Some Effects of Recent Volcanic Ash Falls With Especial Reference to Alaska Bp RAY R WLLCOX INVESTIGATIONS OF ALASKAN VOLCANOES GEOLOGICAL SURVEY RULLETIN 1028-N Prepared in mopemtion with the Office,Chief of Engheers, U.8. Amy UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON :1959 UNITED STATES DEPARTMENT OF THB INTERIOR FRED A. SEATON, Sserrfarj GBOLOGlCAL SURVEY Thomea B. Nolan, Dirtctw For HI# tho Supsrlntendtnt 01 Dommsma, U.S. Govornmmr Prlntiap OAcn Wnrhinlfton 25, D. C.-Price 30 ~ntm(peprr corer) PREFACE In Octohr 1945, the War Department (now Department of the Army) requested the Geological Survey to undertake a program of volcano investigations in the Aleutian Islands and Alaska Penin- sula area. The first field studies were made during the years 1948-48. The results of the first year's field, laboratmy, and library work were hastily asgembled as two administrative re- ports, and most of these data have been revised for publication in Geological Survey Bulletin 1028. Part of the early work waw published in 1960 in Bulletin 97'4-B, "Volcanic Activity in the Aleutian Arc,'* and din 1951 in Bulletin 989-A, "Geology of Buldir Island, Aleutian Islands, Alaska," both by Rob& R. Coats. Addi- tional fieldwork was done during the yeare 1949-64. UnpuMished results of the early work and all the hter studiw are being in- corporated as parts of Bulletin 1028. The investigations of 1946 were supported almost entirely by the Office, Chief of Engineers, U.S. Army. From 194765 the Departments of the Amy, Navy, and Air Force joined to furnish financial and logistic assistance. The Geological Survey is indebted to the Office, Chief of Engi- neers, for its early recognition of the value of geologic ~tudiesin the Aleutian region, and to the several military department~lfor their support. CONTENTS Mace ............ ................. -.---- ................ ..--- ....... .... Ahtract ................ .................................................. .............. .-. Introduction .....-..,..-............ -.-.- -. ......-..... Geography -- . ....... .. +..... ... Chfacter d Almkm eruptiom .... ............ -.. Eruption of Mount Kabni In 1812.. ....... Eruption of Okmok Yolcluto in 1945.-- .- ...-.... Eruption of Trident Volcano in 1062 -..... Emption of Mount Spurn in 1953 .- Emptjve sequencw -........ ............... - Diskribution of ash falC ............. ............. - Mount Katmai -..,- Hekla - . ............. .......... .-..-.. Volcbn Qnisapd -.-.- Gunung Kelud ,..,-. ................................ ..-..-..-.-... ...... ParIcutin ...-........ ..... ..,. ... ......... ........ MetRDmlogical fsctors in Alaeka .......... ....... -.. EfTects of eruptions...-_.-. _.._._ .. ........ ..--- Public hlth and safety ...................................... .-- . Buildings -- + Utilitiee, trampstation, and cmnmunication -.............. - Agriculture md related 4VItia-+.-.-.-. .. - Immediate dwts of ash fall .... ........ Long-mnm effects of ash f dl .. ........... - Reeolonlzation by nataral vg~etation ....................... Literature cited ,..- ... .- .. Index ...,.,... .. .. .... .-............ ... ILLUSTRATIONS P~AT~54. Map of Alaska Peninsula turd Aleutian Inlands. 55. Map rnontam of average upper-air wind directions 1948-68 for Anchoragei Alaaka . 66. Map montage of averaffe uppw-air wind dimtima 1948-63 for Kodiak, Alaska. 57. Map montage of average upper-air wind directdone 194843 for Dutch Harbor. Alaska . 58. Map rnontaga of averam upper-~irwind didmu194845 for Adah Island. Alaska . Map of Maunt Katmai and the Valley of Ten Thommnd Smokes, Alaska, shewing thickness of ash deposits from the eruptron. m" Jane 1912 Map of area affected by aah from the eruption of Mount Spurr, AlasIra, in July 195% .I-L- Map of Rekla volceno, Iceland, showing thickness of ash deposits from the eruption in March 1947 Map of route of airborne ash from the eruption of Bekla volcano, Iceland, in March 1947+.-.--.,.,.,,., Graph showing ~i~erange of ash fall in 1947 at !ncres/sing distances downwind from Hekla mIcano in Iceland -.....-.. Map of successive positions of ash front from the eruption of Yoldn Qniaap6, Chile, in April 1932 Map showing: the thickness of ash depaaib fmthe erup- tion of Voldn QuizapC, Chile, in April 1932 +-...,.-.-...... Map of Java, showing bilateral distribution of m8h fall from the emption of Gunung Kelnd in May 1919 Graph showing variation of silica content of 1919 ash fall of Gnnung Kelud in Jam, with distance ...-.,-.,..----- Mag of vicinitg of Paricutin in Mexico, showing thicknew of ash deposits in 1946 Map of vegetation destroction in the empticn of Mount Katmai, Alaska, in 1912 .. ..... INVESTIGATIONS OF ALASKAN VOLCANOES - .- SOME EFFECTS OF RECENT VOLCANIC ASH FALLS, WITH ESPECIAL REFERENCE TO ALASKA Moat hbbric and lab prehistoric volcanic eruptions of Ahhhave yielded a high pmportfon of fragmental material in the form of mh, whm edpecta am felt aver wider areas than thw of lava flows becnutuse of the wide distribution d ash by winda Some 6 cubic dlea of fragmental material wag empW during the firat 3 days of the spedacular Mwnt Kahai ernption of 1912, and much of it WBLI sp& over large areas of the Alaska Peninmula and Kdiak Idand, producing extensive, but not permanent, damage+ hafnknsre Alaskan eruptions were thme of Okmok Volcano in 1946, Trident: Volcano in 1962, and Mount Spun in f 953. Because of the scmtinim of records of Aldan eruptions and their effecte, data from several IdAmdmrnenhd mptions in othe~parts of the world are used here to fill in the mwof behavior expected of future Alaskan mptiona. The importance of wind didom, wind sped, and rainfall in afFwting the distribution of mh fall is illustratea by the wuptions of Hekla in Eeland, Volc411 Quizapd in Chile, Gunung Kelud in Java, and Paricntin in Mexico, and by that of Mount Katmd in Alaska. Wind mx diagrarm compiled fmm upper-wind data at seldAlaskan. stations enable crude sstimak to be mads of tha probabilities of ash fall fm futnre eruptions in particular AIaakan areas. Muah needlw fear of volcanic eruptions can be pmwnted by a foreknowL edge of the range of ef& that may be expected. The danger from poisonous w,for instance, is aeldom pment, especially at the distances of most Alaskan communities from the potentially active vents, Few historic Alaskan lava flow have extended more than a few mil- from the sow=, and ash fall from the moderate activity that charactmhre the great majciity of AIaakm euptiom is c6mmody less dangerous than it is inconv&nt, fiver- thelem, volcanic activity in Alaska mu& command an attitude of respect became of its great potential and because of the chance that great damage will be done by the mwiond ex~rdiwrilystrong eruption. A mantle of ash more than a fear inch= thick over the countryside can radical1y increase runoff; with accompanying impmtant &ect9 on water supply, tranaporbtion, and amicnlhre, not only durb, but. dso for some time after, the ash fa3L FIoods and mudflows may damage travel arteries, water ressrvoim, and crop land. Ash fall itself may totally destroy growing INVESTIGATIONS OF ALASKAN VOLCANOES cmps; but if Ute deposit is not more than tr Sew indm thick, as at Kodiak Island in 1913, the next few ~eamns'plantim may mult in normal or even improved harvab because of the beneficid mechanical and chemical aflecta of the ash that is worked into the old mil. Volcanic cmmonly contain Important amounh of calcium, potassium, and phosphorus available for plant nutrition-me are rich enough b encourage their we ferttlhr& Tha nearly oomplete Iaek of available nitrogen in moat vohic ash and the special chemical and physical properties of raw ash impose handicaps to its direct ntilization as a mil, however, and theae charackrs must mdified by ~ome means for su~fulcropping. The re~)veryof natural vegetation mymake great progrw in only a season or two in areas where the ash fall dewit is I-% tban a f& thick and rainfall ia adequate, as wm shown at Kodiak Island after the emtion of Mount Katmai in 1912. With -tar thickness of ash or in drier climb, the rate of recovery may h proportionably slower; the initial lack of available ni- in the raw aah appears fa b an important obstacle. On bare lava flowm the rab of recovery is enomnaly slower than on ash under ~imilar climstic conditions; it is delayed both by the lack & nitrogen and by tbe slow rate of Breakdown of the lava to a mil. The course of recovery usually dm not wait on the f ormstion of a midual soil, hawever, for p1mb get a fwthdd in crevieea partly filled by airhe dust. In the case of lava flows covered by ash-fall deposittr of the same eruption or by reworked clmtic material, the progress of colonization by plants becomea much the same m that on ash fall alone. INTRODUCTION More than 250 separate eruptions have been oba~wedfrom 39 Alaskan volcanws during slightly less than 200 years of recorded history of the region, and many more eruptions must have gone unobserved in isolated arm, The frequencies of eruption have apparently varied considerably from dwde to dWe, and ac- cording to Coats (1950) wuptions have occurred with greater frequency about the years 1770,1790,1830,19XO, and 1930. There have usually been one or two eruptions a year, rtnd no doubt airnilar behavior may be expected in the future. This paper will present descriptions of ~everalpmt volcanic eruptions in Alaska, and, with the aid of this and information from certain eruptions in other parts of the world, will attempt to explore the problems that might have to be solved by communities or by organizations operating in the Alaalran region. Although ready solutions are not offered, it is hoped that this diacnasion will result in an awarenass of the nature and mope of the problems that wiIl help in dealing with them when they arise. The wrZter is indebted to wlleagues in the Geological Survey; especially G. A. Macdonald, for helpful criticism and augp;estions in compiling this paper. An early draft of the manuscript was read and criticized by Dr. V. B. Cahalane of the New York State SOME EFFECTS OF RECENT VOLCANIC ASH FALLS ,411 Museum, and by Dr. W. D. Keller and Dr. E. R. Graham of the University of Missouri, and their help is gratefully acknowledged.