Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-06-23
1.-THE GLACIERS OF ALASKA
SOME GREATER EVEN THAN THOSE
OF SWITZERLAND.
Flowers and Forests Growing Above
the Ice Fiords and Mountains
shaped by Glacial Action.
Henry Gannett in Bulletin of the American Geo
graphical Society.

lands, is mountainous = The land every
where rises abruptly from the sea to sum-
mts ranging from 5000 to 1s.o0O feet high.
The mountain slopes are very steep, the
higher submits are extremely rugged and
thousands of them are totally inaccessible.
Level land near the coast is almost I'M
known. except at the heads of the fiords,
which continue inland as valleys or can
yons with precipitous walls.
The most prominent fact connected with
the coast region of southern Alaska-indeed
of the northwest coast of North America,
from Puget sound to the end of the Alas
kan peninsula, is that its features are al
most wholly the product of glacial action.
Not only are its tiordS the abandoned chan
nels Of glaciers, but its hills and noun
tains were shaped by them, and recent
is the retreat of the glaciers that but little,
if any, of the work of the atmosphere and
of streams is thus far to be seen superim-
posed upon the glacial work. There is prob
ably nowhere on earth an equal area in
which the relief features are so purely the
product of glacial erosion and in which
aqueous erosion has done so little. The re-
mains of the enormous glacial system
which at one time covered practically this
whole area are now existent in the form of
hundreds of glaciers. While these are pyg-
mics in comparison with their progenitors,
scores of them exceed in magnitude the
celebrated ones of Switzerland Taken as
a whole, the region is one affording I'M
equaled facilities for studying the work of
glaciers, both in action and by their ac-
complished results.
The fiords present everywhere the charac-
teristic cross section of a glacier-cut gorge,
with steep, almost precipitous walls. be-
coming gradually less steep toward the
bottom. which is nearly level. giving the
common U-shaped section. The floors of
the gorges of branches are commonly at
higher level than the main ford. so that
they open upon it at attitudes of hundreds
or even thousands of feet above it. This
phenomenon, nearly universal and so
striking, has only recently been noted
AT the time these branch gorges were
formed the surface of the ice in them and
In the main gorge was necessarily at the
same level and the difference in elevation
of the floors of the gorges measured the
difference in the thickness of the ice of the
main and branch gorges. For if the surface
of the ice in the branch We're for any con-
siderable time at a higher level than that
of the main gorge the former would cut
its gorge down SO as to bring the surfaces
a level. 1t is furthermore manifest that
the surface of the ice in the side gorge
could not exist at a lower level than that
of the main gorge, as in that case the lat
ter would overflow into 1t. Hence the
gorges of the main and branch glaciers
represent a status which persisted for a
long time. and the recession of the glacier
must have been accomplished rather rap
idly, as otherwise the branch would have
had time to cut deeply into the wall of the
main gorge.
On the Alaska coast are seen fine exam
pies of these gorges In all stages. from
those wherein the main and tributary
gorSeS are both filled with moving ice and
the sorges are in process of formation to
those in which all the gorgns main and
branch. have been abandoned by Iceland Of
these perhaps the most striking those
where the ice in the main gorge has re-
treated beyond the mouth of the tributary
which now dtscends in cascades of ice over
the lip OF the main gorge Fine examples
of this were seen in Russell ford and in
Port Wells, Prince William sound are sew
eral small glaciers formerly tributary 10
that in the head of the inlet. which are now
cascading down the walls of the ford into
the water, from which the msrin glacier has
retreated. The straghtness of the fords
the reflections in their courses produced by
the junction with large branches. also
stamp them Enthusiastically as glacier cut.
There are no glaciers of magnitude in the
Islands of southeastern Alaska, although
their relief forms were throughout carved
by glaciers The large living glaciers are
confined to the mainland.
Glaciers exist in the mountains bordering
the coast from Dixon entrance westward
nearly to the end Of the Alaska peninsula,
but east of Glacier bay none of them de-
scend to the sea. although many are of
great magnitude, among them the Patter-
son, on Frederick sound. and the David
son. in Lynn canal both of which nearly
reach the sea and doubtless not long ago
We're discharging icebergs into it. The ex-
listing glaciers of the Alaskan coast may be
grouped in two classes-those whose fronts
reach the sea and discharge icebergs and
those which do not. The first may be call
ed living. the latter dead. OF the former
the expedition saw and examined no fewer
than twenty-five. including six in Glacier
bay, the Muir. Grand Pacific. Johns Hop
kins. Reid. Charpentier and Hugh Miller;
the Crillon, from the Fairweather range;
three in fakutat bay and Russell ford. the
Hubbard, Dalton and Nunatak, and twelve
In Prince William sound, including the Co
lumbta. In Columbia bay; the Harvard.
Yale. Smith. Bryn Mawr. Vassar and Wei
lesley. in Port Wells. and the Hartman,
Surprise, Serpentine. Cataract and Wash
ington. in Hartman ford
OF the latter class there many hun
dreds. ranging in size from the Great NAL
aspina a lake of Ice sixty miles by thirty.
and fed by scores Of ice streams from the
St. Elias Alps. down to little streams flow
ing down the mountain gorges two or three
miles only In length.
Among the many interesting questions
propounded by the glaciers was that of
their present movement. whether 1t be adj
vance or recession. That In past times
they have greatly receded is shown by
their abandoned channels. the fiords which
make up the entire Alaskan coast and by
the tiord-shaped valleys which characterize
the inshore topography.
Examination of the neighborhood OF eX-
listing glaciers shows that on the whole
they are. with few exceptions sun feceu-
ing. This recession is probably not regular
or continuous. since every winter shows an
advance and every summer a recession ana
since year of heavy snowfall induces
temporary advance. while hot or dry year
produces an abnormally large recession:
still all signs indicate in the case OF every
glacier examined. with one exception the
Crilon). that on the whole they are still re-
treating. The stretch of bare. naked land.
both of valley and mountain slope not yet
covered with vegetation. extending outward
from the glacier front, is in itself sufficient
evidence of this retreat. In the case of
Muir glacier. which is the pest known. the
amount of recession has beeN directly meas
ured. since the front of the glacier has been
mapped at different times by Muir, Reid
and Wright. Here we find recession of
two miles in the last twenty years, and
reduction in the level of its surface of three
hundred feet in the same time.
The glaciers of Alaska take. various forms.
The simple form of stream of ice flowing
down a II puntain gorge, with tributaries
from nelghboring gorges, is common. But
the greater glaciers usually take the form
of a lake of Ice occupying a broad valley
a plateau. fed by streams Of Ice from the
surrounding mountains. and drained by out
lets in one two or more directions. OF this
type the Muir is fine example. 1t occu-
pies broad valley having a gentle slope
to the south, east and wes.: is fed by
streams from the mountains on the north.
east and west, and has three outlets, by the
Davidson glacier to LYNN canal by a gla-