written and designed by Roy Shepherd.

LINKS
Daily Mail story
More White Cliffs geology information

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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