Rolling Boulders…

I’m a bit slow to get started this morning, since I didn’t get home until the wee small hours after a trip to the Royal Astronomical Society yesterday, followed by a pleasantly tipsy dinner at the Athenaeum with the RAS Club. Anyhow, one of the highlights of the meeting was a presentation by Prof. Gerald Roberts from Birkbeck on Marsquakes: evidence from rolled boulder populations, Cerberus Fossae, Mars.  The talk was based on a recent paper of his (unfortunately behind a paywall), which is about trying to reconstruct the origin and behaviour of “Marsquakes” using evidence from the trails made by rolling boulders, dislodged by seismic activity or vulcanism.  Here is a sample picture showing the kind of trails he’s using – the resolution is such that one pixel is only 20cm!

There are enough trails to allow a statistical analysis of their distribution in space and in terms of size (which can be inferred from the width of the trail). I had some questions about the analysis, but I haven’t been able to read the paper in detail yet so I won’t comment on that until I’ve done so, but the thing I remember most from the talk were these remarkable pictures of what a rolling boulder can do on Earth. They were taken after the earthquake in Christchurch, New Zealand, in 2011.

A large boulder was dislodged from the top of the hill behind the house in the second picture. It didn’t just roll, but bounced down the slope (see the large furrow in the first picture; similar bouncing trajectories can be seen in the picture from Mars), smashed straight through the house, exited the other side and came to rest on a road. Yikes.

5 Responses to “Rolling Boulders…”

  1. Loretta Dunne Says:

    yup, a sadly familiar sight round here. lots of roads/tracks closed (18mnth on) and whole streets being demolished from ‘risk of falling rocks’, lots of debate about the methods of risk calculation though.

  2. As an aside, and prompted by your paywall remark, planetary scientists are generally quite bad at putting their papers on astro-ph. No good explanation, other than its a culture thing. I’m often frustrated when researching planetary science stories, and Cardiff University doesn’t pay the journals for access to their papers.

    It’s not clear to me how to persuade the planetary science community to support open access…

    • Monica Grady Says:

      Planetary scientists aren’t ‘quite bad’ at putting papers on astro-ph. They (we) are atrociously bad at so doing, to the extent that we hardly ever do. It is definitely a culture thing, possibly stemming from planetary sciences having a closer link, historically, with Earth scientists rather than astronomers. We must change. Many of us do support open access, very strongly.

      And it was a most pleasant dinner on Friday night, with good wine and good company.

    • Anton Garrett Says:

      I expect you can find preprints on the authors’ own websites, but it’s a pain compared to the one-stop (free) shop of the arXiv.

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