If the subglacial streams flowed under "head," the pressure was relieved when they escaped from the ice.
It is to be kept in mind that subglacial drainage was operative during the advance of an ice sheet, during its maximum extension, and during its retreat, and that during all these stages it was effecting its appropriate results.
Where the subglacial streams did not follow subglacial valleys, they did not always find valleys when they issued from the ice.
Such drift would tend to increase the body of marginal stratified drift from subglacial sources.
When subglacial streams were confined to definite channels, the same may have been constant in position, or may have shifted more or less from side to side.
Subglacial till was under the pressure of the overlying ice.
The subglacial streams doubtless flowed, in part, in the valleys which affected the land surface beneath the ice, but they were probably not all in such positions.
Subglacial waters may have made deposits of stratified drift on surfaces which had been covered by ice, but not by till, and such deposits may have been subsequently buried.
The harder ones yielded less readily to abrasion, and were carried much farther before being destroyed, though even such must have suffered constant reduction in size during their subglacial journey.
In this work the freezing and thawing of subglacial waters in any cracks and crevices of the rock no doubt play an important part.
The streams which drain the glacier have cut their courses in englacial and subglacial tunnels; none flow for any distance on the surface.
These wells lead into chambers and tunnels by which sooner or later their waters find way to the rock floor of the valley and there unite in a subglacial stream.
Subglacial streams, like those of the Malaspina glacier, issued from tunnels in the ice, and water ran along the melting ice front as it is seen to do about the glacier tongues of Greenland.
Subglacial Stream Issuing from Tunnel in the Ice, Norway] =The lower limit of glaciers.
Where the glaciers or ice-caps passed over the summits of the hills the subglacial streams penetrated the limestone of the mountain and formed vast caverns, such as that of Niaux, near the river Ariege.
The materials of these moraines are more rounded fragments of rock which have come up from the bottom layers, and we shall again refer to the origin of such moraines after the subglacial conditions have been considered.
This occurs either in subaqueous or in subglacial deposits.
After flowing for a distance in channels on the surface, they, one and all, plunged with deafening roar into some yawning crevasse, to find their way to the sea through subglacial channels.
Of course, erosion in Scandinavia meant subglacial deposition beyond the Baltic.
At other times the stream has disappeared far back in the glacier, and plunged into a crevasse (technically called a moulin), whence it flows onwards as a subglacial stream.
Within the area in England and Wales covered by the Irish Sea Glacier all the phenomena point to the action of land-ice, with the inevitable concomitants of subglacial streams, extra-morainic lakes, etc.
Such subglacial rivers appear to have been formed along the margins of all the great glaciers.
Not far from the Grand Moulin of the Mer de Glace in 1857 there was a second empty shaft, which evidently communicated by a subglacial duct with that into which the torrent was precipitated.
A subglacial lake had burst its boundary, and carried along with it in its rush downwards the debris which it met with in its course.
There is a strangeness about the place which repels you, and not without anxiety do you look from your ledge into the darkness below, through which the sound ofsubglacial water sometimes rises like the tolling of distant bells.
Strange subglacial noises were sometimes heard, as if caverns existed underneath, into which blocks of ice fell at intervals, transmitting the shock of their fall with a dull boom to the surface of the glacier.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "subglacial" in a variety of sentences. We hope that you will now be able to make sentences using this word.
