Slike strani
PDF
ePub

A

CHAPTER IV.

Climate and Agricultural Resources.

LASKA may be divided agriculturally into three districts; each differing from the others in its climate, vegetation, and physical characteristics. The first and most northern district, which I have termed the Yukon Territory, is bounded on the south by the Alaskan Mountains, on the east by the British boundary line, and on the north and west by the Arctic Ocean and Bering Sea.

The second or middle district, which may be called the Aleutian District, includes that part of the peninsula of Aliáska, and all the islands west of the one hundred and fifty-fifth degree of longitude.

The third or southernmost, which will be designated as the Sitkan District, includes all our possessions on the mainland and islands south and east of the peninsula of Aliáska.

The Yukon Territory. - The character of the country in the vicinity of the Yukon River varies from low, rolling, and somewhat rocky hills, usually easy of ascent, to broad and rather marshy plains, extending for miles on either side of the river, especially near the mouth. There are, of course, no roads, except an occasional trail, hardly noticeable except by a voyageur. The Yukon and its tributaries form the great highways of the country.

The rocks vary, the greater proportion being conglomerate, sienite, quartzite, and sandstone. Trachyte and lava abound in particular districts. The superincumbent soil also differs, in some localities being sandy, and in others clayey. In the latter case it is frequently covered with growth of sphagnum, which causes a deterioration of the soil below it. Over a large extent of country it is a rich alluvial, composed of very fine sand, mud, and vegetable matter, brought down by the river, and forming depos

its of indefinite depth; and in some such localities fresh-water marl is found in abundance.

The soil is usually frozen at a depth of three or four feet in ordinary situations. In colder ones it remains icy to within eighteen inches of the surface. This layer of frozen soil is six or eight feet thick; below that depth the soil is destitute of ice, except in very unusual situations.

This phenomenon appears to be directly traceable to want of drainage, combined with a non-conductive covering of moss, which prevents the scorching sun of the boreal midsummer from thawing and warming the soil.

In places where the soil is well drained, and is not covered with moss, as in the large alluvial deposits near the Yukonmouth, I have noticed that the frozen layer is much farther below the surface, and in many places appears even to be en: tirely wanting.

I have no doubt, that, in favorable situations, by draining and deep ploughing, the ice could, in the course of time, be wholly removed from the soil.*

A singular phenomenon on the shores of Escholtz Bay, Kotzebue Sound, was first observed and described in the voyage of the Rurik by Kotzebue and Chamisso, and afterward in the Appendix to the Voyage of the Herald by Buckland and Forbes.

It consists of bluffs or banks (30 to 60 feet high) of apparently solid ice, fronting the water, which washes on a small beach. formed by detritus, at the foot of the bank. These continuous banks of ice, strange to say, are covered with a layer of soil and vegetable matter, where, to use the words of the renowned botanist, Dr. Seemann, "herbs and shrubs are flourishing with a luxuriance only equalled in more favored climes."

Kotzebue's account is exaggerated and highly colored, as is

* Aiton (Treatise on Peat Moss, &c., see Ed. Ency., Vol. XVI. p. 738) has ascribed the cold and rainy climate of Scotland partly to the accumulations of sphagnum. "Thirty-two and a half ounces of dry moss soil will retain without fluidity eighteen ounces of water; whilst thirty-nine ounces of the richest garden mould will only retain eighteen and a half ounces. Moss is also more retentive of cold than any other soil. Frost is often found (in Scotland) to continue in deep mosses until after the middle of summer. Hence the effect of mossy accumulations in rendering the climate colder."

everything he has written; but the facts were confirmed by Dr. Buckland and his companions, although Captain Beechey had previously reported* that Kotzebue had been deceived by snow, drifted against the face of the banks, and remaining while that in other localities had melted away.

Dr. Buckland and his party not only examined the face of these bluffs, but at various points on the top of the bank, more or less removed from the shore, and found in every instance ice, nearly pure or mixed with vegetable matter, at a short distance below the surface. They report also that the water in the bay is becoming more shallow, by the fall of the detritus, as the ice melts away, and the formation is rapidly disappearing. As no explanation has been offered of this singular phenomenon, I venture to suggest that it may be due to essentially the same eauses as the subterranean ice layer, which is found over a great part of the Yukon Territory. The bank Russia pry are ancient R le haute cout It is quite possible to conceive of a locality depressed and so in deprived of drainage that the annual moisture derived from rainfall and melting snow would collect between the impervious clayey soil and its sphagnous covering, congeal during the winter, and be prevented from melting, during the ensuing summer, by the non-conductive properties of that mossy covering, which would thus be gradually raised; the process, annually repeated for an indefinite period, would form an ice layer which would well deserve the appellation of an "ice-cliff," when the encroachments of the sea should have worn away its barriers, and laid it open to the action of the elements.

The lesson that the agriculturist or political economist may learn from this curious formation is, that a healthy and luxuriant vegetation may exist in the immediate vicinity of permanent ice, bearing its blossoms and maturing its seeds as readily as in situations apparently much more favored. Hence we may infer that a large extent of territory long considered valueless may yet furnish to the trader, fisherman, or settler, if not an abundant harvest, at least an acceptable and not inconsiderable addition to his fare of fish, venison, and game.

* Narrative of the Voyage of the Blossom to the Pacific and Behring Strait. London, 1831.

† See Narrative of the Voyage of the Herald, also the Appendix. London, 18451851. Also Osteology of the Herald's Voyage, by Prof. E. Forbes.

The climate of the Yukon Territory in the interior (as is the case throughout Alaska) differs from that of the sea-coast, even in localities comparatively adjacent. That of the coast is tempered by the vast body of water contained in Bering Sea, and many southern currents bringing warmer water from the Pacific, making the winter climate of the coast much milder than that of the country, even thirty miles into the interior; this, too, without any high range of mountains acting as a bar to the progress of warm winds. The summers, on the other hand, from the quantity of rain and cloudy weather, are cooler and less pleasant than those of the interior. The months of May and June, however, and part of July, are delightful, sunny, warm, and clear. Το quote Seemann again, on the northern coast "the growth of plants is rapid in the extreme. The snow has hardly disappeared before a mass of herbage has sprung up, and the spots which a few days before presented nothing but a white sheet are teeming with an active vegetation, producing leaves, flowers, and fruit in rapid succession." Even during the long Arctic day the plants have their period of sleep, short, though plainly marked, as in the tropics, and indicated by the same drooping of the leaves and other signs, which we observe in milder climates. The following table shows the mean temperature of the seasons: At St. Michael's, on the coast of Norton Sound, in lat. 63° 28'; at the Mission, on the Yukon River, one hundred and fifty miles from its mouth, in lat. 61° 47'; at Nuláto, four hundred and fifty miles farther up the river, in lat. 64° 40′ (approximate); and at Fort Yukon, twelve hundred miles from the mouth of the river, and about lat. 66° 34'.

[ocr errors]
[blocks in formation]

The mean temperature of Unalaklik, on the east shore of

Norton Sound, lat. 63° 42' was, for the winter of 1866-67, +0°.33;

but for that of 1867-68 it was much higher, probably about +9.0. The mean annual temperature of the Yukon Territory, as a whole, may be roughly estimated at about +25°.0. The greatest degree of cold ever known in the territory was seventy below zero, of Fahrenheit; but such cold as this is very rare, and has little effect on the vegetation, covered with six or eight feet of snow. Open water may be found on all the rivers in the coldest weather, and many springs are not frozen up throughout the year.

The real opportunity for agricultural enterprise in a country cannot be deduced from annual mean temperatures alone, but is dependent on the heat of the summer months and the duration of the summer.*

At Fort Yukon I have seen the thermometer at noon, not in the direct rays of the sun, standing at 112°, and I was informed, by the commander of the post, that several spirit thermometers, graduated up to 120°.0, had burst under the scorching sun of the Arctic midsummer; which can only be thoroughly appreciated by one who has endured it. In midsummer on the Upper Yukon the only relief from the intense heat, under which the vegetation attains an almost tropical luxuriance, is the brief space during which the sun hovers over the northern horizon, and the voyageur in his canoe blesses the transient coolness of the midnight air.

The annual rainfall cannot be accurately estimated from want of data. At Nuláto the fall of snow from November to the end of April will average eight feet, but often reaches twelve. It is much less on the seaboard. Partly on this account, and also because it is driven seaward by the wind, there is usually in spring very little snow on the coasts near Norton Sound. In the interior there is less wind, and the snow lies as it falls among the trees. Toward spring the ravines, gullies, and brushwood are well filled or covered up, and transportation with dogs and sleds is easy and pleasant. The warm sun at noon melts the surface of the snow, which soon freezes, forming a hard crust, rendering snowshoes almost unnecessary.

The rainfall, as has been previously remarked, is much greater in summer on the coast than in the interior. The months of May, * More extended data in regard to the meteorology may be found in Appendix.

« PrejšnjaNaprej »