Glaciers and climate in Pacific Far NE Russia during the Last Glacial Maximum

Abstract

A combined geomorphological-physical model approach is used to generate three-dimensional reconstructions of glaciers in Pacific Far NE Russia during the global Last glacial Maximum (gLGM). The horizontal dimensions of these ice masses are delineated by moraines, their surface elevations are estimated using an iterative flowline model and temporal constraints upon their margins are derived from published age estimates. The equilibrium line altitudes (ELAs) of these ice masses are estimated, and gLGM climate is reconstructed using a simple degree-day melt model. The results indicate that, during the gLGM, ice masses occupying the Pekulney, Kankaren and Sredinny mountains of Pacific Far NE Russia were of valley glacier and ice field type. These glaciers were between 7 and 80 km in length, and were considerably less extensive than during pre-LGM phases of advance. gLGM ice masses in these regions had ELAs of between 575 AE 22 m and 1035 AE 41 m (above sea level) -corresponding to an ELA depression of 350-740 m, relative to present. Data indicate that, in the Pekulney Mountains, this ELA depression occurred because of a 6.48C reduction in mean July temperature, and 200 mm a À1 reduction in precipitation, relative to present. Thus reconstructions support a restricted view of gLGM glaciation in Pacific Far NE Russia and indicate that the region's aridity precluded the development of large continental ice sheets.

Testing the efficacy of the glacial buzzsaw: insights from the Sredinny Mountains, Kamchatka

“…Comparison between attributes was made at a basin scale, whilst regional variations were considered by plotting transects and producing interpolated (kriged) surfaces. Barr and Clark, 2011); and (C) cirque distribution (N = 43), in the SE sector of the Sredinny Mountains. Here, the drainage basin is 825 km 2 , gLGM ice extent covers 603 km 2 , and the cirques cover a total area of 33 km 2 .…”

“…The Sredinny are currently occupied by a number of small cirque-type glaciers, and evidence suggests that, during the past 140 ka, the mountains were entirely ice covered on at least two separate occasions, with glaciers extending off-shore and terminating in the Sea of Okhotsk and the North Pacific (see Bigg et al, 2008;Nürnberg et al, 2011;Barr and Clark, 2012a,b), though the duration and timing of these events remains uncertain (see Bigg et al, 2008;Barr and Clark, 2012b). During the global Last Glacial Maximum (gLGM; ~ 21 ka) specifically, the region was occupied by an ice field (~ 57,363 km 2 ) that covered ~ 92% of the mountain range (Barr and Clark, 2011) (see Fig. 1B).…”

“…3. (B) The extent of glaciation in the Sredinny Mountains during the global Last Glacial Maximum (according to Barr and Clark, 2011).…”

Extensive glaciation in Transbaikalia, Siberia, at the Last Glacial Maximum

“…The lack of either geochronology or systematic mapping of the glacial geomorphology has kept Transbaikalia as an empty space on the map between the more closely studied regions of the south Siberian mountains (e.g., Lehmkuhl et al, 2004;Komatsu et al, 2007a, b;Lehmkuhl et al, 2007;Gillespie et al, 2008;Lehmkuhl et al, 2011;Arzhannikov et al, 2012;Zhao et al, 2013) and the mountains of far north-east Russia and the Kamchatka peninsula (e.g., Brigham-Grette, 2001;Bigg et al, 2008;Stauch et al, 2007;Stauch and Gualtieri, 2008;Stauch and Lehmkuhl, 2010;Barr and Clark, 2011;2012). This knowledge gap motivated the mapping survey of …”

A review of topographic controls on moraine distribution

“…This approach relies on chronologically grouping moraines that are assumed to have been deposited synchronously. The processes involved in this grouping are rarely formalised but often involve consideration of moraine morphostratigraphy, location within the landscape, or relative position in a regional sequence (Kerschner and Ivy-Ochs, 2008;Barr and Clark, 2011;Heyman et al, 2011). However, this approach relies on assumptions about moraine deposition and preservation that, as demonstrated in this paper, are not always valid.…”