The ‘Little Ice Age’ in the Himalaya: A review of glacier advance driven by Northern Hemisphere temperature change

Abstract

Northern Hemisphere cooling between 1400 and 1900 in the Common Era (CE) resulted in the expansion of glaciers during a period known as the 'Little Ice Age' (LIA). Early investigation of recent advances of Himalayan glaciers assumed that these events were synchronous with LIA advances identified in Europe, based on the appearance and position of moraines and without numerical age control. However, applications of Quaternary dating techniques such as terrestrial cosmogenic nuclide dating have allowed researchers to determine numerical ages for these young moraines and clarify when glacial maxima occurred. This paper reviews geochronological evidence for the last advance of glaciers in the Himalaya. The 66 ages younger than 2000 years (0-2000 CE) calculated from 138 samples collected from glacial landforms demonstrate that peak moraine building occurred between 1300 and 1600 CE, slightly earlier than the coldest period of Northern Hemisphere air temperatures. The timing of LIA advances varied spatially, likely influenced by variations in topography and meteorology across and along the mountain range. Palaeoclimate proxies indicate cooling air temperatures from 1300 CE leading to a southward shift in the Asian monsoon, increased Westerly winter precipitation and generally wetter conditions across the range around 1400 and 1800 CE. The last advance of glaciers in the Himalaya during a period of variable climate resulted from cold Northern Hemisphere air temperatures and was sustained by increased snowfall as atmospheric circulation reorganised in response to cooling during the LIA.

Heterogeneous Influence of Glacier Morphology on the Mass Balance Variability in High Mountain Asia

“…However, debris‐covered and debris‐free glaciers have mostly similar , meaning that they have to respond through different mechanisms to climate changes. The debris‐covered glaciers thin differently from the debris‐free glaciers: debris‐covered glacier thinning is distributed over their lower reaches independently of the elevation, whereas debris‐free glaciers preferentially experience front retreat (Rowan, ; Rowan et al, ; Salerno et al, ). Consequently, the ice dynamics play a major role for the evolution of debris‐covered tongues, and the stable front positions of debris‐covered glaciers should not be interpreted as balanced mass budget (Scherler et al, ).…”

“…M, meaning that they have to respond through different mechanisms to climate changes. The debris-covered glaciers thin differently from the debris-free glaciers: debris-covered glacier thinning is distributed over their lower reaches independently of the elevation, whereas debris-free glaciers preferentially experience front retreat (Rowan, 2017;Rowan et al, 2015;Salerno et al, 2017). Consequently, the ice…”

Glacio-archaeological evidence of warmer climate during the Little Ice Age in the Miyar basin, Lahul Himalaya, India

“…This probably indicates that Neoglaciation in this part of the world was result of climatic mechanism (Monsoon) that dominates in Eastern Himalaya. The chronological records for the last millennium suggest that LIA existed here between 1300 and 1900 rather than 1300-1600 (Rowan, 2016). Spatially 30 the duration of LIA was short (between 1300 and 1600) in Eastern Himalaya (up to Everest) whereas beyond Middle Himalaya to Tian Shan the LIA records are found prolonged between 1300 and 1900 AD ( fig.6).…”

“…Recent review studies made an attempt to generate the chronological history of this area. Xu and Yi, (2014) reviewed available dates of LIA moraines in and across Tibet plateau whereas Chen et al, (2015) synthesised the proxies of moisture/precipitation in China and surrounding and Rowan, (2016) made an attempt to review the geochronological evidence for the LIA glacier advance in Himalaya. These studies reported asynchronous pattern of glacier 15 attaining their maximum extent (mostly by 1300-1600 AD) in the last millennium.…”

The Himalayan cryosphere: past and present variability of the ‘third pole’

“…during the LGM, which corresponds to the lowering of annual temperature by 8-10°C (Kuhle 2005). Other researchers have noted the synchronous expansion of Himalayan glaciers during the Little Ice Age (Rowan 2017), suggesting overlap with the global climatic conditions. Increasing the resolution clearly requires additional data and studies.…”