One tradition in the Hunter household is that things always fall apart over the winter holiday season. This year, the cable quit in a snit, and the computer decided tonight that speaking to the internet was not part of its job description. This has put a crimp in serious blogging for the evening.
But it does give me the opportunity, now that the computer has been convinced to do its job, to introduce you to one of my favorite geobloggers, Silver Fox, and her end-of-year meme. I haven't got twelve months of posts yet - this blog is only now going on nine months old - but it's the spirit rather than the letter of the thing that counts.
Without further ado, then: link and first sentence for first blog post of each month of the past year.
April: The first thing geology ever said to me was, “Ouch!”
June: While tourists gazed rapt into the billions of years exposed in the layer-rock-cake walls of the Grand Canyon, my mother and I would hop down to Jerome.
July: The Scientific American Blog Network turns 1 today!
August: The mountain boomed.
September: A probe sweeps through space.
October: One of the eeriest things I’ve ever seen is the video shot by KOMO News reporter Dave Crockett on May 18th, 1980.
November: This month’s Accretionary Wedge is all about geopoetry, and you’d think that an SF writer who’s got a story that’s about a poetry war could pull something off.
December: I adore Chris Rowan of Highly Allochthonous.
There we are, then. Eight months of Rosetta Stones, at your fingertips.
I also promised thee reader extras. On our last adventure, in which we explored unfortunately incorrect videos of Parcutin, several of you left comments with excellent points, good questions, and interesting extras. For instance, Erik of Eruptions said, "Nice post … although St. Helens isn’t a caldera, but a crater, right? No implosion, just a highly impressive explosion." It's true, I've not seen anything referring to St. Helens's horseshoe-shaped crater as being caused by an implosion! And as I look at the scientific literature, I see the word "implosion" scattered thickly throughout. It would appear from said reading and Erik's comment that most volcanologists consider a caldera to be created only by implosion. I'd been going by my physical geography text and the dictionary definitions of caldera, which basically call any sufficiently large crater a caldera. I shall refrain in the future.
Khearn requests a post on cinder cones - which is in the works, thanks to RQ having already requested the same! - and notes, "I looked at the cinder cone article at Wikipedia, and it even mentions that Cerro Negro has erupted over 20 times from 1850 to 1999. I suspect this may be as inaccurate as the YouTube videos, but I’d like to learn more from a better source. I’m guessing that you probably classify Cerro Negro as something other than just a cinder cone, or maybe it has erupted from different cones each time." I knew one of you would bring up Cerro Negro. I haven't got access to the paper yet (if one of you has journal access and would like to send it to me, I'd be more than grateful), but that question has already been asked and answered in the scientific literature. Yay! McKnight and Williams, in "Old cinder cone or young composite volcano?: The nature of Cerro Negro, Nicaragua," conclude that
Structurally, Cerro Negro's cone, is a composite of scoria and lavas cut by dikes around a dense volcanic core. Cerro Negro's shape has been more like a composite volcano than a cinder cone, except when infrequent sub-Plinian eruptions have altered the cone to make it look like a cinder cone. Comparisons of Cerro Negro to well-known, historically active cinder cones and young composite volcanoes show that it is best described as a young composite volcano.
That's all I can tell you, as I have access only to the abstract (if one of you has journal access and would like to send it to me, I'd be more than grateful). But it seems we're not dealing with a cinder cone in this case, although it likes to masquerade as one sometimes.
And, finally, Susannah left a wonderful comment about one of the folks who filmed Parcutin in eruption. She says, "I was fortunate to watch, back in 1959 or maybe 1960, a film of the beginnings and growth of Paricutin. A longish film, slow-moving. I remember particularly Pulido’s field, leaking what looked like steam from several cracks. There was no sudden panic, like the final cartoon pretends; the smoke continued, found more small outlets well before ash started to appear." Read both of her comments, and the article she found on the person who filmed a volcano's life, from birth to extinction. This is one of the things I love best about writing, outside of the questions you ask that send me off learning things I didn't expect to learn: I so often get these wonderful stories from you.
So what do we have to look forward to in 2013? We'll be keeping on with Mount St. Helens - Blast deposits! Pyroclastic Flows! Lahars! - until we're finished with Professional Paper 1250. There is plenty more that came after, if you're not completely sick of Mount St. Helens by then. We'll also have a series on basaltic volcanism, including cinder cones, and a nice jaunt over to Parcutin around the anniversary of its eruption. Lest this blog become all volcanoes, all the time, I'll also be writing up rivers: we've got a trip down the McKenzie to take. I'd like to introduce you to more of our amazing metamorphic geology, and if we're very fortunate, there will be a trip out to some fantastically beautiful fossil beds. For the rest - who knows where chance may take us? Geology isn't confined to Earth, either. The sky is no limit. We could find ourselves at the end of the Universe.
Thank you for coming along on the journey, my darlings. Bon voyage!