31 Jan 2026 - Amy
This month’s post feels a little different from the last. Where the previous entry was about framing the big questions—why sea ice matters, and why we should care about its past behaviour—this one is more about the quieter work that underpins those questions. It is about methods, patience, and the uncomfortable reality that much of science happens slowly, incrementally, and largely out of sight.
One of the central challenges in reconstructing past Arctic sea ice conditions is not a lack of data, but a lack of chronological (age) control. Marine sediments from the Arctic Ocean and Nordic Seas contain extraordinarily rich information about past environments: microfossils, biomarkers, sedimentological changes that tell us about ice cover, productivity, and circulation. What they often lack is a robust and precise chronology. Without that, even the most detailed reconstruction struggles to answer the questions we care about most: when did change occur, how fast did it happen, and how did it relate to events elsewhere in the climate system?
This is not a new problem. Arctic marine records are notoriously difficult to date because many of the tools commonly used elsewhere perform poorly there. Radiocarbon dating is complicated by reservoir age corrections that are large and variable. Palaeomagnetic dating is complicated by postdepositional processes. Sedimentation rates can be low, and bioturbation can blur the signal. None of this is particularly glamorous, but all of it matters.
My fellowship sits squarely in this methodological space. The core idea is simple enough to explain: volcanic ash layers—tephra—can act as time-synchronous markers across vast regions. A single volcanic eruption can disperse ash over thousands of kilometres, depositing the same material in ice cores, marine sediments, and terrestrial archives. If that ash can be identified and geochemically fingerprinted, it provides a powerful means of linking records and anchoring them in time.
In practice, of course, “simple” does not mean “easy”.
Much of my time at the moment is spent in the lab, the tedious business of extracting microscopic glass shards from mud. On exciting days, I get to sit at a microscope for hours searching the metaphorical haystack for my own precious needle: a microscopic shard of glass. On my less exciting days, I get to stand for 7 hours coaxing water through a nylon sieve mesh to remove the clays from my samples. For those who want to know more about the day-to-day of cryptotephra, the brilliant Danielle McLean has made this video which lays out the process in detail.
What keeps me grounded is the knowledge that this effort is cumulative. Every securely identified tephra layer adds a fixed point to an otherwise floating chronology. Every correlation strengthens our ability to compare Arctic marine records with Greenland ice cores, North Atlantic sediments, and terrestrial archives further south. Over time, those points begin to outline a much clearer picture of how Arctic sea ice behaved during past warm periods.
There is also something oddly comforting about doing work that is, by necessity, slow. After years of moving between projects, writing applications, and feeling the constant pressure to demonstrate productivity, there is a relief in focusing on careful, foundational research. This is not work that lends itself to rapid outputs, but it is work that makes other research possible. I am learning—sometimes reluctantly—to be comfortable with that.
That is not to say that this month has been devoid of excitement. There are moments, usually unexpected, when a peak in tephra concentration is identified, or a colleague sends me some ash from another core they have been studying, and the broader implications become briefly visible. A single ash layer can suddenly connect an Arctic sediment core to a well-dated ice-core event, collapsing geographical distance and reminding you just how interconnected the climate system is. Those moments are rare, but they are deeply motivating.
They also reinforce something I am increasingly aware of: that our understanding of future climate change is inseparable from our ability to resolve past change accurately. We often talk about uncertainty as though it were a failure of knowledge, rather than an invitation to improve the tools we use. For sea ice in particular—so dynamic, so sensitive, and so influential—getting the timing right is not a technical detail. It is central to understanding cause and effect.
As this fellowship progresses, I expect there will be months where the science feels abstract, months where it feels frustratingly slow, and months where it briefly comes into sharp focus. This has been one of the quieter ones. But quiet does not mean unimportant. It is in this phase—sorting, checking, recalibrating—that the foundations are laid.
Next time, I hope to write more concretely about results. For now, I am content to be in the middle of the process: learning the archives, doing the work, and gradually building a foundation, a chronology, on which larger stories can be told.
I’ll see you next month.