Callan @callan-bentley ?

active 6 hours, 49 minutes ago
  • The Heezen and Tharp (1977) World Ocean Floor Panorama is an amazing map – an ideal amalgam of science and art. It is the result of a collaboration between Bruce Heezen and Marie Tharp, in conjunction with artist […]

  • More 3D models: digital facsimiles of real rock samples. Check them out and explore!

    Clinker from the Powder River Basin, Wyoming:

    Ripple marks from the Rose Hill Formation, West […]

  • As I mentioned last week, I have family in one of the coastal towns in Ecuador that was hardest hit by the magnitude 7.8 earthquake the previous weekend.

    Don and Wendy have asked me to share this opportunity to […]

    • I tried to donate but the transaction crashed as a server error. I also tried visiting the website but Chrome gave me a security warning. I’m not sure what’s going on there, but they should get it straightened out if they want people to donate.

  • Another week, another batch of new images produced on my home-based Magnify2 imaging system from GIGAmacro. This week, you can see that I’ve been on a real brachiopod tear – here are seven images of those […]

    • Callan,
      I think this gigapan work is fantastic. I like the SEM images from your student, too. Is there any way gigapans can include a dynamic scale, that changes as you zoom in and out? Or is it there as an option, and I missed it?
      Have you posted any gigapans of thin sections?
      Bob

    • I am going to guess that No. 4, is from the (Upper Devonian) “Chemung”/Foreknobs.

  • A quick report today on a delightful book – The Floating Egg: Episodes in the Making of Geology, by Roger Osborne. It’s a collection of pieces, some only a few sentences long, others full essays, and still others […]

  • As mentioned yesterday, my student Robin has been having some success lately in making GigaPan-scale imagery using the new desktop scanning electron microscope that our division acquired. They aren’t as super-high […]

  • Today for your folding pleasure, I give you two field GigaPans shot by Jeffrey Rollins, a two-time Rockies field course alumnus and Old Dominion University student working under my colleague Declan De Paor, […]

  • My student Robin has been working (on and off) for more than a year to figure out the best way to make GigaPan-scale imagery using the new desktop scanning electron microscope that our academic division acquired. […]

  • My mother-in-law, Wendy, lives in coastal Ecuador, in the town of Canoa. When Lily and I heard about the earthquake Saturday night, we knew we were unlikely to get any immediate word about her condition for […]

    • I’m not really qualified to make the following comments, but they’re things I’ve picked up up listening to civil engineering lectures about the response and performance of various structures in earthquakes.

      1. Duration – Each cycle of waves does damage. The longer the earthquake, the more damage is done. Large, vertical primary wave (P-Wave) deflections cyclically load the joints between vertical columns and horizontal beams. More loading events means more of them reach failure. Think of hammering a horizontal stabilizer between the legs of a chair. The more hammer strikes, the more likely you are to break the stabilizer free.

      2. Masonry – Block walls are very strong in compression. However, they have very little ability to resist shear forces (sideways or scissors-like forces). Secondary waves (S-waves) move side-side through the Earth a bit like a sidewinder snake. As the move past a masonry block building they apply a large sideways force to the base of the structure. The top of the building cannot go along for the ride because the grouted joint is so weak in shear it cannot transmit the load, so it separates. The building then collapses because its base has been kicked out from beneath it. Masonry buildings have been essentially forbidden by California building codes since about the 1920’s for that reason. Notice all the masonry block and brick you see in the rubble.

      Unreinforced Concrete- Like stone or masonry blocks, concrete has enormous strength to resist compression. It has only a tiny fraction of that strength in shear and even less in tension. That’s one reason steel bars (re-bar) are used as a skeleton inside structural concrete. Steel is very strong in shear and tension, but much weaker in compression. So steel and concrete together complement each others strengths. In photo two above the first thing I noticed was I didn’t see any re-bar in the concrete. I also see lots of masonry block. No wonder it came apart, that building had no shear strength. Is that an apartment building or hotel? Who approved that in an earthquake zone?
      For the “Interior of a friend’s house” photo, notice the reinforced concrete and notice that while there’s damage, it did not collapse. Notice also all the block-work laying on the ground.

      Walled compounds and barred windows – These are key indicators of a low trust, high crime society. I’m not surprised there was immediate looting.

      Last Photo – South American women always seem so well groomed. And the ones I’ve known are extremely sweet and decent people.

  • Occasionally, our big windows get in the way of birds. The latest casualty was a hairy woodpecker, Leuconotopicus villosus.

    While it’s sad that our home being where it is caused the end of this bird’s life, […]

    • Interesting! There’s always so much more going on around us than we’re aware of. I ran across a video a few weeks ago that someone shot of a Florida Panther running past them on the raised boardwalk that winds through Corkscrew Sanctuary. I was there last year with my daughter and her two children. We saw lots of gators, an owl, turtles and tropical water fowl. But I would never have guessed panthers were in the area. Wow.

  • It’s National Park Week, which means free entrance to our nation’s many wonderful national parks. My local park is Shenandoah National Park, astride the Blue Ridge one mountain range over from my house. Monday was […]

  • James Farrell is our newest Friday fold source. Today he shares a primary (not tectonic)  fold – the fold is in the ropy texture of a pahoehoe flow:

    Those colors! What a gorgeous rock. Thanks for sharing, […]

  • David Montgomery is a professor of geomorphology at the University of Washington, in Seattle. I’m a fan of his work in soil conservation and countering creationism, so I was very pleased to find myself sharing […]

  • Another week, another batch of new images produced on my home-based Magnify2 imaging system from GIGAmacro.

    Leptaena brachiopod in (Mississippian?) limestone from Montana:
    [gigapan […]

    • In the 1st two photos of the Mississippian Montana limestone, there’s a nice encrusting bryozoan (like Fistulipora) at the bottom of Photo No. 1. On the shot of the other side in the 2nd photo, besides the fenestrate bryozoans, there are some branching, Cystodictya-type bryozoan fronds, on the right side. Plus, on this side there might be an ostracode, perhaps trilobite debris (both sides), and a crinoid columnal. Sorry, but it’s been awhile since I got to play in a Mississippian “garden” again. Miss those critters, and their pals.

  • Update:
    Here’s a macro GigaPan of the breccia (4 samples of 2 colors):
    http://gigapan.com/gigapans/185868

    In reply to - Callan wrote a new post, Corona Heights Fault, San Francisco, on the site Mountain Beltway On my final day at the AGU Fall meeting, I made a pilgrimage to a place I’d long wanted to visit: Corona Heights, where […] · View
  • Here are a few new images I’ve been working on with my home-based Magnify2 imaging system from GIGAmacro.

    Strophomenid brachiopods from Mississippian Mauch Chunk Formation, West Virginia:
    [gigapan […]

  • Joke, right? No fossils here.

    In reply to - Callan wrote a new post, This week’s batch of 3D models, on the site Mountain Beltway Anorthosite with lovely garnet reaction rims, a spherical hematite concretion, and some sweet breccia. Check them out and […] · View
  • Anorthosite with lovely garnet reaction rims, a spherical hematite concretion, and some sweet breccia. Check them out and explore!

  • Callan commented on the post, Compton Peak columns, on the site Mountain Beltway 1 month ago

    It’s here:
    https://www.google.com/maps/@38.8177076,-78.1755961,16.31z/data=!5m1!1e4
    Park at the Compton Gap parking area at north end of map view, then hike uphill (south) on the AT. At the top, there will be a trail intersection. Right (west) goes to the summit of Compton Peak and an overlook, but left (east, downhill) leads to the columns.

    In reply to - Callan wrote a new post, Compton Peak columns, on the site Mountain Beltway After finding out about the spectacular exposure of columnar-jointed Catoctin Formation exposed on Compton Peak in Shenandoah National […] · View
  • Here are a few new images I’ve been working on with my home-based Magnify2 imaging system from GIGAmacro.

    Archean basement complex gneiss from the Gallatin Range of Montana:
    [gigapan […]

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