Cosmogenic in situ C-14 

My PhD research was centred on measuring and applying the cosmogenic nuclide in situ C-14. This cosmogenic nuclide - which you can learn more about on this page I wrote for AntarcticGlaciers.org - is particularly useful for understanding changes in glaciers in the Holocene because it has such a short half-life. However, it wasn't until the mid-2010s that measuring in situ C-14 in quartz became relatively routine. In the list below, you'll find a short review paper on in situ C-14 in Antarctica recently published in Annals of Glaciology, a methods paper I wrote as part of my PhD research, and another I co-authored with my PhD advisor on the in situ C-14 extraction line I worked with at Tulane University. 

Published papers:

A decade of cosmogenic in situ 14C in Antarctica (Nichols, 2023; Annals of Glaciology)

Isolation of quartz for cosmogenic in situ 14C analysis (Nichols and Goehring, 2019; Geochronology)

A fully automated system for the extraction of in situ cosmogenic carbon-14 in the Tulane University cosmogenic nuclide laboratory (Goehring et al., 2019; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms)

Holocene readvance of the West Antarctic Ice Sheet

As part of my postdoctoral research, I am investigating the recent history of Thwaites Glacier, West Antarctica. Dubbed the "Doomsday Glacier", Thwaites is roughly the size of the island of Great Britain and contains enough ice to raise global sea level by 0.65 m. Specifically, as part of the International Thwaites Glacier Collaboration (ITGC), I'm measuring long-lived cosmogenic nuclides (Be-10 and Al-26), together with collaborators measuring a short-lived cosmogenic nuclide (in situ C-14) in subglacial bedrock to test if/when Thwaites has been smaller than present.

Published papers:

Reversible ice sheet thinning in the Amundsen Sea Embayment during the Late Holocene (Balco et al., 2023; The Cryosphere) (co-first author).

Review article: Existing and potential evidence for Holocene grounding line retreat and readvance in Antarctica (Johnson et al., 2022; The Cryosphere)

Antarctic surface exposure dating

As part of the ITGC, I'm also measuring cosmogenic Be-10 in erratic cobbles collected from surfaces adjacent to Pine Island Glacier (recently submitted to Geology). Neighbouring Thwaites Glacier, Pine Island is of a comparable size and, owing to their vulnerability to future runaway retreat, the two glaciers are collectively known as the "weak underbelly of the West Antarctic Ice Sheet".

My main PhD work focussed on applying in situ C-14 surface exposure dating to investigate how ice in the Weddell Sea Embayment, Antarctica has changed over the last ~20,000 years (in The Cryosphere). I was involved in many of the papers listed below through measuring in situ C-14 in samples for external collaborators whilst working toward my PhD at Tulane University. 

Published papers: 

Offshore-onshore record of Last Glacial Maximum−to−present grounding line retreat at Pine Island Glacier, Antarctica. (Nichols et al., 2023; Geology)

New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica (Nichols et al., 2019; The Cryosphere)

New 10Be exposure ages improve Holocene ice sheet thinning history near the grounding line of Pope Glacier, Antarctica (Adams et al., 2022; The Cryosphere)

Holocene thinning of Darwin and Hatherton glaciers, Antarctica, and implications for grounding-line retreat in the Ross Sea (Hillebrand et al., 2021; The Cryosphere)

Late-glacial grounding line retreat in the northern Ross Sea, Antarctica (Goehring et al., 2019; Geology)

Glacial geology and cosmogenic-nuclide exposure ages from the Tucker Glacier - Whitehall Glacier confluence, northern Victoria Land, Antarctica (Balco et al., 2019; American Journal of Science)

Abrupt mid-Holocene ice loss in the western Weddell Sea Embayment of Antarctica (Johnson et al., 2019; Earth and Planetary Science Letters)