Tree Lobsters: "Science Police"
Labels: art, humor, pseudoscience, science and society
Labels: art, humor, pseudoscience, science and society
Labels: art, humor, stratigraphy
So here's how this works: the top image is a map. It gives you a "bird's eye" perspective on earthquake locations at the subduction zone near Samoa. It shows you the epicenters (location on the earth's surface above a quake's actual location, called its "focus" or "hypocenter") of many earthquakes, along with Tuesday's big quake, shown with a star. The thick red line is the position of the trench, a bathymetric expression of the subduction zone. The epicenters are color-coded for their depth. Orange and yellow are shallow; green and blue are medium depth; and purple and red are the deepest. Notice that they make a sort of "rainbow" pattern, with the shallowest quakes in the east, and the deepest quakes in the west. This is "looking down" on the subducting slab: it's like we're able to "see" the subducting slab as it descends into the mantle.
The lower image is the cross-section. It gives you a "gopher's eye" perspective on the same data. A cross section is drawn along the line A-A' on the map. This is conceptually slicing the Earth open along that line, then removing half, and looking sideways at the remaining half. Note that the A-A' line is now along the top of the figure, representing the surface of the earth. Along the horizontal axis is horizontal distance, measured in kilometers. Along the vertical axis is depth, also measured in kilometers. The two axes are not drawn to exactly the same scale, but pretty close. In other words, 100 km of horizontal distance is approximately equal to 100 km of vertical distance (depth). The same data are plotted, or at least the subset of the map's data which happen to fall on that particular line, A-A'.
With this new perspective, a side-view, what do we see? Well, there's the star, which shows the depth of the quake that triggered all this discussion, and a whole bunch of other (historical) earthquakes. Now, instead of the epicenter being plotted, we're getting a more robust sense of the hypocenter (or focus). Note that the earthquakes are being generated in a big swath, starting at the surface in the northeast, and dipping down deeper and deeper to the southwest. This line of seismic activity reflects the jerking passage of the subducted slab of oceanic lithosphere. As it plunges down, it generates lots of shaking. This zone of seismicity was first described (independently) by two scientists, Kiyoo Wadati and Hugo Benioff: in their honor, it is referred to as the Wadati-Benioff zone. (Wikipedia has more) Their realization is our gain: we can "see" the subducted plate diving at an angle of 30 to 40 degrees. That's what's so cool about this:
Something that no human will ever directly observe is "visible" to us because we can pinpoint the three-dimensional location of thousands of earthquakes. These bumps and jolts reveal the position of the bumper and jolter: the subducting plate!
Labels: analogies, art, earthquakes, plate tectonics, websites
Labels: art, earthquakes, plate tectonics, websites
Labels: art, books, connecticut, maps, maryland, new york, oregon, washington
If you haven't seen this yet, please watch it. Nice work, Mr. Balog!
Labels: art, climate change, glaciation, global warming, ice, meetings
Labels: art, books, california, georgia, idaho, maps, utah, west virginia
Labels: art, books, colorado, indiana, louisiana, maps, michigan, new mexico
Labels: arizona, art, books, delaware, maine, maps, new jersey, pennsylvania
Labels: art, meetings, nova, science and society, tech



Labels: analogies, art, montana, national parks, north carolina, nova, structure, travel, wyoming




Labels: art, geologic time, structure, wyoming






Labels: art, arthropods, contest, fossils, structure












Labels: art, dc, field trips, geology, nova
Labels: art, geology, google, isotopes, maps, tech, virginia
Which of the following haiku poems best describes the formation of oil?
Swamp plants leaf out green
then die and get squeezed, sans air.
Carbon gets more pure.
Plates skitter about
plastering terranes on front
like trucks with kittens.
Surface magma sweats,
devolatilizes. Its
fluids drop out ore.
Phytoplankton bloom
in sunny water then get
cooked and leak black goo.
Fossil fuels get lit
and oxidize; humans thrive.
Damn that CO2.
Not the most challenging question on the exam, but it was fun to write...
Other geoblogger instructors -- Do you amuse yourself (and your students) by injecting humor into exams? Is this poor form on my part? Is it genius? Weigh in. I'm curious to know whether this habit is ridiculous or common.
Labels: art, humor, science and society
Labels: art, ordovician, plate tectonics

Brilliant! Especially in light of the new fossil evidence about the origins of whales released earlier this year.
From last week's issue of the New Yorker, which I've got time to read today because it's a snow day here in DC!

Differences:
National Geographic has a gallery of seven "missing link" species whose fossils have been discovered since Darwin proposed the origin of new species by means of natural selection. It troubled Darwin that the fossil record didn't show more explicitly the transitions between species, but he proposed his hypothesis anyhow. Good hypotheses make testable predictions, and this is a nice example of how the ensuing 150 years of paleontology have validated the notion of species' change through time.
Labels: art, blogs, climate change, global warming, ice, oceans

Labels: art, coal, geologists, geology, news
Labels: art, blogs, books, climate change, global warming, websites












Labels: art, arthropods, birdies, critters, ecuador, hot springs, plants, south america, travel

Labels: art, satellite imagery

Voll, G. , "New Work on Petrofabrics," Liverpool Manchester Geol. J. Vol. 2, 1960, pp. 503-567.

My mom recently had her attic renovated, which meant that I had to go up there and remove all the stuff I'd stashed up there when it was just free storage. Rummaging through that memorobilia this week, I found my old boy scout merit badge sash. It's pictured here, both front and back.
The merit badges are the little circular patches on the front side. As you can see, I earned 28 of those puppies before I got my Eagle Scout award and retired from scouting. They are: swimming, cooking, leatherwork, canoing, mammal study, citizenship in the community, lifesaving, rowing, reptile study, basketry, nature study, environmental awareness (now apparently called environmental science), pioneering, citizenship in the nation, fire safety, first aid, wilderness survival, camping, art, pottery, citizenship in the world, personal management, communications, orienteering, woodworking, soil and water conservation, personal management, and forestry. (Notice that geology is missing...)
On the back of the sash, you can see patches from the Goshen Scout Camps in Virginia, the Philmont axe, the Arrow of Light (the only cub scout award that can be worn on the boy scout uniform), a patch showing that I swam a mile, an Order of the Arrow lodge patch, another commemorative patch from Philmont Scout Ranch, and my Boy Scouts of America Lifeguard patch.
Scouting was really good to me. It gave me a lot of confidence in my skills as an outdoorsman, and gave me a lot of great experiences in nature and in society. I doubt I'd be who I am today without thos formative experiences. Though I don't agree with everything that the BSA stands for today, I think that on the balance they do a great service for our communities and our boys.
Any other scouts out there? Any of you earn the geology merit badge?



Over the winter break, I read the new book Ancient Landscapes of the Colorado Plateau, by Ron Blakey & Wayne Ranney. This is an excellent read, and a terrific introduction to the geologic history of one the world's most dramatic landscapes. Blakey's maps have been featured on this blog before, and he has been kind enough to allow me to modify some for use on my field course websites (like here and here and here). The book goes through geologic time and makes extensive use of beautiful paleogeographic maps to reveal the story of mountain-building, transgression, regression, sand-dunes, faulting, volcanism, and erosion that characterizes the Colorado Plateau. It's not just paleogeographic maps, by the way: there are also plenty of shots of fossils, Colorado Plateau landscapes, and comparable modern depositional environments to enliven the story. It's a graphic story, well told with excellent graphics. I recommend you get yourself a copy if you've ever been to the Colorado Plateau, or if you ever plan on going there.
Find the book: On Amazon ... At the NOVA library
Labels: arizona, art, books, colorado, maps, new mexico, utah




Labels: art, geology, humor, primary structures

Labels: art, climate change, coal, environmental, global warming, politics
Labels: art, geologic time, humor, teaching


This weekend, I was procrastinating working on my final paper of the semester for my online MSSE education class, and decided to search "geology" on YouTube. (I knew there were some gems there, as Bryan reminded me earlier today.)
Anyhow, that search brought me to this piece of utter silliness, which I now share with you:

Labels: alaska, analogies, art, canada, glacial landforms, glaciation, maine, michigan, mountains, new york, satellite imagery, sediment

Labels: art, satellite imagery, sediment
A couple of weeks ago, I mentioned AGI's Image Bank, and to illustrate it I picked three photos by Marli Miller (at the University of Oregon). Dr. Miller has written me and shared a link to a website she has put together to share high-resolution images of geological features and processes. Educators have permission to download the photos for teaching (non-commercial) use. And everyone can benefit from visiting to check out the many gorgeous images there.

Labels: art, geologic time, oceans, plate tectonics

The largest meteorite (or maybe comet?... we don't really know which) impact crater in the United States is in Virginia, underneath the lower Chesapeake Bay. In the Eocene, a large bolide (unidentified space chunk) slammed into the Earth. Dating of microfossils found in the same sedimentary layers as impact ejecta have provided a date of ~35.5 Ma for the event. The impactor hit on the continental shelf offshore of Eocene Virginia, carving through the Atlantic-deposited sediments there and gouging into the crystalline bedrock beneath (igneous and metamorphic rocks like the modern Piedmont province, but buried beneath Coastal Plain layers).
The crater was discovered over a ten-year process that began with offshore sampling near Atlantic City, New Jersey in the mid-1980s. Those drill cores came up with a layer of ejecta (including shocked quartz and little beads of glass called tektites) among the late Eocene layers of sediments. Searching around, eventually the crater was seismically imaged by oil exploration in the Chesapeake Bay in the mid-1990s.
Centered on Cape Charles, Virginia, the crater is about 50 miles across, but appears wider as sedimentary layers adjacent to the hold have slumped inward along listric faults. The James, York, and Rappahannock Rivers all trend into this depression, and ultimately the crater is probably responsible for the Susquehanna River taking on its southerly course. When sea level rose and flooded the valley of the Susquehanna, the Chesapeake Bay was formed.
A similar impact structure offshore of New Jersey, the Toms Canyon Impact Crater, may have formed at the same time as the impactor broke into pieces before impacting.
The lead-off image to this post is by the team at the U-Haul trucking company, which performs a terrific public service by finding out interesting things about the different states (and Canadian provinces) and posting them on the sides of their trucks with eye-catching graphics. A great many of the topics they choose are about geology, from minerals to fossils to impact craters to cartography and canyons. A while ago, I wrote an article for Geotimes looking at their program.
More information on the crater:
Wikipedia's entry on the crater.
W&M Geology Department's page about the crater.
USGS team examining the crater.
National Geographic article (2001).
Labels: art, cenozoic, coastal plain, geology, meteors, new jersey, piedmont, rivers, virginia
Labels: art, connecticut, fossils, humor, museums

Labels: art, climate change, environmental, global warming, humor
Every now and again, I like to post an image that just speaks volumes. Check this one out, of Saturn's moon Enceladus. Wow! What a beauty. This photograph was taken on Monday by the Cassini spacecraft. Enceladus may host liquid water below the surface, since it has geyser-like features near its south pole. There are only three places beyond the asteroid belt where eruptions have been seen: Enceladus, the jovian moon Io, and Neptune's moon Triton. Enceladus is only a few hundred miles wide; These fractures are about 1000 feet deep.
Labels: art, planetary geology
Labels: art, climate change, CO2, global warming, maps
Labels: art, satellite imagery
Labels: art, humor, science and society
Today was the artist's reception at the National Academies of Science for Camille Seaman's exhibit of photographs entitled "The Last Iceberg." I took a break from writing a paper for my MSSE class and went down to check it out.Labels: art, climate change, dc, global warming, primates

Thanks to John Weidner for calling this gem to my attention!

My dad and my two brothers and I are going rafting down the Canyon this summer, and I'm looking forward to exploring the geology firsthand from the river level. My four previous trips to the Canyon have all started at the rim, then hiked down (sometimes to Plateau Point, sometimes to the river), and then back up in the same day. Staying at river level for over a week ought to be awesome.
Labels: art, geology, grand canyon
I watched a cool documentary the other night about the Canadian photographer Edward Burtynsky. The film is called Manufactured Landscapes. (It's available from Netflix.)Labels: art, environmental, movies


Labels: art, global warming, planetary geology
The Smithsonian's department of paleobiology has a webpage devoted to displaying some art that was used in some old scientific papers on fossils. There's a beautiful variety of images there, like this frontal view of a Triceratops skull that was used to prepare a lithograph, which then appeared in a paper by legendary paleontologist Othniel Charles Marsh (archnemesis of Edward Drinker Cope). Check out the full variety of art here.Labels: art, fossils, smithsonian, websites

Labels: antrim coast, art, clouds, northern ireland