GLACIATIONS | Late Quaternary of the Southwest Pacific Region

Trench floor depositional response to glacio-eustatic changes over the last 45 ka, northern Hikurangi subduction margin, New Zealand

“…The staggering maximum rate of ~10 m/kyr occurs at ~21 ka (41 mbsf) during the peak of the LGM (Fig. 4; Barrell et al 2013;Lambeck et al 2014;Williams et al 2015). The SAR reduces to 3.5 m/kyr between 22-24 ka (49-57 mbsf) and returns to very high values of 8-9 m/kyr through the sandy interval between 24-29 ka (57-95 mbsf).…”

“…Hikurangi Trough terrigenous sediments are sourced from both the South (today primarily from Kaikōura and Cook Strait canyons) and North islands (including Madden and Māhia canyons), with rates fluctuating significantly over glacial-interglacial cycles (Lewis et al 1998;Lewis and Barnes, 1999;Berryman et al 2000;Eden et al 2001;Carter and Manighetti, 2006;Carter et al 2008;Alloway et al 2007;Mountjoy et al 2009Mountjoy et al , 2013Pouderoux et al 2012a;Barrell, 2013;Upton et al 2013;Claussmann et al 2021Claussmann et al , 2022. Furthermore, large earthquakes (MW >7.0), internal tides, and stormassociated hyperpycnal flows can trigger turbidity currents, debris flows, and slumps, reworking and transporting large amounts of sediment to the trough (Pouderoux et al 2012b;Kuehl et al 2016;Mountjoy et al 2018Mountjoy et al , 2020Howarth et al 2021).…”

The glacial history of Rocky Top cirque, southeast Fiordland, New Zealand

“…One such period of re-advance was the Antarctic Cold Reversal (14.5-12.5 ka), a cool interval with a temperature reduction of 2-3°C relative to present-day (Putnam et al, 2010a;Kaplan et al, 2013). By the Holocene (~11,700 ka) temperatures in New Zealand had risen to similar levels as preindustrial and glaciers had significantly retreated into the Southern Alps (Barrell et al, 2013a). Glaciers experienced episodic mass balance fluctuations during the Holocene in response to (sub)millennial-scale climatic events such as the Little Ice…”

“…Despite recent progress, precisely-dated, quantitative paleoclimate reconstructions in New Zealand remain relatively limited. Records tend to be focused in the central Southern Alps (Barrell et al, 2013a). It is important to extend the spatial range of paleoclimate records, to better examine past climate in different settings and the variation in natural climate variability.…”