Effects of the August 17, 1959 earthquake and subsequent quaking upon the thermal features of Yellowstone National Park
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Authors Watson, Barry Norton, 1937-
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Link to Item http://hdl.handle.net/10150/553960 EFFECTS OF THE AUGUST 17, 1959 EARTHQUAKE AND
SUBSEQUENT QUAKING UPON THE THERMAL
FEATURES OF YELLOWSTONE NATIONAL U . . ,' . ■ • ■■■ . ' ■ PARK
V> •, - . f- - . ■ V '■>: i ' ; Barry N. Watson U- i : ; r : -N.'n:- -t or '.<• : D:. .. v irr'rO!.- :.• / .Y
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A Thesis Submitted to the Faculty of the
DEPARTMENT OF GEOLOGY
In Partial Fulfillment of the Requirements For the Degree of ' ; . ' ' ‘ ■ • - . r MASTER OF SCIENCE
In the Graduate College
THE UNIVERSITY OF ARIZONA
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• oL'.:: - - v : v \ , . v ' : : ' - > ■ - ^ EFFECTS OF THE AUGUST 17, 1959 EARTHQUAKE AND i SUBSEQUENT QUAKING UPON THE THERMAL FEATURES OF YELLOWSTONE NATIONAL : •• : ! v ■ : • ; . PARK ' f ' 'w . . : u
by
Barry N. Watson
: / i . ABSTRACT
The August 17, 1959 earthquake whose epicenter was placed in the Hebgen Lake region of southwestern Montana caused extensive changes within the hydrothermal network of geysers and hot springs in ... ; . ; . . . v, : - >■■■/■. ■■ ■■■ ■ ■ ■ ■ ' < ; nearby YeUowstone National Park. Although major feature changes due to tectonic and volcanic activities have been noted elsewhere in the world, i. e. Iceland and New Zealand, they had never been recorded in
Yellowstone previous to 1959.
The Firehole River geyser basins in Yellowstone National Park £::v % ...... , : : , .. ‘ ■■ ; - = ’ lie within an extensive rhyolitic plateau developed in late Tertiary and
Quaternary times. Quaternary faulting on this plateau generally trends northwest to north. A similarly northwest-trending fault system was exposed by the 1959 earthquake in pre-Laramide sediments of the Hebgen
ii Lake region 30 miles northwest of Old Faithful village and just off the
Rhyolite Plateau. The results of the quake in the Old Faithful area . - - • : ^: O': , o likewise suggest the distinct possibility of a northwest-trending fault control of the thermal features. Although fault control is undisputed in most other thermal regions of the world it has been previously dis- credited in Yellowstone by such eminent scientists as E. T. Allen and V - - . ' •• ‘ ' ’ , ’ ' :‘ v- ...... > A. L. Day], Or':.'- y. - <.:• : ...... r-
The 1959 quaking caused an increase in thermal activity in the
Firehble River basins. The average temperature of 167 sample springs « • . • ’ *•_ " • — >i •; « increased 6°F, discharge of thermal waters became apparently heavier, ■T:. Vi . . . •; and increased eruptive activity was noted. Some springs experienced, deer eased. or cessated activity. The major groups of thermal features in the Firehole River basins are reviewed on a before-and-after basis : to show earthquake change. • ......
r Thermal feature alignments, interchange of function between various hot springs, new post-quake thermal activity, land structural
evidence from enlarged aerial photographs have convinced the author of
fault control within the geyser basins. Several faults are mapped show
ing a general northwest to north trend; however, evidence of such fault
ing is admitted to be subtle and of extraordinary nature. An extension i L ...... 87 of this northwest-trending fault system in the Firehole River geyser 8 basins would project into the Hebgen Lake region...... iii : TABLE OF CONTENTS...... ; : i ...... ' * *• - • t - a - * , > - ' ,r t > * % . - V . , J \. . < + * * * * * i* * * ' ! » V- - * ; ...... Page
1. INTRODUCTION ...... ; ...... ;...... 1 M. . ... ■ • ■Y'.v, (1.1) Location and History...... 5. O ? (1. 2) Climate and V egetation...... (1.3) Previous Geologic Investigations ...... 3- A (1. 4); Methods Used for Thesis "Work ...... ‘ 3(1.5) Acknowledgments . : ......
2. EFFECTS OF PREVIOUS.EARTHQUAKES IN KNOWN...... * THERMAL AREAS......
(2.1) Iceland ...3:. A... . ;L...... (2.2) New Zealand ...... (2.3) MThe G eysers,M California...... P.
(2.4) Yellowstone National P a r k ...... -3 00 00 (O M M W 1 « K •.. { i;-- Yii'i-'j'-: l . \ ' 3. REGIONAL GEOLOGY...... A 12
(3.1) (Rhyolite Plateau ...... ; 12 (3.2) Faulting on the Plateau ...... 13 v. (3.3) Geyser B a sin s...... A 16
4. 1959 EARTHQUAKE EFFECTS ON YELLOWSTONE...... THERMAL FEATURES...... 18
(4.1) Old Faithful G e y se r ...... 20 - (4.2) Geyser Hill...... h. >23 (4.3) Myriad Group ...... 27 , (4.4) Castle Group ...... 29 (4. 5) Grand Group ...... 33 - (4.6) Oblong Geyser ; ...... > 36 : (4. 7) Giant G roup...... 37 0, (418) Grotto Group :: v . ; ...... 38 (4.9) Daisy Group...... 41 10 (4i 10) Black Sand Basin t ...... 44 iv : t .v Page
; (4.11) Area Between Chain Lakes and Biscuit B a sin ...... 45 (4.12) Biscuit Basin ...... 7 . ___ ...... 46 : (4.13) Midway Geyser Basin ...... 51 (4.14) Great Fountain-White Dome A r e a ...... 52 (4.15) Firehole Lake Area ...... 55 (4.16) Fountain and Kaleidoscope Groups ...... 56 (4.17) Other Thermal Areas in the Firehole Basins ...... 59 (4.18) Other Thermal Areas of Yellowstone P a r k ...... 61
5. CONCLUSIONS ...... 64
6. APPENDIX— TEMPERATURE RECORDS OF YELLOW STONE THERMAL FEATURES...... 71
7. BIBLIOGRAPHY...... 82
LIST OF PLATES
Plate Page
1. Reference and structure map of the Firehole River Geyser B a s in s ...... in pocket
2. Map of the Firehole Lakes ...... in pocket
3. Map of Geyser H ill...... in pocket
4. Map of the Myriad Group...... in pocket
5. Map of the Castle Group ...... in pocket
6. Map of the Grand Group...... in pocket
7. Map of the Grotto Group...... in pocket
8. Map of the Daisy Group...... in pocket
9. Changes in geyser activity ...... 76
10. Changes in geyser activity ...... 77 v Plate Page
11. Changes in geyser activity...... 78
12. Results of the earthquake...... 79
13. Interconnection of thermal features ...... 80
14. Faulting in the Upper Geyser Basin*....;...... 81
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■'•"I" ■ :i:: / ,yy\ v; .... 1. INTRODUCTION ■ v-1 f- -h':
At 11:37 p. m. on August 17, 1959, a major earthquake was
r-^ ■ ': *■• ■ ■■ ■ \ ■ <■ ■ : felt over an area of 550,000 square miles in the northwestern United
States and Canada. Pasadena gave its magnitude as 7.1 on the Richter scale—a magnitude equalled or surpassed but 14 times within recorded
United States history. The shock centered at 44° 50* N. latitude and
111° 05* TV. longitude, just north of the tri-state junction of Montana,
Wyoming, and Idaho. The focus was 10 m iles deep, r .
The earthquake received immediate national prominence tto- cause of its great magnitude and the number of avalanches it precipitated in mountainous terrane near the epicenter. The largest slide occurred in the Madison River Canyon 15 m iles west of the epicenter where an estimated 43.4 million cubic yards of rock buried the Rock Creek ; campground. Twenty-eight lives were lost. ^ ’ v
These were the immediate and publicized macroseismic effects of the earthquake. Attention was also drawn to Yellowstone National
Park whose western boundary lies near the quake epicenter. Several avalanches, a mud slide, and damage to many Park buildings comprised the more sensational aspects of change*which occurred within Yellow-;: > stone. But far more profound were the changes that occurred and are still occurring within the Park* s vast network of hydrothermal featur es. 2
This paper will deal with these changes and will be chiefly concerned with the geyser basins located along the Firehole River on the western side of the Park. -
(1.1) Location and History
y Yellowstone National Park includes 3,475.5 square miles in the northwestern corner of Wyoming with strips of land in Montana and
Idaho. The Park is easily reached by several United States highways, but no railway nor airline service enters within its boundaries. ;
: Member s of the Washburn-Langford-Uoane Expedition of 1870 were the first white men to advertise the uniqueness of the Firehole
River geyser basins. In 1871 Dr. Ferdinand Hayden of the U. 8. i
Geological Survey led an expedition through the Yellowstone area. Re ports of these two expeditions convinced Congress that Yellowstone =' should be set aside in some special cap^ity, and on March ly 1872,
Yellowstone was created the first of the National Parks.
(1. 2) Climate and Vegetation n y_. - '■ :: ; ;Lv : . v ! ' , r u . -- ; b " y v ' . ; , y -y ;:.--.'
.1 y: : Warm weather is confined to the summer months in the high northern latitudes of Yellowstone National Park. - During June, July, ’
and August temperatures range between 15°F and 90°F in the Old Faith ful district along the upper Firehole River, but after September 20 the
area becomes quickly showbound'and temperatures frequently drop y 3 below zero.
Most of the plateau area on the western side of the Park is heavily forested by the shallow-rooted Lodge-Pole pine. The heavy forestation and large quantities of downed timber make exploration dif ficult if no trails are available. The geyser basins, however, are relatively unforested due to the warmth of the ground.
(1. 3) Previous Geologic Investigations
A substantial amount of scientific literature has been written concerning Yellowstone's hydrothermal features—most of it published prior to 1936.
The earliest systematic survey of the geysers and hot springs was conducted by A. C. Peale, a member of the Hayden expeditions of
1871, 1872, and 1878. Nearly 400 pages of Peale's observations were published (12th Annual Report of the Geological and Geographical
Survey of the Territories, Part n, 1883).
In 1883 Arnold Hague of the U. S. Geological Survey instigated a systematic investigation of the geysers and hot springs which lasted
16 summers. The results were published in Part H of Monograph i
XXXH. On the Geology of Yellowstone Park, in 1899 which was followed by the Folio Atlas in 1904.
In 1929 and 1930 the Geophysical Laboratory sponsored drilling of two test holes in Yellowstone thermal areas. C. N. Fenner (1936) 4 organized the data obtained. : . : ^ 7 r
'.r : :'E. T. Allen and A., L. Day of the;Geophysical Laboratory published their monumental volume on the Hot Springs of Yellowstone
National Park in 1935. This volume yet stands as the chief reference to hydrothermal studies in Yellowstone.
Since the work of the Geophysical Laboratory only one man has conducted research of significance on the geysers and hot springs. He is Park Naturalist George Marler, who has been logging data and * keeping observation for over 20 years. Some of his work has been ' published while many of his reports yet reside in the Yellowstone Park
Library at Mammoth Hot Springs, Wyoming, v r ^ V ; .
(1. 4) Methods Used for Thesis Work
; : At the time of this writing no topographic maps of sufficient
accuracy or detail were available to the author. Enlarged aerial photo
graphs were used for some mapping purposes and exploration, while plane table suryey maps of local thermal areas were made for more
detailed examination. The plane table surveys were conducted under
the auspices of the National. Park Service during the fall of 1959 by three
Park Ranger-Naturalists including the author. Geologic mapping con
sisted mainly of recording the location of fissures and possible faults
in geyser basin areas. The reasons for this type of "fissure mapping"
will become self-evident. .• . r . ; •/ r. : .1 v 5
Much was learned through the compilation of statistical data.
Methods of data gathering (i. e. taking temperatures, discharge measure ments, and eruption intervals) will be explained throughout the text.
(1. 5) Acknowledgments
The author worked as a Ranger-Naturalist at Old Faithful village during the summers of 1959 and 1960. Of primary importance were those who made it possible for him to join an earthquake interpre tation staff which studied earthquake effects from late August until mid-
December of 1959.
To the National Park Service I am truly indebted. Robert N.
McIntyre, Chief Naturalist at Yellowstone, allowed complete access to the Park literature and earthquake files, assisted in obtaining copies of plane table maps, and offered general encouragement. Park Naturalist
George Marler opened his vast knowledge of geysers and hot springs to the author in numerous conversations. Ranger-Naturalist W. Germeraad
and K. Higgins, and Naturalist A. Mebane contributed through data and
discussion during the special earthquake interpretation studies and after.
Much was learned through discussion with Dr. Irving Witkind
of the U. S. Geological Survey, Dr. William Fisher of Colorado College,
and through correspondence with Dr. Stephen Nile of the Montana
School of Mines. Acknowledgment is due also to the staff of the Department of 6
Geology at the University of Arizona for help in the preparation of this thesis. In particular the author is indebted to Dr. Willard Lacy who acted as thesis advisor.
V . c ' i
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' r'.', ' , ;• ■,*v’ \ 'X-\ " : " h of .W. i f - f-.r • •; ■: 5 v : V: ■ ' ! - ■: 'n : V:'. v t :] :«: • ; r;;;".'U; (n:j„ ri 7. r c ' - " * y ‘ •'-0 /. .; Vx ■ • ; i r • - 2. EFFECTS OF PREVIOUS EARTHQUAKES IN KNOWN THERMAL AREAS . The effects of earthquakes on geysers and hot springs have been noted in various portions of the world. Before discussing Yellow stone* s past earthquake history, quake effects and fault control in other well-known thermal regions will be reviewed. (2.1) Iceland 3 ; 1 = ■ - . ' > ... . •• ' Barth (1950) cites several startling examples of earthquake / ; - ; - * . ^ , . - . . • . : ■ • ' effects on Icelandic thermal features. It seems probable that the famed ’’Geysir" first came into being with the great earthquake of 1294 when volcano Heckla erupted violently (p. 97). "Strokk," just south of ’’Geysir, ” had played to a height of nearly 200 feet until an earthquake in 1896 put a stop to its performances (p. 100). Another quake in 1896 formed a new geyser at Reykir in Olfus where ’’great quantities of steam, mixed with dirt, clay, and fragments of palagonite rock, are said to have shot 600 to 700 feet into the air” (p. 69). A number of other examples of changes related to earthquakes are listed by Barth (pp. 72, 91, 92, 94, 101, 102, 112, 113, 115, 121, 122, 129). In summation Barth (1950, p. 156) states: ’’All Icelandic springs are strongly influenced by earthquakes and volcanic eruptions. During ; W..::,.. ; ■ .v: ' 7 'h. :.v.:; "V.'1' r , 8 an earthquake some of the existing springs will disappear, and new ones will appear. The lifetime of the individual springs may therefore differ considerably.,v : (2.2) New Zealand In the great volcanic and hydrothermal belt on New Zealand7 s North Island the exposed rocks are almost, exclusively Pliocene to Re cent acid volcanics—ignimbrites and rhyolites. Recent faulting is in evidence (Grange, 1932) and structural development seems to be still in progress (Modriniak and Studt, 1959). v . 1 . ; : Along the Whaketane fault, extending from the Bay of Plenty to Ruapehu, are found the greatest displays of hydrothermal activity. On North Island it is well understood that volcanic activity and earth quakes have a definite effect upon thermal activity. The largest geyser eruptions ever known were ,,Waimungu,s n from 1900 to 1908. This geyser, situated in the floor of a fissure- rent in Tarawera volcano, ejected mud and .water to a height of 1,200 feet (Park, 1910, p. 172). , L v r . (2.3) "The Geysers, ” California - ^ • Allen and Day (1927) conducted extensive work on the volcanic ’'Geysers” area, 90 m iles north of San Francisco. ;They found that the line connecting hot springs was about 25 m iles long, fairly straight. 9 and roughly parallel to the St. Helena Range. Similar relations were found throughout the area where fault lines had been traced. Allen and Day concluded (p. 11): "All geologists agree that these faults must be vitally connected with the cause of hot springs." M (2.4) Yellowstone National Park . - — — — ■ : ' . . - . : i O Although the Yellowstone area has had a long history of faulting and quaking, no record of earthquake effects upon the geysers and hot springs was made before August 1959. An earthquake of the magnitude felt in 1959 had never been experienced by white men in the Park, and consequently curiosity never arose concerning hydrothermal change by quaking. Yet over 100 tremors have been noted since 1871 in the Park (Fisher, I960, table 2), and must have caused some changes in the geysers and hot springs. Long ago, A. G. Peale recognized the association between earthquake and thermal feature phenomena (1878, pp. 363-364): .. j, £ : 1 r,“' ■* ’ ' ^ ' > - . M " 1 1 5 ' ! £ ' ' * *- * - - * * h + * . 4 - - 1 The effect of earthquakes upon thermal springs is a proof of their ultimate connection with volcanic action. In the first place... . the existence of fissures and cracks in the earth* s surface/ by whatever means they have formed, are efficient agents in causing hot springs by allowing meteoric waters to penetrate to great depths, and affording them afterwards free access to the surface. The earthquake-affected thermal springs mentioned here are evidently Icelandic since Peale later cites cases taken from Iceland's literature. . - •. . . . \ ' . • t \ - : 1 ■'j-i ■ - f L ** jt- % t -». - A, ^ • 4 4 — y: \^ ' * 1» It is interesting to note that Arnold Hague in writing upon the 10 origin of the Yellowstone thermal waters (1911) makes no reference to faults or fissures as an important feature bearing on the development of hot springs. ■ > v- B:v.' fr' - From studies'at "The Geysers, " Mount Lassen, and elsewhere, Allen and Day were certainly aware that "earthquakes, the most im portant factor, in fissuring, often affect the temperature and flow of the springs" (1935, p. 26). However, Yellowstone Park was in many ways a different story to them (p. 166): : j The importance of faults in hot spring theories has already been touched upon.... Local fissures, perhaps of a superficial character, are closely associated with hot springs in the : Mammoth area, at Norris Basin, the Upper Basin and Witch Creek, but neither the geologists of the Hayden Survey nor those of Hague7s time have brought to light a genetic relation ship between any of the hot-spring basins and fissures exten sive enough to be called faults. Probably in no other fundamental respect do the Yellow stone thermal areas differ so radically from most others. All observers in Iceland and New Zealand have been greatly impressed by the conspicuous faults and their apparently dominant relation to the hot springs; and while the relation is not universally found, it has been stressed by so many writers throughout the literature, as important .in so many localities, that faults have come to be thought of as a practically ins operable characteristic of hot spring areas. A sequence of craters, fumeroles or hot springs in an approximately straight line has been observed in many parts of the world and has been interpreted as evidence of a fault not otherwise indicated. In the experience of the writers, the phenomenon has been obvious in several hot-spring or fumerole localities. In the Yellowstone Park no striking relations of this kind have been discovered. Allen and Day, then, do not argue the fact that quaking may 11 have an effect upon Yellowstone7 s thermal features, but they do dis credit any fault control— at least surficially visible fault control. Reasons for this author7s disagreement with Allen and Day on fault con trol will be presented later on. ; ... Finally a quote from C. Max Bauer (1948, p. 52), former Yellowstone Chief Park-Naturalist, should be included: "That the geyser basins occur along zones of faulting is not disputed, but the belief that the faulting has had any appreciable effect on the appearance of the topography in the basins seems to us unwarranted." Evidently Bauer feels himself to be in possession of enough evidence to discredit the opinions of Allen and Day. . : :xi; . n . V .'i . ■ • • Yv-l ‘ 0'''~ 3. REGIONAL GEOLOGY Before presenting the effects of the 1959 eartluiuake and sub sequent quaking on Yellowstone* s thermal features and drawing con clusions therefrom, it will be helpful to review the regional geology of the western side of Yellowstone National Park. (3« 1) Rhyolite Plateau The Yellowstone Rhyolite Plateau represents a distinct physio graphic unit surrounded on the northwest, north, east, and south by mountain ranges, and dropping off abruptly to the Snake River Plains in Idaho on the southwest. The plateau covers about 2,000 square miles in the Park alone, at an average, elevation of 8,000 feet. The total amount of rhyolite within the plateau has been estimated at approximately 600 cubic miles making it one of the largest areas, volumewise, of salic volcanics known. ; : * r • The Continental Divide crosses the plateau from southeast to northwest. The western slope is drained by the Snake River and the eastern slope by the Firehole, Gibbon, Madison, Gallatin, and Yellow stone Rivers. The Firehole River running northward on the west side of the Park bisects the plateau and Old Faithful village along the Firehole 13 can be considered the center of the plateau. The Yellowstone Rhyolite Plateau proper is divided into the Madison Plateau (west and northwest of Old Faithful), the Pitchstone Plateau (south of Old Faithful), and the Central and Mirror Plateaus (east and northeast of Old Faithful). The rhyolite, which covers two-thirds of the Park, was ex truded on an erosion surface during Pliocene and Pleistocene epochs. Previous to the erosion interval an extensive thickness of Paleozoic and Mesozoic sediments had been covered by andesitic breccias of probable Eocene age. i : .? The volcanics making up the Yellowstone Plateau consist mainly of a thick series of rhyolitic flows and welded tuff inter bedded with minor amounts of basalt (Boyd, 1957). Subsequent to the eruption of the volcanics, the plateau was covered by a discontinuous veneer of glacial deposits. Recently, rhyolitic flows have been found overriding morainal material (Love, 1959). Extensively altered rhyolites attest to inter-rhyolitic hot spring activity, both pre-glacial and post-glacial, in several portions of the Park. O' 0 . • .0 , :oo";o (3.2) Faulting on the Plateau ; ■ V • .0 ■ . : 0. . .-VO v.-;-: -o.; Boyd (1957), using fault scarps as physiographic evidence, maintains that two recognizable periods of block faulting-have occurred during and subsequent to the rhyolitic eruptions. No regularity of trend of the faults was claimed for either period. ; . h\ ; i Love (1959), however, seems to haveuncovered a general - northwest to north trend while mapping Quaternary faults. (These Quaternary faults, determined by use of glacial movement and ice ; scours, would be included within Boyd* s second or post-rhyolitic faulting period.) Quaternary faults or fault systems and their trends according to Love are as follows: r ; ■ r: ■ 1. The northwest-trending Lamar "normal fault and the : ; i northwest-trending Mirror Plateau fault zone, both • ■ located in the northeast portion of the Park; - : • 2. The northwest-trending Yellowstone Falls fault system also on the Mirror Plateau; . u 3. The north-northwest-trending Solfatara fault ' i - t system, inithe.northern part of the Central • ,- '\ Plateau; i ' ■* .. T / . U '....;-u ■: y 4. The north-trending Heron Lake fault system ; . ^ , o:: ’ (thought to be a northern extension of the Tetcm : rv , ,v fault) in the southern portion.of the Pitchstone ■' • '.o.rr;-: % Plateau. .. i - ;; u v Boyd (1957) denies the use of hot springs as reliable criteria for important faults as very few hot springs actually exist along his larger faults (generally his older or first period of faulting). In a few places thermal features obviously had been localized by faulting and in 15 some cases hot springs appeared to have been localized by flow fronts. On the other hand Love (1959) lists the linear distribution of hot springs coinciding with linear topographic breaks as one of his major criteria of Quaternary fault recognition. On the Mirror Plateau, where hot springs emerge along many fault planes, springs are most numerous in the general area of greatest fault displacement. Outside the Rhyolite Plateau, Witkind (1959) has mapped a northwest-trending fault zone in the Hebgen Lake area northwest of Old Faithful village and to the west of the Yellowstone Park boundary. Evi dence was in the form of fresh scarps created in pre-Laramide sedi ments by the August 17, 1959 earthquake. A northwest trend of faulting and mountain range alignment is common in the Northern Rocky Mountains, but attempting to link the northwest-trending faults of the Hebgen Lake area with northwest trending systems in plateau rhyolite would be difficult. The Rhyolite Plateau is densely wooded and not easily accessible. Fault mapping in this monotonous rhyolitic expanse must proceed (in the preliminary stages, at any rate) by use of photogeology. Aerial photographs show the terrane to be relatively expressionless and it is doubted that proof of faulting through the thickness of volcanic material can be gained by this method alone. * •;. 16 (3.3) Geyser Basins The term ’’basins" here refers to relatively low areas in which large concentrations of thermal features occur. The basins of concern in this paper are drained by the Firehole River. These basins (Upper, Biscuit, Midway, and Lower from south to north) are flanked by canyon walls with a relief of 200 to 500 feet. Flow fronts, glaciation, and quite possibly faulting have influenced the topography of basin areas. The basin floors consist of gravels and volcanic rocks capped by opaline siliceous sinter (geyserite) deposited by hot spring activity. In a few places the hot spring deposits are calcareous in composition. In the Lower Geyser Basin glaciofluvial gravels indurated by thermal activity are overlain in many places by later outwash, product of a more recent glaciation. In 1929 C. N. Fenner (1936) headed a Geophysical Laboratory project which drilled two boreholes in geyser basin areas in order to determine subsurface conditions. The first hole was placed in the Upper Geyser Basin Myriad Group (PI. 4) a quarter of a m ile southwest of Old Faithful Geyser. It represented an environment of alkaline waters. Siliceous sinter was encountered from the surface to a 7 -foot depth. At this point pebbles of rhyolite appeared and their proportion gradually increased to 40 feet where the core consisted essentially of gravel cemented with opaline 17 silica and secondary quartz. Downward the gravels were altered and thoroughly indurated. At 220 feet and continuing to 400 feet rock of original dacitic composition was found, some of which had been obsidian and some lithoidal rhyolite. The second hole drilled in 1929 and 1930 was placed in an area of acid sulfate waters at Norris Geyser Basin 30 miles farther north. There were little or no sinter deposits and no superficial gravel beds at this location. In situ rock, evidently broken by fissures and joints, was found much closer to the surface. Pressures and temperatures in creased much more rapidly with increasing depth than was the case in ' ; Z • v/ Z. iZ ,■ Z:-. . C.. Z ; the Upper Basin. Fenner (1936) speculates that the great thickness of gravels in the Upper Basin might be due to overdeepening by glacial scour. The beds have the characteristics that might be expected of sediments de posited in lakes ponded by glacial ice. Fenner concludes that the hot spring system suggested by drilling is one in which an irregular main conduit extends from the surface to a moderate depth, and is connected ; - v: : ’ ; ■ Z : i:..' Z:- - Z - / . ,-Z v C1: :: '..Z: : ;,y Z " - ■ more or less freely with ramifying fissures, cavities, and channels ex- ■ z a =ZV'Z- ■ Zv.Z--- Z % x-Z y z,.'., :v - v ^ z.' v zzz:" tending upward, downward, and horizontally. Essentially, this conclu sion is in agreement with those of his colleagues Allen and Day. 1G7 " C ;' 4. 1959 EARTHQUAKE EFFECTS ON YELLOWSTONE THERMAL " : FEATURES v ; 7 ■ :;:7 >.■ t; . v ■ ' Following the August 17, 1959 earthquake the Firehole River geyser basins underwent immediate changes far greater than any in re corded history. Overall changes in thermal energy would certainly have been impossible to obtain quantitatively; however, from all visual and mechanical methods used, the effect of the quaking appeared to re- suit in a pronounced thermal energy increase. Many springs without previous records of geyser function became eruptive. Numerous geysers began playing on shortened intervals, some with increased duration of active periods. Very few geysers were found to have lengthened intervals between eruptions and only a handful were cessated. While a majority of springs experienced increased discharge of thermal waters, the water level in others dropped below normal. In a number of springs where ebbing had taken place geyser expert George Marler was convinced that the ebbing had been preceded by a sudden surging and discharge. Evidently the main earthquake served to trigger : :: " 1 7 i.o: .v-i I" /.r.; - ' 7- o'//- 77 r : 7 a discharge or an eruption from hundreds of features. ‘ 7f .7?'7..: "7,^ : 'i. - L ' 7 7- 7-;- Throughout the years temperature logs have been kept for a number of the major hydrothermal features in the Firehole River geyser *v-V.\ 18 19 basins. Temperatures of 167 named features, felt to represent a rea sonable cross section of thermal activity, are presented in the Appendix. The average temperatures for September 1951 and for the period 1958- 59 (pre-quake) are 185.9°F and 185. 6°F, respectively. This slight decrease in average temperature may have also been reflected in a slight lengthening of interval times in a number of major geysers in the several years before the earthquake. The average temperature of these 167 sample springs in September 1959, one month after the Hebgen quake, was 190. 6°F, representing a 6°F increase per thermal feature due to quake effects. The last temperature survey made before the writing of this paper was in August 1960. The average temperature of o o the sample features at that time was 190.9 F— . 3 F higher per feature than recorded 11 months previous. (A slight seasonal fluctuation in temperature can probably be disregarded. ) v ’ • The facial expression of Yellowstone hydrothermal activity changes from year to year, and a major question arises concerning the - line.between changes due to the 1959 quaking and those changes coming: about through ordinary processes of nature. This writer feels, however, that the increased temperatures noted in August I960 over September 1959 can still be attributed, for the most part, to the 1959 earthquakes." The : 30F. rise represents a reversal of the decreasing temperature trend apparently established in the decade before the August 17, 1959 earthquake. Furthermore,. those familiar with the thermal activity ; 20 during the pre-quake months of the summer of 1959 and then again dur ing the summer of 1960 appear unified in opinion that activity was much more erratic during theUatter period. This may be due to the fact that a number of minor seismic shocks were still occurring in the summer Of 1960. i r . " ' ;; . , i - " v n a. ' In the following discussion the main thermal groups of the ?. Firehole River geyser basins will be examined with regard to earth-- quake change and possible fault control. The discussion will be limited to major changes since to catalogue all happenings would require, a vol ume of extraordinary length. (Refer to Plate 1 for location of the groups under discussion.) ’ ' • vU .i>-'.r: (4.1) Old Faithful Geyser Contrary to popular belief this famed Upper Basin geyser is not noted for punctuality of eruptions. The eruption interval varies from 33 to 96 minutes; Since its discovery in 1872. however. Old Faith ful has gained a reputation as the most consistent of the geysers, having never undergone a period of dormancy. Its consistency may. well be ex plained by the fact that there are no other thermal features within its immediate vicinity and consequently it does not share its heat and water supply. ' Numerous other thermal features have subterranean connections with adjoining springs thereby causing irregularities in their functions (as will be brought out shortly). However, Old Faithful as a single unit 21 experiences no such change-qf-function irregularities. v This independence of Old Faithful Geyser from any other fea-: hire was thought to explain the "fact" that the geyser had apparently ex perienced little change after the earthquake. Its function was noted to be somewhat more erratic as far as interval extremes were concerned, but its overall interval average (hiring the last two weeks of August 1959 showed no great variation from interval averages for the earlier sum mer months. However, in September 1959 Old Faithful1 s intervals began lengthening, reaching a maximum interval peak in December 1959. Since World War n Old FaithfuTs average interval has been slowly decreasing from its "advertised" 65-minute interval to a 62. 8- minute interval in 1958. The intervals were shortening even further in the first half of 1959. Old Faithful Geyser--1959 ? Month No. of determined intervals Average (minutes) May 172 60.9 June 356 61.4 July . 397 62.0 August 1-17 224 61.0 August 18-31 175 62.1 September 399 65.0 October 47 66.8 22 Old Faithful Geyser— 1959, Continued Month No. of determined intervals Average (minutes) . -r e1: ' v c U- November no check : v oriV-y':.:- December* 255 67.4 : :t . Av".fr : .1:"; vv: .-r Old Faithful Geyser— 1960 A - 1 : i f 'n v . ':ix ■ -y _ Hr- riv r- ' v ' Month No. of determined intervals Average (minutes) f11r-; • ";,:i y , 'T'. January* 607 66.7 • ' ' : ' v ! ■ S -: ':.r -v ■ A. February* 607 66.5 :'UC rs G..:.. <:• yv: i r-- 1.- '-xy •! ; i ::: • March* 437 65.7 ■ • : ' v ;y -, ••f;.:. YAS.A::.: . A:::/ / A ^ -.0 A 'v 'yy:;; April* 228 65.7 ' A: i A:.- •An-- May* 470 65.8 . -)1 * : l '.."u. r: A.y '. y /A 1 .. AA \ . .VC;:vA, June 314 66.3 — ’';a ■ ' or :riV"y'1 y:;'"y ; y • ... 1A A:- .? July 367 66.0 • i , "• :v': 1" o:-: ' /::: /. - 'y]- .A — a a - : .. i August 358 66.8 oVi - ■ (A ■ »- ' --■ * A .y/A--"' ' / - '-AT'- - rt :;r ATTJ\AT' A A ■ y - -- -/ ♦The intervals for the months from December 1959 to May 1960 were recorded on a special time-clock mechanism operated by Park - Ranger Riley McClelland. .o: r-. The temperatures, averse lengths of eruption, and height of play (125-foot average) of Old Faithful Geyser do not seem to have - changed,- and thus, upon the evidence of interval averages, it is con cluded that the geyser has experienced a decrease in activity since the 1959 earthquakes. A.'.: -K- I-'v/ h: A - y., >y nv.-:;-y;v l;y;.v;:cy f: -i:: ; 23 (4.2) Geyser Hill . ''.v • :• ': % V ' < -v: Geyser Hill (PL 3), located 300 yards north of Old Faithful Geyser, contains many of the better-known hydrothermal features in Yellowstone* According to George MarlerTs records, 13 springs on ■ . ; ■ .'; /■/ ■ . ^ .V'r ' - ! v .:'r; re. , . . 1, -r. the hill had shown eruptive activity during the early part of 1959. • ■- . ' . r r ■ . - . r- ' r r n . ; .•■'■.l-'-' rv;v Following the earthquake this number increased to 29, with the majority showing new patterns of eruption behavior. V . . '::v : / . . ; ■ ■ . V ■ :■■■■■'■■ 5 - = Giantess Geyser is a large superheated spring located in the 1 . :f r " ' : : • ..r. . :v : :.r ■ . r r ' ; rr- central Geyser Hill area. This feature, capable of playing to 150-foot heights, erupts only two or three times a year on uncertain time in- tervals. Before the earthquake the longest eruption on record was 38 hours'of "on-and-off” or intermittent-type play. The August 17, 1959 quake induced an eruption from Giantess which continued intermittently for over 100 hours. Following this record performance the geyser went into a period of dormancy until experiencing a relatively "tame" erup- tion in February 1960. Giantess is known to affect a number of other thermal features V . 7:.. 37 ; 7 . 7- 7. 7-7 " 7. , 77 7 " 77 .7. h 7:7: : 7 7 with its powerful and voluminous eruptions. Springs experiencing water- drawdown and/or increased eruptive behavior due to Giantess1 earth- ...... -i. * . - : . . ■ ■ : - - * "■ .'1 - . t ■ ' • ' •, •. rv ' / . * quake-induced eruption included Sponge Geyser, Pump Geyser, Vault ■ .7 ’':'• .; ' 7’ .7 U. 7/7. : 7 7 , ■; 7 7, ^ : 7 '0 :L Geyser, Teakettle Spring, Infant Geyser, and possibly Dragon Spring : 7.7; f V7 " 7' ! : ■ - 777 7 v . _• 7,; 7,7. :r7 7/ 7,-77;; and Beehive Geyser. It is also possible that Giantess had a far-reaching 7 . -77 .77 , :.-r77:7 : ' 1 7 7 7. ; 77'7 - - 77 7 j [ 7. 7,/77 7;7 7 7'77, 7,, 7:7 .,7 .7,. 24 effect over much of the rest of Geyser Hill. • v . j. i.’: ; Lion Geyser,.a 75-footer on the west side of the hill, would go into an active phase about one day per week before the earthquake. Afterwards no activity was observed for several weeks (possibly due to the lengthy performance of Giantess). • In November, however. Lion r underwent a marked rejuvenation, i going into an active phase every second or third,day. ; ; i 1/ v : ' c ;i. : The morning after the major earthquake a hew feature was found to have come violently into existence about 250 feet south of Lion Geyser. Fragments of silica sinter were found scattered over a 15- foot radius about a new 6 x 6-foot feature: This feature, appropriately named "Blowout Spring, M exhibits the extremely cavernous nature of . areas of hydrothermal activity. . * * ~ f Beehive Geyser, capable of playing:220 feet high,: probably erupted at the time of the earthquake but its frequency of eruption did not seem to be noticeably changed in the following months. Its erup tions occurred two or three times a week as they had during the earlier part of the season. In November 1959, however, its function increased and for the remainder erf the year there were periods when Beehive would have, several consecutive daily eruptions. This increased function was also noted throughout the summer of 1960. h . : Plume Geyser near Beehive was one of the most punctual fea tures known prior to the earthquake. Its average eruption interval : : 25 during the 1959 season had been 63.8 minutes, interval lengths varying from 55 to 79 minutes. Following the quake Plume's activity seemed definitely curtailed some days totally unobserved in eruption. The author noticed, • however, that water was flowing into Plume* s crater from a steadily '■ erupting spring which had started playing the night of the 17th. Several shovelsful of silica sinter fragments served to - divert the air-cooled runoff away from Plume* s vent and the response was almost immediate. Consecutive intervals of 44, 44, 44, 42, 42, 41, 42, 41, 42, 43j 42 minutes were observed—-an amazing punctual ity! The results of the experiment showed without a doubt that the cooled runoff water was the main-—probably the sole—factor con tributing to the erratic play and lengthened intervals of Plume Geyser. The results also show that^ - given ordinary pre-quake surface condi tions, Plume Geyser tiad experienced a marked increase in thermal activity after August 17."" ; : ( •b — A rash of post-quake activity broke out in the area immediately northeast of Plume*Geyser. "Spume Geyser” and ”Spew Spouter” burst through the sinter and into activity for the first time on the night of the big quake. A quiet, unnamed spring began surging activity and was named ’’Surge Geyser." "Baker Hole” was named for a Ranger-' ; Naturalist who stepped through a thin sinter cover .the week following : the quake, creating a new spring while receiving severe leg burns, i Three small geysers^began activity at GH 5, while a large sinter patch 26 at.GH ,7 became perforated with small springs in what may be the prel ude to, the development of a neWilarge feature, h , e iv r; , r i v i - v : ^ to i Anemone Geyser; consists of three vents, all in a direct line, over a 7-foot distance. A chain reaction=was the typical performance pattern/ the central vent initiating the eruption about every 10 minutes, its water draining into the north vent. Following less than a minute of activity, discharge would shift to: the south vent. After the earthquake a small fissure opened near Anemone whose extension would have in cluded the geyser's aligned vents. Energy shifted to Anemone's south vent which has erupted most of the time since August 17, 1959. The central vent is now only;rarely observed in action, c ck ; : c : : ^ ; From available;records it seems that Cascade Geyser south of Anemone went dormant in*;1904. The earthquake initiated a new eruptive phase in• Cascade which was observed from August 18 to September, 15. Thirty-foot eruptions were seen with considerable regularity, (about every 15-minutes) for a couple of weeks following the quake. During September the eruption intervals lengthened out until Cascade,finally returned to dormancy in the middle of the month. ^ , ; cr.y.2. The highest cone on GeyseriHill:is located just south of Ova Pool. This feature must have had eruptive activity over a considerable time span in the past in order to create such a large cone but had never been seen in eruption. On November 4/. 1959 it burst into activity with jet-like eruptions 25 to 30 feet high, r This ^feature/ newly named - 27 "Dome" or VCone Geyser, " continued to have occasional eruptions through the summer of 1960. "Whether or not its activity can be attrib uted to the quaking is certainly questionable; however, the author , ob served so many delayed reaction effects of the quaking upon the thermal features that he does not hesitate in placing Dome^s activity in the quake-effect column. ; ; ; o • ; v : < v : • Many other features on,Geyser Hill were quake-affected but only the major changes or occurrences have been herein mentioned. (4.3) Myriad Group ; : -1,0 :: i o: ,:':: . v ,r ^ r ■ v , ; ;,v The Myriad Group (PI. 4) is a concmtration of acidic springs; located a quarter of a mile west of Old Faithful Geyser. These features have a murky, or muddy appearance, which is caused by their lack:of water. Close records were never kept for most of this group and con sequently there is little comparative data available on pre- and post quake activity, v:-.,. o v : . v " P u ; ; ; ; Pit Geyser,.;Bell Geyser,: Strata Geysm*, My 9, My 3, ami "White Geyser (Were found to be extremely active following the earth-? quake. The latter,feature was known to have been inactive during the first part of the 1959 season.: Two new geysers named 'West Trail" and'HEast Trail" (due to, their .proximity to a horse trail) played around 50 feet in height quite frequently for a few weeks following the main quake, then lapsed into dormancy. These two features, located 40 feet 28 apart, played simultaneously thus indicating direct underground connec tion. The main features in the Myriad Group are the Three Sisters Springs which actually consist of seven separate vents. During known history these springs have been characterized by frequent geyser ac- tivity but the pre-quake period of 1959 showed no activity from any of the vents. The entire springs area was filled with water. Following the earthquake the water began to ebb in all the craters, and by October - . ■■ ■ ::: ,:iy -■■■ Lovi.- • r"-: ' v \ ■ the two southernmost craters (F and G) became eruptive for the first time in their known histories. Before the end of the year vents A, C, D, and E also began periodic activity. By the summer of 1960 a cyclic pattern of eruptive activity between vents A, D (named "Little Broth er"), and E became dominant. The fissure-control of the Three Sisters Springs is quite obvious in the field and on the map. An area of new and energetic mudpot activity was watched after the main quake. The center of this activity centered about "Pink Cistern," a small mud volcano with a visible large chamber beneath the ;; ■ -j. ■ <■ :.v V ^ / . v;- • ; B :B / : v cone from whence the noise of slapping mud echoed for many yards. Activity in this area decreased after 3 months. ':' = ■= vl< r : f: IX-.; .V The location of the Geophysical Laboratory's 1929 drill hole within the Myriad Group is indicated on Plate 4. B: X;. vl'- • c r ; :X X : . . ■' B.;-- ... ’ ; i . ■■ i-y- : " i: -i " i :, 29 v .C (4.4) Castle Group r^ ..L-• -2 .x, - : The Castle Group (PL 5) is located about a quarter of a mile northwest of Geyser Hill and is bisected by the Firehole River. This group apparently has no water-supply problem since numerous joints k % 1 : k 1 • 1 :: • " •: U' - ■'' ' V-'-: ' ;"1 M ’ :■ : •- and cracks in the river channel are thought to provide ready access for ' ' '■ : r 1 " water to the underground hydrothermal "plumbing." (In fact most of the major thermal groups in the Upper Geyser Basin are located in close proximity to the northwest-flowing Firehole River.) Castle Geyser possesses a 17-foot sinter cone which has taken over 8/000 years to form. (The measured annual incremmit of silica sinter in this vicinity is 1/40 inch per year.) The geyser's average eruption interval before the earthquake was 15 hours and 53 minutes. Following the quake it became evident that Castle had received addi tional thermal energy since eruptions were being seen three times a day. On August 19 a 3-hour and 55-minute interval was clocked with \K’ no radical change in length of eruption or height of play observed. By September Castle had slowed to a 6- hour interval and then to a 9-hour average interval by mid-November. In the summer of 1960 it had U: ;;i.y r o;'. settled to a fairly consistent 10- 11-hour interval. "Whether the increased thermal energy was made available to Castle by the earthquake or by a shift of thermal energy from other springs is not known. The latter possibility is strengthened by the fact 30 that Crested Pool, 120 feet north of Castle, ebbed 12 inches and dropped 45°F in temperature after August 17. The ebbing water level caused cessation of a steady 15 gallons per minute (weir measurement) pre quake discharge. Marler feels that the dormancy of Grand Geyser (to be discussed shortly) may have had something to do with Castle's in creased play. " " - Subterranean interconnection of thermal features resulting in sympathetic or reciprocal behavior has been witnessed in Yellowstone for many years. -Marler (1951) writes: . . . in certain pair s of springs and geysers, changes of ! behavior take place in a strikingly reciprocal way. The water level in a given spring may undergo a rise> and that in a nearby spring will correspondingly recede. Or a given geyser will cease to erupt, while a neighboring * spring or dormant geyser simultaneously enters upon an 6 eruptive cycle.... In every instance thus far recognized : of interchange of function between neighboring units there is clear evidence of their subterranean interconnection. -- Indeed, it appears to be only by virtue of their common accessibility to the same local supply of underground hot water that their reciprocal interchange of behavior is ' possible. ' " ' ^ ; ^ - Giantess Geyser bri Geyser Hill and Grand Geyser are two major fea tures already mentioned which almost surely are connected with other thermal features. Sprinkler Geyser located bn the south bank of the Firehole River 350 feet northeast of Castle entered an extremely active cycle the night of August 17: The quake also initiated activity in a small fea ture immediately across the river from Sprinkler. -An eruption from 31 this new feature, .^Spatter Geyser, ” -followed almost instantaneously the cessation of an eruption of Sprinkler. In September a third spring joined the cyclic riverbank activity. Named "River Sprinkler," this small geyser would burst into activity even before Sprinkler (located 10 feet south) would cease. ; River Sprinkler in. turn would be cut short by the start of a Spatter eruption. ; : :v Sawmill and Tardy Geysers, in the midst of the Castle Group have been prime examples of sympathetic reaction for some time. In a typical pattern; of play. Sawmill will start an hour-long eruption all alone and then be joined after some length of time by Tardy (60 feet southeast of Sawmill). Tardy would continue to play for some time after Sawmill had ceased. Following the earthquake: Sawmill was seen in constant action,: sometimes accompanied by Tardy and sometimes alone, for several days. After a week Sawmill• had returned to inter mittent but frequent activity. On two different dates Sawmill went dormant and on both of these late August days a geyser 100 feet north east of Sawmill played continually., This; small: geyser erupted from : ’ five different orifices to a 20-foot height and was soon named "Penta Geyser." ^ v--- : 1 - r -c-y-u- vy-v;'1 v--: r ; ; Other, prominent earthquake-induced changes in the Castle Group included: :y ; - !-;ivv/y -y;yy- y lyyyyvyh- in : I;: Incrmsed temperatures and activity in the Orangey r y • ^ c . Spring sub-group on the west, including two new - 32 vgeysers at CG 31 and CG 36; 2. Increased activity from Bulger and Old Tardy {•:. >•} G: c \ Geysers in the north; 3. L Rejuvenation of Terra Cotta Springs whose C t ? f ; - v several vents began .cyclic activity; -- ; ^ i ■ p • . 14; A 6-inch water ebb in Spasmodic Geyser ac- . / r ' G ' companied by a temperature riseland in- ^ I creased vigor of boiling; . . ' J v.t 5. . An initial increase in activity and temperature ■ Ti ?!' in Oval Spring followed several months:later by ; : / a 34°F temperature drop and ebbing water level; ■ • ::-V 76. ' A 140°F temperature increase in CG 1 (the Frog Pond) on the ea sy and a corresponding 7 d 40°F temperature increase in nearby Liberty d . - : : dp . Pool. p: d . , : d d—P-: r di.-v-i' . .p ■' G > • , A clearly-marked^ northwest alignment of major thermal fea tures, some showing subterranean interconnection^ begins in the north ern portion of the Castle Group. The author feels that a probable fault exists along this trend and has called this rift the "Geyser Fault" (see PI. 1). This fault traverses several thermal areas while paralleling the course of the Firehole River and will be referred to frequently in the following pages. Continuation of the fault to the southeast of the Castle Group is most probable, but its strike in continuation is 83 questionable. r - vvy 1 C, :" . : v v::;/ v- * V:;: :-''v: "v-% :'p (4.5) Grand Group : n Located just northwest of the. Castle Group, the Grand Group (PI. 6) contains several of the more-famed thermal sjprings in the Upper Geyser Basin. The powerful 200-foot Grand Geyser (PL 9A) with its rocket-like eruptionsiis located in the southeast portion of the group; During 1959 the average interval time of Grand Geyser was 9 hours and 2 minutes (242 intervals checked); Its interconnection with Vent, Turban, Rift, and Triplet Geysers is indisputable. Before the earthquake Turban Geyser would have a minor surging eruption about every 17 minutes. As Grand neared its eruption its bowl would fill to overflowing with the approach of a Turban play. Next, South Triplet would begin to fill, and finally to overflow. Very soon then Grand would be triggered into eruption by one of Turban* s plays. Shortly after Grand began. Vent would join in concert.with the;now aroused Turban and both would continue their action long after Grand had finished. South Triplet would generally have a minor eruption while Grand was playing, but ir Rift .would wait several hours after;Grand's eruption before becoming active. f'-V-..;: v :n-vi v.T ':C: L\ . T. . : S::/k rvxhu/ 21 : Grand playW the morning of August 18 and then lapsed into dormancy. Its temperature had dropped from approximately 176°F n before the earthquake to 165°F afterwards:; : Grand did not play again 34 until this temperature deficit was erased. : On February 19, 1960 an erratic eruption: of Grand was observed, and eruptions continued to - occur about three times monthly throughout the summer of 1960. Vent and South Triplet were quiet through Grand1 a dormancy and Turban's o activity was greatly diminished. Rift was occasionally seen in action.' During one recent summer season George Marler claims to • have noted sympathetic responses in function between Castle and Grand Geysers that seemed ?'a bit more than coincidental. V Possibly the in activity of Grand after the earthquake was yoked to the increased ac tivity of Castle Geyser. It is quite probable that increased post-quake activity: northwest of Grand along the Geyser Fault had its effect upon Grand's inactivation also. . . " Economic Geyser northwest of Grand had been dormant since around 1925. with the exception of three reported 8-foot eruptions in 1957. The earthquake reactivated Economic and, even more surprising, started geyser activity from a cool water pool 25 feet northeast of u Economic. The new geyser, named "Short-run," played 40 feet high on undetermined intervals for approximately a week before terminating actiyityi(Pl. 10A). : Short-run's function was cyclic with that of Economic Geyser (whose maximum height was 25 feet). After September 21 Economic's intermittent activity ceased and the pools of both geysers cooled. "Whether or not Short- run had ever experienced geyser action before 1959 is questionable, but certainly no great activity had come 35 from its vent in many decades. Several Lodge-Pole pine trees whose heights indicated at least 60 years of growth were killed by hot water from the few bursts of Short-run following the earthquake. Temperature and turbulence increases of particular note also occurred in Wave Spring, Calida Pool, and newly-named "Milk Spring" in the Grand Group. A new 6-foot geyser called "Crack Geyser" began playing from a fissure in the northern portion of the group. Crack's activity started 2 weeks following the main quake and continued inter mittently throughout the rest of the year. Beauty Pool and Chromatic Pool in the northern portion of the Grand Group are known to have reciprocal activity. While one of these two features becomes "hot" and begins to overflow the other will "cool" - - - : ■: i • ’ ■ , . : and ebb in its crater. Interchange of function might occur every few months. Beauty Pool was overflowing at the time of the earthquake and its discharge was doubled following the quake to the accompani- • > . : o ment of a 4 F temperature increase. The only change in Chromatic Pool was further ebbing. It should be noted that the most pronounced changes within this group of thermal features occurred along the Geyser Fault. Increased activity northwest along the fault (Economic, Short-run, and Crack Geysers, and Wave Spring) might well have partially accounted for the decreased activity in Grand Geyser and associated features southeast along this fault. 36 (4 .6) Oblong Geyser ' . - : • : : Oblong Geyser, situated west-northwest of the Grand Group, is not a member of any well-defined thermal group. Yet this 25-foot geyser with its tremendous eruption discharge is one of the more in- teresting spouters in the Park. It is located on the bank of the Firehole River. . During the pre-quake period of 1959 Oblongrs eruptions occurred every 6 to 8 hours—the same frequency it had shown for several sea- sons. The eartlMiuake doubled this frequency. During the last week of September, 47 intervals were mechanically checked disclosing an av erage eruption interval of 3 hours and 31 minutes. For the remainder of the year it continued to play on essentially the same frequency, with its activity decreasing only slightly by the 1960 summer season. Since only five men participated in the earthquake change studies in the Upper Geyser Basin after mid-September, some mechanism had to be invented to help keep track of the numerous thermal changes oc curring. Ranger-Naturalist William Germeraad devised a "geyser time-clock," several of which helped provide valuable information on eruption intervals (Pi. 10B). The clock would be placed in the runoff channel of the geyser it "watched." Following an eruption, water flowing down the runoff channel moved through a chute attached to the clock. A metal gate within the chute would be swung open, moving a 37 pencil on the dial of an operating clock over which a circular time-sheet had been pasted. After the runoff channel had cleared of water the gate would swing shut. Time sheets had to be changed every one to two days and the clock kept wound. Battery-charged electrical clocks were also devised but fared poorly in operation. (4. 7) Giant Group Giant Geyser and most of its associate thermal features are located on a large sinter mound northwest of the Grand Group and along the projection of the Geyser Fault. Giant, when active, is reputed to be the highest playing geyser in'the Park—the initial burst of an eruption climbing well over 200 feet. Giantrs action is, however, sporadic. During some seasons it will be completely dormant. Giant has now been dormant since a 1952-55 active cycle. There is no doubt about Giant's connections underground with Mastiff, Catfish, and Bijou Geysers all located upon the Giant Geyser mound. In 1948 Marler noted that the Purple Pools, located across the Firehole River from Giant, would constantly overflow during Giant's dormancy but would ebb during one of the large geyser's active periods. ' - - : ' ' - -- ' Certain actions in the 1952 season revealed a major cause of Giant's long record of irregularity. During that summer a subterranean connection between Giant and Grotto Geyser 220 yards to the northwest. 38 became apparent. Marler wrote (1952): "There would seem to be little question but that the Grotto Group has been the dominant cause of the GianVs record of cyclic behavior. As has been the case during the ; : current season, there is little doubt but that the Giant's earlier active cycles must have been attended with a decrease in function of the Grotto Group" (PI. 13B). : ■ v 1 ' At the end of the 1955 season Grotto became active sending Giant into dormancy. Grotto's activity continued up to and through the period of quaking with little apparent change. Following the August 17 shock Giant and some of its associate features experienced slight tem perature increases and stronger surging action but none of the group was restored to activity. Several times since the earthquake ■ Giant has appeared to be on the verge of activity, but the steady function of Grotto has evidently nullified its efforts. 0 , ; (If and when Giant is reactivated it will be of particular in- 1 ter est to watch for: signs of subterranean interconnection between it and either the Oblong and/dr Daisy G eysers.) - : ■ \ *v'’I- V i:, ;'f:Jr" - :vr v ' a'"-?;i>: (4 .8) Grotto Group ' • Grotto Geyser and its immediate neighbor springs are located northwest of the Giant Geyser along the Geyser Fault, while a little farther northwest alongIthe same projection are found the Chain Lakes (PI. 7). It is thought that activity shifts along a northwest-southeast 39 line between these two portions of the Grotto Group although evidence . is not yet satisfactorily tangible. Incr eased activity in the southeast part of the group evidently means decreased activity in the Chain Lakes, and vice-versa.. />'..■ ‘x--- x-x/x - x x.-x xv:1 /-x: .x ; Grotto Geyser is known to be immediately connected with n Rocket and Surprise Geysers, Indicator Spring, several other nearby unnamed springs, and probably more distantly with Spa Geyser. Ac tivity is so frequent in this sub-group that it is difficult to perceive of a change in amount of activity, but it is doubtful that any major change resulted in these features from the 1959 earthquaking. A typical . - pattern of play here in the 1960 season was as follows: Following a 3- 5-hour Grotto eruption. Indicator Spring would slowly fill, and vents GG 2, GG 3, and GG 4 would become more and more active; as Indicator Spring filled to within about an inch of overflowing Surprise Geyser would begin erupting, building up slowly to 70-fqotheights during a 20- minute play; only a few minutes following the start of Surprise, Grotto would have an initial 25- to 40-foqt burst, and then, joined by; Rocket, would play with low surging activity for several hours; Indicator Spring would empty at the close of all activity. Weir measurement showed that Grotto and Rocket together would discharge 468. 6 gallons per minute while in eruption. - , w v u : x ;; -r : ; - Occasionally the triggering mechanism between Surprise and Grotto would .not . . .function. •. .. On . these .. occasions .» - -. Grotto ' would . . "jump ... w . . m j the 40 gun” by beginning its eruption before Surprise had started. I This !'pre mature" activity in Grotto would quiet Surprise which would then ex perience no eruption.. _ ; North of Surprise Geyser four small features are located along a northwest alignment. These thermal springs all experienced small temperature increases and great ebbing following the earthquake. CL 15 farther north became hot and began overflowing late in the fall of 1959, its activity continuing through 1960. : . : Riverside Geyser across the Firehole River to the northeast is placed in the Grotto Group although it shows no connection with any of its springs (or any other springs). Riverside plays to a maximum height of 70 feet, arcing its waters out and over the Firehole River. Its eruptions last 20 minutes and are preceded by a period of overflow where about 60 gallons per minute (measured with bucket, hose, and stopwatch) spill off the geyser cone’ and into the river: The preliminary overflow lasts about 90 minutes. Prior to the 1959 quaking Riverside performed on a 7- to 7- l/2-hour interval. Following the earthquake the length of the overflow period deer eased as did the eruption interval. Several 5-1/2-hour intervals were timed before Riverside slowly began to shift back to its pre-quake style of play. . J. =: r : • j The Chain Lake features experienced a little ebbing and some increase in temperature. • Little increased activity was noted. - ; It should be pointed out that the line between increased and 41 decreased activity in many of the features following the earthquake was practically impossible to ascertain. On the maps accompanying this paper the author has indicated changed activity, either increased or \ decreased, hi those features where definite change has occurred but its direction quantitatively is uncertain, the author has used his own judgement based on observation; -For instance, if it is felt that a tem per atur e incr ease in a particular feature,was enough to: offset cessation of overflow and/or ebbing, the featureihas.been marked as one of in cr eased activity. v : v v.: Hr .-.re--. : - (4.9) Daisy Group ■ i - •■■u.Hvr v ; . r r ■ y ; r . ; H: - ; • This small but significant group is located an eighth of a mile west of Grotto Geyser (PI. 8). Splendid,} Comet, and Daisy G eysers,. and certain other springs are found in a due east-west alignment which most certainly represents either a large fissure or a: fault (possibly a result of. tension) joining the Geyser Fault. Activity would shift east- • . ward or westward along this opening in pre-quake days. Daisy Geyser is known to be affected by wind. _ On a calm day its eruptions (pre-quake) would occur regularly about every 2 hours. A slight breeze fanning across its pool would delay an impeding erup tion up to 30 minutes* while a strong wind had been known to hold Daisy over 2 hours past its predicted time of play. - The delay is probably due not so much to a cooling effect of the ^wind but to a slopping of water 42 from the geyseribowl. This loss of water decreases pressure in the geyser vent ’causing• the extra- sensitive Daisy to.build up additional pressure before erupting. 'Several other geysers (i. e. Grand Geyser, and Morning Geyser in the Lower Geyser Basin) are similarly affected by the wind. , U::i w.rylnz C7; r.c : - U:.-. C " Daisy would play normally and regularly during clear, wind less weather, (PI. 13A). Its average height would be 70 feet with the eruption lasting 3 to 4 minutes. Following an eruption, much of the erupted water .would flow back into the Daisy vent. However, with the approach of a storm front Daisy would become inactive and Splendid Geyser to the west would go into an eruptive cycle playing to ,150-foot heights. As the barometric pressure increased following the storm, activity would shift back to Daisy and Splendid would become .inactive. On some, days, a small geyser. 40 feet’southeast of Splendid called "Daisy* s Thief" would become active halting Daisy’s regular function. No explanation for this strange occurrence can yet be offered other than refer mice to Daisy! s extreme sensitivity: , ; . t . ; Q : > . The l959 earthquakes str ongly over -shifted activity to the east profoundly increasing the function of Daisy. Geyser and several other features from" Radiator-Spring to Bank Geyser, t It seems probable that Splendid erupted in concert with Daisy at the time of the main quake (for the f^st time in recorded history). However, Splendid has not been seen in eruption since the earthquake— evidently stopped by the 43 lover-shifted’activity’away to the east, o u ; - < ; k , ] - 1.,. 01 ; : : In the pre-quake months 84 intervals/ averaging 136i 8 minutes, were recorded on Daisy." For the first couple of weeks after the earth quake 34 intervals were logged showing an aver age eruption interval of 82.6 minutes,' < but varying anywhere from 35 to 145 minutes, i On September 1, 1959 a geyser time-clock was placed near Daisy giving the following results: Date Maximum interval Minimum interval Average interval Sept. 1 85 minutes ~~ 69 minutes 74.3 minutes Sept. 3 1 v73:,. i-; 55 I"-'./? zv vv-.;'. 60.9 : • Sept. 4 ' :% 71 v: " : G‘y.,- . 1:45. -xlivi’y Sept. 5 •::: h' 61 Cvr.. iz- ..-. 47.-. 1; r Sept. 6 55 M - 37 :" ..1: 47.9 The 28-minute, interval on September 5 is the shortest known for Daisy Geyser. . Following September 6 Daisy's activity slowly de creased^ :'X: u'i ." , r r,;: : y f1 u v.- ( " O n 'r :.1,'-::. ia- 'ay Bonita Pool just east of Daisy Geyser had been quiet and at o sub- 90 F temperatures for many years. Its last known activity was in 1938 when small eruptions caused a corresponding dormancy in Daisy. On February 22, 1960 Bonita began to erupt with a strong pre-eruption = overflow. Ranger Riley McClelland reported that Daisy's interval at- fthat time, roughly 80 to 90 minutes, increased to 85 to 125 minutes. Bonita's activity at a temperature of 1909f persisted through 1960. 44 Due to Bonita’s activity'Daisy has now become quite’erratic, playing on a 2- to 4 -hour interval. A dike placed around Bonita in August 1960 to V 1 retain its overflow caused greater regularity in Daisy (yet wind-affected) and increased its function to an average interval of 100 minutes. Very probably the main reason that Daisy did hot become inactive with Bonita* s resurgence would be the over-shift of activity eastward in the Daisy Group. r ' '-v:: ■' 1 l : . (4.10) Black Sand Basin 3 ^ J r The Black Sand Basin is located 1-1/2 miles west of Old Faith ful Geyser in the Upper Geyser Basin. (PL 1). - Its activity is concen trated along Iron Creek, a tributary to the Firehole River. The author feels that the Black Sand activity and Hillside Springs activity (a mile farther north) might well tie due to a fault which is represented by high rhyolitic cliffs bounding the west side of the basin. These cliffs are too high and too gently arcing to represent merely flow fronts and are in correctly aligned to be the result of known glacial movements in this portion of the Yellowstone Rhyolite Plateau;1' This possible fault has been named the Upper Basin Fault ' < h ; " r ’ ’ - The Black Sand Basin experienced numerous changes due to the earthquake but only a few will be mentioned here. Most of the thermal features experienced a slight temperature increase and many underwent temporary increased activity. - Sunset Lake; erupted the night of the 45 earthquake s ending'scalding water: over: the beautiful algal- cover ed • 1 v c banks of Iron Creek, v The hot waters destroyed the algae indicating a water temperature in excess of 1680F.:i tt took several months for.the algae to grow back. Cliff Geyser became extremely active playing to unprecedented 40-foot heights on several occasions. A previously u suspected subterranean connection b^ween Green Spring and Rainbow Pool to the northwest was not evidenced. ■; : . ^ ' i * (4.11) Area Between Chain Lakes and Biscuit Basin : L Vv .cni:. On Plate 1 a number of thermal features can be seen to exist between the Chain Lakes and Biscuit Basin to the northwest. J Most of these features lie close to the Firehole River and are located near the. trace of the Geyser Fault. The majority of.these hydrothermal springs experienced increased activity after August 17, 1959. Famous Morning Glory Pool increased 6?F.in temperature while ebbing several inches. : L v The most pronounced change in this area occurred in the vicinity of Hillside Geyser. Several small geysers, including "Baby Daisy," became very active on the flat shelf northeast of Hillside. . Greatly increased activity was noted on the west bank of the Firehole River directly across from Hillside. / V F a y ^ - :c yy; : ' in . y V. . Hillside Geyser has:surged to 8-foot heights in the last few years,; and in 1952 it played upwards to 25 feet. After the earthquake Hillside became extremely active, playing 15 to 30, feet high and y 46 throwing a great.volume of water into the Firehole River. Four or five eruptions -would occur on ah average 28-minute interval, followed by a ; major play after another 65 minutes. Here an eruption would evidently be "missed" causing the long wait; i ; u 0 1 V :u : During the I960 season Hillside continued to play at least once an hour. Throughout the summer months the ground southeast of Hill side increased in temperature killing all vegetation. This hot spot wiU bear close observation in the future. (4.12) Biscuit Basin The Biscuit Basin is a compact thermal area located at the lower or northwest end of the Upper Geyser Basin (PI." 1). It is regret- able that the 1959 earthquake study crew did not have time to conduct a plane table survey of this area before the extreme winter cold set in> since Biscuit Basin underwent probably the greatest and most spectac ular change in the months foHowing the Hebgeh Lake quake. > • Temperatures increased all throughout this thermal area after August 17, 1959. A large patch of ground (approximately an acre in size) on the southern side of Biscuit Basin became very hot destroying all vegetation. Several new springs of 200°F temperatures formed in this "hot" region. On the west most of the hydrothermal springs ex perienced increased, sometimes violent, activity while their water levels ebbed. Two rather obvious thermal feature alignments noted 47 before the earthquake became pronounced northeast tiaids by late , August. ’A new northwest-trending fissure in the middle of the area was discovered. • v - • m.' Mv v_ -.: : y. : - ■ /.'Og/:-:.'; V';':' :' : • To the east the southern banks of Black Opal and Wall Springs experienced slumping: A hot spot developed in the northern end of the latter feature! To the southeast alcmg the banks of the Firehole River and within the river itself, a rash of new springs broke out along the trace of the Geyser Fault; < P:. • \ A; -P P .■ G. i.c; - The most spectacular change occurred in Sapphire Geyser. Before the earthquake a wooden bridge1 existed:along the western side of this 20 x 20-foot spring and it was possible to look‘down 30 feet into clear blue waters.’ About every 17 minutes the calm surface of Sapphire would break into a '’boiling'' activity caused by rising gas bubbles. This " eruption” would last several minutes," sometimes roiling up to 5 feet. Following the earthquake Sapphire was in a state of constant i activity playing 5 to 12 feet high. This condition lasted almost 3 weeks. Early on the morning of September 5 the Old Faithful area rolled under one of the several strong after shocks 1 of the main earthquake. This shock induced a gigantic nighttime eruption from Sapphire which, al though unwitnessed, left much evidence in the way of strewn sinter i , : fragments and wash marks aU about the spring*s• circumference: On!. -* the morning of September 5 the water level in Sapphire was down about 10 feet; Through the morning the water level rose, and as it did the 48 churning .water became calmer and calmer. Finally the waters^ now ominously silent, reached the rim and began overflowing.The water .. surface began to bulge .and shortly ther eafter the geyser exploded into action. - J.’ .) ^ r e' - c vf '-,;n r-:' ; v The Park-personnel present at the time had seen geysers play to the near .200-foot height that Sapphire did that morning. But none had ever witnessed such a massive and voluminous display of power , and water as they were seeing (PI. 11A). Jets of water shot over 100 feet in every direction. After this first burst.the entire hillside • , . streamed with hot waters; a foot deep in places, for several minutes. Several other mushroom-like bursts came from Sapphire on 5-minute intervals before the eruption ended. : Now, with the water level far down in its crater, the geyser began the slow buildup to the next eruption. • Sapphire continued to play on 2-hour intervals until the morn ing of September 14. ; Another strong after shock was recorded early in the morning, and by dawn Sapphire was back to a constantly roiling and overflowing state. This subdued activity lasted until September 29 when another good-sized aftershock was felt and Sapphire again; resumed periodic violent activity. ] Y; o , i Y i; i n r ^ Sapphire did not react noticeably to every moderate or strong . afterquake. Consequently there were a few people skeptical toward the idea of a geyser so sensitive to quaking. However, after the geyser's third or fourth- change in function, which coincided with a strong quake, ( 49 even these people became convinced of Sapphire’s sensitivity. : y/-’.: Byimid-October the=swift runoff;waters from Sapphire's erup tions had carried enough sinter material to form three different deltas extending 20 feet into the-Firehole River a couple of hundred yards distant. Two of these deltas were built to the east of the geyser (PI. 1 IB) and the other. to the south.- The decreased activity of Sapphire , through most of the winter and spring coupled with the high river waters in the spring washed these deltaic deposits, away. < ; - ^ - - Sapphire's sporadic activity continued through the summer of 1960. The author witnessed one 200-foot plus eruption in June which occurred just before a long period of inactivity set in. This inactivity, was not broken until August 7 when Sapphire again began an eruptive cycle. This reactivation coincided with the dsde of two dish-rattling ’ tremors felt to the south in the Soda Springs, Idaho area. Whatever. it;is that certain tremors do to the underground mechanism causing such extreme functional clmnges in Sapphire Geyser is still very much a matter of speculation, r, Of probable importance ;> ‘ would be the: shifting of sinter blocks or the movement along fault or : fissure planes: It might be productive to analyze Sapphire's function c changes with respect to directions to the epicenters of causitive quakes. This might show a certain type of movement to be responsible for the ; geyser's erratic activity.. The author did not have enough information to perform this check. - . - ^ • 50 The volume of water and the energy released by a large Sapphire eruption are incalculable. Much of the water flows back into the crater and the rest, discharged to the Firehole River, is unmeasur able by any method available. Measurement of river volume changes downstream from Biscuit Basin would probably not give satisfactory results. As for the geyser’s power, blocks of sinter which must have weighed close to 400 pounds have been wrenched from the crater walls and thrown out and over the sinter rim. The size of the crater is con stantly enlarging due to material cast out during eruptions, and this growing crater may cause the cessation of geyser activity as it has already caused a greater width and a lesser height to major eruptions. ■ . ■ : ...... • ■ . Cessation of activity could result from too much surface area on the pool allowing gas to escape rather than to be trapped below. Sapphire’s activity is being keenly watched in Yellowstone. A green sandy material has been emitted from Sapphire and neighboring Jewel Geyser since the earthquake. A sample of this sand under microscope shows about 70 percent orthoclase, 20 to 25 percent quartz, and 5 to 10 percent analcite. Analcite was found also by Fenner (1936) in the Upper Geyser Basin borehole and is undoubtedly authigenic. u . ' :n\;-V ■•: ‘ ■ :v' J . ■ v - The greenish hue of the sand is probably due to feldspar alteration. A present-day geochemical sampling of thermal waters and deposits which : 'll" ' ' ' ; i i ...V . . ' ' ' could be compared with the results obtained by Allen and Day several decades ago might be rewarding. 51 (4.13) Midway Geyser Basin > i • ' * ' ' - ; ...: •: .. . ' . ■ » - ' . - < • • •. - .. / • . - ,r i If any thermal area along the Firehole River could be said to - ' f xi" Lifo'.ir/ :;v: ;L_ have undergone a decrease in activity after the earthquake, it would be : 'u -:' v':. ' ' L-v.'V.: - I- -;.; -JL y- the Midway Geyser Basin located between the Upper and Lower Basins - -' v r: / 'v; L.l l:' .-'f i , - v v [•- •.;>:? .n: '■ : :■ v." (PI. 1). Comparatively little time was spent by the earthquake crew in this area and consequently little detail of its change is known. Excelsior Crater, which housed a reputed 300-foot geyser of the 1880? s, experienced little or no change. (It is curious to note that photographs taken of ExcelsiorTs eruptions show its shape and volume to be comparable with that of Sapphire G eyser.) Grand Prismatic Spring : o - - . .•;- : W'V. lL . ;P1, : i::..'‘p. - was tilted slightly to the east but was otherwise little changed. Turquoise " l..; :: L ’U-iOL l p: ■ L ;■ • v lv r , . y vv:'’ Pool emptied through a fissure in its floor, and Indigo Spring ebbed a foot. Both features are recovering slowly. Many of the other thermal springs were murky the morning after the quake (as were most of the springs in the geyser basins) and some underwent definite changes of - : '■ ■ ; Gr-v;. v .X,y:;;:.; i v:';; '.Ovy': W v -'Vv:: :v.. ;v.v L function. ■ ' - ■■ • v V: v'l '.vr L:.?v V,.-, VV w v / r.'.P , V v L. Th-: To the east of the Midway Basin proper is located a region of '■•;Lv vv .v. : ,"" . y •,:vv y . /v .vxi •'('> 'vv."Fr-Lv:;-' widely scattered and unnamed springs known as the Rabbit Creek thermal L-LL’V Lv ?•' ''U v; : w F w i'-;'-: "VlvL". vv c,v LLv. v% area. A number of these features are found in a linear arrangement : V - L 'VL: ; vv-: F ’v:.: v, ; v r •: L -3 ivFv.v.'.; v. v, v v-vrrrK;- along a mountainside bench which topographically represents a fault, v: v L..:; v v: v : ■) . v: •• :;v ’ v;vv v vv' D L-u :: v w : L L ■ " :■ v,.. herein called the Grizzly Fault. No roads or trails enter the Rabbit vv ; V: L . v,v:L !V! ' vv:"-i v;.:;h Lvv vvv-ti'r r;v.-v.v«'V ::v:v ’ Creek thermal area and Park visitors are not encouraged to visit the Avywi -wv ,-v.'F'Fv v L vv. &2 features tiue to the presence of a large number of Grizzly bears that feed at a nearby dump. The author, however, was able to visit this region once prior to the earthquake and several times following it, and did notice considerable change. Some features had become hotter and were overflowing into meadow areas. Other features had drained or ebbed greatly. Mudpot activity in two locations was definitely increased^ No temperature records were kept in this area, l v> ■ i (4.14) Great Fountain-White Dome Area Great Fountain Geyser is located in the southeastern portion of the Lower Geyser Basin near White Creek (PI. 1). During the 1959 summer season this 150-foot plus geyser played on an average interval of 12 hours and 46 minutes. Its intermittent activity would last approxi mately an hour. - - '' l : . '--y- ■ y ■ ■ y.7.’: " Following the earthquake it was impracticable to stay in the ° vicinity of Great Fountain long enough to determine any change of function, but from all appearances its function had altered. The first determined interval on August 22 was 3 hours and 40 minutes. From September 18 to 20 an eruption time-clock was placed on the geyser showing an average interval of 5 hours and 46 minutes with a minimum of 3 hours and 10 minutes and a maximum of 9 hours and 15 minutes. The interval continued to lengthen through the winter months and by August 1960 was roughly 8 hours. ' .; .o ' 1 ; 53 :• Many of the pre-emption indicators (various overflow stages) were also changed making the previously quite predictable Great Foun tain Geyser quite unpredictable for a year's time. . l • Just south of Great Fountain Geyser lies a large meadow through which flows the heated waters of TVhite Creek. A number of the thermal features found in this meadow area and.southeastward along the banks of the creek underwent an activity increase. Several areas experienced hitherto unseen geyser activity. Westward down White Creek and along the Fir ehole Lake Loop Road other hydrothermal springs underwent various activity changes (Lemon Spring, Broken Egg Spring, Fir ehole Pool, Surprise Pool in the Appendix). X" ' ; * ; Several hot-water creeks in this vicinity are of interest in reference to their origins. The author; has traced three of these flows into the forests to the southeast of the Lower Geyser Basin to find their headwaters originating from small springs set against rhyolitic cliffs or at the.base of rhyolite outcrops. The rock is certainly fractured in this region and one would guess that the meteoric water supply comes from farther up on the Central Plateau. . Four-hundred yards north and a little west of the Great Foun tain Geyser is a high sinter cone from which a thin stream of water periodically sprays 30 feet high. This feature, White Dome Geyser, is in the process of sealing its vent, and for a while it looked as if the earthquake had lent a helping, hand. For two weeks following the main 54 quake no activity was reported from "White Dome. In early September the geyser became rejuvenated, playing cm intervals quite erratic in length, varying from 25 to 118 minutes. A month later "White Dome seemed to be back to its pre-quake pattern,of play. . > h r, ,at(«, ; Just northwest of 'White Dome Geyser is a tract of sinter land punctured by numerous springs which add hot waters to the adjacent i Tangled Creek. This area underwent greatly increased activity follow ing the earthquake with some springs showing new geyser activity and a couple of ^groups'! of these features displaying functional intercon nected activity, never before.noticed. . r , 1 C v, : :; i . ^ : 1 Across the Loop Road east, of "White Dome;several vents began geyser activity .after August 17. One of these vents, inactive for many years according to George Marler, began an eruptive cycle in October. Ranger-Naturalist Germeraad and the author were roving by truck in the vicinity as it began its activity. Tree branches, rocks, and rusty beer cans were observed being thrown from its vent. This little 8- footer, located on a fissure cracky was very active on certain daysc throughout the remainder of the year. (- i l r- G r G :: . • ; . i Northeast of IWhite lk)me Geyser is found the small but .interest ing Bead Group; Bead Geyser is one of the most punctual features,in the Park, r Prior to the earthquake it would play: a 20-to 25-foot,water column every 33 minutes (varying no more than half a minute). Im mediately following the quake it performed on 60-minute intervals, but 55 then increased activity' and by late October was erupting every 15 to 16 minutes. This doubly increased activity persisted throughout the re mainder Of the year; : v . v-Uon Five;’ ;:v Just west of Bead Geyser a superheated spring with thin sinter rims erupted a few times in the days immediately following the earth quake. Evidently the author is the only person to have seen an actual eruption of this feature, known as ,fLedge. " Its play was unspectacular dimensionally— erupting no higher than 10 feet—but its discharge was of considerable proportions.: O F : i :! Chie other geyser in this group. Pink Coney experienced greatly increased activity following the quake. Before, it had played only two or three times a week, lasting from 90 to 120 minutes. Following the quake it was observed playing at least one-third of the time for several months. ' • • ’-""vv ' '"V.vv: F F.' , ■ 1 • : 'Fv'.’ - vr1 F:.:-U F. 1:0° K. (FL. Tlx: .. (4.15) Firehole Lake Area ex r FT :;y i :"';1 ir:::: :;:':11 " Firehole Lake, Hot Lake, and several other large hot-water springs are located in the far eastern end of the Lower Geyser Basin (Pis. 1 and 2). The earthquake openW many fissure cracks in this area and plane table mapping was initiated in late October to record the extent of the cracking. ^ Plate 2 shows the results— 9,072 feet or L 72 miles of fissure cracks; The pattern is obviously one of subsidence, much of the fissurhig ringing the hot-water lakes. Firehole Lake 56 slumped and tilted to the north (PI. 12A) and is still evidently in the process of correcting its level. A constant check of the changing shore lines of the lake has confirmed the observation that Firehole Lake is in the process of tilting back to its pre-quake position. A plausible explanation for the subsidence lies in the nature of the sinter. Unlike most of the geyser basin sinter deposits which are almost totally siliceous in nature, the Firehole Lake sinter capping is a combination of silica and travertine. The calcic content helps de crease the strength of the deposit to the point where strong shaking will collapse some of the cavity-riddled material at nominal depth. (4.16) Fountain and Kaleidoscope Groups Both the Fountain Group and the Kaleidoscope Group, situated along the Grand Loop Highway in the Lower Geyser Basin, appear to be controlled by large fissures or faults striking N. 80° E. (PI. 1). These parallel alignments are probably not controlled by the same fracture at depth beneath the glacial gravels and sinter deposits since no thermal activity exists over a 250-yard width between the two groups. Several east-west surficial fissures exist in the Fountain Group, but all other visible fissures appear to be north-south tension openings. It was the author's fortune to have been riding on the highway near the Fountain area at the time of the earthquake. A decision to check the area by flashlight proved to be rewarding. 57 Morning Geyser within the Fountain Group was so-named be cause only on very windless mornings would its eruptions (up to 150 feet high) occur. This geyser would initiate a cycle of activity that., would lead to an eruption of Clepsydra Geyser to the southwest and pos sibly of Fountain Geyser, immediately adjacent to the south. Clepsydra would frequently erupt from all four vents on its,cone rather than from a single vent. This concerted action in Clepsydra was known as the "wild phase. " :v,.:y r.v.-/y.-v: ? About five minutes after the earthquake but with the ground still quivering, the author arrived at the Fountain parking lot to find Morning Geyser in an unprecedented midnight eruption escorted by one vent of Clepsydra Geyser. Unfortunately at the time the author was not, familiar with much of the activity in this area and cannot state positively which features, other than Morning and Clepsydra Geysers, were in action. A number of smaller features were playing in the vicinity of Clepsydra and quite possibly the Fountain Geyser was. among them. > The roar of numerous geysers and the constantly shaking ground was. something that-will not be soon forgotten. ; : J t ^ ; > • ■ Fifteen minutes after the initial shock. Clepsydra's other three vents sputtered into action and the wild phase began (PI. 9B). The next morning found Morning, Clepsydra, and Fountain all playing simulta- : neously and a hew 100-foot geyser, named "Earthquake Geyser, " ■ occasionally erupting in the. Kaleidoscope Group to the north. 58 Fountain’s eruptions' ceased by August 19, Morning continued intermittently with waning activity until September 1, but Clepsydra Geyser continues to this day to play continuously from its four vents. Fountain, Morning, Jet, and Spasm Geysers, aU highly active im mediately following the earthquake, have now been dormant for 16 months (since October 1959) or longer—-their water supply and heat source apparently diverted to the constantly playing 15- to 50-foot Clepsydra. Their activity may not start again until (and if) Clepsydra ceases. To the west of Clepsydra Geyser greatly increased activity from a number of vents was seen following the quake and much of this activity continues. To the east the famed Fountain Paint Pots displayed a somewhat delayed reaction to the quaking. Mudpot activity here be came more and more violent with each passing day. Large hunks of mud spattered over the wooden railing and out onto the sidewalk and parking lot pavement. Activity began to undermine several portions of the parking lot, while several new large pots opened just to the north. Mud seeped into the underground tubing of Leather Pool to the north arid Silex Spring to the south, muddying their generally clear waters. Both Leather Pool and Silex Spring experienced ebbing and increased temperature." Leather Pool erupted once to a 40-foot height while Silex roiled its muddy waters to 5- and 6-foot heights for over a month, taking on the appearance of a giant chocolate malt-mixer. 59 . In the Kaleidoscope Group numerous changes occurred to many small, unnamed features. The ground in the western portion became so "rotten" that the earthquake study crew members were hesitant to explore, into the area. Many new geysers, some bursting almost 50 feet high, were: seen. IXiring the. 1960 summer season this western- : most activity seemed to be still on the increase. ; i j f ; : v On the eastern side of the Kaleidoscope Group the new Earth quake Geyser was seen several times following the quake. As its ac tivity ceased,, countless small springs in its vicinity became more ac tive. : 3;';'' : ,v 7 " c:- "■ : ‘ : Beautiful Gentian Pool, just east of Earthquake Geyser, ebbed 41 inches in the month following the quake; Then, slowly, its waters began to rise until it once again neared its pre-quake overflow by Christmas. 7 . - ; -7 : ":':v ' 777-7 l7'7 777 77 ■ ■ : : r,: ' 7. _ • "7 , .7. 7/ -7;., .:7 (4.17) Other Thermal Areas in the Firehole Basins ‘7. U - .:77' 7, - C. \ 7 V. ■■7 >7 7~ i r . 7 -7'. " r :7 70 .,7 7.; 7 G 7.7-7:v_7' The author visited a number of other thermal areas in the Fire- hole River basins after the earthquake. A brief resume of the findings will now be mentioned. Several of these areas are shown on Plate 1. 7:7;;■77 The,Lone Star Geyser Basin is found 3-1/2 miles southeast of Old Faithful village along the Firehole River. Little comparative data is available to show pre- and post-quake conditions, but no great:changes appear to have taken place in this area. The Lone Star Geyser continued 60 the same pattern of activity. A few springs ebbed while others began . greater flow; o: he -nc:-,. c-up::/"x, :::;d s ‘.:;rL: h ••••■• The l^er-Tracksrare along the Firehole River juM ^ st of the Old Faithful campground. Increased mu<^pt and spring activity was evident here. The Pipeline Creek thermal area to the northeast showed minor changes (including increased mudpot activity) within its few rather small features.' kK r/ r rd--: : V.v ' ‘ Solitary Geyser,- a man-made spouter caused by pumping of the spring* s hot waters for the bid Inn swimming pool, appeared to be little affected by the quaking. Solitary sits alone on a hillside above Geyser Hill. d'o-.. ,1 •; v';"u : -r..... : v’ v ":v; r : : ■ . - v It was impossible to tell if the Hillside Springs southwest of Biscuit Basin had undergone change. Any change would have been only manifested in increased or decreased discharge from this mixed travertine-silica sinter area of deposition; u a : - ' :! ; In the Fairy Creek meadow onithe western side of the Lower Geyser Basin change in function and/or discharge was noted in several springs. To the west of. these meadows and against the glacially-de posited Twin Buttes is found the old Imperial Geyser crater and as- v’. .a: sociated features. This geyser played over 100 feet high in the late 1920* s before becoming inactive. The earthquake did not restore the Imperial's activity but did increase adjacent mudpot activity and the function of nearby:Spray Geyser. aThe earthquake also opened a number 61 of steaming fissures Mgh up on the western member of the Twin Buttes. ; Signs of earthquake-night eruptions and slightly increased ac tivity were found in the Sentinel Creek meadows north of the fairy Creek district, and also in the River Group whose features are scattered in proximity to the banks of the Ffrehole River west of-the. Fountain Group. , . T-vr-n;-aiu.-o ) h. . cu: :- • - : Pocket Basin, located about three-quarters of a mile north west of the Kaleidoscope Group, underwent spectacular mudpot activity change. This increased,activity persisted into June and. early July of I960.; One huge mud crater was found to have thrown mud a measured 100 feet from-its crater rim. ; Activity here seemed to slack off in late summer, probably due to lack of water, and may become quite violent again by spring of 1961 when its water supply will be replenished. : ; H North of the Fountain Paint Pots are located several other i . smaU thermal areas where it is difficult to ascertain, the nature, of r earthquake change .due to the fact that these areas are rarely-visited and no data upon the springs! is kept.: Some evidences of change, pos sibly due to the earthquake, were found in these areas. . ;■ Lu ! u. p i c- ';.''.’y ij;-’ ::h v-:. : k ■ vc ILc lilrli; (4.18) Other Thermal Areas of Yellowstone Park u r tiifi l..:';:':;: '-?. Naturalist Alan Mebane and Ranger-Naturalist JXck Frisbee were.assigned to check thermal areas other than!those;along the Fire- hole River to see if any; earthquake change could be found These meal 62 had only 24- to 75-year did literary-descriptions to serve as pre-quake comparisons,' a situation which made their work extremely difficult. Generally they did not find many evidences of earthquake-caused ac tivity, but several of their discoveries are worthy of mention. Norris Geyser Basin, 12 miles north-northeast of the Lower Geyser Basin, underwent some change. Temperature measurements are of interest. In 1927 Allen and Day (1935) derived an average temperature of 185°F for 60 thermal features. A 185. 5°F average was found by Ranger Verde Watson for 43 of these same features between 1952 and 1954. Mebane and Frisbee arrived at an average of 180. 5°F for the same 43 springs after the quake— a fact which seems to point to an overall activity decrease following August 17, 1959. Several miles southwest of Norris, pronounced changes occurred in the Sylvan Springs area. Increased temperatures and activity in both mudpots and clear-water springs were found here. A new mud volcano broke out in a portion of the forest near Sylvan Springs creating a scene of havoc (PL 12B). The author and others noted that a number of trees in the vicinity of the new mudpot had had their upper extremities "topped," evidently by the violent shaking which must have accompanied the birth of the new feature. Some new activity was found by Mebane and Frisbee in the Gibbon Geyser Basin, Monument Geyser Basin, Nymph Lake area. Heart Lake Geyser Basin, and Shoshone Geyser Basin. In general, all 63 obvious physical changes that were found were restricted to the west ern half of the Park. v-. .. ?: r--i\ a ; : ^:X.; * 'C ’ ' : c' ■ ■; L: ■. , ru / • ; ' ■ V ;V: V :"-v ?.-r\ i\A \' hz'V-- ■ r-' - : "' . ■ r ! r -1'-.: ‘ -.r . 5. CONCLUSIONS : h; - \ '-Wx.-x-'/ •’ ■■ ■ It has been semi that the;August 17j 1959 earthquaking and subsequent quaking extensively altered hydrothermal activity within the Firehole River geyser basins. There is little reason to doubt that previous earthquaking—before white men entered the Yellowstone region in the early 1800*Sr—has also produced significant changes with in the vast thermal feature network. It could be argued that the hydro- thermal activity had its inception with some of the tectonic events that certainly accompanied the building of the great Rhyolite Plateau. Furthermore, temperature and discharge measurements and visual knowledge of eruptive activity point toward an increase in thermal activity throughout most of the Firehole basins since the earthquake. It is interesting to note that greater change occurred in the Firehole basins than in the Norris and Gibbon Geyser basins to the north even though the latter areas are located a bit closer to the quake epicenter.' The only exception seems to be the Sylvan Springs area located in the Gibbon meadows which did experience some profound alteration. V - ; On Plate 1 the author has shown the existence or implied existence of several faults in the Firehole River basins region. Various persons have suspected the presence of several of these faults; Until 64 65 now, as far as the author knows, t these faults have never been-mapped. Aerial photographs, topographic expression, thermal feature alignment, and interchange of activity have all influenced the author's judgement. The difficulties encountered in trying to map faults in the plateau areas and depositions! basin areas have already been discussed. Aerial photo graphs are certainly not; infallible since; expressions of faulting, glacial movement, and human occupation can become confused. An apparent scarp located by photograph about a mile northeast of Morning Glory Pool turned out to be nothing but the border of an area timbered several decades ago to supply construction material and fuel for the Old Faith ful area. Unfortunately, clear-cut conclusions such as this one cannot be made very often following backwoods inspection, -k ■ - < 1 - Probably the most important fault implied is the Geyser Fault trending about N. 35° W. throughithe Upper Geyser Basin (PI. 14B). The existence of such a fault seems to have been in the mind of George Marler for some time.G His work on the detection of interchanging func tion between various thermal features coupled with many of the results of the 1959 earthquakes have thoroughly convinced the author of the existence of such a fault; It is shown as probable only because some people might argue that clear-cut evidence of such a fault is lacking. The author believes, however, that the evidence is reasonably clear- . cut and has been established with further certainty by the results of the 1959,-earthquakes, v; -■ .. v / c c :-y : 66 Thermal activity in the Upper Geyser Basin is found largely along the banks of the Firehole River. One might think that this re- iy:( lationship is 5 due to the simple fact that the river must serve as a - water- supply source for the springs.: But large areas of thermal ac tivity exist away from streams (characterized by acid waters and/or mudpot activity) while many areas' along river banks in active thermal basins are devoid of thermal;activity. ; The author proposes that the course of the Firehole River in the Upper Geyser Basin is therefore controlled by the strike of the Geyser Fault. This would seem to :* satisfy the scientific mind more than would the explanation of activity along the river banks due to proximity of water supply. ; ’ • The Geyser Fault probably continues to the southeast past the Castle Group and up the course of the Firehole River. No reliable clues as to the extension :in this direction could be found, however, so the. extension is left in question.: Thermal feature alignments in both the Myriad Group and Geyser Hill area suggest the fault's continuation. In pure speculation it might be proposed that a split in the fault occurs in the vicinity of Grand Geyser; one branch striking south through the Myriad Group (which might account for the hint of interchanging func tion between Grand and Castle Geysers) and the other branch striking southeast through the Geyser Hill area and on up along the Deer Tracks, v : r The IWsy Fault (or fissure) has been discussed and there is little question of its existence. /> It appears to; occupy a tension direction 67 with respect to the Geyser Fault. ; = >:d ; i.--.* v ? . ‘ v : : Any, continuation of the Geyser Fault past the cliffs overlooking Biscuit Basin is questionable. However, aerial photographs show a rather pronounced topographic trough trending:northwest across the . Madison Plateau and the author has named this feature the Madison Fault. The fault extends at least 2 miles farther to the northwest than can be shown on Plate 1. A faint indication of a trace continued off the aerial photographs that were in the author* s possession. A small but definite canyon does exist along the trace of the Madison Fault as shown on Plate 1, running somewhat transverse to the other canyons hi this region. The author found this depressions! area to be quite linear and located several small rock slides along its walls.that were evidently caused by the 1959 earthquakes (PI. 14A). ' : ; . : : Whether the Madison Fault is a continuation or an offset con tinuation of the Geyser. Fault or is en echelon with respect to it is un known. The Upper Basin;Fault(?) lends a little credence to the pos sibility of offseLh ll: 1 . \ ■ ' • '-...v::-. *:':: ■ : The Upper Basin Fault(?) has been thought by some to repre- sent the flow front of rhyolitic lavas coming from the west. The 300- to 500-foot cliffs which smoothly arc along the course of this possible fault would seem to be ia rather steep and abrupt termination of a flow or series of flows. Willard; Lacy has suggested that these cliffs might r epr esent a lava flow over an: already existing scarp. The author thinks 68 that the possibility of subsidence should not be overlooked, considering the adjacent areas of hydrothermal activity. The existence of the Hill side Springs along the cliffs and the proximity of the Black Sand Basin to the trace of the fault(?) do not detract from the possibility of a fault. Several people have voiced discontent with the flow-front idea, and Bauer (1948, p. 39) evidently contends that there is a fault or fissure - along these cliffs. c v.r : : r : V':-. • The north-south striking Grizzly Fault is quite apparent both from the ground and on aerial photographs. It is too linear to repre sent a flow front and does not correspond with any known glacial move ments in the area. "Walking south along the trace of the fault from the vicinity of the Great Fountain Geyser one cannot help but be impressed by the straight valley which runs contrary to all canyons joining the Firehole River from the Central Plateau. Sinter deposits from ancient thermal activity are found all along this fault. Just to the east of the Rabbit Creek thermal area the fault occupies a north-south trending bench along which mudpots and springs are found in conspicuous align ment. Oh to the'south the Grizzly Fault is not so well defined on the ground but is quite obvious for another 1-1/2 miles on aerial photographs. : A - Just east of the Great Fountain Geyser the Grizzly Fault marks the eastern border of the Lower Geyser Basin.; The hot waters of : Tangled Creek are diverted by the fault. The Bead Geyser Group is located directly along the northern continuation of the Grizzly Fault and 69 strong north-south thermal feature alignment is obvious here. Three further speculatory faults have been included on Plate 1; The straight course of Tangled Creek northwest.from White Dome Geyser along with certain small thermal feature alignments gave rise to the concept of this fault(?)—the Tangled Creek Fault(?). It would be easy to extend its trace southeast along the ’White Creek thermal ac tivity except for the existence, of the Grizzly Fault. Arbitrarily the author has designated the White Creek Fault(?) an individual break fully realizing that such a fault(?) might well be the offset continuation of the Tangled Creek Fault(?). . If an offset has occurred due to the Grizzly Fault, thermal feature activity, in existence suggests the possibility of left-lateral movement of that fault. ; • ^ n-;. - The Midway Fault(?) has been introduced as a possible explana tion for the sudden northwest swing in the Firehole River upon entering the Midway Geyser Basin. > The northwest-running river is remarkably straight here. This fault(?) could well be responsible for ?the Midway Basin activity and some of the adjacent Rabbit Creek activity, v i f.-jf.i The faults or fissures controlling the Fountain and Kaleido scope Groups have been discussed and their relation to, the developing picture of fault control is,uncertain. Their strikes and demonstrable lengths are similar to the Daisy Fault (or fissure) suggesting openings by tension. Surficial fissures in these areas would seem to indicate, on the other hand, that these two alignments are shear directions. The 70 true picture may be wound in complexity. It is of more than passing interest to note that the apparent picture of northwest-trending openings herein developed for the Fire- hole River geyser basins can be extended northwestward to the Hebgen Lake area where Witkind (1959) mapped a similarly-trending fault ; system after the 1959 earthquake. It has been pointed out earlier in this paper that projecting the Hebgen Lake fault system in sedimentary and metamorphic rock to northwest trends on the Rhyolite Plateau is ' -. --k Ok':;.".-- ■-v , ■: :u. highly speculative. However, the author earnestly suggests that such a projection from the Hebgen Lake area to the Old Faithful area may, iv. C-v; kk in fact, exist. This would help explain why the Firehole River geyser basins experienced the greatest amount of earthquake change among Yellowstone thermal areas in 1959. •« ' The northwest fault trends noted in the Firehole basins are in accord with the pattern developed by Love (1959) for the Rhyolite Plateau i: v. 1' -n. f'k" vv.: ' ‘ ' .. ;Vv as a whole. A northwest fault trend and mountain range alignment is ' r,v r - - ■ f- if" ; ;• f common to the Northern Rocky Mountains. Considering the evidence Vf, k ■ a v """v from almost every other area of thermal activity in the world it would - ...... - , -k" ^ ' - . : % : . seem quite strange to doubt the existence of fault control in the great thermal basins of the Firehole River simply because no clear-cut . k k r ./k. : k . v. k 1: .k.:;: surficial evidence is at hand. v :k: kv;..:' k k :kk "0:: .4. ‘ » ' • • 4. . . j . \ .1 :k>.: ki/k: k'-k kv -k c<- 17 ,7, . 7-0.. 7''"> : r: 1 ULv ' c : :7:/ 1:7-7) 6. APPENDIX— TEMPERATURE RECORDS OF YELLOWSTONE " THERMAL FEATURES :■ ; ; 777 7u.. 0'\ r: : O ' ;-' ■ i 7 i 77 ; ,. •. '; • -!” -i - •• " ^ Sept. 1958- Sept. Aug. ,, 1951 1959 1959 1960 '1. ■Si."" r . .[.V 7 V.' / 1. Morning Glory Pool ; r i 169°F 163°F 169°F 164°F 2. E. • Sentinel Geyser • r; 200 200 202 203 3. Spiteful Spring 198 199 200 204 4. Fan Geyser - v' 199 199 202 202 5. Mortar Geyser r n 199 199 200 202 6. Riverside Geyser 200 200 200 203 7. Link Geyser <7 202 157 163 151 8. Bottomless Pit Spring 140 195 198 194 9. Square Spring 201 199 200 194 10. Culvert Geyser 198 200 202 202 11. Rocket Geyser 200 200 200 204 12. Grotto Geyser > i - 201 201 201 204 13. Spa Geyser 182 183 183 201 14. Surprise Geyser 200 200 198 190 15. Giant Geyser 203 202 203 204 16. #7 Grotto Group ’ • 177 175 184 182 17. Catfish Geyser 200 198 202 202 18. Mastiff Geyser : :: 204 203 205 203 19. Turtle Geyser 199 200 200 198 20. S. Purple Pool 140 145 182 150 21. E. Purple Pool 196 196 196 202 22. N. Purple Pool 196 197 197 202 23. Chromatic Spring 171 164 164 192 24. Beauty Pool 161 164 169 170 25. Inkwell Spring 200 200 201 202 26. Oblong Geyser 197 198 200 203 27. Bonita Pool 140 104 105 196 28. Daisy Geyser 196 196 200 200 29. Brilliant Pool; 194 194 203 197 30. Comet Geyser 200 200 202 205 31. Splendid Geyser 200 200 202 202 32. Daisy's Thief Geyser 199 199 200 202 33. Punch Bowl Spring 201 201 202 203 34. Black Sand Pool 197 197 200 202 70, m r.oo O 7 : 71 72 Sept. 1958- Sept. Aug. 1951 1959 1959 1960 35.. "Whistle Geyser > 199°F 143°F 144°F 170°F 36. Spouter Geyser 197 198 200 204 37; Green Spring > 159 177 179 172 38. Emerald Spring 155 147 150 142 392 HandercMef-Pool 176 177 165 158 40. Rainbow Pool 166 166 163 162 41. Sunset 'Lake ■ ” 185 183 190 190 42. N.' Three Sisters Spring 181 182 198 204 43. M: Three Sisters Spring 171 171 185 182 44. S. Three.Sisters Spring 183 183 185 202 45.. Orange Spring 138 139 180 174 46. Orange Pear Spring 137 137 141 128 47. Round Spring •>;; 178 137 142 142 482 N. Round Spring : 151 150 165 152 49. Pear Spring : ; ; 166 165 194 161 50.. "W. Round Spring 142 142 160 161 51. Castle Geyser 200 200 201 202 52; #26 Castle Group 199 199 200 199 53. Tortoise Shell Spring 203 202 202 207 54; Crested Pool 200 200 155 151 55. Sprinkler Geyser 194 194 198 201 56. Chimney Fumarole 200 200 200 200 57. S. Scalloped Spring 198 198 202 200 58.. Scalloped Spring 200 198 201 196 592 Deleated Teakettle 200 200 199 201 60. Churn Geyser : ;; 151 155 161 171 61.. Sawmill Geyser 167 189 194 179 62. Tardy Geyser ■ 194 194 196 200 63.. Frog Spring : 64 64 196 199 64. Liberty Pool 132 133 163 182 65. Spasmodic Geyser 199 199 203 204 66. Oval Spring Go 199 199 201 167 67. Old Tardy Geyser 201 200 202 202 68.. Belgian Pool , 164 163 161 167 69. Bulger. Geyser 198 199 202 194 70. "W. Triplet Geyser :' 184 185 182 179 71. Grand Geyser 169 176 165 176 72. Turban Geyser. 196 197 187 198 73. Economic;Geyser 144 154 200 170 74. "Wave Spring : ; 131 134 163 188 75. Calida Pool 183 183 192 191 76. Milk Spring 190 194 200 202 73 Sept. 1958- Sept. Aug. 1951 1959 1959 1960 77. Lime Kiln Spring 200°F 200°F 200°F 201°F 78. Witches Cauldron 200 200 200 203 79. Terra Cotta Spring ! 196 196 197 200 80. Infant Geyser 199 198 201 202 81. Giantess Geyser 200 198 200 204 82. Vault Geyser 198 184 197 186 83. Teakettle Spring 199 199 203 203 84. Dome Geyser 193 191 194 200 85. Rock Pool 198 198 198 202 86. Pump Geyser : 199 199 199 202 87. Sponge Geyser ; 202 202 200 204 88. Model Geyser 192 192 194 204 89. Dragon Spring 198 198 200 180 190. W. Doublet Spring 178 180 193 194 91. E. Doublet Spring 193 193 196 194 92. Beach Spring 178 185 201 200 193. Aurum Geyser 201 201 201 202 194. Pendant Geyser: ; 201 201 201 202 95. Ear Spring 200 200 202 203 96. W. Goggle Spring 196 196 200 204 97. Lion Geyser 201 200 200 204 98. Big Cub Geyser 200 200 203 204 99. Lioness Geyser 200 200 201 204 100. Little Cub Geyser 200 200 200 200 101. Heart Spring 200 199 200 196 102. Arrowhead Spring 177 175 200 184 103. Depression Geyser 182 186 188 190 104. E. Scissor Spring c 200 200 200 202 105. Beehive Geyser 203 203 203 206 106. Cascade Geyser 186 186 200 194 107. Plume Geyser ' ‘ . 195 197 201 200 108. N. Anemone Geyser 197 198 198 198 109. S. Anemone Geyser 197 197 197 201 110. Blue Star Spring 184 185 186 186 111. Chinaman Spring 200 200 201 203 112. E. Chinaman Spring 196 196 198 196 113. Old Faithful Geyser 200 200 200 200 114. Cone Fumarole 200 200 200 202 115. Artemesia Geyser 180 180 181 190 116. Atomizer Geyser 198 198 198 200 117. Iron Spring 193 193 193 202 118. Gem Pool 188 189 194 186 74 Sept. 1958- Sept. Aug. 1951 1959 1959 1960 119. Spright Spring 167°F 164°F 181°F 154°F 120. Calthos Spring 184 184 195 180 121. Shelved Sp. W. Calthos 199 199 201 194 122. Hillside Geyser 202 202 202 203 123. Cauliflower Geyser 192 190 192 190 124. Mirror Pool 183 183 184 166 125. Black Opal Spring 172 172 173 134 126. Sapphire Geyser 202 202 204 204 127. Black Pearl Geyser 199 199 : 200 , 200 128. TV. Mustard Spring 164 163 200 202 129. E. Mustard Spring 136 157 200 200 130. Avoca Spring 198. 198 202 204 131. Shell Geyser 198 198 202 199 132. Lemon Spring 147 143 137 134 133. Broken Egg Spring 151 152 187 156 134. Firehole Pool 196 196 196 197 135. Surprise Pool 200 200 202 204 136. Great Fountain Geyser 202 202 203 204 137. White Dome Geyser 199 199 199 202 138. Pink Cone Geyser 200 200 201 203 139. Bead Geyser 182 183 177 185 140. Shelf Spring 199 199 202 204 141. Narcissus Geyser 171 171 168 178 142. Zomar Spring 166 166 167 170 143. Black Warrior Spring 195 195 177 199 144. E. end Firehole Lake 165 165 174 176 145. E. side Firehole Lake 150 151 148 174 146. Young Hopeful Geyser 200 200 198 202 147. Silex Spring 190 190 200 190 148. Celestine Pool 196 196 200 195 149. Fountain Paint Pots 188 192 200 196 150. Jelly Geyser 193 192 193 209 151. Spasm Geyser 196 196 200 202 152. Bellefontaine Geyser 198 198 200 192 153. Fountain Geyser 157 159 159 159 154. Morning Geyser 189 188 193 188 155. Center Vent Clepsydra 198 198 200 200 156. E. Vent Clepsydra 176 177 200 200 157. W. Vent Clepsydra 198 196 201 202 158. Sub Geyser 184 188 196 196 159. Jet Geyser 198 199 199 199 160. Thud Geyser 180 180 183 194 75 Sept. 1958- Sept. Aug. 1951 1959 1959 1960 161. Thud Spring 179°F 179°F 189°F 201°F 162. Stirrup Spring 191 190 191 192 163. Gourd Spring 158 157 186 180 164. Jug Spring 163 163 161 172 165. Cliff Spring 197 197 196 196 166. Oak Leaf Spring 196 196 196 200 167. Kidney Spring 195 198 196 197 Totals 31, 041 30, 989 832 31, 881 Average Temperature 185. 9°F 185. 6° 190. 6°F 190.9°F PLATE 9 CHANGES IN GEYSER ACTIVITY A Grand Geyser experienced 6 months of dormancy after the August 17, 1959 earthquake. Its ac tivity throughout the summer of 1960 was in frequent and unpredictable. B Clepsydra Geyser has been in a constant state of eruption since the Hebgen Lake earthquake. It plays simultaneously from four separate vents on its cone—a phenomenon known as Clepsydra’s "wild phase." 76 PLATE 9 PLATE 10 CHANGES IN GEYSER ACTIVITY A Short-run Geyser, just northwest of Grand Geyser, played several times in the week following the main earthquake—then became dormant. This spring had never been known to erupt before the earthquake. Note the Lodgepole pines that are dying from the hot water "baths." B A geyser time-clock is being placed in a runoff channel near Oblong Geyser. The clock m e chanically records times of eruption, lengths of eruptions, and intervals. 77 PLATE 10 PLATE 11 CHANGES IN GEYSER ACTIVITY A Sapphire Geyser began having enormous eruptions following a heavy aftershock on the morning of September 5, 1959. Its function has been altered by several different tremors since that time. This picture was taken about 100 yards from the crater's rim. B Sapphire Geyser's runoff was of sufficient quantity and velocity to build deltas into the Firehole River during the fall of 1959. Some of the fragmental silica sinter was washed a distance of over 200 yards. These deltas were swept away by high waters in the spring of 1960. 78 PLATE 11 ■ PLATE 12 RESULTS OF THE EARTHQUAKE A Approximately 1-3/4 miles of slump cracks were mapped in the Firehole Lake area (see also PI. 2). Firehole Lake tilted to the north, spilling its thermal waters over previously dry sinter (upper right). B A new mud volcano broke out violently near Sylvan Hot Springs following the Hebgen Lake quake. No sign of any such activity was known in this forested area before August 17, 1959. 79 PLATE 12 PLATE 13 INTERCONNECTION OF THERMAL FEATURES A As Daisy Geyser (background) erupts, Brilliant Pool ebbs about a foot. Brilliant will fill again before Daisyrs next eruption. B Grotto Geyser (right center) is known to have sub terranean connections with Giant Geyser (arrow). "While one is active, the other is dormant. Grotto has been in an active cycle since 1955 and was seemingly unaffected by the 1959 quaking. Giant has not erupted since 1955. 80 PLATE 13 PLATE 14 FAULTING IN THE UPPER GEYSER BASIN A Small slides were caused by the earthquakes along the trace of the Madison Fault northwest of Biscuit Basin. (Looking northwest.) B The Firehole River and major geyser activity are found along the northwest-trending Geyser Fault in the Upper Geyser Basin. Looking southeast from the cliffs above Biscuit Basin, the alignment is obvious. Major thermal activity is found between Biscuit Basin (center) and Old Faithful village 2 m iles distant (upper right-center). 81 PLATE 14 7. BIBLIOGRAPHY Allen, E. T ., and Day, A. L ., 1927, Steam wells and other thermal activity at the geysers, Carnegie Institute of Washington, Pub. No. 378. ______1935, Hot springs of Yellowstone National Park, * >i - * > ^ w"" * y Carnegie' Institute of Washington Pub. No. 466." Barth, T.-F. W., 1950, Volcanic geology, hot springs and geysers of Iceland, Carnegie Institute of Washington Pub. No. 587. Bauer, C. M., 1948, Yellowstone—its underworld, Univ. of New Mexico Press. Boyd, F. R ., Jr., 1957, Geology of the Yellowstone Rhyolite Plateau, unpublished doctoral thesis. Harvard Univ. Fenner, C. N., 1936, Borehole investigations in Yellowstone Park, . . • - • Journal of Geology, vol. 44, pp. 225-315. Fisher, W. A., 1960, Yellowstone's living geology. Special issue of Yellowstone Nature Notes, vol. XXXm. Grange, L. I:, 1932, Taupb earthquakes, 1922, New Zealand Journal of Scientific Technology, vol. 14, pp. 139-141. Hague, Arnold, 1911, Origin of the thermal waters of Yellowstone Natio^ P^k, G^ Soc; America Bull.!^ vol. 22,' pp/ 103-122. 82 83 Hayden, F. V ., et a l., 1883, Twelfth annual report of the U. S. Geological and Geographical Survey of the Territories for 1878, Part II, pp. 1-488. Love, J. D ., 1959, Reconnaissance study of Quaternary faults in and south of Yellowstone National Park, Wyoming, for GSA publica tion. Marler, George, 1951, Exchange of function as a cause of geyser ir regularity, Am. Jour. Sci., vol. 249, pp. 329-342. ______1952, Yellowstone Nature Notes, vol. XXVI, No. 6, p. 67. Modriniak, N., and Studt, F. E ., 1959, Geological structure and volcanism of the Taupo-Tarawera district, New Zealand Journal of Geology and Geophysics, vol. 2, pp. 654-684. Nile, S. W ., et a l., 1959, Preliminary report of the Hebgen Lake Montana earthquake, U. S. Coast and Geod. Survey, Washing ton, D. C. Park, James, 1910, The geology of New Zealand, Whitcombe and Tombs Ltd., Melbourne. Witkind, I. J ., 1959, The Hebgen Lake earthquake, Geotimes, vol. 4, No. 3, pp. 13-14. Further information has been taken from the Yellowstone Park Library files at Mammoth Hot Springs and from the files of the Old Faithful Ranger Station. PLATE 8 SYMBOLS / EXISTING FISSURE PROBABLE FISSURE OR FAULT POSSIBLE FISSURE OR FAULT SINTER CCNE FEATURE SHOWING INCREASED ACTIVITY 0 SINCE 8 - 1 7 - 59 FEATURE SHOWING DECREASED ACTIVITY <0 SINCE 8 -1 7 -5 9 DG DAISY GROUP THERMAL FEATURE ' WHITE PYRAMID GEYSER I j ------EAST EDGE OF WHITE PYRAMID RADIATOR SPRING ^ /- " D G 6 ' o ____ — ■ ■ Q BONITA POOL. ) — - A ^ ^ ^ DG 7 DG 5 COMET GEYSER SPLENDID GEYSER DAISY GEYSER 0 BANK GEYSER DG 8 BRILLIANT POOL DG 4 DG 2 DG 3 o DAISY'S THIEF MUD POOL DAISY GROUP UPPER GEYSER BASIN ^ YELLOWSTONE NATIONAL PARK SCALE l" = 40' MAPPING CONDUCTED 10-59 BY W GERMERAAD a B. w a ts o n interpretation by b. watson u se of map with c o n s e n t OF THE N P. S. N £ f7 f, PLATE 7 ' t W £2 SYMBOLS \ CL 2 PROBABLE FAULT POSSIBLE FISSURE OR FAULT SINTER CONE RIVERSIDE GEYSER FEATURE SHOWING INCREASED ACTIVITY O SINCE 8 - 1 7 - 5 9 FEATURE SHOWING DECREASED ACTIVITY SINCE 8 - 1 7 - 5 9 CL CHAIN LAKE THERMAL FEATURE GG GROTTO GROUP THERMAL FEATURE SPA GEYSER \ SURPRISE GEYSER \ (GROTTO'S FOUNTAIN) INDICATOR SPRING FISSURE GG 2 GG 3 \ G G 4 GROTTO GROUP UPPER GEYSER BASIN YELLOWSTONE NATIONAL PARK ROCKET GEYSER SCALE l" = 40' — -i-J0 MAPPING CONDUCTED 9 - 5 9 GROTTO GEYSER BY W. GERMERAAD » B. WATSON GG 5 INTERPRETATION BY B. WATSON GG 6 USE OF MAP WITH CONSENT OF THE N.P. S. GG 7 to ALGAE POND N e fiff PLATE 6 tfM 23 c h r o m a t ic p o o l \ \ \ SYMBOLS BEAUTY POOL \ EXISTING FISSURE CRACK GEYSER PROBABLE FAULT OR FISSURE POSSIBLE FISSURE GR 4 0 o FEATURE SHOWING INCREASED ACTIVITY SINCE 8 - 1 7 - 5 9 FEATURE SHOWING DECREASED ACTIVITY \ SINCE 8 - 1 7 - 5 9 \ \ SINTER BASINAL AREA WAVE SPRING GRAND GROUP THERMAL FEATURE o GR l SHORT-RUN GEYSER ECONOMIC GEYSER \ \ G R 17 ----o \ O GR 6 *. • • G R 2 0 \ \ -GR 18 GR 19 GR 29 CAUDA POOL MILK SPRING 0 VENT GEYSER a GR 26 GR 28 FOUR-VENT CRATER G R 27 GRAND GEYSER GR 33 -----CRATER OF THE MOON > NORTH TRIPLET * r>\ EAST TRIPLET ' GR 34 G R 32 :c? cC> NEW EAST TRIPLET GR 3 0 SOUTH TRIPLET GR 31 V. RIFT GEYSERS o GRAND GROUP & \ LIME KILN WITCHES CAULDRON UPPER GEYSER BASIN . GR 35 YELLOWSTONE NATIONAL PARK o GR 42 GR 41 GR 3 6 SCALE l" = 50' Q * x . 0 20 40 8 0 120 o . .0 0<£> +----- GR 38 MAPPING CONDUCTED 10-59 BY W. GERMERAAD 8k B. WATSON GR 3 7 INTERPRETATION BY B. WATSON USE OF MAP WITH CONSENT GR 40 ->- o OF THE N.R S. o GR 3 9 0° ^ D ^ ------SPANKER SPRING SPANKER GEYSER Ff7f/ PLATE 5 BELGIAN SPRING BULGE R GEYSER Q* c 3 \ CRYSTAL SPRING ------CG 8 • \ CG 10 OLD TARDY GEYSER V \ OVAL SPRING - WEST VENT " EAST VENT \ @ OF SPASMODIC GEYSER PENTA GEYSER • v X % ^ — - SOUTH VENT CG 6 — v % CHURN GEYSER o % RIVER GROWLER 0 Q M------— CG 4 C G 5 o SAWMILL GEYSER *♦. P TARDY GEYSER O SCALLOPED SPRING TEAKETTLE GEYSER FLUME SPOUTER DARK ALGAL POND SOUTH SCALLOPED SPRING CG 2 ^ 0 0> CHIMNEY CONE O «>: CG II LIBERTY POOL TERRA COTTA SPRING CG I < coo OLU coo < Lu VENTS - CG 12 CG 13 O FISSURE SPRING • Ss—- SPATTER GEYSER / 1 t ; ______----- CG 31 o 4— CG 3 'X' i RIVER SPRINKLER CG 30 SPRINKLER GEYSER ORANGE SPRING CG 2 0 — *- 0 G D CG 35 36 CG 23 O HEARTBEAT SPRING CRESTED POOL O ------TILT GEYSER SYMBOLS EXISTING FISSURE CASTLE GROUP PROBABLE FAULT OR FISSURE CG 2 4 ------CG 2 5 ------TORTOISE SHELL—------POSSIBLE FAULT OR FISSURE UPPER GEYSER BASIN FEATURE SHOWING INCREASED ACTIVITY c ? CASTLE GEYSER SINCE 8 - 1 7 - 5 9 YELLOWSTONE NATIONAL PARK o FEATURE SHOWING DECREASED ACTIVITY SCALE 50' SINCE 8 - 1 7 - 5 9 20 40 eo 120 SINTER BASINAL AREA CG 26 MAPPING CONDUCTED 11 -5 9 BY K HIGGINS & B. WATSON SINTER CONE N interpretation by watson CG CASTLE GROUP THERMAL FEATURE — C G 2 7 USE OF m ap WITH CONSENT CG 28 OF THE N P. S. CG 29 e n t / PLATE 4 If6/ SYMBOLS EXISTING FISSURE PROBABLE FISSURE POSSIBLE FISSURE FEATURE SHOWING INCREASED ACTIVITY O SINCE 8 - 1 7 - 5 9 C 7 FEATURE SHOWING DECREASED ACTIVITY three sis t e r s springs SINCE 8 - 1 7 - 5 9 SINTER BASINAL AREA MARSH M Y MYRIAD GROUP THERMAL FEATURE BASIN SPRING % STATION SPRING MY 16 a ■+- MY 15 $ o » o o• o O MY 17 ? 1 0 r. • • 1 o O ^ b * PINK CISTERN •• $ * 0 MY II O o 0 , ? 0 ' > o o • • -O''- X a «• ? 0 4*. CM e o 4 0 0 . 0 - 6. 0 » l V \ MY 10 o 0 / ' 0 0 • ° t> * o L'-G,' o •: ■ o. ? °o06 \ • *• » Q .<• 'o' ti* o 0 MY 14 -x •" •• »*.!, ><7 • • • a 0 ' » K th 0 0 o * MY 13 O 9 °* „ : n WEST TRAIL GEYSER .«p° o e ^ .*• XD o- » • 4 6 C> e* *£> • * i * o % , o Q ? •*: oQ o .* r 0 ^ 'A 0 ... EAST TRAIL GEYSER 0 : ° Z5 MY 4 MY II -STRATA g ey s e r O x ' J FISSURE < C 2 " x ROUND GEYSER ABUSE SPRING MYRIAD GROUP c > > STEAM VENTS UPPER GEYSER BASIN YELLOWSTONE NATIONAL PARK o MY 2 ------► o' o k % SCALE l" = 50' o BLUE LEMON SPRING MAPPING CONDUCTED 11-59 BY W G ERMERAAD 8. B. WATSON 4) INTERPRETATION BY B WATSON USE OF MAP WITH CONSENT N OF THE N R S -<7,'L « 0 »• • o PLATE 3 0 GH 2 8 \# *:• > SYMBOLS EXISTING FISSURE GH 29 PENDANT GEYSER o PROBABLE FISSURE POSSIBLE FISSURE BEACH SPRING < 0 FEATURE SHOWING INCREASED ACTIVITY SINCE 8-17-59 GH 30 AURUM GEYSER o FEATURE SHOWING DECREASED ACTIVITY SINCE 8-17-59 EAR SPRING O - GH 31 SINTER CONE GH 32 GEYSER HILL THERMAL FEATURE DOUBLET POOL N GOGGLE SPRING GOGGLE SPRING GH 27 GH 35 LION GEYSER BIG CUB GEYSER STEAM VENTS LIONESS GEYSER LITTLE CUB GEYSER PUMP GEYSER GH o TOPAZ CRATER TEAKETTLE SPRING o HEART SPRING o 0 SPONGE GEYSER — . o %VAULT GEYSER GH 14 o -< GH 34 PLATE GEYSER ~ O ? •« SLOT GEYSER— <=> INFANT GEYSER o DOME GEYSER GH 17 «. GIANTESS GEYSER GH 13 ARROWHEAD SPRING £> 4°. MODEL GEYSER GH 16 GH It ROOF GEYSER GH 10 8 r DRAGON SPRING 0 (9 GH 7 o GH 9 V GH 26 r\ 6 o ROCK POOL O ^ ------GH 8 GH 5 £ ? \ # • • O' s \ & » GH 15 '— O I \ <8 & l • BLOWOUT SPRING < f. ° 1 •o a OLD CONE 0 v p/ o O GH 4 GH 6 SCISSORS SPRINGS — y GH 2 4 BAKER HOLE % ANEMONE GEYSER o 0 0 SULPHIDE SPRING \ PLUME GEYSER GH I GH 3 GH 2 V\ GEYSER HILL BEEHIVE GEYSER ^ UPPER GEYSER BASIN INDICATOR VENT YELLOWSTONE NATIONAL PARK CASCADE GEYSER 120 Q a U — SPUTTERER SPRING MAPPING CONDUCTED 1 0 - 5 9 BY W. GERMERAAD ft B. WATSON INTERPRETATION BY WATSON / USE OF MAP WITH CONSENT OF THE N. P S. E. CHINAMAN SPRING CHINAMAN SPRING o i"i BLUE STAR SPRING o* 0 PLATE 2 t i n / S i IV " r)J SYMBOLS SLUMP CRACKS CREATED BY MAJOR EARTHQUAKE 8 - 1 7 - 5 9 c r ^ ' '-t X \ > — (3 X SULFOSEL SPRING IP \ x X 0 a 6 . 7r STEAM VENTS 4 \ ARTESIA SPRING GRAY BULGER A' YOUNG HOPEFUL LOWER GEYSER BASIN YELLOWSTONE NATIONAL PARK SCALE l" = 50' 40 80 120 "£zz Z- MAPPING CONDUCTED 11-59 BY K. HIGGINS 8 B. WATSON USE OF MAP WITH CONSENT OF THE N. P. S. N t ?7 f/ PLATE I