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

Abstract

Abstract. Impressive glacio-archaeological evidence is described from the Miyar basin, Lahul Himalaya, India. Three ruins, namely Tharang, Phundang and Patam are identified along with evidence for past settlement and rich irrigation practices in the basin. These ruins are located in the end moraine complex of Tharang glacier, just ~ 2–3 km from the present glacier snout. Reconstruction of these ruins was undertaken based on mapping and radiocarbon (14C) dating. The radiocarbon dates (9 samples were dated) indicate that the settlement was occupied between cal AD ~ 1170 and cal AD ~ 1730, thereby encompassing the majority of Little Ice Age period. The settlement’s occupation at ~ 3700 m a.s.l. (whereas present habitation is restricted to areas below ~ 3500 m a.s.l.) for almost ~ 550 years during the 12th to 17th centuries suggest warmer conditions than today. Moreover, the study finds no evidence to suggest any noticeable glacier advance during this period.

Late Holocene Glacier Dynamics in the Miyar Basin, Lahaul Himalaya, India

“…Our assumption of a stable/semi-stable terminus position since the last~1000 years is supported by the fact that such places (Tharang end moraine complex) were inhabited and had settled agriculture, as suggested by the irrigated abandoned fields and ruins within 3 km of the present terminus. Ruins date to AD 1168-1726 [69], covering the whole LIA period and located on the KH-II stage end moraine complex. In addition, there are other proxies that reveal the paleoclimatic conditions across the Indian subcontinent.…”

“…Though this event of glacier advance has not been dated, we observed the existence of ancient human settlements near the Tharang end moraine complex and put them into the Little Ice Age (LIA) period [69]: three agricultural ruin sites with irrigation systems existed between 1168 and 1726 AD ( 14 C dates). Therefore, we believe that this advance may be a historical episode related to 200-250 years BP termed Bhujbas in Gangotri [68] and Sonapani-1 elsewhere in Lahaul [24,70].…”

“…This is because of a poorly constrained relationship between the meteorological and glacier conditions and the absence of continuous meteorological records. Thus, the ∆ELA obtained between different glacial stages is converted to relative temperature decline by multiplying the ∆ELA values by the widely used mean air temperature lapse rate of 6.5 • C/km, as has been done for Chhota-Shigri Glacier in the Lahaul Himalaya [69]. For the Miyar basin, we put the temperature decline at 3.9 • C for the local LGM, and at 2.7 • C for the early Holocene (Table 4).…”

Imagining Himalayan Glacial Futures

“…6 Th eir work echoed other publications that indicate the Himalayan glaciers are not acting in a uniform way (Armstrong et al 2019;Immerzeel et al 2012). A third article that Sharma published with additional co-authors (Saini et al 2016) cast further doubt onto past studies by stating that glaciers such as the Th arang in the Lahul Himalayas, India, were either in their current position or even 'further up-valley' during the Little Ice Age (circa 1300-1800). Th is claim allowed them to additionally question, and potentially undermine, the predominant narrative about runaway glacial melt in the contemporary Himalayas.…”

“…Th ese terminus points are oft en presented as barometers of ecological transformation that can be used to predict environmental futures. Yet, while many glaciers are retreating, a select number of high-altitude glaciers have expanded beyond their previously recorded terminus points (Kulkarni et al 2021;Saini et al 2016;Sharma and Chand 2015).…”