PLEISTOCENE GLACIATION IN THE SHANKALPA DIVIDE
M. K. BANDYOPADHYAY
THE area is located approximately between latitudes 30° 15' N. and 30° 28'N. and longitudes 80° 15' E. and 80° 25' E. It is a part of the Munsiari subdivision of the Pithoragarh district of eastern U.P. The Shankalpa Divide lies in northwest-southeast direction and extends for about twenty kilometres from Bamba Dhura to beyond Rajrambha and gives rise to a large number of glaciers on either side of it.
The main glaciers on the west side of the divide are (1) Kalabaland, (2) Yankchar, (3) Shankalpa, (4) Shivu, and (5) Rajrambha. The eastern side of the divide contains a still larger number of glaciers namely Chiringtashi, Chiring Mabang, Nassa, Damolia, Ghugtan, Jhulang, Nipchukang, Yarkand and Ngalphu glaciers.
There are a large number of high peaks on the divide which separate the two sets of glaciers. The most important amongst them are Bamba Dhura (6334m), Chiring We (6559m), Suli Top (6300m), Sui Tilla (6333m), Rimla We (6242m), Lachar We (6291 m), Chaudhara (6510m) and Rajrambha (6527 m).
The largest glacier in the area is the Kalabaland glacier which originates from the Bamba Dhura-Chiring We section of the divide and flows in a southeasterly direction.
The Kalabaland Dhura peak lies in the direction S. 30° W. from the Bamba Dhura peak and is located at a straight line distance of about 3 km from it. To the NW. of the Bamba Dhura-Kalaba- land Dhura line lies the snow-covered divide which separates the Kalabaland from the Kalganga glacier, the latter flows in the opposite direction and contributes directly to the flow of the Gori Ganga. In fact, this divide may be regarded as the source of the Kalabaland glacier. It is an asymmetrical arcuate arete whose steeper slope faces! the northwestern side, i.e. the Kalganga glacier, and the gentler slope forms the uppermost part of the Kalabaland glacier on the southeast. Incidentally, the steeper side is the convex side of the arc, whereas the gentler, i.e. southeastern side, is concave in plan. The steep slope on the northwest causes frequent avalanches especially after heavy snowfall whereas the southeast face has a smooth and gentle snow surface which offers little resistance to climbing. Even during the driest period of the year the arete remains concealed under a thick cover of ice. The Shankalpa divide forms a sharp-crested ridge at places, particularly in the areas where two glaciers drain its surface on opposite slopes. There are several peaks on the divide such as Suli Top, Sui Tilla, etc., which are glaciated from all sides.
Several small cirque glaciers exist on the south-facing slope of the Shankalpa divide which faces the Kalabaland glacier.
The whole area between the Bamba Dhura-Chiring We peaks and about two kilometres down from the arete, may be regarded as the main snowfield or feeding ground of the Kalabaland glacier. Annual precipitation as well as avalanches from the main peak supply snow to this snowfield which, in turn, feeds the Kalabaland glacier. There are several steps along the course of the glacier. One such step lies below the Bamba Dhura-Chiring We line. It is aligned in a north-south direction and steps down from the east to the west. Several crevasses occur in the step-zone. The second step lies along the Chiring We-Kalabaland Dhura line and steps down from the northwest to the southeast. The fall is about 200 m in 500 m or 2 in 5. This area may be regarded as the starting point of the glacier at the lower end of the snowfield. Several oblique and tranverse crevasses are formed in the area which reflect the irregularity of the underground topography. Another icefall zone occurs in the middle course of the glacier where the slope is approximately of the same nature as in the upper zone. Crevasses in the area are mostly of transverse nature. In the uppermost part of the icefall several oblique crevasses also have formed. A. zigzag route has to be taken by mountaineers to cross this icefall zone. Starting from the bottom of this icefall the rest of the glacier body has a gentle surface. Very few crevasses are found in this area and approach to higher elevations is quite easy.
It is interesting to note that snowline in the area lies just above this icefall at an elevation of about 5200 m whereas the general elevation of the snowline in the central Himalaya is much above it. It is probably because of the southeasterly exposure of the glacier where the monsoon can penetrate easily.
Lateral and medial moraines have formed prominent features on the glacier surface downward from the bottom of the icefall. No trace of moraine is found above the icefall. Ridges of lateral and medial moraines continue for several kilometres. Moraines in this area are contributed not only by the main glacier but also from the side glaciers. The tributary glaciers are short but have steeper slopes and have tremendous power of eroding the sides of the mountains. They erode the materials from the upper slopes and transport them downward. Even the englacial and subglacial materials are exposed to the surface of the glacier in the zone of ablation. Thus there is a great concentration of moraines in the lower part of the glacier. This is particularly found in the Shankalpa glacier which is nothing but the combined volume of the Kalabaland and the Yankchar glaciers. The Shankalpa glacier is covered by a thick cover of surface moraine which makes it difficult terrain for climbing.
The Yankchar glacier has its source at Ralam Dhura Pass (5630 m) which is located between the Rimla We (6242 m) and the Laehar We (6299 m) and is supposed to be the easy track across the divide though it lies above the perpetual snow line. As a contrast to the general characteristics of the area the Yank- char glacier has a very steep slope in the snowfield area whereas the whole length of the glacier has a very gentle slope. The Rimla We-Lachar We divide, which contains the Ralam Dhura pass, is nothing but a snow-covered arete which has a symmetrical slope. The arete is formed by glacial sapping caused by the head- ward retreat of the Nipchukang glacier on the east and the Yank- char glacier on the west. The slope of the snowfield in the upper part of the Yankchar glacier faces west but the glacier itself occupies a north-south trough almost throughout its whole length. Very few crevasses have formed on its surface. This indicates that the bottom of the trough occupied by the glacier is a smooth one and very little undulations exist on its surface. The lower part of the glacier is aligned, in an east-west direction where it meets the Kalabaland glacier and then turns at right angles to the south to form the Shankalpa glacier. This appears to be somewhat abnormal where two relatively large glaciers meet from opposite directions and form one small outlet.
The present length of the Shankalpa glacier from the meeting point of the Yankchar-Kalabaland glaciers is about 3500 m. Its surface is covered by large and small glacial boulders. There is very little cover of fresh snow on its surface during the dry period. The valley pattern, surface topography and especially the break of slope on the cross-profile and other topographic characteristics of slope on the crossprofile and other topographic characteristics suggest that during the late pleistocene period the Shankalpa glacier came down the Ralam Gad even beyond the Ralam village and probably down to Wabi. Also there is evidence of glacier advance down to Galpar Thaur during the Little Ice Age. Above all, lichenometric evidences suggest that the glacier snout was located at Shankalpa only about sixty years ago. This means that the glacier has retreated by about 1200 m within a period of sixty years only. Retreat of the glacier at such an alarming rate may lead to serious consequences in the lower reaches of the river. It is, therefore, necessary to continue such glaciological studies in the surrounding areas, taking into consideration the major tributaries of the Gori Ganga in order to see if such rate of retreat of the glaciers is of regional character and if it may lead to any serious ecological imbalance in the lower parts of the basin.
Characteristics of the Glaciers of the Shankalpa Divide (West) Area
||Name of the
Length (km) Breadth
|NW to SE
||S to N
|Snout 3720 Source 6355
|NNE to SSW
|Snout 4190 Source 6511
|E to W (upper) SE to NW (lower part)
||E to W
NE to SW (lower part)
NOTE : The first three glaciers in fact form one single glacier; the Kalabaland and Yankchar join together and form the snout which is named Shankalpa glacier. This is somewhat unusual in glacier literature.
|Condition of Crevasse
|Lower part smooth, middle & upper part highly cre- vassed with icefalls
||Dangerous icefall in middle portion and also in upper part. Smooth up to 4680 m. At 4600, 5400 & 6000 m ice-wall.
||Several parallel lines of lateral and medial moraine in lower part; none in upper part
||Easy in lower part. Difficult in middle part due to icefall and crevasses. Less difficult in upper part
|Only in upper parts
||At 4800 m and 5200 m
||Two prominent and continuous ridges of medial moraine
||Excellent in lower part. Icefall in upper part.
||Three ridges of lateral and medial moraine
|Only in icefall in upper part
||4600 m & up
||Four ridges in lower part; none in upper part
||Moderate slope in lower part; very steep ice- wall in upper half.
|Very few in lower part. A few in upper part
||4400 m and up
||No prominent moraine except one right lateral fixed in lower part
||Moderate slope with small breaks in lower part; very steep ice-wall in upper part
See Sketch map and article 'Mountain of Long Life' and note, 'First ascent of Bamba Dhura' in the present journal-Ed.