The retreat of the Antarctic Peninsula Ice Sheet since the Last Glacial Maximum provides key insights into ice-sheet dynamics, climate interactions and sea-level fluctuations. Terrestrial cosmogenic nuclide (TCN) dating of glacial deposits on the western Antarctic Peninsula (WAP) offers valuable temporal and spatial information regarding this retreat. However, many erratic deposits are found near the present sea level on the WAP archipelagos, limiting the applicability of TCN dating. This is because some of these deposits were previously submerged and later emerged due to ongoing post-glacial isostatic uplift and global sea-level rise. Here, for the first time on the Antarctic Peninsula, we present TCN dating results for emerged erratic boulders and bedrock samples located below the post-glacial marine limit of the WAP. Samples were collected from three islands along a latitudinal range from 64°S to 68°S: Nansen Island in Wilhelmina Bay (n = 4), Galindez Island in the Argentine Islands-Kyiv Peninsula region (n = 5) and Horseshoe Island on the northern coast of Marguerite Bay (n = 1). Our study indicates that nearshore boulder emergence occurred sometime between 1.4 ± 0.3 and 3.8 ± 0.3 ka ago on the WAP. The bedrock samples on Galindez Island provide somewhat older ages (17.9 ± 2.8 and 11.8 ± 1.9 ka), indicating the earliest emergence following deglaciation of the WAP. We discuss the challenges associated with sampling emerged erratic boulders along the Antarctic Peninsula shorelines and propose methods for overcoming these complications.

The ‘Maritime Endangered Archaeology’ (MarEA) project is conducting remote, large-scale identification and assessment of vulnerable maritime heritage to assist in its management in the face of challenges such as climate change and rapid urbanisation.

Most glaciers in the British Columbia Coast Mountains reached their maximum Holocene extent during the Little Ice Age. Early- and late-Little Ice Age intervals of expansion and retreat fluctuations describe a mass-balance response to changing climates. Although existing dendroclimatic records provide insights into these climatic fluctuations over the last 400 yr, their short durations prohibit evaluation of early-Little Ice Age climate variability. To extend the duration of these records, submerged coarse woody debris salvaged from a high-elevation lake was cross-dated to living chronologies. The resulting chronology provides the opportunity to reconstruct a regional June–July air-temperature anomaly record extending from AD 1225 to 2010. The reconstruction shows that the intervals AD 1350–1420, 1475–1550, 1625–1700 and 1830–1940 characterized distinct periods of below-average June–July temperature followed by periods of above-average temperature. Our reconstruction provides the first annually resolved insights into high-elevation climates spanning the Little Ice Age in this region and indicates that Little Ice Age moraine stabilization corresponds to persistent intervals of warmer-than-average temperatures. We conclude that coarse woody debris submerged in high-elevation lakes has considerable potential for developing lengthy proxy climate records, and we recommend that researchers focus attention on this largely ignored paleoclimatic archive.