Synthetic diagram of palaeoenvironmental changes in the Antarctic Peninsula region for the past 4,000 years.

Interestingly, the lake hosted diverse biotic assemblages even during the cooler temperatures of the past ~2,000 years, a period known as the Neoglacial, characterised by glacier advances.

The lake record thus exhibits a long-term Antarctic greening trend from palaeolimnological perspective. /end

Camping near Monolith Lake, on the lee side of the large hyaloclastite boulders to find a shelter from the wind.

Monolith Lake with the Davies Dome in the rear.

By analysing these layers, akin to reading ice cores, we estimated the timing of deglaciation in this part of James Ross Island, near the J.G. Mendel Czech Antarctic Station.

Here, the glacier retreated ~2.5 ka ago, leaving behind blocks of hyaloclastite breccia, which gave the lake its name. 6/

Map of Monolith Lake catchment,

Additionally, we drilled into Monolith Lake bed and retrieved sedimentary cores.

We dated this lacustrine archive using another dating method, luminescence (OSL), which indicates when quartz sand grains were last exposed to sunlight before burial. 5/

linkinghub.elsevier.com/retrieve/pii...

Erratic boulder lying on the periglacial blockfield made of volcanic rocks, on the flat surface of Clearwater Mesa, actually a tuya formed in a subglacial volcanic eruption.

Sampling the material for surface exposure dating from the top of a large stable granite boulder, deposited by a glacier, on the Long Island, with the Antarctic Peninsula seen in the distance.

Our age constraints come from granitic erratic boulders left behind by retreating glaciers. We estimated duration of their surface exposure using cosmogenic radionuclides 10Be and 26Al. These nuclides begin to form in rock surfaces once the overlying ice no longer shields them from cosmic rays. 4/

Reconstruction of the palaeo-ice flow in one of the troughs adjacent to James Ross Island.

Around this time, global sea level rise from melting ice sheets at the end of the last Glacial period caused grounded ice to become buoyant and float.

This buoyancy led to accelerated retreat of the grounding line, where a glacier transitions to floating as an ice shelf or ice tongue. 3/

Map of the study area in the Antarctic, James Ross Island, with its glaciers, deglaciated areas, and bathymetry of the sea bed.

The fast-flowing, marine-based parts of the former ice sheet—or ice streams with the base below the sea level—retreated rapidly ~8,000 years ago.

This recession occurred after the oceans and air around Antarctica warmed enough to trigger glacier thinning. 2/

linkinghub.elsevier.com/retrieve/pii...

Outlet glacier of Mt. Haddington Ice Cap flowing into Croft Bay, in pastel colours of long Antarctic twilights.

Yesterday was Antarctica Day, so I find it opportune to recap the recent findings of our research there.

I was fortunate to participate, alongside @iceybethan.bsky.social, @geomikesh.bsky.social et al., in a quest to determine when and how Antarctic glaciers retreated after the last Ice Age. 1/

Aurora borealis also from Eryri (Snowdonia), one of international Dark Sky Reserves. Lucky to have been camping, awake, and under clear skies in Wales; unfortunate not having a better camera.

The Aberystwyth Old College, or Yr Hen Goleg in Welsh, emblematic landmark from the 18th century. Now the scaffolding sadly obstructs the view, but reconstruction should bring new life to the building.

Crimson sunset over the Ceredigion Bay and the town of Aberystwyth.

Winter sunset over Ceredigion Bay from my office window. Aberystwyth University.