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For more information about this project please go to: www.weathering78n.org

Neptune

2016 Posted on Feb 12, 2016 15:55

For the next few months I will be a visitor at the Department of Earth Sciences at the University of Cambridge. I don’t have very good timing as their labs are currently being renovated but fingers crossed it doesn’t take too long before I can get in them. In the meantime I am learning how to use the Neptune (a multi-collector inductively-coupled-plasma mass-spectrometer MC-ICP-MS) which I plan to use to measure lithium (Li) isotopes in my field samples.

I’m interested in measuring lithium because the sites in Svalbard contain shale which has a high clay content. Li isotopes fractionate when they adsorb or are incorporated into clays and likely to different degrees depending on the type of clay. The two sites have different clay compositions so I expect them to have different Li isotope compositions in the water too.



Arctic Frontiers

2016 Posted on Feb 12, 2016 15:43

It was a busy week in Tromsø at the annual Arctic Frontiers conference. I was looking forward to this conference as it explicitly tries to combine science, business and policy and I wanted to see the interaction between science and policy which you don’t normally get at a typical geochemistry conference. Ultimately, though, I was disappointed. The different sections were split into different days with little overlap of delegates. The disconnect was really brought home in a discussion about designing Arctic towns to minimise social problems. The researchers had come up with a number of solutions but it didn’t seem like the people in charge of planning were listening or just treated it as an academic exercise.

Through APECS, I was involved in the Science for Schools program which was a side event to the conference. School pupils spent the day at the science centre, with talks from early career researchers followed by presentation of posters they had made about science issues relevant to the Arctic. It was very enjoyable and hopefully those children will maintain their enthusiasm for science. Coverage of the event (in Norwegian) can be found here and here.

Articles about APECS events during Arctic Frontiers:
Poster Awards
Science for Schools
Young Politicians
Communicating Science Panel



Paper published

2015 Posted on Feb 12, 2016 15:28

November

It was a long process, first two rounds of major revision then rejection from the first journal we tried, followed by more major revisions but then acceptance in Chemical Geology. The title of the paper is “Influence of glaciation on mechanisms of mineral weathering in two high Arctic catchments” and can be accessed here.

In the paper we discuss the geochemistry of the two streams along with the S and O isotope data and the bacteria data. Our main conclusion is that bacterially mediated pyrite weathering of silicate and carbonate rocks is a major process in these catchments. Weathering is normally assumed to occur using carbonic acid derived from atmospheric carbon dioxide, so if sulfuric acid (from pyrite weathering) is widespread then it would affect estimates of how much carbon dioxide chemical weathering removes from the atmosphere.



Cambridge

2015 Posted on Feb 12, 2016 15:13

February

I still had a few remaining samples from my trip to Michigan where I hadn’t measured the Sr isotopic composition. Since the machines in St. Andrews were still not up and running I went to the University of Cambridge for a week and with the help of Hazel Chapman I filled in this missing gap in my data set.

My water data set is now complete but to properly interpret it I need to analyse the rocks and sediment samples that I collected. First I will need to find a good method for dissolving shale which is one of the harder rock types to fully dissolve.



U data

2014 Posted on Feb 12, 2016 15:06

November

U data now in! Here too there are interesting differences between the two catchments.



New labs!

2014 Posted on Feb 12, 2016 15:03

Summer

The new clean labs in St. Andrews are complete! They consist of two rooms for doing isotope work and one room for the instruments to measure the isotope ratios of samples. There is still some work to go though to make sure all the necessary equipment is there, but hopefully I can start to process my samples, especially the sediment samples, in the not too distant future.



No sulfate reduction

2014 Posted on Feb 12, 2016 14:59

June

We had observed a positive correlation between the oxygen and sulfur isotopes of sulfate in the stream water from Dryadbreen (glaciated catchment). This is often attributed to sulfate reduction. At the temperatures found on the Earth’s surface this reaction is microbially mediated so to see if any microbes were reducing sulfate we looked for the dsrAB gene. But we didn’t find any which means something else is causing that correlation…



EGU

2014 Posted on Feb 12, 2016 14:48

April

Poster presentation at EGU: the sulfur and bacteria data are coming together into a coherent story!

I also made a video for the EGU ‘Communicate your Science’ competition about this project which can be viewed here.



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