What Is? – Defrosting the Freezer

What is: Open Access publishing?

Peer review is generally accepted to be the least-worst way to generate trust in the scientific publishing process. By allowing experts in the field to read, critique, confirm, challenge and improve your work before it enters the mainstream body of science, poor quality or erroneous work should be filtered out before it gets the chance to distort public perception and policy. However, it’s not without its critics. Anonymous reviews allow reviewers to partake in spiteful and/or personal attacks which do nothing to improve the science behind the work, and can delay or even prevent publication of perfectly acceptable work. Also, the system is based on a financial system that only seems to benefit the publishing companies. In traditional journals, scientists relinquish their copyright to a company that then charges them and their colleagues to read the work, restricting access to those in universities or with big budgets (individual papers can cost $30 or more, subscriptions run to the thousands). Journal reviewers and editors work for free, considering the process as part of their community obligation despite the for-profit journal getting the real benefits.

Recently, open-access publishing has started to change the way that ordinary people can read the research that they, through their taxes and charity donations, have paid for, but the business model for the publishers is generally similar. In a typical open access publishing workflow, the researchers submitting the paper pay an “article processing charge” (APC) once the work has been accepted. Paying this charge, which is often £1000 or more, allows them to retain the copyright, and lets anyone, anywhere in the world, read the paper for free. It shifts the costs for access from the distributed consumers, who would often lack the resources to pay for the research, to the universities producing the work in the first place. Most research grant bodies now request open access publishing, and have provided some funds to cover the APCs, for now at least. Reviewers and editors are still unpaid, and publishers still make a profit, in fact since many articles are not open access then universities (i.e. taxpayers) are on the hook for both the journal subscriptions and the APCs.

So why are researchers still paying these companies such large amounts of money (profit margins are amongst the best of any industry)? Well, academic promotion is mostly decided by your publication history; the easiest way to judge a publication history is to look at the journals that a researcher publishes in, rather than reading the papers themselves. Therefore the pressure is on, especially for young researchers, to publish in the most prestigious journals, and they tend to be the most expensive ones, where articles are either restricted access or have high APCs.

Recently, there has been a shift towards more open and accountable publishing systems, with journals allowing researchers to publish either draft versions or even the finished paper on their website without violating copyright. Many universities have created online repositories to let researchers store and share their work (mine is available through my Manchester profile page), which are imperfect, since it’s often hard to find the papers, but better than nothing.

Even within my short career, the way that people publish and access science has changed; open publishing is still in development and it’s likely that further innovation in the next 5-10 years will change the landscape even further.

What Is: GRAR?

Russia is big, really big, and to go with that, it has some very big rivers. The majority of the Russian river outflow is into the Arctic Ocean, especially in the central and eastern parts of the country, and this is generally concentrated into a series of very large rivers. The largest of these are known as the Great Russian Arctic Rivers (GRARs). From west to east, these are the Ob, Yenisety, Lena, Indigirka and Kolyma, of which the Ob and Lena are largest, and Indigirka the smallest (small enough to not count in some people’s list of GRARs).

Catchment areas of the Great Russian Arctic Rivers

The Ob river is the world’s fifth-longest and has the sixth-largest drainage basin, yet has only the 19th highest annual discharge, being overtaken by the smaller Yenisey and Lena rivers to the east of it. All of these river basins contain some permafrosted land, which can reduce discharge during the winter months and have a very large flood-period in late spring / early summer when the meltwater arrives (the “freshet”).

Permafrost within catchments of the GRARs

As the amount and continuity of permafrost increases from west to east, so the proportion of each permafrost type increases within the river basin. The Ob and Yenisey are largely free of continuous permafrost, allowing water to flow through the ground to the bedrock and into the river, whilst the Indigirka and Kolyma are practically 100% continuous permafrost, and thus any water discharging will have run along the top of the ground before entering the river itself. This can have consequences for the type of material, especially carbon, carried by the rivers.

Proportion of each type of permafrost within river basins

This east-west contrast is worth exploring in more detail in a later post, since it shows how Siberia may behave very differently if the permafrost were to thaw. As a final reminder of just how large the rivers are, even the smallest, Indigirka, manages to cover more area than the British Isles! As usual the full-resolution PDFs of the figures from this article can be downloaded here: River catchments no permafrost, Catchments and permafrost, Permafrost chart, Catchments and UK.

Comparing the catchment areas to the British Isles

What Is: Gas Chromatography (GC)?

Gas Chromatography is the separation of molecules from a mixture using a gaseous carrier medium.

Gas Chromatography allows an organic geochemist to identify and quantify some of the molecules present in a sample. The procedure is similar to Liquid Chromatography (LC), in that a collection of molecules is split into its constituent parts by passing them through a column of material. As the different molecules emerge from the column they are measured by a Flame Ionisation Detector (GC-FID) or identified by a Mass Spectrometer (GC-MS). A GC consists of a sample injector, a column housed within an oven, and an outlet to the detector.

The sample injector is responsible for putting a precise amount of sample into the column at the start of the sample run. A syringe is washed in solvent to remove any contamination, and then sucks up-and-down in the sample a few times to mix the sample and make sure there is no air in the syringe. Once the oven is ready for injection, the needle pierces the seal on the top of the GC and injects the sample onto the column. The sample is a liquid at this point, but will evaporate quickly and pass through the column as a gas.

The column is a 30m coil of glass tubing, just thicker than a hair, which is coated on the inside with an adsorbant material that slows the organic molecules as they pass through. The column is kept inside an oven which is carefully calibrated and can change its temperature during the sample run. In general, smaller, simpler molucules will pass through the column quicker, especially at lower temperature. Molecules will move easier when the temperature is hotter, so the easiest way to separate a mixture of molecules into their constituent parts is to start off at cool temperatures and slowly increase during the run (e.g. 40 to 300 °C over one hour). Simple molecules such as benzene or hexane might pass through the column in 2-3 minutes, whilst large, complex molecules might take up to 45 minutes. The slower the oven temperature increases, the further apart each molecule will be, making it easier to separate each one.

Once the molecules have passed through the column they exit into the detector. This can be a Mass Spectrometer (MS), which identifies the molecule, or a simpler detector that counts the concentration of molecules exiting the column but cannot identify them, such as a Flame Ionisation Detector (FID). Simple detectors, such as the FID, are most useful when the sample is less complex, such as comparing the concentration of a target molecule.

What Is: Organic (Geo)Chemistry?

Organic chemistry is the study of materials that contain carbon atoms

Carbon atoms for the basis for all life on Earth. By building molecules out of carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorous and an array of other elements, we can create and regulate our bodies. Organic compounds range from simple methane gas (CH₄) up to very long and complex molecules used to protect our cells from toxic environments. Organic chemists work to identify these molecules, learn where they come from an how they are made, discover their function within the cell and investigate their effects on organisms and the environment.

Organic geochemists look at organic molecules within sediments and the rock record. They can use them to identify the source of organic material, looking to see whether carbon present in a sample came from soils, vegetation, marine algae or a range of other sources. Organic molecules can also be used to investigate the decomposition of material, looking to see how it changes over time, to identify the biological processes that were happening in ancient fossils, to identify the source and economic potential of hydrocarbon deposits, and many more applications.

What is: Permafrost?

Permafrost is soil or sediment that is permanently below zero °C

When most people talk about permafrost, they think of frozen, empty soil with very little living on it, in it or near it. They think of a harsh, icy environment with glaciers, blizzards and possibly a few reindeer roaming around. But permafrost is much more varied than this. It does not necessarily have a covering of ice, but can be a thin layer of grass or peat with frozen soil underneath it, there can even be forests growing on the surface with frozen soil underneath them. There can be animals living on it, and bacteria living within the sediment. In fact, the permafrost might not even be on land! Here are just a little information about permafrost and what it contains.

Northern Hemisphere Permafrost. Also shown are subsea permafrost and the Arctic ice cap.

Permafrost soils, which are frozen so solid so you need a pneumatic drill to sample them, cover a quarter of the northern hemisphere land area, and can be up to 1500 m thick. They store more carbon than there is in the entire atmosphere. The very top layer will thaw each summer and freeze each winter, which allows plants to grow and animals to graze, but the lower parts remain frozen all the time. In the southern parts, there can be trees growing on top of the permafrost, this is known as the ‘taiga’. When it is too cold, and the growing season is too short, only grass, moss, shrubs and lichen can survive, this is the ‘tundra’.

Another example of permafrost is frozen methane-ice trapped on the seabed. Subsea permafrost is often ignored, but these icy crystals of frozen, flammable gas and water contain a large amount of trapped carbon, are prone to melting and gas release, and have been blamed for one of the most extreme climate events in geological history.

The last type of permafrost to be discussed here is ‘yedoma’. This is a feature of the very furthest reaches of the Arctic, and is formed by windblown dust freezing together to form a layer of dirty ice and sediment. These thick ice layers are often found on the Arctic coast, where they have no defences against the incoming waves from the Arctic Ocean and are eroded easily. As the Arctic warms, the sea ice that usually protects the coastline from the force of the waves is reduced to nothing, allowing the full power of the sea to erode into the shoreline

The map shown above can be downloaded here. The data was sourced from the University of Zurich Global Permafrost Zonation Index Map.

What is: Liquid Chromatography (LC)?

Liquid Chromatography is the separation of molecules from a mixture using a liquid carrier medium.

An organic geochemist will often have the problem of having a test tube containing a large amount of different molecules, but only being interested in one or two of them. Much like a child might place felt tip pen and water onto some filter paper to watch the colours run and separate out (with some very artistic results), with liquid chromatography (LC) we split our mixture of molecules up into its individual components so that they can then be analysed. An LC, sometimes known as HPLC where (HP means High Performance or High Pressure), consists of three main parts: the autosampler, the pump, and the column, labelled in the picture below:

The autosampler collects a syringe full of sample from a vial and injects it at the right time onto the column. You can do this job yourself if you have good timing, are very accurate, and have an exceptionally high boredom threshold; the autosampler allows you to queue up a large amount of samples ready to run while you are away from the machine.

The pumps mix two solvents together and push them through the column. Each chemical in your mixture will behave differently when exposed to each solvent, it will be more soluble in one than the other, and will be differently soluble to the other chemicals in the mixture. Often one of the solvents will be polar (have an electrical charge associated with it, e.g., isopropanol alcohol) and the other will be non-polar (be electrically neutral, e.g., hexane). During the sample run, the amount of each solvent being washed through the column will change, and therefore different chemicals will wash through at different times.

The column is a metal tube filled with small solid particles. These are slightly ‘sticky’ to the molecules passing by (they adsorb onto the particle surfaces) and so the chemicals in the samples are not washed through the column that quickly. The solvents that are being used in the experiment remove the molecules from the column particles and move them through the system, until they reach the end of the column and can be detected. At the end of a sample run, the flow on the column is reversed and anything that did not make it through to the end is cleaned out (the ‘backflush’)