Asynchronous Holocene behavior of mountain glaciers in the European and Southern Alps

Unraveling global patterns of Holocene climate variability is important for deciphering possible causes, and for placing industrial-age warming and mountain-glacier retreat into a robust palaeoclimatic context. Here we present a 10Be moraine chronology and palaeo-snowline-derived summer temperature reconstruction for the last ~11,000 yrs in the Southern Alps of New Zealand. We compare this southern glacier record to the well-documented Holocene glacier signature on the opposite side of the planet in the European Alps. Our moraine record suggests that Southern Alps mountain glaciers tracked snowline changes over the Holocene that were asynchronous with snowline changes in the European Alps. The lack of a clear LIA signal (as defined from the European Alps) in the Southern Alps also implies that sub-millennial North Atlantic climate switches were not globally synchronous. We discuss the roles of orbital variability and oceanic/atmospheric mechanisms in driving such asynchronous glacier behavior at these antipodean locations. Finally, we consider that net glacier retreat in the Southern and European Alps since the early 20th century is anomalous in the context of asynchronous glacier fluctuations at these two locations over the Holocene.