Tuesday, April 17, 2018

The European Astronaut Centre


HI! It is my pleasure to report that I ~passed~my~MSc~defense~.  I'm almost done! :D Now I need to revise before re-submitting. I've made excellent progress so far, I think.

Next stop for me is Cologne, where I am very, very excited to visit the European Astronaut Centre next week!

Interior of EAC facility. The CSA logo is near the back! Photo credit: ESA - D. Baumbach, 2010
Before I discuss the European Astronaut Centre (EAC), I'll mention that it is located on the premises of the German Aerospace Centre  (DLR - Deutschen Zentrums für Luft- und Raumfahrt) headquarters. I became familiar with DLR at the International Astronautical Congress in Adelaide last year, learning about their contributions to European space missions, including the High Resolution Stereo Camera on Mars Express, the framework for Rosetta, and cameras for Dawn. For our favourite Earth observation technique, DLR launched the TerraSAR-X polarimetric X-Band radar. But I digress.

Staffed by a team of ESA, DLR, industry, and French Space Agency (CNES - Centre national d''études spatiales) professionals, the EAC is a site for selection, training, and flight preparation for ESA astronauts. Here, European-constructed payloads for the International Space Station are tested before flight. The EAC is also a centre for astronaut physiology and nutrition - very important for the future of human solar system exploration. EAC also studies psychology and mental health. Group psychology is a very important factor in the success of isolated team mission work. Our Axel Heiberg Island expedition team in July 2017 filled out surveys in support of a study for team dynamics in extreme environments. I hope that the results of the survey is fruitful for advising the future of crewed space exploration.

A team of astronauts work together to navigate the
Sa Grutta caves system. Photo credit: ESA

What I think is one of the coolest parts of ESA astronaut training are the CAVES and Pangaea programs. Both of these programs are designed to be analogue training courses. CAVES (Cooperative Adventure for Valuing and Exercising) focuses on the behavioural aspects of space missions, whereas Pangaea teaches planetary geology. CAVES places the astronauts in the Sa Grutta caves system in Sardinia, Italy. The teams need to work together to perform different geological, biological, or engineering tasks with an emphasis on communication and problem solving.

Pangaea is a course for training European astronauts in communicating Earth and planetary science with Earth-based science advisors. This course trains the astronauts in planetary geological environments and processes, field note taking and sampling techniques, and astrobiological environments for life on other worlds. The field portion of the course takes place in Lanzarote, Spain, which you may be familiar with from Gavin's recent trip. Lanzarote is an excellent site for studying volcanic processes and for lunar analogue research due to its abundance of cinder cones, lava flows, and fissures.

An astronaut practices interacting with a rover
Photo credit: ES
I look forward to telling you more about my visit next meeting! I really look forward to learning about the recent projects and contributions ESA is making towards the future of crewed space flight.


Tuesday, April 3, 2018

Let's talk about walnuts


I submitted my thesis a couple weeks ago!

Everything I have been working on these past two years is culminating. I need to prepare a pretty long public lecture, (~45 mins at Western? Whaaat? At SFU it was only 20!) and study for any and all questions that may be asked of me.

So instead of talking about that, let's talk about something completely different.

"Isn't your blog supposed to be professional?"

That seems out of nowhere. But, as I am moving away from LondON at the end of May, I've been going through my worldly possessions in exhausting attempts to prioritize what I'll be sending home with my parents to Vancouver, what I'll be bringing to Houston, and what I'll be leaving with Rachel, giving away, selling, or throwing out. One category of these things are non-perishable food items.

I have a lot of nuts.

A. Lot. of. Nuts.

Especially walnuts.

Why do I have so many walnuts, you may ask? Well, I like baking. After a few months of deliberation and buying small, tiny-yet-still-pricey pouches of walnut pieces from various stores, I decided upon purchasing one of those giant 12 cups/3 lbs packages of walnut halves from Costco. I expected this would last me my duration of time at Western, despite, dear readers, being a frequent baker. And it would have been. It would have been.

Alas, during trip home to Vancouver to join my parents on a road trip into the US to see the eclipse and visit Yellowstone, I made some comment or another to my mother about the price of nuts, bulk items at Costco, and the thrifty life of a graduate student.

I'll tell you right now that a walnut is
over 3x that. (~26 kcal  vs ~7 kcal)
My mother is a very generous person, and such comments should not be made lightly.

The trip drew to a close, fall semester began, and life carried on as it would. Little did I know that a heavy care-package was on its way for me. You see, during this time my parents were also moving, and were downsizing on the non-perishable food items that they would be taking with them. In this package I would find nuts. Nuts of all kind. Almonds. Pecans. Walnuts. So many walnuts. Walnuts were in the greatest abundance in this package, and when coupled with the large kirkland-brand bag sitting scarcely touched in my pantry became a colossal accumulation that months of baking hath barely scathed.

It doesn't help that I've been perpetually dieting since Australia.

Fortunately for me, walnuts are the best of nuts to have surplus. They are extremely versatile in cooking, baking, and make an excellent complement to salads and various breakfast dishes. They are also extremely rich in omega-3 fatty acids. My diet has contained considerably less omega-3 since I stopped eating fish 13 years ago. Did you know that a mere seven walnut halves provides an adult's daily in take of omega-3? A diet rich in omega-3 is important for mental health [1] and brain development [2]. Lately I've been trying to make a decided effort to eat 0.5 oz of walnuts a day.

One of my favourite family recipes is for "birds' nest cookies". After making the dough, you roll it into little balls, dip the balls in a beaten egg, then roll them in chopped walnuts. Next, you press a little well (or 'nest') in the middle and fill it with jam before baking.  Now that I've written a lengthly blog post all about walnuts, I can be like all those food blogs that tell you their life story before finally sharing a recipe.

Elise's Mom's Special Birds' Nest Cookie Recipe.

  • 1 cup butter (softened)
  • 1/2 cup sugar (granulated)
  • 2 large eggs (separated)
  • 2 tsp vanilla (pure is best, extract works fine)
  • 2 cups flour (all-purpose)
  • dash of salt (whatever that means)
  • chopped walnuts (volume required depends on the surface area of your cookies)
  • raspberry jam or jelly (in my opinion, more is better)
Preheat oven to 300°F (148.889°C for you purists out there)
Cream butter and sugar together
Beat in egg yolks, vanilla
Mix in flour and salt
Make balls of chosen size (recommended, 1")
Dip in egg whites
Roll in chopped walnuts
Place on cookie sheet
Use thumb to make well in dough balls
You can put in the jam before or after baking
Bake for an indeterminate amount of time, because this recipe card doesn't say how long (12-15mins)

You're welcome.

Speaking of delicious walnut baked goods, this past Easter weekend, Rachel introduced me to a nice Korean bakery/street food store in Toronto. Their specialty is 호도과자 ("hodo kwaja") which are these little cakes in the shape of walnuts, filled with a sweet paste made of either red bean+walnut or sweet potato+walnut. These are really nice. Not to sweet, but definitely a nice treat with tea or coffee. I don't have a walnut-mold, but I think I'm going to try and see if I can replicate them at home as spheres.
These are really good, and if you are ever in KoreaTown on Bloor St.you should check them out.

[1] Grosso G, Galvano F, Marventano S, Malaguarnera M, Bucolo C, et al. (2014) Omega-3 Fatty Acids and Depression: Scientific evidence and Biological Mechanisms. Oxid Med Cell Longev 2014: 313570.

[2] Bourre JM (2004) Roles of unsaturated fatty acids (especially omega-3 fatty acids) in the brain at various ages and during ageing. J Nutr Health Aging 8: 163–174.

Tuesday, February 27, 2018

The (XRD) Results Are In!


Huzzah! The XRD results are in!

If it weren't for my e-mail exchange with Mark at the beginning of the month, some of the mineral assemblages would have certainly confused me.

Recall: I divided my samples into four categories
  • Solid - in tact, relatively hard crystalline diapir material
  • Intermediate - softer diapir material, can be crumbly
  • Crusty - very friable, vuggy material found on diapir surfaces, often adjacent to intermediate rock
  • Surficial - salts precipitating on soils and rocks downstream of salt diapirs
My hypothesis was that the "solid" diapir samples would be composed of anhydrite, the "crusty" samples would be gypsum (anhydrite that has been aqueously altered), that the "intermediate" would be... maybe both? Given the strong gypsum/anhydrite signatures of secondary salts in the ASTER TIR data, I hypothesized that the surficial salt would be gypsum with halite (after identifying some secondary halite in the field).

Let's start simple.

Here are what some of the XRD analyses show:
  • Solid samples - Anhydrite + Gypsum (more anhydrite than gypsum)
  • Intermediate - Gypsum
  • Crusty - Gypsum, sometimes with traces of quartz or calcite
At first glance, these results are fairly close to the hypothesis, although I had thought the solid samples would be anhydrite only.

A few of the solid samples, though, were not anhydrite. One was calcite (i.e. limestone) with secondary gypsum, and another was dolomite with secondary gypsum, trace quartz and other minerals. This is not alarming. The literature describes the diapirs containing "subordinate limestone, [and] rare dolostone," (Harrison and Jackson 2014). In hindsight, these two rock samples look more like a carbonate than anhydrite or gypsum, but no better "solid" rock exposures were present at these outcrops (Whitsunday Bay Diapir, Strand Diapir).

What surprised me more, though, are the compositions of the surficial salts. 

These samples proved very diverse. Often, they include traces of non-salt minerals (i.e. quartz, clays) but these are extremely likely to be contamination from the soil. It was difficult to scoop up bits of precipitated salt without getting a little dirt or sand mixed in too. So it is not surprising to see common sediments. However, the compositions of the salts were very varied, with:
  • Pure halite
  • Gypsum with mirabilite and dolomite
  • Gypsum with thenardite
To be honest, if it weren't for the e-mail exchanges with Mark, I would not have even thought of checking for thenardite or mirabilite. These minerals are Na2SO4 and Na2SO4·10H2O respectively. Nesse (2012) explains that thenardite can be found in saline lake evaporite deposits, and can be found as an efflorescence on soil. I had to look up what efflorescence means, but it effectively describes the means by which our secondary surficial salts are precipitating on soils and rocks on Axel Heiberg Island. It makes sense that mirability, the hydrated form of thenardite, would be found in the similar settings. Now, unlike halite, thenardite does not have an isometric crystal structure - it is orthorhombic. The implications of this are that thenardite would have spectral absorption bands. I think I should look them up, and see if they are similar to gypsum or not - will thenardite salts be disguised as gypsum in our spectral images? Or can we use different spectral bands to isolate thenardite secondary salts from gypsum secondary salts? Future work will tell, but for now I'm just going to work on finishing my thesis.

P.S. One final highlight -



I have been told that this is exceedingly uncommon. Nesse (2012) says that some samples of halite may be fluorescent (anyone have a UV light?) but that does not necessarily explain how the white powder would turn into a dark grey powder permanently after being run through the XRD machine. Maybe the halite contains radiation-sensitive impurities? Maybe I shouldn't have been licking it in the field?  Who knows. I'm definitely curious, and the XRD technician is also interested in investigating this phenomenon. 



Harrison, J.C., and Jackson, M.P.A. 2014. Exposed evaporite diapirs and minibasins above a canopy                  in central Sverdrup Basin, Axel Heiberg Island, Arctic Canada. Basin Research, 26: 567–                    596. doi:10.1111/bre.12037.

Nesse, W.D. 2012. Introduction to Mineralogy: Second Edition. Oxford University Press, New York.

Tuesday, February 6, 2018

Some salty waters: Thenardite, halite, and gypsum


In my drafts and writing revisions, I noticed that I had a few missing pieces of information.

To clarify a few questions I had regarding the chemistry of perennial springs on Axel Heiberg Island, I reached out to Mark Fox-Powell, who joined us in the field last year. Mark is a post-doctoral research fellow at the University of St. Andrews, with a background in microbiology. His current research is in astrobiology, with emphasis on geochemistry of natural waters.

On our trip, Mark sampled the water and precipitates in and around perennial springs. He is using these samples to analyse their water chemistry, and to produce visible and shortwave infrared spectra of the precipitates. Existing spectral databases of hydrated sulphate and chloride salts are derived from pure minerals produced in controlled laboratory conditions. By using the salts from perennial springs, his team will be able to measure the spectral signatures of impure, naturally occurring salts.

The ultimate goal is to use terrestrial salts as an analogue for "non-icy" materials on Jupiter's moon, Europa. Europa is an ocean world. Its surface is a shell of ice of unknown thickness, over an ocean thought to have the potential to support life. For this reason, Europa is the target of the next NASA flagship mission Europa Clipper which will launch in the early to mid 2020s, and will carry instruments to image its surface at higher resolution. While still unknown, the non-icy materials identified on Europa are hypothesized to be salt precipitates - by understanding the spectral properties of naturally occurring terrestrial salts under Arctic and European conditions, we may be able to better constrain which salts are occurring on Europa. By gaining insight into what chemical materials are present in Europa's waters, astrobiologists will have a better understanding of what kind of life could potentially inhabit these oceans.

So, what did Mark and the team at St. Andrew's find?

We visited three perennial springs during our 2017 Axel Heiberg Island field season. These were Lost Hammer Spring (north of Wolf Diapir), Stolz Springs (emerging from Stolz Diapir), and Colour Peak Springs (southern base of Colour Peak).

Aerial view of Lost Hammer Spring, north and downstream of Wolf Diapir. 

The main vent of Lost Hammer Spring is a >1 m high accumulation of mirabilite and thernardite. Halite precipitates in the surrounding white areas. There is evidence of seasonal layering within the vent.
Lost Hammer Spring has been previously studied by Western alumni Melissa Battler (2013). The water chemistry analysis falls in line with these data, with the spring water being dominated by sodium and chloride. Interestingly, it has the highest sulphate concentration of the springs we visited. Some of these sulphates are precipitating as mirabilite (Na2SO. 4· 10H2O) or thernardite (Na2SO4)  rather than gypsum (CaSO. 4· 2H2O) or anhydrite (CaSO. 4), though. I'm planning on looking into sodium sulphates to see if they have similar or different spectral signatures than their calcium sulphate counterparts.

Segment of the very extensive perennial springs emerging from Stolz Diapir. According to Mark's analysis, the white minerals are dominated by halite and hydrohalite, whereas the darker, greyish minerals are predominantly mirabilite and thernardite
Stolz Springs has the highest concentration of chloride in its waters. This makes sense, given that Stolz Diapir has an outcrop exposure of halite at surface. Different parts of the spring deposits are dominated by halite, and others mirability/thernardite.

Perennial spring at the base of Colour Peak. The dark terraces are calcite+gypsum spring precipitates. The white minerals are halite forming at the edges of the springs.

Colour Peak has multiple spring outlets, which have appear to have lower chloride concentrations than the other sites. The dark terraces are only present at Colour Springs, and are made up of a combination of calcite and gypsum. There are also halite crystals precipitating on the soils adjacent to the terraces. If the terraces contain gypsum, then they certainly are contributing to the strong gypsum signature in our ASTER TIR images downslope of Colour Peak. The streams are very smooth compared to Colour Peak itself, which fits our hypothesis and radar observations!

One of the main takeaways here is that there are certainly more sodium-sulphates around Lost Hammer and Stolz springs than I thought.

Digging through some literature, Howari (2004) writes that thenardite has absorption features at 1.5, 2.0, and 2.3 µm due to the inclusion of water molecules. The latter two are very similar to the absorption features in gypsum at 1.9 and 2.2 µm. Similarly, although crystalline halite does not produce any notable spectral signatures, when aqueous it can also absorb at 2.0 µm from trapped water. Similarly, Howari et al. (2002) write that the SWIR signatures of thenardite can obscure that of gypsum when both are present in soils. This implies that thenardite, halite, and gypsum might look similar in our visible-near infrared and short-wave infrared and composite images. 

Stuff to consider.

I'm going to get back to writing.

Battler, M.M., Osinski, G.R., and Banerjee, N.R. 2013. Mineralogy of saline perennial cold springs on Axel Heiberg Island, Nunavut, Canada and implications for spring deposits on Mars. Icarus, 224: 364–381. doi:10.1016/j.icarus.2012.08.031.

Fox-Powell, M.G., Osinski, G.R., Gunn, M., Applin, D., Cloutis, E., and Cousins, C.R. 2018. Low-Temperature Hydrated Salts on Axel Heiberg Island, Arctic Canada, as an Analogue for Europa. In 49th Lunar and Planetary Science Conference. Lunar and Planetary Institute, Houston. p. Abstract #2564. Available from http://www.lpi.usra.edu/meetings/lpsc2018/pdf/2564.pdf.

Howari, F.M., Goodell, P.C., and Miyamoto, S. 2002. Spectral properties of salt crusts formed on saline soils. Journal of Environmental Quality, 31: 1453–1461. American Society of Agronomy, Crop Science Society of America, Soil Science Society.

Howari, F.M. 2004. Chemical and Environmental Implications of Visible and Near-Infrared Spectral Features of Salt Crusts Formed from Different Brines. Annali di chimica, 94: 315–323. Wiley Online Library.

Tuesday, January 23, 2018

New Year - The Final Countdown

This semester is the final push to graduate on time.

No pressure.

I need to have my thesis ready to submit to my committee by March 12th.

So far I have drafts up to my results section. I'll be submitted monograph style as opposed to manuscript style. I hope I'll be able to put together a manuscript together afterwards.

I've crushed an adequate selection of samples and submitted them for XRD analysis. I tried to represent a range of diapirs, and rock textures at the different sites.  These include crystalline diapir material which is soft but has high toughness (scratches easily, but does not break easily), a friable "crust" which is very vuggy, and an intermediate rock which has varying degrees of friability, but is not vuggy, and surficial salts that crystallized on the surface of non-diagenetically related rocks and soils. The crust rock is frequently found in association with the intermediate rocks, suggesting that these samples represent different degrees of weathering.

Crystalline Rock

Crusty Rock, containing vugs and botryoidal crystal growths
Surficial Salts - Rock was found at the edge of a stream bed
with white salt minerals encrusting it.

"Intermediate" Rock - Friable, but lacking the vugs and
microcrystalline structure of the crust

In choosing samples in the field, and in the lab, I ran into a few difficulties.

One, is that not every sample type (i.e. crystalline, crust, intermediate, surficial) were present at each site.  This would be scientifically interesting.  However, it is possible that each type were present at each site, but I either:

1. Didn't sample them
2. Didn't see them
3. Didn't adequately define the types

I am mostly able to rule out #1, because I established early-on what I wanted to sample to gain a representative rock selection. However, at a few sites (like Whitsunday Bay Diapir, at which the helicopter landed in two places and we jumped out to go grab some rocks while it was still running) it is entirely possible I just didn't have enough time to search thoroughly. The absence of evidence isn't evidence of absence. Third, by its own definition, the intermediate rock has variable degrees of friability, and is often found in close associate with both crystalline and the crust rock. I separated it out to see if we can learn anything about the nature of weathering. As such, there is wiggle-room in determining which category some of the samples best fit.

Another problem is that it was terribly challenging to sample the surficial sediments. The best sample I was able to prepare for XRD required me to scrape off a sufficient amount of salt minerals off of a few pebbles I collected from a stream. The worst samples were where I found the salt precipitating on sand, and scooped up the salt and sand together. As a result, I only submitted a couple for XRD that I thought might provide reliable results, so data in this type may be lacking.

I should get some of the results back this week. It will be cool to see how the diapirs are weathering between anhydrite and gypsum, and how that is affecting their surface textures.