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A real-life geological map, no colouring in required

Posted on January 23, 2014 by Chris Rowan

A post by Chris Rowan There’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, 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.

Source: NASA Earth Observatory

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.

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.

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.

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.

Source: NASA Earth Observatory

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’.

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.

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

Antarctica field log: Ice in a multitude of forms

Posted on January 18, 2014 by Anne Jefferson

A post by Anne Jefferson A post by Chris Rowan Sifting through more than 30 gigabytes of photos and videos from our trip to Antarctica is taking longer than we expected. (The start of the semester might have something to do with that too.) To tide you over until we are ready to properly blog our adventures, here are some photos and videos from a 48-hour period of our trip that provide a glimpse of the many faces and forms of ice in Antarctica.

Icebergs in Neko Harbor, 23 December 2013. Photo by A. Jefferson

Icebergs are formed from broken off bits of glaciers or ice sheets. Icebergs are larger than a house (bigger than 300 m²) and stick up more than 5 m above the water line. The ones above are pretty small icebergs. They can get a lot bigger: as we cruised through Antarctic Sound – also referred to as ‘Iceberg Alley’ as it acts as a bottleneck for bergs moving out of the Weddell Sea – on 22nd of December, we zig-zagged through a series of massive tabular bergs that dwarfed our ship.

Tabular Icebergs in Antarctic Sound, 22 December 2013. Photo: Chris Rowan.

Keep an eye out for the part of this video where a small section of this tabular iceberg’s sheet sides calved off into the sea.

When ice is about the size of a house (100-300 m²) and extends 1-5 m above the water line, it’s officially called a “bergy bit.” Smaller than that and they are called “growlers.”For a primer on iceberg and sea ice terminology, check out this page.

chunk of ice creating a green color under the water

Petite and pretty “growler” ice in Neko Harbor, 23 December 2013. Photo by A. Jefferson.

Looking down upon two glaciers and a harbor with icebergs.

Outlet glaciers spilling from the Antarctica Peninsula into Neko Harbor, 23 December 2014.

In addition to the myriad glacier chunks, we also saw a lot of sea ice, which forms from the freezing of sea water. The video below shows us moving slowly through open pack ice and brash ice as we tried to make our way to Palmer Station on the night of 23-24 December, 2013.

We nosed into the Weddell Sea early in the morning of 22 December. The sea ice was too close or compact for us to go anywhere in the Weddell Sea. This is the sea that sank the Endurance after all. But, we did get some lovely photos in the early morning light of ice in its myriad forms.

Iceberg and sea ice in the Weddell Sea, 22 December 2013. Photo by A. Jefferson.

Iceberg and sea ice (and penguins) in the Weddell Sea, 22 December 2013. Photo by A. Jefferson.

Sea ice flanking Rosamel Island, a volcanic plug guarding the Weddell Sea end of Antarctic Sound, 22nd December 2013. Photo: Chris Rowan.

Tabular icebergs backlit by dawn’s early light in the Weddell Sea, 22nd December. Photo: Chris Rowan.

Categories: Antarctica, ice and glaciers, photos

Megaphones, broken records and the problem with institutional amplification of sexism and racism

Posted on January 17, 2014 by Anne Jefferson

This week in the science communication world has been a broken record, playing over again a suite of unappealing sounds designed to again remind people of color and women that they are not seen as equal members of the scientific community. The record tells us that we are not viewed as equal in calibre, that when we are included it is done for tokenism and done with distaste, and that are our voices are not respected.

The week started with Dr. Kate Clancy sharing her story of the back-handed invitation she received to participate in a cool science thing by a dude, acting under “marching orders” from a prominent female scientist urging the inclusion of more women in the cool science thing. After Dr. Clancy submitted her essay to the cool science thing, her invitation was rescinded because her essay was inappropriate. Eventually, the essay was accepted at the urging of the prominent female scientist, but done so with some of the most condescending language I have ever read. While Dr. Clancy is careful not to name names, I will note that she had an essay published by the Edge Foundation this week, in its Annual Question series. Her essay on the way we produce and advance science is among the most broadly relevant and important essays published in this year’s Edge collection (i.e., you should go read it).

Yesterday, the journal Nature saw fit to publish a letter about why women *should be* under-represented in the pool of authors and reviewers for Nature. The letter is full of logical gaps and lacks consistency with the large body of literature on why women are under-represented in the science glamor magazines and research careers. Its from someone who has neither taken the time to familiarize himself with what is known about the biases against women (and people of color) in the sciences, nor had any personal experience with them (i.e., white, male, non-scientist). It’s misogynistic and it’s worthless. Yet, Nature chose to publish it. Kelly Hills and Hope Jahren have excellent take downs.

Here’s where the broken record comes in. In 2011, Nature published the appalling Womanspace piece, knowing full well it was full of sexist crap. They got called out on it. As I wrote, back then:

“Dear Nature, you got a sexist story. But when you published it, you gave it your stamp of approval and became sexist too. …
It’s one thing to write a not-very-funny witty story full of sexism and gender stereotypes, but it’s a completely different thing to publish it with the stamp of approval of one of the world’s leading scientific publications.”

In 2013, Scientific American (a part of Nature Publishing Group) took the side of a troll who called their black woman blogger an “urban whore”, by taking down Dr. Danielle Lee’s defense of herself in response to that slur. They got called out on it. As I wrote, back then:

“More broadly conversation about Danielle’s treatment, first by biology-online and then by Scientific American, has reminded me of the wider issues in our treatment of women and minorities in science and leadership. For all those wondering why we still lack diversity in STEM, Scientific American’s actions illustrate the problem quite nicely. First, we have to put up with harassment from jerks like the editor of biology-online. Then, we call out that bad behavior, respected institutions ignore, or worse censor us. It sends a pretty clear message: “We don’t want you here.” Or as Khadijah M. Britton refined my thoughts: “We only want you as a token to make us look good until you “cause drama” or “get emotional,” then you are out.” That sentiment matches perfectly with what Danielle said in her video: “For far too long, the presumption has been that if you are a woman, or a person of color, or from a lower socio-economic status that folks think that they can get you, your talent, your expertise, and your energy for free.” As Lara Deruisseau said “This perpetuates fear of women standing up for themselves when wronged. Unknown rules come out of the woodwork.”

And then there was Bora, and we know that Scientific American knew about at least one of his actions before the rest became public.

There are countless more examples of this sort of bad behavior that I could cite. It is a broken record continually repeating, after all. But back to this week. It wasn’t just major scientific publishers and cool science things acting badly.

DrugMonkey picked up on and then picked apart an NIH report that he says shows that if more applications by African-American PIs were discussed during the review process, it would go a long way to addressing the discrepancy between funding rates for African-Americans and whites. To my read, it appears that implicit or explicit biases are reducing the number of African-American applications that get scores that make the discussion cutoff, but that once an application is discussed it has equal likelihood of getting funded regardless of the color of the applicant’s skin. The suggestion DrugMonkey makes is that NIH should ensure that equitable numbers of African-American applications get discussed during the review process. Instead, it appears that NIH is focused exclusively on blaming the victims for getting poor mentoring rather than doing what is under their direct control in reforming their review process. As a geoscientist, I don’t speak NIH, so I can’t follow all the details of the discussion at DrugMonkey’s blog, but there’s a striking parallel here. At Nature, they note an under-representation of women in their reviewer and author pools, and blame the victim by publishing an article that alleges that women are having too many babies to be equitably represented. At NIH, they note an under-representation of African-American PIs getting funded and focus the blame on mentoring.

Here’s the thing: There are sexist and racist people out there in the scientific community. They are bad actors and they are toxic to the people around them. There are few women and people of color in the sciences (or any field) who haven’t had to deal with quite a number of these toxic people. We hear from their words and their actions that they don’t respect us and they don’t want us here. We know what they think. We don’t need our prominent scientific publishers, funding agencies, and think tanks to pass the megaphone to the bad actors and amplify their messages. We don’t need the broken record blared over a loud speaker. When our publishers, funders, and think tanks amplify these sexist and racist messages, they are accomplishing three things. First, they implicitly apply an institutional stamp of approval on the racist and sexist messages and taint their own reputation. Second, they give the sexists and racists a sense of legitimacy that only makes them more noisy and insistent. Third, they advertise to people of color, women, and allies which organizations “don’t get it” when it comes to diversity and respect. (Have you noticed how many times Nature Publishing Group has been guilty of these amplifications? I have.)

So here’s a few simple tips for publishers, funders, and other institutions that have megaphones and amplifiers in the scientific community. If you are part of an organization that’s been caught out on issues of sexism and racism in the past, or you think there’s a possibility it could happen in the future, you might consider printing these tips out and pinning them to your colleague’s cubicles.

1) If you receive racist or sexist material for publication, DON’T PUBLISH IT. Throw it out. Shake your head, laugh about the backwardness of the writer with your colleagues, but DON’T PUBLISH IT. It doesn’t deserve your printed or virtual space, and it’s not “contributing to the conversation.”

2) If you woman and/or person of color is describing problems with racism, sexism, or harassment, assume that what they are saying is true and do not attempt to silence or gaslight them. This is a general rule, but because apparently it needs to be said. Even if, especially if, the women and/or people of color are part of your organization or are accusing your organization of racism, sexism, or harassment, you should let their voices be heard.

3) If your organization is responsible in any way for selecting which voices get heard in science (you know, like publishers, funders, and think tanks do), make sure that women and people of color get representation, and that when you do, that you don’t do with a side helping of victim blaming or condescension.

See, they are pretty simple tips. Easy to follow. But maybe some are wondering why those tips are necessary. Shouldn’t individuals and organizations be allowed to weigh the merits of racist and sexist material and exert their own editorial judgement about whether to pass the megaphone? Nope, and here’s why.

It’s 2014. You will get caught. You will get called out on it. The memory of the internet is long. It will not be good for your brand. It will not be good for your bottom line.

But really, it’s 2014, this sexist and racist junk should have withered a long time ago, because it’s outdated and wrong. Only the megaphones playing broken records let people thinks its still part of acceptable discourse today. It’s not. Don’t be part of the problem.

Categories: by Anne, ranting, society

Puerto Rico sends the Caribbean a sobering seismic anniversary present

Posted on January 14, 2014 by Chris Rowan

A post by Chris Rowan Four years ago on Sunday, Haiti, and particularly its capital, Port-au-Prince, was devastated by a shallow magnitude 7.0 earthquake, which killed many tens, and possibly hundreds of thousands of people*, and left more than a million people homeless. Even today, the effects of the earthquake linger: rebuilding is still a work in progress, and 150,000 people are still living in temporary accommodation.

As a geologist, I am also watching with concern as one of the poorer countries in the world struggles to increase its resilience to future earthquakes. For this was not a one-off event: located close to the active plate boundary between the North American and Carribean plates, and with many large, seismically active onland faults throughout the region, Haiti and neighbouring countries like the Dominican Republic will certainly experience more large earthquakes in future years, decades, and centuries; how devastating they might be to these countries’ inhabitants depends not just on the size and location of the quake, but also on the strength of buildings and infrastructure, and the preparedness of the population.

Major earthquakes in the Northern Caribbean since the 1600s. Source: The New York Times

On the anniversary of the Haiti earthquake, we have been reminded of that underlying fact, with a magnitude 6.4 earthquake shaking Puerto Rico in the late evening local time, on the very day of Haiti’s sober anniversary. The focal mechanism is transpressional, indicating either left-lateral strike-slip with a bit of thrusting along a east-west oriented fault shallowly dipping to the south, or thrusting with a bit of right-lateral strike-slip along a steep northwest-southeast oriented fault. Both of these are consistent with the overall northeast-southwest convergence between the North American and Caribbean plates**

Location of the Puerto Rico and Haiti Earthquakes

Map of the Caribbean, showing the location and focal mechanism for the 12th Jan 2014 earthquake off the coast of Puerto Rico, and the location of the 12th Jan 2010 Haiti Earthquake

It’s actually quite difficult to work out which of the possible fault planes is the real one. The plate boundary in this region is associated with the Puerto Rico Trench. On Twitter, Jascha Polet (@CPPGeophysics) pointed to this nice, recent bathymetric map of the region, to which I’ve added the location of the recent earthquake. The major fault in the area seems to be the E-W trending Bunce Fault, which is interpreted as a strike-slip fault – it is also described as being steeply dipping in seismic data, so seems unlikely to be the fault that ruptured here. There is also a recent extensional graben with NW-SE trending faults a little to the east. I’ve suggested that the emerging pattern of aftershocks could indicate a rupture on a south-dipping fault propagating north towards the surface, which is not unreasonable but hardly definitive.

Bathymetry of the Puerto Rico Trench. Location of the Jan 12 2014 earthquake is marked by a yellow dot. Source: USGS

Fortunately in terms of human impact, compared to the Haiti earthquake this earthquake was smaller in magnitude and also located both off the coast and deeper underground (28 km rather than 13 km). These factors all reduced the surface shaking to the extent that damage and casualties seem to be minimal. Nonetheless, this was a strikingly timed reminder that even when attention is rightly focussed on recovering from the last natural disaster, we still need to pay some attention to the risk from future ones, lest the next big rupture also repeat the human misery.

*it’s not easy to estimate the death toll from a massive natural disaster when you don’t have good ‘before’ records, but even the lowest estimates are still pretty devastating

**if you want to get technical, there’s probably a microplate or two involved in the deformation across this plate boundary, but the big picture is sufficient in this case.

Categories: earthquakes, focal mechanisms, geohazards, society

Festering Questions from the West Virginia Chemical Spill

Posted on January 12, 2014 by Anne Jefferson

A post by Anne Jefferson
The massive impact of last week’s chemical spill into the Elk River in West Virginia continues to cause hardship for the up to 300,000 people affected by the water ban and to pose tough questions for scientists and authorities involved with assessing and mitigating the spill’s effects on central West Virginia’s water supply.

Before Thursday morning, West Virginia’s Elk River was a well-known river for fishing and the sole water supply for the city of Charleston and populations in parts of nine counties. On Thursday morning, West Virginia Department of Environmental Quality Division of Air Quality was alerted to licorice or anise odor and traced the source to a leaking tank at a Freedom Industries facility located on the bank of the Elk River. The leaking tank contained 4-methylcyclohexane methanol, a chemical used in frothing during the coal washing process. The tank has been described as “antique” and was made of riveted stainless steel, which is an old construction technique. Unfortunately, the leaking tank was located near the river bank, and up to 7500 gallons of the chemical made it into the river. (Here’s what the site looks like from the river) Even more unfortunately, the water intake for West Virginia American Water was located only one mile downstream. West Virginia American Water is the major water supplier for 9 counties in central and southwestern Virginia, including the state’s capital, Charleston. Water treatment plants typically aren’t designed to remove industrial chemicals, and West Virginia America Water wouldn’t even have known to test for this one. At some point Thursday afternoon, the dots were connected and a water ban was put in place for anyone served by the water supply. Residents, businesses, and institutional facilities were told not to use the water for drinking, cooking, bathing, or washing clothes or dishes. The only allowed uses are toilet flushing and fire fighting. As of Sunday afternoon, three days after the spill occurred, the water use ban is still in place, state and federal emergencies have been declared, and FEMA and the National Guard are distributing bottled water and water from tanker trucks.

Google Maps view of white industrial tanks adjacent to a river.

Freedom Industries site adjacent to the Elk River, upstream of Charleston, West Virginia. Image from Google Maps.

Google Maps of Elk River and surroundings.

Point A indicates the Freedom Industries site and Point B indicates the water treatment plan. Image from Google Maps.

There aren’t a lot of data on the toxicology or safe levels of 4-methylcyclohexane methanol (MCMH) in water. We know that it is an organic solvent and a light ~~non-aqueous phase~~ liquid, which might be why there have been no reports of fish kills, since fish are hanging out in warmer, deeper pools at this time of year. Deborah Blum did some sleuthing and surmising from related chemicals, and so far the health effects appear to consist of a lot of people worried about symptoms but few people having problems clearly related to the spill. But the axiom of not ingesting industrial chemicals still stands. Officials are scrambling to find out what they can from the chemical’s manufacturer and to test samples to determine what level of contaminant is actually in the water supply. At some point, the state decided that a level of less than 1 part per million (1 ppm) of the contaminant was safe, and now the goal seems to be to have the water treatment plant consistently producing water at with contaminant levels lower than 1 ppm. There will also be some delay between samples being collected and the test results coming in, though it sounds like they may be making rapid on-the-ground strides in the rate at which they can test samples in four labs that have been set up for this task. Some reports say the state reported river water concentrations of MCMH had declined to 1.7 ppm on Friday, from 3 ppm. No numbers seem to have been released Saturday or Sunday, though NBC News is reporting on a news conference indicating 0 ppm going into and out the water treatment plant on Sunday morning. This article from the Bluefield Gazette gives some idea of the plan to flush parts of the massive water distribution system, which goes over mountains. All indications are that it will be days more before the water ban is lifted for everyone.

As an outside observer to this disaster, gleaning what I can from the media reports, here are my questions about the past, present, and future of the central West Virginia water supply.

Why was a tank farm allowed to locate on the river bank only a mile upstream of a major municipal water supply intake? And if the tank farm was upriver before the water treatment plant was built, what safety concerns were raised in selecting that site?
Were any special emergency procedures in place at either the industrial facility or the water treatment plant given this proximity? (I can find a risk management plan for the water treatment plant to deal with its risk of spilling chloride, but I can’t find anything similar for Freedom Industries or how the water treatment plant planned for risks of spills upstream from its facility. These plans may exist off-line.)
How was an acceptable maximum contaminant level of 1 part per million decided upon?
When the water treatment plant is producing less than 1 part per million of MCMH in the water supply, how will they test and ensure that all parts of the water distribution network are at that level?
What will the flushing recommendations be for water users? How will the recommended flushing times be determined?
Will there be longer term monitoring of MCMH levels at various points in the distribution network to ensure that levels remain below the acceptable maximum contaminant level?
Will there be long term studies of the environmental and human health effects of the exposure, particularly on vulnerable populations like children?
Most importantly, how will this incident change policy and procedures in this region, in West Virginia, in the coal processing industry, and in the nation?

Based on what I’ve learned, the risks of this human-caused disaster could potentially have been substantially mitigated by more stringent watershed planning that prevented the tank farm from operating so close to the river bank so close upstream of the water treatment plant and tighter regulation and routine inspection of the tank farm and its safety procedures. If the spill had still occurred even with those risk reductions, it would have been useful to have more information on the toxicology of the chemical that spilled (and all industrial chemicals) to provide better guidance on what maximum contaminant level is acceptable. As Deborah Blum points out, “Our Toxic Substances Control Act is more than 35 years old and we (by which I mean Congress) haven’t conjured up the backbone to update and strengthen it as of this date.”

This spill and its disruption of West Virginians lives shows what can happen when environmental regulations are not stringent, rigorous, and routinely enforced. The spectre of 300,000 US residents unable to drink or bathe in their tap water for days on end should stick in our collective consciousness for a long time. We don’t need to invoke the threat of terrorists or climate extremes to disrupt our water lifelines; West Virginia reminds us that business as usual can do that too.

Categories: by Anne, hydrology, public science, society