J ~E , 1918. MONTHLY WEATHER REVIEW. 277
surface as Hildebrandsson has already shown (61, is divided into positive and negative centers of action sepa- rated by intermediate regions which may be of a tran- sition type, or ma be under the sway h t of one center and then of anot t er. In these centers, ap arently in harmony with solar changes, there occur &nost syn- chronous changes of pressure as well as of temperature. These changes are, a parently, common to all the centers of action, but their c R aracter is reversed according as the centers are positive or negative. The changes in pressure appear to precede the changes in temperature. Another noteworthy feature of the centers of action is that one type suffers changes of temperature rou hly in harmony with the chan es which occur in tro ica 7 midcontinental regions and w % ch are apparently 1 ue in p o d part to variations in the radiation of solar heat. he final con- clusion of our Norwegian authors is that chan es in pres- sure and winds which are presumably of so 5 ar origin, temperature and are on the
gap between the present of variations in temperature
subject of study.
and the hypothesis of the present paper as t.0 the effect of nontliermal solar variations. Apparently theso solar variations follow a course rough1 but not strictly, parallel with that of changes in &e sun’s emission of heat. Increased solar heat warms the earth’s surface in certain regions, special1 within the Tropics or in conti-
to increase the rapidity of both oceanic and atmospheric circulation. At the same time the seemingly nonthhennal energy with which we have been mainly dealing in this paper, apparently causes an e.xpansion of areas of high pressure and a consequent weakening of gradients in their centers. This crowds the low-pressure areas and thus in such areas strengthens the gradients. Perhaps, as Veeder has suggested (7), these changes are due to an actual transfer of parts of the upper air toward the centers of high pressure. However this may be, the result seems to be a remarkably quick readjustment of atmospheric pressure. This is apparently followed at once by a
strengthening of the ‘winds, and an increase in cyclonic activity. Hence in the high-pressure areas the cold upper air must begin to settle downward, so that the temperature of the earth’s surface is lowered. In the low-pressure areas, or at least along their equatorward sides, an unusual amount of warm air must be drawn inward. Thus the temperature rises, and the condition of such places vanes inversely to that of the centers of high pressure. Ultimately the warm air is carried up- ward so that the eneral temperature of the earth’s sur-
certain areas have been warmed by the winds while other areas are being warmed by the sun and still others are being cooled by the descent of air from aloft. One of the next eat tasks of meteorologists would seem to
conditions of solar activity.
nental interiors where t K ere are few clouds. This tends
face is lowered. h is, however, does not happen until
be to map J? e areas of these three types under different
REFERENCES.
1. Kap m W. Lyfttem eraturen, Sonnedecke und Vulkanaus- bruche. %dtteorol 2. Abbot, C. G .r p r t a in Annals of the Aetrophysical Observa- tory of the S m i b n i a n Institution. 3. Huntin ton, ElleUr0rt.h. The Solar Hypothd of Climatic Changes. Bulletin of &e Geological Society of America, vol. 25, 1914.
4. HelW-Ha9iam, B. & Nansen, Fridtjo Temperatur-echwan- kungen dea Nord-Atlantischen Oeeana und in k r Atmoephkre. 1917. (summary in this REVIEW, A ril, 1918, pp. 177.) 5. Asefawsh, Hmryk. Tie aolar constant and the yariations of atmoepheric temperature at Arequipa and Bome other stationa. .Bulle-
he &itachrift, XXXI, 1914.
tin of the American GeTphical Society, XLII. 1912. A study of the changes in the dlstri ution of temperature in Europe and North America duriq the yeara 1900 to 1909. Annals of the New York Academy of SclenceR, XXIV, 1914. 6. Hildcbrarr&on, H. Hildcbrand. Que1 ues recherchee sur le8 centres d’wtion de l’atm hhe. K o a Svenaka Vetenakap Akademiena Handlingar. X%X No. 3, 1897: XXXII No. 4, 1699; XLV No. 2, 1909; S L V No. 11, 1910: LI No. 8, 1914. 7. HwntSnqfon, Ellsworth. Geographical work of Dr. M. A. Veeder. Geog. Rev. f: 168-211, 303-316.
CORRIGENDA.
PART I.-Page 127, 1 end for ii ure 1. the dotted line and t.he solid line hod be interc%mged. Page 129, lower msrgin of,right-hand of figure 5, “inmaee” should read “de-se. Page 139, columu 3, h e 14 from bottom, sentence beginning “Let it” should read “Let u?.,, 11.-Page 170, Table 8, column 1, thud line, “1907” should read “1908 ”. P y e 176. second line p i note to fi lire 14, “mn” should read sun’i”; at b inmug of f?ur& line “froni” &odd read “of”, and 6gN& hi same hne Bhould m l “NE”,
LACUSTEAL BECOBD OF PAST CLIMATES.
By CHARLES ROLLIN KEYES, Ph. D.
c
[Dated Des Moines, Iowa, July 14, 1917.1
It is not at all surprising that such apparent climatic anomalies RS the occurrence in arid regions of large bodies of inland waters should call forth varied expla- nations. At first glance interior seas seem to portend former meteorological condi tions that were fundmen- tally different from those now existing. They even sug-
gest that they may be tell-tale clues to epochs when greater humidit revailed. In this re ard the vast extinct lakes of t e reat Basin of western a orth America especially are the theme of warm and prolix discussion on possible climatic changes in late geological times. Whether or not ultimate analysis of recorded observs tion support the thesis of permanency of climate, rhyth- mic alternation of climatic change, or variable and .irregular succession, it is quite certain that the tendenc of opinion toward the middle coume thus far fin B s
greatest favor. When the sumptuous monographs on tho van uished Great Basin lakes were written by King, diitney, Gilbert, and Russell, such a thin as desert eolo was entirely unknown in the Unitef States. l%nci?es of
modern physiography were ‘not yet formulate$ The tremendous potency of eolic erosion under conditions of aridity was unsuspected. On the other hand, the duality of the Glacial Epoch.was ‘ust beginning to receive cre-
et undreamed. Since these new fields of investigation iave opened up, old views are capable of something like quantitative measurement, where before much was either ure fancy or unwarranted distortion to fit dimly out- L e d hypotheses. And regions present as their most characteristic relief expression innumerable shallow depressions. In a tract of close-patterned orogeny as, for exam le, the Great
with the intermontane plains. .To the ex lorer fresh from his homeland of humid climate the su I T ace hollows a pear as potential lake basins. As a direct consequence
drainage features at d. That some of them, under such dry-climate conditions, should be actually occupied by broad expanses of water is a wholly unespected phe-
dence, although its real mu i tiplicity and complexity wero
Basin, these broad depressions are usualy Q coterminous
o P desert erosion the are really not an expression of
278 MONTHLY WEATHER BEVIEW. JUNE, 1918
nomenon; and at first thought the fact appears singularly incongruous. At the present time the lakes of the notably arid Great Basin possess special interest not onl because of
account of the fact that there has been a concerted effort on the part of writers on the region to establish for all of them the same climatic origin. That all of these lakes can not possibly be brought under a sin le genetic con- trol is onl be inning to be realized. &at they really have widely dfierent and wholly unrelated origins is
amply attested by recent critical observations. That some are composite and others complex is a late conclu- sion from whch there is no escape. Although all the details of the life histories of many of these strange bodies of water are yet to be deci hered, enough is now definitely known to assume that a Yl are ca able of satis- factory explanation without recourse to cfhatic condi- tions so very different from those now prevailing in the region. The vastness of es anse of two of the ancient bodies
tan, is no doubt the chief cause for seeking an ade uate explanation by appeal to atmospheric conditions &ffer- ent from those now enjoyed. Instead, however, of a single genetic agency controlling the existence of these two lakes and numerous other smaller bodies of water in the region, recent inquiry indicates rather a multiple origin. In place of an assumed common genesis each lake has to be separately tested concernin its being.
different means of development that any broader con-
trolling agent, as a climatic one, is entirely precluded. Grouped with reference to ori in of lake-basin a dozen
the Great Basin. Arranged as to sources of water-sup ly
into account. In humid climates the lineaments of lake genesis are masked because of the fact that the barriers are usually overflowing, and it is not a1wa.p ossible clearly to dis-
bo& of water seldom overflow their basins. ‘&a spe- cific derivation of each is more or less readily discerned. Even those bodies of water that are close together may have widely different origins. How great then must be the incongruities encountered when such lakes as Bonne- ville and Lahontan, for instance, are grouped together in the same class, especially when the essential taxoncimic factor is made the number of prominent shorelines cor-
responding to the number of ostulated advances of a
test is indicated by the recent recognition of an entirely different number of glacial epochs. Neither of these lakes is to be regarded as arising from imperfect drainage such as ordinarily prevails in pluvial lands. Both are accidental features of the arid country in which they are found. When tmhe data for the Bonneville and Lahontan mono- gra hs ’ were being assembled the novelty of conception
the front of the geological sta e. The main pur ose o
truth of the notion. Discovery of two shore terraces more cons icuoua than others is cited as indisputable
1 Mon. u. 8. OWL surv., vols. I and xt.
their number and the great sizeof some of t K em, but on
of water in the Great E asin, Lakes Bonneville and Luhon-
Whether classified accordm to the genesis o 7 lake-basin or according to source of la a e waters, there are so many
distinct categories of lakes are f ound to be represented in
there are half as many additional categories to be ta l! en
tin uish the underlying factom. P n arid lands ex ansive
contincntal icesheet. The ina B equacy of such a cliinatic
7
of t Yl e duality of the Glacial Epoch was noisily occupyin
these accounts almost seenu to B ave been to cstabish the
evidence o P a twofold Ice Age. Without adducing any
really critical testimony, a marked moderation of the present arid climate is made to account for the lake con- ditions. Singular as it now seenu that recourso should be limited to a single working hypothesis, the fact is easily explained when it is remembered how overpowering in that day was the Glacial argument. For a long time there has been a general tendency to connect in some way or other the exlstence of the Great Basin lakes with the presence of glaciers and to associate the desiccation of the former rent bodies of water with
be all grouped under three heads. I)r. E. M. Endlid was under the impression that the old glaciers of the Rocky Mountains in Colorado were produced by the ex- cessive moisture derived from the broad sheets of water formerly existing to the westward. A second h pothesis, advanced by Prof. J. D. Whitney, regards the P s eistocene lalcea as sequels to the laciers, being produced b their meltin .In the “Geofogical History of Lake Bonne- ville” prof. G. K. Gilbert considers that the same changes in climate introduced both the glaciers and the lakes. The fundamental weakness of both of the last- mentioned h othesea as general esplanations lies iii the
worked, the glaciation was sufficient1 extensive to be ‘competent to produce the results; wl 9 ’ e in the Wasatch Mountains, where Gilbert studied, the larger lake was in reach of such petty glaciers that the Wliitney explanation could not possibly be sustained. At the same time that the Great Basin lakes were asso- ciated with the regional glaciation there also developed the idea tlint with the pussing of the mountain glaciers the region entered into a stage of general and greatly accelerated desiccation. Wlitne indeed, fancied that all the intermontane laiiis or Iksins of Nevada were
tial lake basim extend far beyond the liinita of the Great Basin. They reach southward a distance of 2,000 i d e s to the Tropics. That these so-called lake basins were really a characteristic surface feature of desert lands enerall was not then suspected. Neither wa9 i t 5rearneJthat they were not drainage features at all, but owed their origin and prevalence to erosional powers in which m i i n g water takes no part. For ths reason mainly the real significance of the phenomenon of desert lakes is so often entirely mistaken or largely misinter- preted.
A marked proneness to generalize too widely with regard to these desert lakes, and the attempt to bring all
of them under the same genetic head, have done more than anythin else to obscure the real issues involved.
as glacier-born is only one angle of the problem. Throughout the West the lacustral hypothesis of the origin of geological formations has been so long over- worked that i t would be no surprise if the reaction that
is now setting in against it go much too far. Many of the so-called old lake beds are now known to be fluviatile deposits. Still larger numbers are manifestly strictly e irotic in character. Others are art1 one and partly
widely recognized “ Severn Lake” deposits of Nevada
part. In the last-mentioned deposits are fossils as T o d are discovered to be marine in origin, a t least in 1
as the Eocene age, and the strata, infolded as the are in the Sierra Nevada and Sierra Madre, are tracea I? le in a broad belt to the Pacific Ocean. So the published data on the terranal aspects of the ancient desert lakes can
the waning of the Glacial Epoc % . The various views ma
fact that in YR t e Sierra Nevada, where Whitney mainly
formerly occupied by f eautiful inland seas. But poten-
The forced e H orts to consider the ancient bodies of water
t K e other. Very few are actually f 9 ake- aid strata. The
JDNEI, 1918. MONTHLY WEATHER REVIEW. 249
not now be viewed with the same e uanimity that they
stored much of the region of the Great Basin has to be critically examined anew. Without outlining a full genetic scheme of lacustral taxonomy, which arid regions seem to su ply the data
to note that each body of water requires separate con- sideration when its genesis is under surveillance.. Many desert lakes of conse uence are no doubt simply the es-
posure of the grounl-water table to sky, due to local accentuation of the cleflative processes. Others, as Lake
Bonneville, seem to be due to orographic movements chiefly. Lake Bonneville’s history is a long one. It goes back far beyond the inauguration of the Glrrcin.1 Epoch. To all appearances man traces of its early development
the arid climate. Brieflv, the course of events seems to be that this vast body of water of which Great Salt Lake is conimonly believed to be a llwt vestige, is not, after all an anomaly amon desert features, but that it merely
that was not uite large enough to master the orogenic
other hand, ita nearest neighbor and parallel relative, t-hhe GTeen River, reinforced by the Grand ani1 other lwge eastern tributaries, was sufficiently powerful to hold its
were a few years ago. Before co i denca is again re-
for in unmasked form, it is important in t 1 IS connection
are still retained; and d iey antedate even t,he coming of
represents a specia 5 phase of a tlirough-flowing stream
barrier which P c. lanced to arise athwart its pat8h. On the
Bfxked by such a forniidal>le ranipart,
own against all vicissitudes and to carve ra idly bulging Colorado dome a Titan
River, r~ it may be called, spread out far and wide over
the ad’oining intermontane plains, and rivaled in niagni- tude &e Laurenticle Great Lakes, with 20,000 square miles of area and a depth of 1,000 feet. Finally, the lies being diverted, the waters of the great f%?$z?$rowed to evaporate until equilibrium was again establihed bet.ween i t and its remaining tribu- taxies.’ That the seemingly vast changes in the water condi- tions of this desert region were physiographic rather than climatic in their nature finds strong su port in the recent
This author shows by quite conclusive evidences that ini- mediately before the inauguration of the Glacial Epoch the basin of the Snake River extended nearly 200 d e s farther to the northeastward than it does at the present time, and included an area of nearly 300 miles square that has since been separated from it. This area was mainly that part of the basin of the present Missouri River lying above Great Falls. Passing Idaho Falls and Pocate!lo, was a combined volume of waters of the present Snake River and the Missouri River at the Great Falls orge.
This noble stream is believed to be the Old Virgen giver, the superior companion of the Green River. In the
recent migration westward a distance of 150 miles of the Continental Divide in Montana, the Yellowstone River took art of the old-Snake or Virgen headwater drainage, the a%lseouri River the greater portion, Clarke’s Fork of
the Columbia a art, and the Salmon River of Idalio a art.
blocked by basalt flows at Pocatello, the remiiantal pre- Glacial stream turned out over the Idaho lava fields the diminutive Snake River that we find to-day. In the early considerations of Bonneville Lake the geological age of the attendant deposits was a matter of
results of Prof. W. W. Atwood: in sout E western Montana.
Deprived of so f arge a portion of its headwaters, and P ater
1 Bull. Ged. Soc. America, Vol. XXVIII, p. 351, 1917.
Ecmomlo Qeology, Vd. XI, pp. 697-740, 1917.
extreme uncertainty. Bearing on this point no satis- testimony was ever aclduced. More recently
factox sever distinct but mutually supporting lines of evidence seemed to settle this question. The elevation of the southern mountain barrier of the old valley was niani- festly coeval with the formation of the inner gorge of the Grand Canyon of the Colorado River in Arizona- Mid or Late Tertiary in date. At Red Rock Pass, the low-rim oint of the basin at the north and an assumed
direct continuation of the Bozeman beds of southwestern Montana and southern Idaho. In age these were inainly Mid Tertiary. The uplifting of the Beaverlied range athwart the draina e and the capture of the original
took place in Late Tertiary time. The complete diver- sion of the Snake River drainage from the Bonneville basin was probably also a Late Tertiary occurrence. Antedating Pleistocene or Glacial times there still re-
mained the Earl uaternary Epoch.
ville already a mature body of water, it had far passed its widest expansion, and it was redly inore. than two- thirds desiccated. All drainage coniinuiiication with the C!mltinental Divide about Butte, Mont., being cut off, the lake basin received no augmentation to its waters froin the nioiuntain ghciers in this direction. Since the recent careful mapping of tlie old glaciers of the Wasatcli and Uinta mountains the iiiost conspicuous feature brought out concerning them is their utter iii-
si nScance. So inconsequeiitial iiiust have been their
why the two henomena were ever genetically associated. The Glacial 8 ocli came too late to be witness at the lake’s birth. !t narrowly escaped not being present at the death. Whatever may have been the course of events in the history of Lake Bonneville, it is not at all probable that that of the other great bod of Great Basin water, Lake
h othesis demands. In duration, in espanse, in niagni- tu T e of gatheriw ground the last-mentioned body of water is hardy to%e com ared in importance with ancient Lake Bonneville. Wlietter or not Lake Laliontan still retains any vestige of pre-arid draiiinge lines is liard to
say. There are good reasons for believing that it stands in the path of a former through-flowing river that was
comparable to the Green or Snake River of to-day. Relatively recent orogenic movements and volcaiiic dis- turbances are ani le effectually to block the course of
the Sierra Nevada and to enipouiid its waters. If such
a master stream did actually exist in pre-lacustml or re- arid times, nearly if not all traces have probahly on
t,he ordinary desert erosional processes. 1 et, in this connection, such features as the t,housnnd-feet,-deep canyon at the south end of Death Valley, Chi., nciw occupied for a number of miles by tlie little brook called Amargosa River, need careful esamination. The lakes which, in Ion succession, now lie at the foot
be, however, merely the basal reservoirs of the different mountain streams and may have no relations to any former connection with a pre-arid mnster-stretiin of t81ie region. In pre-Glacial times these mountain rivers probably were much larger than now, owing to the
outlet o P the lake, the gravels and silts proved to be a
headwaters of the 8 iiake River by the Missouri River
Thus before t 9% e lacial Epoch set in was Lake Bonne-
in 5 uence on lake conditions that one can not but wonder
Lahontan, had nearly the c K ose parallel which a climatic
any stream that P iappened to skirt the eastern foot of
since completely disappeared through the oprntion Pq o
of the great orographic b f ock of the Sierra Nevada may
280 MONTHLY WEATHER BEVIEW. JUNE, 1918
fact that the position of the Sierra Divide was much farther to the westward than at present. Waning glacie tion over this lofty region waa certainly com etent to
qute possi le t at Whitney's esplanation of melting ice is art1 correct. $he Zsappearance of the great Lake Lahontan, as well as the dimunition in size or vanishing of many of the other bodies of water once much la er than now, is
flow occasioned not so much by a change from moister climatic conditions as by the rapid eastward migration of the Sierra Nevada watershed and by the capture of its chief catchment basin by the Columbia River. The east
base of the great snowy range is 4,000 feet higher than the west foot. Headwater erosion thus goes on so much more speedily on the sunset flank than on the other side that the divide has already nearly reached the eastern margin of the orographic block. Some of these west-
flowiiio streams are now actually crowding down the east sfope of the rid e. The headwaters of Feather
high escarpment overlooking the Great Basin. Pitt
River in the same State has already broken through the range and drains lakes that not so very long o were
of which the Southern Pacific railway runs 3,000 feet above the bottom, shall have been cut back completely through the Sierra, capturing the Truckee River on the eastern side. At a little later date the waters of Huin- boldt River may be flowing uninterruptedly to the Golden Gate. Bearilia directly on tho question of an independent genesis 07 the two !a.rgest lakes of the Great Basin is the attitudes of the mmor lakes of the region. Admittedly
of a half score distinct ori ins, these several classes of
confines of the Great Basin. Their congruous relations to normal desert enviroiinient continue southwafi quite to the Tropics; so they are the same in regions far beyond supposed influences of Glacial climate. In cll- matic discussions of the Great Basin the s nificance of
arguments against ap reciable change in climate since
nental glacier front is far too remote Influence the climate of Nevada. All lacustral testunony seems to sup ort conclusive1 the ostulate that during late eo f ogic times the cgmatic luctuation in the region has
Eeen no inore ra id than the larger orogra hic change.
wtis any ap reciable modification in the climrttological
appreciabl a meat the basal lake supplies. P t is thus
readily explained by postulating great P y diminished in-
River in California reac f i even now quite to the brow of the
strict1 Great Basin features. The time can not 5 e lon until t T le canyon of the American River, along the brinf
desert waters retain their c % aracteristics far beyond. the
this fact is little considered. It is one of % t e strongest
the time when these P akes began to Iorm.. The coati-
It is doubtful w R ether during the Glacial E poch there
features of t P le arid lands.
CROP CENTERS OB THE UrJITED STATES.
By J. WARREN SMITH, Meteorologist.
[Dated. Weather Bureau, Washington, D. C. June28,lQlS.I
Dr. Adolph E. Waller, h o c i a t e a t the Botanical Laboratory of the Ohio State University, Columbus, Ohio, contributes an article under tho above head in the Journal of the American Society of Agronomy for Feb- ruary, 1918, vol. 10, pa,oes 49-83, that is of more than
assing interest to students of agricultural meteorology. Fhe author writes from the point of view of the ecologst,
tbs shown in the development with natural vegetation as
of t,he climate of inter-relation of
author states that:
In every stage of their development plants respond to the moisture and temperature changes of the habitat. The nature of the soil has such a far-reaching influence upon plant life that it must be considered second in importance to but one factor, the climate. Those plant- growth factors related to the soil have been named by Schimper (1'JOd)
the edaphic factors. Warming (1909). impressed with the fundamental relatiou between plant growth and available water sup ly of the habitat, grouped vege- tation into three principal clsases, hylrophytes, mesophytes, and xero-
phytea. The water-content of soils was made the b a s of his work, but when he recently reclassified the three types in order to accommo- date them more closely to plant distribution, the new sptem WBB too involved to receive general recoguition from plant geographers. Bchimper made practically the same grouping that Warnling inade of water-content associations. He also pointed out that the terma forest. gramland, and desert me a subconscious claaeification of the rincipal climatic formations and are only another way of expmwing t f e water- content of wih. The effect of the edaphic factors is to modify the cliniatic influences. The physical and chemical properties of mila tend to diminish or intensify the effect of climatic factors upon plant growth. * * * The phyaical nature of soil structure more im )ortant to plant life than the chemical composition of the soils due to b e relation between soil texture and water-content.
In discussing the relation between the crop centers and centers of natural vegetation, the aut.hor says:
The corn and wheat belts agree with the deciduous forest and the prairie centers in the United States. * * * Three sets of factors are operating in combination to establish thia region as the center for the production of our great cereals. These factors may be grou d as clunatic. eda hic, and economic. By reason of t h e r o t , almost tro icafsummers with the relative humidit rather high and the annuarrainfall sufficient for the growth of the $nt, the entire area from Ohio to central Nelxaska on the north and southward to the Gulf of Mexico is suited to corn produc- tion. * * * The climatic factor in Indiana and Ohio is suited to the profitable production of corn, but production centeq in Illinois for edaphic reasons. * * * In the United States wheat production centers on the 60 per cent rainfall-evaporation ratio line. This means that the center of wheat production liea west of the best corn lands, although on many farms throughout the prairie and deciduous forest climaxes both wheat and corn are usually grown, i f rotations are practiced. In the matter of growing wheat in regions too dry for corn, the United Statee is not an exce tion to the rule. The great wheat- roduchg regions all over the wor1Xm-e level lains with a cool, rather 8,y climate. It is known that wheat. particnLrly winter wheat, yields larger cro in the more humid sections, et in normal times other crops can grown in the humid parts of d e United S t a b with greater profit than wheat. It
is competition with these crop that drives wheat to the plains. * * *