1 week down, 3 to go on 28 days of #sciwrite

A post by Anne JeffersonA post by Chris Rowan
Sciwrite logo, by Chris RowanA week ago, we invited our readers to join in our challenge of making the short month of February into a productive writing month, but sharing our goals and progress. Our invitation was enthusiastically accepted, and we had 21 people share their own goals in the comments section.

Unbelievably, we’re now 1/4 of the way through our month-long writing challenge, so it’s time to check in and see where we are. We’ll go first, and then you can share your successes and challenges in the comments.

For Anne, this week brought both fire and ice to her professional life, so she didn’t quite as much done as she had hoped, but some progress was made. She says:

“My student and I have made a lot of progress on one extended abstract, and I’ve just gotten a draft going on the one I’m leading. Both are due on the 17th, and the posters themselves are due shortly thereafter, so they will be the major focus this week. I got a figure and its text section finalized on one paper, but was reminded how many figures there are still to go. This week’s I need to get at least one more figure completed, along with its associated text. On the other paper, my co-authors and I had a great discussion, and we agreed that we just need to get it done! So, I need to buckle down and work on the introduction that I’ve been avoiding. I don’t feel like I’m 25% along on my goals, but something is better than nothing.”

Chris’s progress on his New Zealand tectonics paper was also slower than he might have liked, but knows that this is par for the course when it comes to paper production. He says:

“My paper writing always seems to start with a lot of work that doesn’t really increase the word count but sets a good foundation for later writing, namely making sure the data is correctly processed and working out the best ways to present it. Good figures are an important part of telling your scientific story, and getting them started early ensures they are central to the narrative, rather than an afterthought. On that score, I’ve had a few wrinkles on the data processing side that took longer than I would have liked, but I’ve made progress, and I’ve also made some encouraging intellectual strides in how my discussion section is going to be structured. It’s actually quite stimulating to come back to this problem again with a bit more knowledge and perspective – not that that’s an excuse for putting off writing this paper for so long! Hopefully the foundations have been laid for getting a lot more writing done by the time I check in next week.”

How has everyone else been doing this week? Let us know about your progress in the comments.

Categories: academic life, publication

28 days of #sciwrite

A post by Anne JeffersonA post by Chris Rowan
Sciwrite logo, by Chris RowanBack in November 2011, Anne performed an experiment. Anne wanted to see if being publicly accountable for my writing progress would get me to my goal of a paper submission before AGU. She didn’t quite make it, but that month of weekly check-ins and progress reports on the blog did get her a lot closer to that paper being drafted than she would have been without the #sciwrite challenge. More than 40 other blog readers also participated in the challenge, and at least a few actually got manuscripts and theses submitted in that month. Ever since #sciwrite, we’ve been thinking that we need to do it again.

If we’ve learned anything in our careers as academic scientists, it’s been the following:

  1. Writing is the major metric of professional success and is the only way of making neat results in the field and lab into something useful for others.
  2. All that academic advice about how writing every day is the only sustainable path to getting things done turns out to be true. Darn it.
  3. Yet writing tasks can easily and repeatedly slip to the bottom of the to-do list because they don’t have the same urgency of deadlines imposed on them like teaching, review assignments, and the crush of email.
  4. Loop back to #1.

With the idea that a little public accountability never hurt anyone, and that maybe having a community of people all going through the same writing process at the same time could actually help make life better, we’d like to introduce February 2014 as #sciwrite v 2.0. For the next four weeks, we’ll be committing to writing every day and sharing our goals and progress here on the blog on a weekly basis. We’d love it if other people joined us.

Anne’s goals:

  • Two extended abstracts, shortly followed by two posters for the CUAHSI/USGS workshop on laser specs in hydrology. Abstracts are due February 17th, posters are due the 24th, and a virtual poster session will be held on February 28th. I’m the lead on one poster, and an undergraduate student is the lead on the other.
  • For a paper in which the setting, methods, and results are already written, I’m going to make publication-ready figures, and write the introduction, discussion, and conclusions, with the help of a co-author.
  • For a paper in which my co-authors and I endlessly tinker and improve, I’m going to finalize my piece of the results and get the introduction written. More if possible.

Chris’s goals:

  • My big goal is finally finishing the big New Zealand tectonics paper that I have started, tinkered with, restarted, and then let lapse again for rather longer than I care to admit. Let’s just say that if I achieve my target of getting a completed first draft to my co-author by the end of the month, they’ll probably die of shock. It’s a challenging goal, so I’d be happy with ‘substantially completed’.
  • I also want to write an internal grant application, due in the first week in March, for funding to substantially improve my Geophysics course before I have to teach it next.

If you are interested in participating in #sciwrite this month, leave a comment below with your goals, and if you’re on twitter, use the #sciwrite hashtag to share your progress. Then check in on the blog every Saturday for more encouragement.

Categories: academic life, by Anne, publication

Augers v. Augurs

A post by Anne Jefferson

These are augers.

Black and white photo of screw auger, barrel auger, sampling tube, mud auger, and peat sampler.

NRCS photo of soil augers. Click image for source.

 

This is an augur.

Drawing of robed figure holding curved stick.

A Roman augur. Image from Wikipedia. Click image for source.

 

The free dictionary defines augur as follows:

n.

1. One of a group of ancient Roman religious officials who foretold events by observing and interpreting signs and omens.

2. A seer or prophet; a soothsayer.
v. au·guredau·gur·ingau·gurs

v.tr.

1. To predict, especially from signs or omens; foretell. See Synonyms at foretell.
2. To serve as an omen of; betoken: trends that augur change in society.

v.intr.

1. To make predictions from signs or omens.
2. To be a sign or omen: A smooth dress rehearsal augured well for the play.

 

More often that not, my students I are talking about augering not auguring. Though one could argue that when we make hypotheses, we are in fact auguring. I think however, we should avoid using that word in our writing.

Prof Trelawney and crystal ball from Harry Potter

“I augur that our sites will be quite extensively augered to determine the soil characteristics.”

Categories: by Anne, field gear

Antarctica field log: Penguin Island? Surely you mean Volcano Island!

You can tell a trip is going to be pretty special when not only was the site of our first landing in Antarctica called Penguin Island – and we were given reason to believe it was not misnamed – but it was also very obviously a volcano.

Penguin Island, South Shetland Islands

Penguin Island, South Shetland Islands. Basaltic lava flows topped by a scoria cone. Photo: Chris Rowan, 2013

There certainly were penguins, and they were certainly fascinating:

Adelie Penguin, Penguin Island, Antarctica.

An Adelie Penguin atop a rounded basalt boulder on the shore of Penguin Island. Photo: Chris Rowan, 2013.

but let’s face it – we’re geologists, and this is a volcano.

Basaltic lava cliffs on Penguin Island

Yes, yes, I do see the lava flows forming those cliffs – oh, you mean the penguins? Photo: Anne Jefferson, 2013.

Technically Penguin Island is one of the South Shetland Islands, which are separated from the Antarctica Peninsula by the Bransfield Strait. It has been historically active – according the the Global Volcanism Program it last erupted in the mid 19th and early 20th centuries – and is likely to do so in the future. But right now the only rumblings are from the penguin rookeries, so there was nothing to stop combining some wildlife-watching with a hike up to the summit. As we climbed, we got a nice view of the larger ice-covered King George Island. It shows up quite nicely in the photo, but it actually took a while for your eyes to key in to the fact that the line marking the top of the ice sheet was in fact the top of the ice sheet, and not a line of clouds in the sky.

King George Island from slopes of Penguin Island, Antarctica

View from the slopes of Penguin Island: a thick ice cap blankets King George Island to the northeast.

Our climb was really more of a scramble, up a slope of scoria – chunks of dark, vesicular volcanic rock formed from blobs of cooling, gaseous magma thrown out of an erupting vent.

Lichen and Scoria, Penguin Island, Antarctica

A hardy lichen growing on a bit of volcanic debris (scoria) near the summit. Photo: Chris Rowan, 2013.

We were rewarded with a great view at the summit*: within the central crater was a little cinder cone, and a tall plug of basaltic lava.

Panoramic view of the summit crater,  Penguin Island. Cinder cone towards the centre, volcanic plug on the left. Photo: Chris Rowan, 2013.

Panoramic view of the summit crater, Penguin Island. Cinder cone towards the centre, volcanic plug on the left. Photo: Chris Rowan, 2013.

We can interpret a little geological history from this: the summit was once a bit higher, and the plug formed from lava that cooled and solidified at the top of a conduit that fed the vent of this higher cone. It was then excavated by a later slightly more explosive eruption that formed the main summit crater, with the smaller internal cinder cone having formed most recently. Although in fact, the last eruption on Penguin Island was actually much closer to the shore, where the combination of hot magma and cold Antarctic seawater created a lot of an explosive steam, excavating a maar – a large crater that is now home to many nesting seabirds.

Penguin Island Maar

Maar formed by the most recent eruption on Penguin Island. Photo: Chris Rowan, 2013.

Of course, as geologists, we also want to know, why is this volcano here? There was a lot of talk on our cruise about how the Antarctic Peninsula is a continuation of the Andes – and it is certainly true that if you take the wide view you can kind trace out a link in the topographic and bathymetric features, although it takes a rather circuitous route. When the Andes reach the bottom of South America, their continuation does not directly cross the Drake passage: instead it cuts sharply east through Tierra del Fuego out into the South Atlantic, running south of the Falklands before lazily looping back west via the Sandwich arc to finally link with the tip of the Antarctica Penisula.

Bathymetry and tectonic plate boundaries in the Drake Passage.

Bathymetry and tectonic plate boundaries in the Drake Passage between South America and the Antarctic Peninsula. Subduction zones are blue.

Chris is still trying to get the full tectonic history of this area straight in his head, but it seems that originally the Andes and the Antarctica Peninsula were indeed once northern and southern segments of a single chain of mountains and volcanoes. However, this simple arrangement was disrupted in the past few tens of millions of years due to the opening of the Drake Passage and the associated formation of several micro-plates. Nowadays, subduction off the Antarctic Peninsula – and hence volcanism on it – has mostly shut down; The exception is on the Drake-ward side of the South Shetland Islands, where there is a subduction zone (the South Shetland Trench). The South Shetlands are on their own little micro-plate that is breaking away from the Antarctic Peninsula. This rifting causes the crust to stretch and subside, forming the Bransfield Strait, and allowing the underlying mantle to rise, melt, and erupt at the surface at places like Penguin Island (and Deception Island, the other historically active volcano in the South Shetland Group). Based on this geophysical survey (pdf), from which I took the figure below, the rift has yet to get to the stage where new oceanic crust is being produced.

Bathymetry of the Bransfield Rift

Bathymetry of the Bransfield Rift, an actively stretching basin that separates the South Shetland Islands from the Antarctic Peninsula. From Catalán et al. (2013)

So Penguin Island is the product of rifting, rather than subduction, which explains all the basalt. Of course, the penguins probably don’t care either way.

Chinstrap Penguins negotiating the basalt boulders on the shores of Penguin Island.

Chinstrap Penguins negotiating the basalt boulders on the shores of Penguin Island.

Adelie Penguins playing in the snow, Penguin Island. Photo: Chris Rowan, 2013.

Adelie Penguins playing in the snow, Penguin Island. Photo: Chris Rowan, 2013.

*What do you mean, I’m looking in the wrong direction?

Categories: Antarctica, outcrops, photos, tectonics, volcanoes

A real-life geological map, no colouring in required

A post by Chris RowanThere’s much more to geological mapping than colouring in, but a big part of the process of reconstructing the geological history of an area is spending a lot of time examining the exposed rocks to work out how to distinguish the different units in the field, and then marking their distribution on your map using easily distinguishable colours, that enable you to more easily see the regional patterns that reveal sandstones and limestones; stratigraphy and structure; and faults and folds. It can be a lot of hard, meticulous work.

But then, there are places where the Earth just decides to do all that work for you.

Satellite view of the foothills of the Tien Shan mountains

Satellite view of the foothills of the Tien Shan mountains, northern Tarim Basin, Xinjiang province. Click to enlarge. Source: NASA Earth Observatory

This amazing Landsat 8 image was an Image of the Day at the NASA Earth Observatory last week, and it’s pretty much a geological map all on its own. A convenient combination of active tectonics that leads to erosion and exposure of fresh surfaces (the Tien Shan mountains on the northern edge of this image are a distant product of the ongoing collision of India and Eurasia), virtually no obscuring vegetation due to the arid climate, and some extremely distinctive rock units formed in very different environmental conditions 400 to 500 million years ago, allow us to easily identify the different rock units. We can easily trace the horizons of tan Cambrian and Ordovician limestones, green Silurian marine sandstones and red Devonian terrestrial sandstones as they get contorted by a complicated set of faults and folds.

Just like a man-made geological map, the arrangement of colourful strata contains a lot of information about the structure and geological evolution in this area – information that can be retrieved. The easiest things to spot are the places where the linear ridges jump sideways, offset by strike-slip faults.

Tien Shan strike slip faulting

Strike-slip faults cutting through and displacing the multiple ridges composed of multicoloured, dipping Paleozoic rocks.

But what of the ridges themselves? There are a number, all running parallel to each other in the same east-west direction, all with the same tan-green-red striping that suggests that we are seeing the same units geologically cut-and-pasted across the landscape. This repetition of the same layers of rock over and over tells us that faults and folds are afoot. Heading south from the top of the image, on the first ridge you would encounter you would cross cream, then green, then red, going up section from the oldest unit to the youngest. But then on the next ridge the order is reversed: continuing south you would cross red, then green, then cream, going down-section from youngest to oldest. This apparent reversal in the flow of geological time tells us that we have crossed a trough-like fold – a syncline. The edges of the trough have been tilted up and eroded, exposing the older rocks, whereas the younger rocks are preserved in the less tumultuous middle. Thus the sequence is mirrored on either side of the east-west trending fold axis, which indicates this fold was formed by north-south compression.

The change from moving up section to moving down section as you traverse the two northern ridges indicates the presence of a syncline - a trough or bowl shaped fold.

The change from moving up section to moving down section as you traverse the two northern ridges indicates the presence of a syncline – a trough or bowl shaped fold.

An oblique view clearly shows beds dipping towards the centre of the image, which marks the axis of a syncline.

An oblique view clearly shows beds dipping towards the centre of the image, which marks the axis of a syncline.

But what of the third ridge, to the south? Here, the sequence is repeated but not reversed: you would again go down section, crossing red, then green, then cream rock units. Not a simple traverse over another fold axis, then: this repetition is most likely due to faulting. Even when tectonic compression starts off by forming a serious of gentle folds, continued convergence and shortening will make the rocks continue to crumple up: eventually the rock units refuse to bend any more and break up into faulted segments that can then get stacked more closely (imbricated) together.

Interpreted compressional (thrust or reverse fault) between the southernmost two ridges.

Interpreted compressional (thrust or reverse fault) between the southernmost two ridges.

Originally flat lying sediments form a syncline in the northern part of the image, and have been broken apart and stacked by thrust faulting in the south.

Originally flat lying sediments form a syncline in the northern part of the image, and have been broken apart and stacked by thrust faulting in the south.

For proof of this, we just need to go a little further east, where we get three ridges apparently meeting at a central point.

It’s a bit of a geometrical headache, until you realise that what we really have is a single ridge running across the top of the image, and the ridge entering from the bottom left simply terminates against it – clear evidence of a fault.

Interpretation of the fault that has caused two ridges to 'merge'.

Interpretation of the fault that has caused two ridges to ‘merge’.

It’s even more obvious in oblique view.

An oblique view clearly shows how the ridge on the right terminates against the ridge on the left - a clear sign of a faulted contact.

An oblique view clearly shows how the ridge on the right terminates against the ridge on the left – a clear sign of a faulted contact.

I really could spend all day looking at this – there’s lots more to see. Grab the KML file from the Earth Observatory page and have a look for yourselves.

Categories: geology, structures