Callan @callan-bentley ?

active 2 days, 16 hours ago
  • Lichen covers the slopes of a small cinder cone in southwestern Iceland:

    The colonization of the reddish black cinders by the off-green lichens yields a remarkable suite of colors to these volcanic […]

  • For the Friday fold, let’s travel to the northern edge of the Isle of Arran in southwestern Scotland, where near the town of Lochranza, you can find Dalradian metagraywackes that display a lovely suite of folds. […]

  • In the past couple of months I listened to the audiobook versions of Ernest Cline’s two novels. They are of a common piece, and so I opt to review them in tandem. There is a feeling I have that I am increasingly […]

  • One fun thing about examining the Port Askaig Tillite in the field is to find odd-shaped exemplars of the unit lying on Islay’s beaches. My favorites were shaped like wands, or antennae, or perhaps the […]

  • Thanks. Yes – I keep that camera busy!

    In reply to - Callan wrote a new post, Islay’s Port Askaig tillite, on the site Mountain Beltway Have a look at this: Pretty uninteresting rock at first glance – massive gray stuff. But what about those pink bits? […] · View
  • Have a look at this:

    Pretty uninteresting rock at first glance – massive gray stuff.

    But what about those pink bits? What are those?

    Turns out those are pebbles and cobbles of granite. Here are a few […]

    • I have been following this blog for about a year. it is most interesting. One feature I particularly like is the fact that many different examples of the rocks are given. Thanks.

  • Here’s a look at some of the wild critters that have been visiting my yard this year:

    The video’s organized in alphabetical order, so it starts with bears, and ends with a walking stick insect.
    See how many […]

  • A good question. I don’t know the answer; I didn’t measure anything systematically when I poked around there. That said, Eriboll is more or less north-south oriented, meaning the exposures I visited also had that strike. So the fold hinges pictured in outcrop would have at least been oblique to that, and maybe even perpendicular. (Tectonic…[Read more]

    In reply to - Callan wrote a new post, Friday fold: intrafolial folds in Eriboll mylonite, on the site Mountain Beltway Loch Eriboll in the North-West Highlands of Scotland, east of Durness and west of Scrabster, is a beautiful […] · View
  • Loch Eriboll in the North-West Highlands of Scotland, east of Durness and west of Scrabster, is a beautiful place.

    It’s also a place of immense importance to the development of geologic thinking. It was […]

    • Are the hinges of the intrafolial folds in the original mylonite perpendicular or parallel to transport direction?

      • A good question. I don’t know the answer; I didn’t measure anything systematically when I poked around there. That said, Eriboll is more or less north-south oriented, meaning the exposures I visited also had that strike. So the fold hinges pictured in outcrop would have at least been oblique to that, and maybe even perpendicular. (Tectonic transport direction is roughly east-to-west.)

  • Aha. I see. Yep, you’re right.

    In reply to - Callan wrote a new post, We are in unprecedented territory with global sea ice, on the site Mountain Beltway The amount of our planet’s ocean area covered by ice is at an unprecedented low for this time of year. […] · View
  • Callan wrote a new post, U-turn, on the site Mountain Beltway 1 week, 6 days ago

    Scotland was glaciated during the Pleistocene “Ice Ages:”

    The signatures of glaciation are manifold in a scene like this. Most prominent and easily recognizable is the broad, relatively flat-bottomed […]

  • Yesterday, I mentioned climate change visualizer extraordinaire Zack Labe. As delineated then, he’s a PhD student at U.C. – Irvine in the Earth Systems Science department. He’s producing some really excellent […]

  • You’re perhaps aware that the dataset cited is the range of the satellite (direct) record. Proxy datasets go back much further, and teach us about numerous changes to the planet’s climate over its 4.5 billion year history. I’m not claiming that the current anomaly is unprecedented within that span, and neither am I claiming the planet Earth is…[Read more]

    In reply to - Callan wrote a new post, We are in unprecedented territory with global sea ice, on the site Mountain Beltway The amount of our planet’s ocean area covered by ice is at an unprecedented low for this time of year. […] · View
  • Point me at your data. The graphs above do not show Antarctic ice solo, only Arctic solo and combined (global), area (not volume) in both cases.
    This graph shows that the Weddell Sea basin had a 2016 peak, but the “total Antarctic” summation graph does not show a peak. Maybe you’re looking at different data than I am.

    In reply to - Callan wrote a new post, We are in unprecedented territory with global sea ice, on the site Mountain Beltway The amount of our planet’s ocean area covered by ice is at an unprecedented low for this time of year. […] · View
  • The amount of our planet’s ocean area covered by ice is at an unprecedented low for this time of year. It is the Arctic winter, the long night when no sun shines on that northerly ocean, and yet temperatures there […]

    • It also appears that the 2106 total ice level at the peak of the Antarctic summer was the lowest on record (but not by much).

    • Hmmm, 1978 to 2016. Not a whole lot of history to “the record” is there? Earth has been ice free most of its history with exception of the Quaternary, the Huronian, the Cryogenian, Andean-Sahara, and the Karoo. IMHO this is nothing to worry about and certainly the geologic record speaks for itself.

      • You’re perhaps aware that the dataset cited is the range of the satellite (direct) record. Proxy datasets go back much further, and teach us about numerous changes to the planet’s climate over its 4.5 billion year history. I’m not claiming that the current anomaly is unprecedented within that span, and neither am I claiming the planet Earth is itself at risk. My understanding of the Huronian, the Cryogenian, and the Quaternary inform my view, as well as what follows. I am claiming that the current anomaly is unprecedented within the period we have been actively directly observing, and I’m claiming that it’s likely unprecedented within the time our species has existed and civilization has grown and thrived. Would you challenge those claims? I would also argue that the rate of change currently observed is unmatched except during times of major perturbations to the Earth system (i.e., the PETM, the K/Pg event).
        I’m pleased your view is so sanguine as to the resilience of the biosphere and the perpetuity of human civilization. Please justify that specific aspect of the situation? Thanks in advance.

    • Thanks for your question.

      The point I am making here, is the data set covers no more than 40 years and you essentially have a one point anomaly which statistically, mathematically and geologically is meaningless. Even if you limit the period of comparison to the current interglacial 40 years out of that length of time is meaningless statistically. Using the term “unprecedented” only pertains to the fact that this phenomenon has not been observed in the time period records have been kept. You cannot extrapolate this single point of so-called deviation from the norm to mean much of anything. Whether it is anomalous depends on whether the trend continues. Have we seen other anomalies in this time period which correlate or could explain this deviation? Question to you and the Ph D candidate from California. Then, please define over what period of time you are calculating “rate of change”..

      I think you can also leave the PETM and K/Pg out of this discussion from the standpoint that you are again comparing a single year of data (or 40 years if you wish) to perhaps 100’s of thousands of years. I point out that the changes with respect to the K/Pg probably took place over some 3 million years.

      If one observes any natural trend, there will always be deviations from the “norm” (if you can define what the norm is) that may appear as spikes one side of the norm or the other. One single point of change is again not significant in the face of no other supporting data regarding a trend and 40 years of data is not significant over the length of the overall cycle it is supposed to sample.

  • Here are three pairs of GIGAmacro images to illustrate a few techniques I’ve used in preparing the samples and the images. The image pairs here illustrate the effects of transparent acrylic coatings, […]

  • I tried something new this morning, and polled Twitter for their choice of Friday fold:

    Quick poll – What do you want for the Friday fold? 30 minutes to respond.
    — Callan Bentley (@callanbentley) November 1 […]

  • I listen to a few podcasts, and I’ve been meaning for a long time to write down some thoughts about them to share, in the same spirit in which I review books, or less frequently movies or television […]

  • Now that we’ve examined the geology of the outcrops at Funzie Bay on the island of Fetlar in northeast Shetland, let’s stroll along two beaches. Here we have cobbles from Funzie Beach and a small beach eroded from […]

  • It’s been a week since Donald Trump defeated Hillary Clinton in the race for the President of the United States.

    I’ve been processing the news, and I’m not happy about it. I’ve been on “radio silence” for a […]

    • I echo your last paragraph. I just don’t know where we can go from here. Four years of at best inaction on climate change really ends all possibility of a sustainable future.

    • What to do? Keep doing what you’re doing, Cal. it makes a difference.

    • Dear Callan,

      I am following the perspectives and views from very few selective scientists, that I have a concrete opinion concerning their personal integrity and value in science reading their blogs as well.

      You are one of them. Your words are most appreciated because of your stamina to the scientific integrity and merit while your opinion and critique highly appreciated and overseas.

      I strongly believe that your perspectives and considerations have their place in time and worth the attention from those that can take political responsibilities and decisions for the best for all.

      I agree with the comment from Mr. Freeland: “Keep doing what you’re doing, Cal. it makes a difference.”

      Respectfully,

      Gavriil.

    • Dave replied 3 weeks ago

      I agree completely with you Callan. A small bit of good news, at least Ben Carson has declined the position, citing that he has no government experience.

      In other news, I’ve really enjoyed your posts on Scotland, somewhere I dearly want to visit.

  • Load More