Posted by Chris M Wednesday, November 21, 2007
All of My Faults Are Stress Related did a couple posts about how to teach climate change to students. Sadly given the level of my students (very few are science majors) I don't think a discussion would work. My idea is to talk about the past climate and climate change first. Show them the various types of evidence used from many different techniques and types of scientists. The evidence doesn't point different directions, but converges on an accept view of what the climate was like in the past. Only after this will I talk about present climate change. Then using the same lines of evidence that were discussed before, show them that the climate is now changing primarily because of the actions of us humans. Then end with some predictions about how the world will be different in the future.
There are some excellent resources available, including the IPCC reports, real climate, and nice images at global warming art (see image below) which should make my job easier.
Posted by Chris M Wednesday, November 14, 2007
Anyways, I thought of another subject that would be perfect and I have an interest. Zoogeomorpholgy is the study of the impacts of animals on the landscape. Man is the most obvious geomorphic agent. Some of our actions are only important on short temporal scales of our perspective, but others will surely be found in the geological record in the future. Removal of natural vegetation cover increases erosion resulting in an larger sediment fluxes entering oceans . Anthropogenic climate change will also have an influence on geomorphology. However, for this I want to focus on non-human animals. A comprehensive review of this subject is available in the book Zoogeomorphology by David Butler . Termite mounds, crayfish burrows (>40,000 kg per hectare), birds ingesting sediment for use in their gizzards, animal paths to salt licks, and rabbit holes are only a sampling of geomorphic roles animals can play. I am going to focus on American Beavers (Castor canadensis) and Gray Whales (Eschrichtius robustus).
Beavers use mixtures of wood and mud to make dams across streams to create ponds. These dams vary greatly in size, with largest dam reported at 652 m long, although they are more typically tens of meters in length . They can store large amounts of sediment. Researchers examining streams in a Quebec, Canada, found that an average size single dam could store 6,000 cubic meters of sediment . Over a watershed of hundreds of square km, this could be on the magnitude of hundreds of thousands. Using estimations of pre-European contact beaver numbers, sediment stored behind beaver dams in North America is greater than 100 billion cubic meters . After dams are abandoned, the ponds often form new valley floors.
In terms of hydrology, beaver dams also raise the local water table. Finally, dam burst can cause extreme floods, greatly affecting stream morphology. Butler reported a dam burst that increased flow 1000 times over normal rates and moving 1 m granite rocks. This flood ended up killing four people. A dam burst in the Sierra Nevada Mts in California resulted in a dramatic drop in local base level and an associated .5 m of stream channel incision .
One of the more surprising examples of zoogeomorphology is the action of Gray Whale (Eschrichtius robustus) feeding. They winter near Baja California, but migrate to the Chukchi and Bering Seas between Alaska and Siberia during the Arctic summer. This is the longest mammalian migration in the world. In the Arctic sea, they feed on benthic crustaceans, or those that live in or on the sea floor. Using their mouths, gray whales scoop sediment from the sea-bottom. The sediment filtered via baleen, although some is ingest along with crustaceans. This filtered sediment is released near the surface in plumes. Off the California coast, researchers found that in areas of only a few square km, gray whales moved hundreds of tons of sediment . In the Bering Sea, it has been calculated that 120 million cubic meters of sediment is moved by gray whales every year. This is 3 times the annual load of the Yukon River, that also empties into the sea .
: Walling, D.E. (2006). Human impact on land–ocean sediment transfer by the world's rivers. Geomorphology 79:192-216.
: Butler, D. (1995). Zoogeomorphology. Animals as Geomorphic Agents. Cambridge University Press.
: Naiman, R., Melillo, J., Hobbie, J. (1986). Ecosystem Alteration of Boreal Forest Streams by Beaver (Castor Canadensis). Ecology 67:1254-1269.
: Butler, D., Malanson, G. (2005). The geomorphic influences of beaver dams and failures of beaver dams. Geomorphology 71:48-60.
: Kondolf, G., Cada, G., Sale, M., Felando, T. (1991). Distribution and stability of potential salmonid spawning gravels in steep boulder-bed streams of the eastern Sierra Nevada. Transactions of the American Fisheries Society 120:177-186.
: Cacchoine, D., Drake, D., Field, M., Tate, G. (1987). Sea-floor gouges caused by migrating gray whales off northern California. Continental Shelf Research 7:553–560.
Termite mound: Litchfield Park - Termite Mound by Daryl Fritz
Beaver: Beaver by Tancread
Gray Whale: Gray Whale by NMFS
Posted by Chris M Monday, November 12, 2007
There is interesting ecology present too. Drier sites are a mixture of White Pine (Pinus strobus), Pitch Pine (Pinus rigida), Virginia Pine (Pinus virginiana), White Oak (Quercus alba), Scarlet Oak (Quercus coccinea), and under-stories of Mountain Laurel (Kalmia latifolia) as shown in the first image. The second image shows a tough Virginia Pine hanging on a cliff and the third a photogenic Common Buckeye butterfly (Junonia coenia).
Finally, the park has many signs of past human activities, from Native American to European settlers to industrial logging and coal mining. The last image shows the house and English-style barn built around 1900 by John Litton.
Posted by Chris M Saturday, November 10, 2007
Posted by Chris M Sunday, November 4, 2007
After spending so much time in wet, cool, and dark cove forests doing my thesis field work, I enjoy going to open oak-pine forest. There was a nice variation in forest composition, based on altitude and location on the ridge. Near the valleys, there were numerous Chestnut Oak (Quercus prinus) and White Pine (Pinus strobus). On closer inspected, I noticed a few Shortleaf pine (Pinus echinata), although most were dead or dying as the more shade tolerant White pine finally made it to the canopy. Further up the ridge, Virginia Pine (Pinus virginiana) dominated, although they too were being replaced. There were also a great number of Black Oak (Quercus velutina), a species I am not very acquainted with. The understory was dominated by Sourwood (Oxydendrum arboreum) which was flame red in color. I was also surprised by the large quantity of American Chestnut (Castanea dentata) sprouts, some up to 20 ft.
The trail doesn't go all the way to the top of Fodderstack, although a bushwhack pretty easily gets you there. It is marked by a cairn and a USGS benchmark.
Posted by Chris M Saturday, October 20, 2007
Recently I was reading a paper and saw a reference that could be useful to me. It turned out to be a PhD dissertation at a university in a neighboring state. It was from 2001, so I suspected there was a good chance it was available in an electronic form. I went to WorldCat, searched, and found it was available in an electronic form. When I tried to download it, I was surprised when this came up.
At the request of the author, access to these materials is limited to the *** campus network only.
At request of the author? An author of a dissertation is limiting electronic access to their work to their university only? A journal restricting access is the status quo, but an author doing it.... I was not only surprised, but also dismayed. Fine I will just get the paper copy via interlibrary loan. I sent in my request and this morning I got this email in reply.
A request you have placed:
Author: *** 2001
has been canceled by the Interlibrary Services staff for the following reason:
(NML) No More Locations.
We have exhausted all sources for your request. This doesn't circulate from *** and is not available for purchase from Dissertation Express.
If you have a question about this canceled item or any Interlibrary Services policies and procedures, please contact us at ***.
Not only was I being refused the electronic copy, but even the paper copy was restricted to their university. I was shocked. I didn't want to copy it or print it, I just wanted to read it. Why would somebody restrict access to scientific material? Why would a fellow student, a colleague, refuse me the right to read their work? I had never heard of this person before and I couldn't find where they currently were with a google search. I would like to ask them why they did it? Were they tricked into thinking that restriction on access is the same thing as protecting ones work from plagiarism. Did they consider the harm they would cause by doing this? How would they feel if this had been done to them?
A small issue to be sure. I doubt there was anything present in it that other studies haven't found, but I will never know. It is a reminder of the damage that can be done by restrictions on information.
Posted by Chris M
Posted by Chris M Monday, October 15, 2007
Posted by Chris M Saturday, October 6, 2007
The streams have more fish and salamanders than I ever saw in any other site while doing my field work. However, this may have to do with the weather. It was cool and rainy that day while all other days I was out were warm and dry.
However, the most amazing features were the trees. I had to hike through Albright Grove to get to the stream, but the huge trees didn't end there. Although there were numerous large Hemlocks (Tsuga canadensis) and Tulip Populars (Liriodendron tulipifera), the Yellow Buckeyes (Aesculus flava) were what stood out. Not only were their sizes amazing, but there were many of them (outnumbering the Hemlocks).
A large Yellow Buckeye is a beautiful site. The bark takes on an attractive and distinct shaggy quality. The trunk itself is massive and I would guess perhaps 3rd in wood volume of GSMNP species (after Hemlock and Tulip Popular?). Despite the trunk size, it is quite graceful looking.
The first image is a Tulip Popular with a nice looking symmetric buttress. The other two are Yellow Buckeyes. I measured the CBH (circumference at breast height) of the last one as 14 ft 9 in!
Posted by Chris M Sunday, September 30, 2007
Grassy cove's drainage is connected to the valley underground and the Sequatchie River starts at several springs at the head of the valley. Unfortunately, the spring are on private land and I was unable to see them, however, that may change. These first couple of pictures are of the Sequatchie Valley far up near the head.
The first 1.5 miles of the trail was on private land and as I reached the top of the mountain I ran into several logging roads and machinery.
The forest was pretty young (20-40 years) but was mostly nut producing oaks (Red, White, Chestnut, Chinkapin) and hickories (Pignut, Shellbark, Shagbark). I sampled a few hickory nuts, although most were the slightly bitter Pignut. While I was eating one, a group of 3 Gray Squirrels surround on me on trees about 15 ft way and made the loudest chattering and the most extreme tail-flicking I have ever seen from squirrels.
The trail also had numerous wildflowers, including several asters and a species of goldenrod. I did find one American Chestnut sprout, but was to short to have any nuts.
Posted by Chris M Sunday, September 23, 2007
I found (almost stepped on) a really nice looking Indian Pipe and a Red Admiral (Vanessa atalanta) while getting to a stream
Finally, one day I followed a very steep stream several hundred meters and found no suitable location to do a measurement. Instead of going down the way I came, I climbed a nearby ridge and followed it down. It had been a while since I had not been in a cove forest but instead in a nice, open oak-pine forest. This ridge was mostly Chestnut Oak (Quercus montana) and Eastern White Pine (Pinus strobus).
Posted by Chris M Sunday, September 2, 2007
Clastic Detritus is starting a geology blog carnival (The Accretionary Wedge) with the first subject as "Why do you study geology?". For several days I had been trying to think of some captivating story for why I study what I do. For most important choices we make in life, there is no neat storyline connecting point A to point B. Rather, thousands of little strands of life combine to direct us where we end up at. I did think of one anecdote, though it certainly doesn't completely explain why I study what I do, that provides some illumination.
Like most children, I had a sandbox. I can still remember it. I was blue, roughly 1.5 ft x1.5 ft x 8 in, and stood on the back patio of my house, out of the sun under a maple tree. Although I can't recall it ever being fixed, no doubt it had been rebuilt several times as water I poured in the sand rotted the wood, especially the bottom. Buying a new bag of sand every Spring took on a Christmas type significance, at the same time a reminisce of past and the promise of future fun. I am not sure what the normal age was to stop playing in the sand, but I am sure I did it much later than most (perhaps I was 10 or 11 when I stopped?).
However, unlike most kids, I don't remember ever wasting much time on Army Men or castles in my sandbox. Instead I attempted to make replications of real world locations that I had never seen. The fact that I was from a place (Ohio) where glacial drift covered most rocks, except some erratics, helped to make sand a suitable medium. I also loved maps as a child and had not only atlases, but also road maps, city maps, and a DeLorme Gazetteer. So I would find an interesting location I had never been in my life on a map and try to use the information I had available to make it in my sand box. For example, I might find a location where two roads came together and crossed a stream. Looking back, my goal wasn't really some sort of photo-quality realism, but a view of how this place was now, how that compared to the past, and how humans had interacted with it. Why did the road follow the stream for 50 ft, then turned swiftly away? Was the slope next to the stream too steep for a road or had the settler's horse just decide to turn for no reason? Was the hillside smooth or did rocks stick out like chocolate chips in cookies? Did the stream have little sand bars in it or was it uniform?
Of course, as a 7 year old, I didn't have access to topographic maps or air photographs, but had to use real world examples available to me. The stream in my backyard twists like a rope while the stream down the road was perfectly straight with no curves at all. This steep hillside is rocky while that gradual hillside is not.
In time I learned some of the why for what I had sculpted in my sandbox. That stream was probably so straight because some farmers had made it that way many years ago. I also learned the damaged that had done to the stream.
Fast forward to where I am today. I am a geomorphologist that studies how we affect the landforms and landscapes we live with. Ostensibly I do this so we can learn how to rehabilitate the landscapes we have already scarred and decrease the amount of damage we do to them in the present and the future. However, just as the cosmologists finds a beauty in understanding the workings of a star, I think just understanding how we interacted with the landscape (and how it reacts back) is fun, interesting, and worthy of study in itself. Perhaps I haven't outgrown the sandbox.
Photographs: Sandbox by JayeClaire; Curved Road by cindy47452
Posted by Chris M Saturday, September 1, 2007
The turbines are huge (260 ft tall, the blades are 135 ft long) and there are 18 of them along the mountain. The mountain is >3300 ft in elevation with occasional views of the surrounding mountains (although most have been coal mined).
The dead bats we are looking for are pretty small (bodies 1-2 in in length). Here is a dead, I think, Little Brown (it may be Eastern Pipistrelle).
Finally, this mountain, and the surround region, has taken multiple hits. In the past it has been coal mined and there are old coal benches everywhere. Now, part of the mountain is the WIndrock ATV area, that is also extremely damaging the mountain. The first two are a eroded gully on the mountain top, the third an old bench, and the last two are current ATV trails (there are much worse ATV trails, these images turned out the best.... we where driving when they were taken).