A Tale of Two Museums: Part 1 — The Cleveland Museum of Natural History

December 6th, 2011

Last week I had the marvelous opportunity to visit two very different museums with Wooster Geologists. This is the first of two posts with short vignettes of the memorable sights and sounds.

The first museum was the Cleveland Museum of Natural History. Greg Wiles and his Climate Change class invited me to accompany them to see the visiting climate change exhibit. It was an excellent display of the latest ideas about changing climates, including accurate accounts of the evidence, controversies and possible solutions to the problem of anthropogenic global warming and its associated troubles. It was a pleasure to see this presentation with Greg because of his deep and very current knowledge of the science and politics.

Since the above links give plenty of information about the museum and climate change exhibit, I’ll just highlight two features in front of the museum I found very interesting:

The large sundial above represents the history of life by geological periods. Note the beautiful ammonite fossil model as part of the gnomon (the portion that casts the shadow).

Each segment of the horizontal portion of the sundial is a geological period. Can you tell which periods are shown here?

Finally, I think this sculpture in the front garden entitled “Venus From The Ice Field” by Charles Herndon is ingenious. It is carved from a granite boulder found in the local glacial till.

My next post will be about the second museum — a very different place!

Wooster’s Fossils of the Week: Sponge and clam borings that revealed an ancient climate event (Upper Pleistocene of The Bahamas)

September 11th, 2011

This week’s fossils celebrate the publication today of a paper in Nature Geoscience that has been 20 years in the making. The title is: “Sea-level oscillations during the Last Interglacial highstand recorded by Bahamas coral”, and the senior author is the geochronological wizard Bill Thompson (Woods Hole Oceanographic Institution). The junior authors are my Smith College geologist friends Al Curran and Brian White and me.

The paper’s thesis is best told with an explanation of this 2006 image:
This photograph was taken on the island of Great Inagua along the coast. The flat dark surface in the foreground is the top of a fossil coral reef (“Reef I”) formed during the Last Interglacial (LIG) about 123,000 years ago. It was eroded down to this flat surface when sea-level dropped, exposing the reef to waves and eventually terrestrial weathering. The student sitting on this surface is Emily Ann Griffin (’07), one of three I.S. students who helped with parts of this project. (The others were Allison Cornett (’00) and Ann Steward (’07).) Behind Emily Ann is a coral accumulation of a reef (“Reef II”) that grew on the eroded surface after sea-level rose again about 119,000 years ago. These two reefs show, then, that sea-level dropped for about 4000 years, eroding the first reef, and then rose again to its previous level, allowing the second reef to grow. (You can see an unlabeled version of the photograph here.) The photograph at the top of this post is a small version of the same surface.

The significance of this set of reefs is that the erosion surface separating them can be seen throughout the world as evidence of a rapid global sea-level event during the Last Interglacial. Because the LIG had warm climatic conditions similar to what we will likely experience in the near future, it is crucial to know how something as important as sea-level may respond. The only way sea-level can fluctuate like this is if glacial ice volume changes, meaning there must have been an interval of global cooling (producing greater glacial ice volume) that lowered sea-level about 123,000 years ago, and then global warming (melting the ice) that raised it again within 4000 years. As we write in the paper, “This is of great scientific and societal interest because the LIG has often been cited as an analogue for future sea-level change. Estimates of LIG sea-level change, which took place in a world warmer than that of today, are crucial for estimates of future rates of rise under IPCC warming scenarios.” With our evidence we can show a magnitude and timing of an ancient sea-level fluctuation due to climate change.

Much of the paper concerns the dating techniques and issues (which is why Bill Thompson, the essential geochronologist, is the primary author). It is the dating of the corals that makes the story globally useful and significant. Here, though, I want to tell how the surface was discovered in the first place. It is a paleontological tale.

In the summer of 1991 I worked with Al Curran and Brian White on San Salvador Island in The Bahamas. They were concentrating on watery tasks that involved scuba diving, boats and the like, while I stayed on dry land (my preferred environment by far). I explored a famous fossil coral exposure called the Cockburntown Reef (Upper Pleistocene, Eemian) that Brian and Al had carefully mapped out over the past decade. The Bahamian government had recently authorized a new harbor on that part of the coastline and a large section of the fossil reef was dynamited away. The Cockburntown Reef now had a very fresh exposure in the new excavation quite different from the blackened part of the old reef we were used to. Immediately visible was a horizontal surface running through the reef marked by large clam borings called Gastrochaenolites (see below) and small borings (Entobia) made by clionaid sponges (see the image at the top of this post).
Inside the borings were long narrow bivalve shells belonging to the species Coralliophaga coralliophaga (which means “coral eater”; see below) and remnants of an ancient terrestrial soil (a paleosol). This surface was clearly a wave-cut platform later buried under a tropical soil.


My colleagues and I could trace this surface into the old, undynamited part of the Cockburntown Reef, then to other Eemian reefs on San Salvador, and then to other Bahamian islands like Great Inagua in the far south. Eventually this proved to be a global erosion surface described or at least mentioned in many papers, but its significance as an indicator of rapid eustatic sea-level fall and rise was heretofore unrecognized. Finally getting uranium-thorium radioactive dates on the corals above and below the erosion surface placed this surface in a time framework and ultimately as part of the history of global climate change.

This project began 20 years ago with the discovery of small holes left in an eroded surface by humble sponges and clams. Another example of the practical value of paleontology.

References:

Thompson, W.G., Curran, H.A., Wilson, M.A. and White, B. 2011. Sea-level oscillations during the Last Interglacial highstand recorded by Bahamas coral. Nature Geoscience (DOI: 10.1038/NGEO1253).

White, B.H., Curran, H.A. and Wilson, M.A. 1998. Bahamian coral reefs yield evidence of a brief sea-level lowstand during the last interglacial. Carbonates and Evaporites 13: 10-22.

Wilson, M.A., Curran, H.A. and White, B. 1998. Paleontological evidence of a brief global sea-level event during the last interglacial. Lethaia 31: 241-250.

Non-stationarity in climatic response of coastal tree species along the Gulf of Alaska (Senior Independent Study Thesis by Stephanie Jarvis)

April 15th, 2011

The crew in their XtraTufs. From L-R: Stephanie, Deb, Dan, and Greg.

Editor’s note: Senior Independent Study (I.S.) is a year-long program at The College of Wooster in which each student completes a research project and thesis with a faculty mentor.  We particularly enjoy I.S. in the Geology Department because there are so many cool things to do for both the faculty advisor and the student.  We are now posting abstracts of each study as they become available.  The following was written by Stephanie Jarvis, a senior geology and biology double major from Shelbyville, KY.  Here is a link to Stephanie’s final PowerPoint presentation on this project as a movie file (which can be paused at any point). You can see earlier blog posts from her field work by clicking the Alaska tag to the right.

For my IS field work I traveled to Glacier Bay National Park & Preserve, Alaska with my geology advisor, Greg Wiles.  Our field crew also consisted of Deb Prinkey (’01), Dan Lawson (CRREL), and Justin Smith, captain of the RV Capelin.  My focus was on sampling mountain hemlock (Tsuga mertensiana (Bong.) Carrière) at treeline sites to study climate response and forest health using tree ring analysis.  While in Glacier Bay, we also sampled interstadial wood (from forests run over from the glaciers that were now being exposed on the shore) and did some maintenance work on Dan’s climate stations throughout the park.  Back in the lab, Wooster junior Sarah Appleton kept me company and helped me out with some of the tree-ring processing, as did Nick Wiesenberg.

The view from treeline.

An interstadial wood stump, in place. The glacier ran over this tree and buried it in sediment, which is now being washed away.

Site map

I ended up processing cores from only one of the three sites I sampled this summer (the others can be fodder for future projects!).  In addition, I used data from several other sites sampled in previous years.  My data consisted of 3 mountain hemlock sites forming an elevational transect along Beartrack Mountain in Glacier Bay (one described by Alex Trutko ’08), 3 mountain hemlock sites at varying elevations from the mountains around Juneau, AK, and 2 Alaskan yellow-cedar sites (Chamaecyparis nootkatensis (D. Don) Spach) from Glacier Bay used by Colin Mennett (’10).   My purpose was to look into the assumption of stationarity in growth response to climate of trees over time and changing climatic conditions.  According to the Alaska Climate Research Center, this part of AK as warmed 1.8°C over the past 50 years.

Tree-ring base climate reconstructions are important in our understanding of climatic variations and are a main temperature proxy in IPCC’s 2007 report on climate change.  Climate reconstruction is based on the premise that trees at a site are responding to the same environmental variables today that they always have (thus, they are stationary in their response), allowing for the reconstruction of climatic variables using today’s relationship between annual growth and climate.

Greg coring a tree at treeline.

Crossdating using patterns of variations in ring width.

Temperature reconstructions using different proxies, including tree-rings, from the Intergovernmental Panel on Climate Change’s 2007 report.

Recent observations, such as divergence (the uncoupling of long-term trends in temperature and annual growth) and worldwide warming-induced tree mortality, suggest that this assumption of stationarity may not be valid in some cases.  Using mean monthly temperature and precipitation data from Sitka, AK that begin in the 1830s, I compared correlations of annual growth in mountain hemlock to climate at different elevations over time.  My results indicate that mountain hemlocks at low elevations are experiencing a negative change in response to warm temperatures with time, whereas those at high elevations are experiencing a release in growth with warming.  Low-elevation correlation patterns are similar to those of lower-elevation Alaskan yellow-cedar, which is currently in decline due to early loss of protective snowpack with warming.  An increasing positive trend in correlation to April precipitation and mountain hemlock growth indicates that spring snowpack may be playing an increased role in mountain hemlock growth as temperatures warm.  The high elevation mountain hemlock trends suggest the possibility of tree-line advance, though I was not able to determine if regeneration past the current treeline is occurring.  Tree at mid-elevation sites seem to be the least affected by non-stationarity, remaining relatively constant in their growth response throughout the studied time period.  This indicates that reconstructions using mid-elevation sites are likely to be more accurate, as the climatic variable they are sensitive to is not as likely to have changed over time.

Cedar chronologies (green lines) compared to temperature (brown line). Bar graph represents correlation coefficients between annual ring width and temperature, with colors corresponding to labels on the chronologies (orange is lowest elevation PI, blue is higher elevation ER). Asterisks represent significant correlations. Note that the relationship has changed from being positive at ER during the Little Ice Age to negative by the second half of the 20th century.

Mountain hemlock chronologies (green lines) compared to temperature (brown line). The top graph is of the Glacier Bay sites, the bottom is of the Juneau sites. Red represents the low elevation sites, green the mid-elevation, and purple the high elevation. Note that the low elevation sites are decreasing in correlation as the cedars have, while the high elevation sites have experienced a release in growth with warming.

 

Coring Odell Lake

July 9th, 2010

Odell Lake in the early morning hours.

The dedicated team of Wooster Geologists, Sarah Appleton, Stephanie Jarvis, and Dr. Greg Wiles met up with the sleep deprived team of Geologists from The University of Cincinnati, Bill Honsaker, Gianna Evans, and Dr. Tom Lowell. The goal of day one was to field test equipment destined for a trip to Greenland, acquire lake cores for the Climate Change class at The College of Wooster and map the lake using geophysics, a branch of earth science dealing with the physical processes and phenomena occurring especially in the earth and in its vicinity.

Odell Lake is located in Holmes County, Ohio and is a natural lake that was formed by a glacier. Portions of the glacier broke off and melted forming a kettle lake. In the case of Odell Lake three pieces of a glacier broke off during the termination of the last ice age, about 15,000 years ago, and melted. As a result Odell Lake has three basins. The first basin is the largest but also the shallowest, the second basin is smaller and deeper and the westernmost basin is the smallest and deepest attaining almost 30 feet in depth.

Our first day began early in the morning in an attempt to beat the heat of the day. Once we arrived at the lake we began to unload our supplies. Most of our equipment came “some assembly required”.

A whole new meaning to some assembly required.

After several hours of assembling the necessary tools and equipment we were ready to divvy up jobs. Sarah and Gianna were assigned to the geophysics boat. Gianna was the geophysics specialist and Sarah was the boat driver (Gianna was a brave soul because this was Sarah’s first time driving this type of boat). Stephanie, Dr. Wiles, Bill, and Dr. Lowell boarded the coring vessel for her maiden voyage.

Sarah is learning to drive the boat and Gianna is ready, just in case, with the paddle.

Sarah and Gianna began crossing the lake mapping the depth and using sonar to determine the stratigraphy under the bottom of the lake. The wind was blowing pretty strongly and it caused a problem when the pair attempted to map the shallower water. The boat-mounted shade tent, as it turned out, made a terrific sail and the boat was blown aground. After some delicate maneuvering and dismantling the “sail” the team was back on track.

The geophysics team (Sarah and Gianna) deciding their next move.

The coring vessel was paddled out into the deeper water. It was a slow going process. Once the coring team was near to the location Sarah and Gianna were flagged down to identify the deepest part of the second basin. After assisting the coring raft the geophysics team returned to mapping. 

Onboard the coring raft the team worked diligently to test the equipment. At the end of the day they had a good set of cores and the geophysics team towed in the raft to save a lot of paddling.

Posing for a picture during a break.

After a hard day’s work the group went out for ice cream in the lovely town of Shreve. Over ice cream the team made plans for the next day.

Day Two:

Another early start to beat the heat with less assembly required than the previous day. The first task was to untangle the mass of ropes and anchors that held the raft in place during coring. It was decided that burlap sacks of rocks for anchors would be needed for Greenland. The raft was towed out to the third and deepest basin for coring. Once the raft was in place and firmly anchored the team went to work using two different types of coring methods.

The coring team (Dr. Wiles, Dr. Lowell, Stephanie, and Bill) hard at work.

Meanwhile, in the geophysics boat, Sarah and Gianna switched places. Gianna was captaining the ship while Sarah was learning to use the sonar and computer programs. Gianna was excellent about teaching Sarah to use the equipment and answering her endless questions.

Stephanie awaiting the core hand off so she can wrap it up for transport back to the Sediment Core Analysis Lab.

Both groups worked until they heard thunder. Sarah and Gianna moved back to the third basin to tow in the raft. Fortunately the first thunderstorm missed the lake. The group arrived safely on shore and began to disassemble the equipment and reload the trucks and trailer. When the group was nearly done a torrential downpour ensued causing the group to scamper for cover in the cars and trailer, where they received the sever thunderstorm warning for the area. The down pour only lasted for a few minutes before the team was back to work with a renewed vigor to beat the next storm which they were sure was right behind the first one. Once the equipment was packed away and tied down the team headed for some much deserved ice cream.

Thraspberry Thrashing

June 14th, 2010

All of us by the Bartlett River.

guest blogger: Stephanie

It’s been a full week! On Monday, Justin (the captain) and Tom (captain of another boat who Justin was training for the Capelin) took all of us around to climate stations Dan maintains throughout the park to offload data and repair any snow/bear damage. We went up the West Arm and saw several beautiful glaciers. We stayed that night at the Russell Cove raft, a raft for researchers (not all of us fit…so we got to sleep on the island!). Greg found a new toy.

Greg, Deb, & Dan hard at work at a climate station.

The well-used "ursabahn" by one of the stations.

The Wooster flag in the West Arm.

Free ice! Justin nets a couple small icebergs for the cooler.

Home sweet home--the researchers' raft.

A new toy for Greg.

Tuesday the Capelin’s unidentified mechanical problems seemed to worsen, so the day was called off and Greg and I were dropped off at Sandy Cove. As we drove in, we scared a moose off the coast, and not long after a black bear came rolling long grazing on the grass. We got a late start (and subsequently a very late finish…) up Mount Wright. After about 4-5 hours of nothing in view but thorny brambles and devil’s club (which I am still picking out of my hands), we finally made it to the top of one of the ridges to find a beautiful landscape of karren limestone outcrops, snow, and mountain hemlocks. We made a quick side trip to the nearest top (~3000 ft) just for fun, looked down on a goat (always a good sign), and then got to work. It was 8 or 9 before we finished sampling, so we took an express route down and had a nice walk in the almost dark along the coast (every boulder looked like a bear…). Along the way we came across an awesome tufa waterfall, where the water was coming out through the limestone and precipitating (like in a cave). Unfortunately, it was too dark to get a good picture.

A welcome view.

Mushrooms! In the snow!

Steph at 3000 ft.

Greg at 3000 ft, with the Beardslees in the background.

The next day we walked along the river looking for interstadial wood (trees that were run over by glaciers and then buried). We didn’t find any, but we did find a good lunch spot, where we could ponder over the delta sediments the stream was cutting through and later piece it with the lake sediments farther up. The glacier, when it came down to the mouth of this valley, had blocked it off and formed a lake here.

An interesting outcrop (I know, I know, no scale. I think the bushes are ~4-6 ft.)

A relaxing lunch (we earned it!).

A nicely stuck boulder.

Meanwhile, Deb, Dan, and Justin were trying to get our boat situation worked out. The Capelin was pronounced ok, but quickly showed it wasn’t, and they were able to negotiate using a different one. The Petrel was much speedier than the Capelin, but required a ladder to get in and out on shore and didn’t like rough water very much. They met up with us at Sandy Cove on Wednesday and joined us in the ranger raft that was there (much like the researchers’ raft, without the star wars sheets…).

Thursday was another, very buggy, climate station, and then Gieke Inlet, where they had some radiocarbon dates on interstadial wood going back 3000 yrs. The particular outwash we were in had, according to Dan, been formed in a couple days of rain in November of 2005, so it was pretty rich with wood being weathered out.

Dryas patches in Gieke Inlet--the first plant to move in once the glaciers recede.

We came back to Gustavus Thursday night (showers!!!), and went out with Tom on Friday, again looking for interstadial wood. We went to Willoughby Island, where we found some really cool layers of peaty organics under gray silt/clay under gravely glacial sediments. Bad weather rolling in made it an early day, and that night we went to open mic night at the pizza place, where I realized just how much talent could be squeezed into a little town like Gustavus.

A stump (spruce, we think) in growth position at Willoughby Island.

Dan left Saturday morning, and more bad weather resulted in the calling off of our plans to go to Pleasant Island to look at Cedars stripped by the natives (the Tlingit). Instead, we went kayaking in the Beardlees and got hammered by some rain and hard wind. Much fun! The night was topped off by our housemates, sea otter researches with USGS, bringing back a huge king salmon they had caught (they forced me to try some…). Yesterday we made the trek up Excursion Ridge, where we got to see the new hydroelectric dam that is now powering Gustavus and do some slip and sliding on the steep snow patches. Got lots of good samples, and came back to find out the otter folks had caught another king salmon. They happily shared again :)

The dam that powers Gustavus.

Lunch...I'm sensing a pattern here...

Flowers! On the way up we came across several meadows and bogs.

A good view of Gustavus.

This morning, it’s back to Juneau. Mendenhall glacier is in the plans, as is a look around town. It’s back to Wooster on Wednesday.

Beartrack Mountain

June 6th, 2010

guest blogger: Stephanie

On Friday Justin, Capt. of the Capelin, dropped Greg and I off at Beartrack Cove. We hiked up (straight up!) to the Repeater Station (used for the park radio station), where we set up camp and then made our way a little further up to our study site. We cored a few trees that night, then melted some snow to make some delicious navy bean soup (courtesy of Fred Meyers in Juneau) and hot chocolate, and turned in. An early morning start to finish up the bulk of our sampling there, then it was back down (which didn’t take nearly as long as the up had, but resulted in much more soreness…) to meet the Capelin again. On the way back to Bartlett Cove, where the visitor station and park headquarters is, we saw sea lions, sea otters (one riding our waves on its back), whales, puffins, and porpoises (I didn’t get any good pictures of these, but I will try next time!).

The Capelin

A view from the way up. The line is where cloudy glacial runoff is meeting the incoming tide.

Beartrack repeater station

Fresh bear tracks on the way up to the site.

Sun coming through some clouds over the water.

Sun coming through the clouds over the water.

Where Greg would like to go... There is a tiny white speck up there--it's a goat!

The Beardslee Islands. You can see the repeater station below Greg.

Hanging a bear bag.

Soup!

and cold feet...

Mushrooms!

A little later and we would have some yummy strawberries.

A barnacle encrusted snail.

Beartrack from the boat. I think we were just the the left of that first small snow chute on the right.

We met up with Dan when we got back, and Deb Prinkey, ’01, a high school teacher in Mt. Vernon. Greg and Dan are finishing up a report for NSF right now, then it’s a short hike today and back out tomorrow.

Up to Alaska

June 4th, 2010

guest blogger: Stephanie

We arrived in Juno last night a little past 10 PM local time (that’s 2 AM for us…) after a long day of traveling, to be greeted by stuffed bears in the airport (awesome!). After spending a night in the lovely Breakwater Inn, we had an amazing breakfast at Donna’s, swung by the Mendenhall glacier in the Tongass National Forest, and then waited in the airport for Dan Lawson, of CRREL (Cold Regions Research and Engineering Laboratory).

The Breakwater Inn

Mount Juneau

The Mendenhall glacier

The "stream" at the hatchery. When spawning time comes, the salmon hatched here return.

Shopping followed, as did lunch and a quick trip to the salmon hatchery. Then it was back to the airport to catch our flight to Gustavus, which provided us with some awesome views of the inlets and mountains in the area.

Our plane!!

A cirque, a basin formed by a glacier, seen from our plane.

Once in Gustavus, we went on into Glacier Bay National Park to the headquarters to plan for the next few days and learn some bear safety tips. Tomorrow, it’s to the field!

Environmental Geology Fieldtrip – Soils/Geologic History and Groundwater

October 15th, 2009

The class at the No-Till experimental plots at the OARDC in Wooster. Stduents took soil cores from plots that were convnetionally tilled and those taht have not been tilled for 50 years. The soils and organin content in each of the soil cores clearly showed differences in soils structure and organ content

The class at the No-Till experimental plots at the OARDC in Wooster. Students took soil cores from plots that were conventionally tilled and those that have not been tilled for 50 years. The soil structure and organic content in each of the soil cores clearly showed the differences in the farming practices.

Richa took this spectacular shot of a recently-harvested soybean field. This shows the flay lake plain from Lake Killbuck and the underfit Killbuck River. The view to the north looks up the Killbuck Spillway. This field was stripped of a foot of fertile topsoil during the 1969 flood.

Richa took this spectacular shot of a recently-harvested soybean field. This shows the lake plain from Lake Killbuck and the underfit Killbuck River. The view to the north looks up the Killbuck Spillway. This field was stripped of a foot of fertile topsoil during the 1969 flood.

Rob and Palmer pose with coring device that they used to recover a sediment core from the bottom of the Killbuck River where is has downcut into the blue lake clay sediments. The blue clay is the confing layer of the Wooster buried valley aquifer.

Rob and Palmer pose with coring device that they used to recover a sediment core from the bottom of the Killbuck River where is has downcut into the blue lake clays. The blue clay is the confining layer of the Wooster buried valley aquifer.

Mike from the Wosoter water plant explains to the class the challenges of keeping Wooster's supplied with clean groundwater.

Mike from the Wooster water plant explains the challenges of keeping Wooster supplied with clean groundwater.

Processing the Lake Core (and Tree Cores)

October 13th, 2009

Earlier posts from the Climate Change class showed the students coring trees and a lake for the various analysis described below. The goals are to examine climate in Ohio since the last Ice Age as recorded in lake sediments and to determine how various tree species respond to changes in temperature and moisture.

Kelly and Adrian finish up the European Larch tree-ring chronology. The larch trees were sampled at the Secrest Arboretum in Wooster.
Kelly and Adrian finish up the European Larch tree-ring chronology. The larch trees were sampled at the Secrest Arboretum in Wooster.

Roz and Houston photographed the A and B core in their entirety - over 25 meters of mud.  Lower down in the post are three of their photos showing the variability in the sediment core.
Roz and Houston photographed the A and B sediment core taken from Long Lake located just south of Wooster. These core is over 14 meters of mud. Lower down in the post are three of their photos showing the variability in the sediment core.
masusc
Travis and Adonis collect magnetic susceptibility data on each of the thrusts
interdisc
This interdisciplinary team of English, Archaeology, History and Geology majors pick through the mud to locate organics for radiocarbon and to identify some of the flora and fauna in the mud such as seeds, charcoal, chironomids and fly wings

The is the base of the core - Late Glacial sands and gravel - at this horizon, Lindsey and Amanda  removed a stick that has been sent out for radiocarbon analysis.
The is the base of the core – Late Glacial sands and gravel, Lindsey and Amanda removed a stick from this interval that has been sent out for radiocarbon analysis. A date here will give a good estimate of when the region near Long Lake was deglaciated.
These laminated sediments represent the glacial-interglacial transition, which includes the glacial-Bolling-Allerod and Younger Dryas-Holocene transitions.
These laminated sediments represent the glacial-interglacial interval, which includes the Glacial-Bolling-Allerod and Younger Dryas-Holocene transitions.
The upper portions of the cre are primarily back, organic-rich muds with occasional loess layers - are these abrupt climate changes? The class is working on sorting all that out.
The upper portions of the core are primarily back, organic-rich muds with occasional loess layers – are these abrupt climate changes? The class is working on sorting all that out.
Rob and Bridgett picked this chironomid ffrom the 7th meter down in the core.
Rob and Bridgett picked this chironomid from the 7th meter down in the core.

Coring Round Lake – A Record of Post Glacial Change

September 26th, 2009

Dr. Tom Lowell and tow University of Cincinnati graduate students Estaben and Bill were kind enough to make the trip to Long Lake to help the Climate Change class extract two long (14 meter) sediment cores from the middle of the lake.

Dr. Tom Lowell and two University of Cincinnati graduate students, Esteban and Bill, were kind enough to make the trip to Long Lake to help the Wooster Climate Change class extract two long (14 meter) sediment cores from the middle of the lake.

The first step was to build the raft. Dr. Lowell (aka "the core boss") is in the trailer. Bill and Rob assemble the parts and pieces.

The first step was to build the raft. Dr. Lowell (aka "the core boss") is in the trailer. Bill and Rob assemble the parts and pieces.

Terry Workman (Archaeology major and course TA) drives the geophysical craft. Under the tarp os Esteban who is colecting bathymetric and seismic data. Based on these data a core site was chosen.

Terry Workman (our course TA) drives the geophysical craft. Under the tarp is Esteban who is collecting bathymetric and seismic data. Based on these data a core site was chosen.

The core boss gives us a short course on the operation of the coring platform. Dr. Lowell has custom-built this rig and he points out the automated coring system. A hydraulic system drives the Livingstone corer into and out of the mud.

The core boss gives us a short course on the operation of the coring platform. Dr. Lowell has custom-built this rig and he points out the automated coring system. A hydraulic system drives the Livingstone corer into and out of the mud.

Well into the Holocene - Esteban wraps up another meter of lacustrine sediment.

Well into the Holocene - Esteban wraps up another meter of lacustrine sediment.

Tom and Terry work the platform sending the piston corer down for another meter.

Tom and Terry work the platform sending the piston corer down for another meter.

The crew rows to shore. The class will now obtain organic material for radiocarbon dating and then the work begins analyzing a suite of parameters in the cores. Class members Lindsey and Amanda located a stick at the base of the core that has been sent for a radiocarbon age and should give us an estimate of the timing of deglaciation in the region. Will Hansen (red short) wil be using the upper part of the core together with our other collections from Round. O'Dell and Browns Lake for his Independent Study.

The crew rows to shore. The class will now obtain organic material for radiocarbon dating and then the work begins analyzing a suite of parameters in the cores. Class members Lindsey and Amanda located a stick at the base of the core, this has been sent for a radiocarbon age and should give us an estimate of the timing of deglaciation in the region. Will Hansen (red shirt) will be using the upper part of the core together with our other collections from Round, O'Dell and Browns Lake for his Independent Study.

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