Man and the Glacial PeriodWright, G. Frederick (George Frederick)
History
Man and the Glacial Period
Wright, G. Frederick (George Frederick)
Glacial epoch; Prehistoric peoples
We are now able to demonstrate that a movement of ice from the central
regions of Greenland to the coast continually goes on, and must be
supposed to act upon the ground over which it is pushed so as to detach
and transport fragments of it for such a distance.... The plainest idea
of the ice-formation here in question is given by comparing it with an
inundation.... Only the marginal parts show irregularity; towards the
interior the surface grows more and more level and passes into a plain
very slightly rising in the same direction. It has been proved that,
ascending its extreme verge, where it has spread like a lava-stream over
the lower ground in front of it, the irregularities are chiefly met with
up to a height of 2,000 feet, but the distance from the margin in which
the height is reached varies much. While under 68-1/2° north latitude it
took twenty-four miles before this elevation was attained, in 72-1/2° the
same height was arrived at in half the distance....
A general movement of the whole mass from the central regions towards the
sea is still continued, but it concentrates its force to comparatively
few points in the most extraordinary degree. These points are represented
by the ice-fiords, through which the annual surplus ice is carried off
in the shape of bergs.... In Danish Greenland are found five of the
first, four of the second, and eight of the third (or least productive)
class, besides a number of inlets which only receive insignificant
fragments. Direct measurements of the velocity have now been applied on
three first-rate and one second-rate fiords, all situated between 69°
and 71° north latitude. The measurements have been repeated during the
coldest and the warmest season, and connected with surveying and other
investigations of the inlets and their environs. It is now proved that
the glacier branches which produce the bergs proceed incessantly at a
rate of thirty to fifty feet per diem, this movement being not at all
influenced by the seasons. . . .
In the ice-fiord of Jakobshavn, which spreads its enormous bergs over
Disco Bay and probably far into the Atlantic, the productive part of the
glacier is 4,500 metres (about 2-1/2 miles) broad. The movement along its
middle line, which is quicker than on the sides nearer the shores, can
be rated at fifty feet per diem. The bulk of ice here annually forced
into the sea would, if taken on the shore, make a mountain two miles
long, two miles broad, and 1,000 feet high. The ice-fiord of Torsukatak
receives four or five branches of the glacier; the most productive of
them is about 9,000 metres broad (five miles), and moves between sixteen
and thirty-two feet per diem. The large Karajak Glacier, about 7,000
metres (four miles) broad, proceeds at a rate of from twenty-two to
thirty-eight feet per diem. Finally, a glacier branch dipping into the
fiord of Jtivdliarsuk, 5,800 metres broad (three miles), moved between
twenty-four and forty-six feet per diem.[AK]
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account