Updated on January 4, 2018
This does not happen often in a scientific career: the world-famous scientific journal “Nature” has just published our work.
Our article “Mean global ocean temperatures during the last glacial transition” bases on a record of atmospheric noble gases from ice core samples. This data allows us to reconstruct past global ocean temperatures in an unique way and provides new insights into the temperature regulation mechanism of the global ocean. The topic has already been part in this previous post. Read the freely accessible Empa News article (German and English version) and the News and Views article in Nature for more details.Share This:
Updated on March 20, 2017
Time flies, footage stays. A bit more than a year ago, I lived the life of an ice core driller in Antarctica. Here is the long-awaited ice core drilling video with some explanatory elements for everybody to share and learn, with great music of field mate Andy Menking.
All the best,
Posted on July 4, 2016
Several months after drilling the ice cores on Taylor Glacier, they finally arrived at our lab. A moment to celebrate that nothing went wrong on the way, and before.
I have to admit, it was a pretty special moment when I drove to Zurich Airport that rainy late afternoon a few weeks ago to meet the ice core boxes I packed last December on McMurdo Station in Antarctica. So much work for a few tens of kilograms of ice and now it finally arrives at the lab… Good Times!
From the drill site on Taylor Glacier the ice was brought to McMurdo Station by Helicopter where it was stored in a first freezer. There, we prepared the boxes for their long journey in an on-board freezer of a ship from McMurdo to L.A., followed by a transportation with a freezer truck to the labs in the U.S.. Special care is required for this transportation as all could be lost by a gap of a few hours in the cold chain. As an example, one of the special safety measures is that always two freezer trucks are used for the delivery to the labs: One loaded with the boxes, the other one empty as backup in case the main truck breaks down. All of this is organized by the U.S. Antarctic Program and works perfectly. Thanks!
The ice that made it to Switzerland is part of a collaboration between the Scripps Institution of Oceanography in San Diego and the University of Bern, for which reason our ice was brought to San Diego first. From there we had to organize the transportation by ourselves and had to work with carriers that are not used to handle such precious freight. It is always interesting to explain to a carrier that the freight does not have a “price” (which they need for their insurances), because this freight is just not buyable! Its effective price would be so high that no one would ever take the responsibility for the transportation. There is no other way to give a fictive price (way too low) and basically do the transportation without any insurance, a common way if you deal with shipping of research products.
Therefore, you take special care to minimize the risks during the transportation and we boiled it down to a fast transportation without cooling from San Diego via L.A. airport and Zurich airport to Bern within 28 hours. The boxes got loaded with cold packs such that they could stay cold for 48 hours without any external cooling. You probably understand now why it is a moment to celebrate when all the ice arrives as planned – still nice and cold – and you can place it in your freezer at the lab.
Posted on March 13, 2016
The past week, ice core scientists from all over the world have met in Hobart, Tasmania, to share the latest results as well as ideas for future work. The ice core science expertise that came together for this second edition of the IPICS Open Science Conference is unique for which reason many colleagues call this conference the best in their field.
About 10 years ago the International Partnerships in Ice Core Sciences (IPICS) has formed and released a few white papers as a guide for future ice core research. In 2012, IPICS called for the first IPICS Open Science Conference in South France, which marked the first true international ice core meeting ever. The past week, all 18 member countries of IPICS sent their researchers again – this time to beautiful Hobart – for the second edition of this conference, which was again a very successful and fruitful one week conference with about 250 attendees.
The presented topics covered all fields of ice core research. Special sessions were hold for example about new insights from non-polar ice cores (from tropical and alpine regions), or where to find the oldest ice in Antarctica (expected to be as old as 1.5 million years old) as well as new results about ice flow of the large polar ice sheets (which is essential knowledge for future sea level change predictions based on ice sheet modeling). In total about 65 scientific talks were given and probably about 250 posters were presented, an ideal size for fruitful exchange.
Interesting progress in the search for the oldest ice in Antarctica could be presented and a couple of regions in east central Antarctica are now under closer investigation for possible drill sites for this prestigious project. Also a new approach to use trapped gas in ice cores to reconstruct past ocean temperatures gained some attraction. For the first time useful results from this kind of analysis of two different labs were presented, which seem to be able to deliver a lot of new insights into the energy budget of the climate system.
Besides the scientific topics, also the very recent announcements of strong cuts at the Australian Research Institute CSIRO were discussed. Many of our Australian ice core colleagues with whom collaborations have been undertaken over decades are now in danger to lose their jobs because political leaders in Australia believe climate science does not need observations anymore, but needs only research on climate mitigation. This political tendency away from observation oriented research towards research on climate mitigation is not only an Australian phenomenon. Unfortunately, this tendency forgets the fact that climate mitigation and observation is very strongly linked and only with the continuation of high quality observation, good mitigation is possible. There is the hope that the Australian government rethinks its plans during the ongoing hearings and they don’t waste the money they have invested over the last decades to build up the knowledge they now want to get rid of.Share This:
Posted on February 18, 2016
This is very off-topic, but for a physicist just a must to share. The world of fundamental physics just has changed, because it is proofed: Einstein’s general theory of relativity is true!
Einstein has brought up several theories that changed the way we look at the fundamental forces in the universe. One of his later – and probably the most fundamental – theories is the general theory of relativity. It describes the way how gravity works – that mass bends the spacetime. This is fundamentally different to the thinking of “the other way”, which would be that there is a gravitational force (like magnetism) pulling two masses together. Yes, strictly speaking, it is wrong to talk about the gravitational force from now on. You can say “today, the spacetime feels very straight” if you want to say that you feel very light-footed today – but that’s just for nerds 🙂 .
What does it mean for our daily lifes? Pretty much nothing, but it is exciting to see a 100 years old theory finally to be proofed. The most prominent impact of the general theory of relativity finds application in the GPS network. The positioning system would not be as precise as it is if the theory would be ignored (see this Ohio-State Page for more details).
A scientific perspective on this groundbreaking finding and how it has been proofed can be found in these Nature articles:
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Posted on December 11, 2015
After three weeks of field work on Taylor Glacier, four of us left the field (incl. me) while eight are continuing until beginning of January. Here some impressions from an amazing time at an amazing place.
To be continued…
P.S.: Follow the Rochester blog for more reports directly from the field.
Updated on November 16, 2015
The most spectacular work that is done on the field is probably melting every day 1 ton of ice in a huge vacuum chamber. Back in the lab, the released air from the ice will be analyzed for its radiocarbon content, which has fundamental implications for dating purposes and identification of sources of atmospheric carbon.Radiocarbon, or C14, is a rare radioactive carbon isotope with a half-life time of 5730 years. Because carbon is found in almost all natural products, the activity of C14 in a material can be used to trace back the time when the carbon was built in that material. This basic concept lies behind the widely used C14 dating method (but works also with other radionuclides) und builds probably the most prominent dating technique for natural materials.
Not only dating is an application of C14, but also can we use it as an identifier of sources of atmospheric carbon at a specific point in time. In the application in our field work, C14 in methane (CH4) is measured and used to figure out whether the CH4 came from a recently formed archive (i.e. biosphere sources such as tropical and boreal wetlands) or an archive that has been sealed away from the atmosphere for very long time (i.e. carbon in the deep ocean and permafrost). For example, if C14 in CH4 drops during an event when the CH4 concentration is increasing, we know it must come from an “old” source, and vice versa.One motivation to investigate this in the past is that the current human-made warming has potential to destabilize some old sources such as permafrost and clathrate hydrates and, hence, add to the release of greenhouse gases emitted by human activity. This so called positive feedback could have taken place in the past for example during the last glacial transition when the global climate changed from the last ice age to the current warm period. By identifying such events and their links to natural climate change, we can better asses by how much we have to take this effect into account for the current warming event.
The group from the University of Rochester around Vas Petrenko that leads this project (which is by the way also the flagship project of our field work), is the first group ever that analyses C14 of CH4 in trapped air in polar ice, and also managed to significantly improve the precision for C14 in CO2 and CO with their methodology. The reason for their significant step forward in the analytics lies in the large amount of ice/air from the same time period it can be taken from Taylor Glacier. At normal ice core drill sites the ice layering is horizontal and only a limited amount of ice is available for a certain time, whereas at Taylor Glacier the layering is vertical which allows accessing basically unlimited amount of ice from the same time period.
In a previous work done a couple of years ago, the team of Rochester could show that during a specific event about 12’000 years age, an “old” source was clearly active. In the current campaign they want to extend their C14 record on a much larger time span and also try to rule out an inherent problem to C14 in air from polar ice samples: production of C14 in the ice itself (in-situ production).
More details about the interesting work of the University of Rochester group can be obtained from their blog.Share This:
Updated on November 16, 2015
In ice core research we would love to probe a time period that was warmer than today for better predictions of our future. However, these time periods have been rare in what we can cover with ice cores, with probably one exception which we want to probe on Taylor Glacier.
With ice cores it has been possible to probe the climate as far back as 800’000 years before present. This is an extremely long time range, but only during about 10% of this time, the globe was in a state of warm climate, as we are since the last 10’000 years. All the past warm periods were either a bit colder or equally warm than the present one, but none of them significantly warmer than the present one. This was the state of the art until a couple of years ago, when research started to find evidence that the last warm period (about 125’000 years ago) was probably the one exception.
With a few degrees warmer climate than what we have today (maybe only true for certain regions), this time period has potential to give us insight in our future climate and can serve as a kind of analog for where we are heading to with human-made global warming. It won’t be the perfect example, that’s clear, because greenhouse gas concentrations have not been as high as we are driving them to (they were about 30% below the current concentrations of CO2), but other mechanism seemed to have made the globe slightly warmer than today (at least regionally). To find out what these mechanisms were, how they worked, and what it meant for the climate is what drives our interest in this specific time period.125’000 years old ice is old even for Taylor Glacier standards (see picture for a reference of the ice age). With the past few years of fieldwork it was possible to identify and nicely date a well preserved section on the glacier that covers the time period between about 6’000 and 52’000 years before present (the so called main transect). This transect is part of a unique ice fold that extends over a large part of the lower glacier tongue. However, this main fold is highly disturbed on its edges and it has been proven difficult to find older ice on the glacier.
Nevertheless, the search for older ice further down the glacier tongue has continued and it has been possible to find shorter sections of ice that date back to around 70’000 years (the so called MIS 4-5 site) and even older ice around 125’000 years of age. The ice, however, is highly compressed and the stratigraphy disturbed such that the first attempt to retrieve a record for this period was not fully satisfactory. Therefore, we are revisiting this site and hope to drill a core a couple of meters away from the original site that hopefully contains the period in a better fashion. Due to the complex stratigraphy of the glacier, in particular at the sites down the glacier, it is to some degree a try-and-error work and some luck is needed to drill in a good section.
We plan to go twice to that site: at the very beginning of the season and sometime in the middle. The plan is to drill a few tens of meters away from the original site, bring the cores back to the main camp where we can do some analytics to see what we got, and then go back again to hopefully get the best possible core from that site. Regardless whether we find a slightly better site or not, the ice we will get from there will be used to address different questions. Two examples are given here:
By measuring the Krypton and Xenon content in the trapped air it is possible to reconstruct the global mean ocean temperature back in time. With these measurements – which rely on fairly large sample and are therefore easy to perform with ice from Taylor Glacier (see previous blog for details) – we will hopefully shed some light on the question how warm the ocean was back in the last warm period (was it warmer or similarly warm than today?).
Another focus is going to be absolute dating of a certain event around that time. Dating of the trapped air based on the radionuclide Kr81 (similar concept as explained in a previous blog) is possible at Taylor Glacier, only because we can take so large ice samples. This technique will give us an independent and very precise age for the trapped air and tell us at which point in time this event has actually happened.
More happy science coming soon!Share This:
Updated on November 16, 2015
After a week of training and preparation in McMurdo station we are flying to our field site: Taylor Glacier in the McMurdo Dry Valleys.
The protection of Antarctica through the international treaties make visiting this continent a bit more complicated than other places, but the McMurdo Dry Valleys go along with one more layer of protection. The region is a so called Antarctic Specially Managed Area (ASMA) which is set up to protect the regions very unique and fragile environment (see https://en.wikipedia.org/wiki/McMurdo_Dry_Valleys and http://www.mcmurdodryvalleys.aq for more details). For us it means that we will be able to visit a very unique and beautiful part of Antarctica, and that we also have to take special care to minimize the traces of our work in the field. With the exception of holes in the glacier (in some places people say we make the glacier look like a Swiss cheese 🙂 ) we put a lot of effort in not leaving traces (from human waste through spilled oil to food waste… everything has to be collected and brought back to McMurdo).The McMurdo Dry Valleys are mostly ice and snow free. The glaciers in the valleys are fed from the inland ice shield where snow can accumulate over time. In the McMurdo Dry Valleys it is so dry, sunny and windy that no closed snow layer can build up and the glaciers flowing into the valleys constantly sublimate at their surface (in very rare cases melting occurs). In glaciology terms this is a so called ablation region. Therefore the glaciers are not covered by a nice white and soft layer of snow, but they consist only of pure ice, hard as rock, slippery as hell.
Obviously it is not the most pleasant place to set up camp and live for a couple of weeks (besides the beautiful scenery), but it provides very unique access to ancient ice. The ice layers of equal age – which are horizontally orientated at the inland ice shield – are rotated by 90° at Taylor Glacier in a vertical orientation. This has very practical advantages because we can drill parallel to the layers and can get basically endless amounts of ice from the same age. In classical ice coring at an inland site you drill rectangular to the layers which means you have only a limited amount of ice per age.It is a nice coincidence that the layering is so practical orientated for drilling and it is in fact surprising how well preserved the layering is considering the rotation of the ice, the long distance and curved landscape the ice has been flowing through. You can stand on the glacier and see certain layers by the naked eye and just walk rectangular to the layering to change the age of the ice you are standing on.
In fact you can very easily observe the dusty layer of the last glacial period on the google maps satellite images and in this way study the stratigraphy of the glacier on your computer (go on earth/satellite view; coordinates -77.760389, 161.715335). The little feature rectangular to the glacier flow direction you see at these coordinates is our trench of our main transect (you have to zoom a lot to see it…). Near this point we are going to camp. We use these satellite images a lot in combination with our on-site measurements to figure out where certain ice can be found. For some reason, the McMurdo Dry Valleys are very well resolved in the google maps satellite images. Have a look and play a bit the glaciologist :-).While we are out there we do not have any web access. We can communicate via a satellite phone and are in regular contact with McMurdo station. There is a little chance a blog from the field makes it online via a USB stick in the helicopter and the McMurdo IT people. So until the return most blogs are going to be prepared.
Stay tuned!Share This: