57

BulletinofGlaciologicalResearch20（2003）57L63⑥JapaneseSocietyofSnowandIce

lcecoredriHingatKingCol，MountL．ogan2002

TakayukiSHJRAIWAl，KumikoGOTO・AZUMA2，SumitoMATOBA2，TetsuhideYAMASAKl3，
TakahiroSEGAWA4，Syosaku KANAMORll，KenichiMATSUOKA5andYoshiyukiFUJH2
1InstituteofLowTemperatureScience，HokkaidoUniversity，SapporoO60−0819Japan

2NationalInstituteofPolarResearch，Kagal−9−10，Itabashi．ku，Tokyo173−8515Japan
3Avangnaq，House2TokilOl，KoyamalL19Lll，NerimaTku，Tokyo176rOO22Japan
4FacultyofBioscienceandBiotechnology，TokyoInstituteofTechnology，00kayama，Meguro−ku，Tokyo152r8551Japan
5ResearchInstitutefor HumanityandNature，Kyoto6068502Japan（ReceivedOctober3，2002；RevisedmanuscriptreceivedOctober25，2002）

Ab8traCt

Anicecoreof220．52mwasdrilledatKingCol（60035 20 N，140036 15 W；4135m），aSaddlenear
MountLogan（5959m），theCanada shighestmountain，inordertobetterunderstandl）anthropogenic
impactonthePacificsectoroftheArctic，2）decadalandinterdecadalclimatechangesintheNorth
Pacific，and3）dynamicalbehavior of cold mountain glaciers．The thickness of the glacier was

estimatedbyanice−penetratingradarsurveyatfivepointsandthedrillingsitewasdecidedatthe
flattestsurfaceofwhichdepthwascalculatedas222m．Therecoveredicecoresshowedthesitewas

locatedatdrysnowzonewithaverylimitedamountofmelt−freezeicelayers．Temperatureofthe
boreholewas−18．00CatlOm・depthand L17．70Cat220．52m．The坤etimescalesuggestedthatthe

ice core covers approximately severalhundreds years to a millennium record ofpast climate andatmosphericproxysignals，prOVidedannualaccumulationratesfromO．4tol．Oma￣1inice．

1．tntr鵬uction
Ice cores from mid−andlow・1atitudes mountains

arenowconsideredtobe one ofthemostimportantanti−COrrelatedwithtime−frequenciesof32．1，12．2，5．1，
and3．7years．Thesestudiessuggestedapossibilityof

Climatesystemwhichisobviouslysee−Sawingoverthe
North Pacific．Itis necessary to extract additional

hightime−reSOlution records to ensure this relation−archives recording time−Series of proxy climate sig−nals（e．g．Wagenbach，1989；Thompson，2000）．MultipleShipforthelastmillenniumtimeperiods．
ice cores were retrieved from the world mountains

andprovidedvariousproxyclimatetime−Seriesspan−

ningfromtheLastGlacialtothe20thcentury．
Among variousice cores，those obtained frommountainsfringlngtheNorthPacificareofparticularinterest because they are found to have recorded
annual，decadalandinterdecadalclimatefluctuations
which aredifficult to reconstructfromlacustrineandmarine sediments due mainly to theirlow time−

OurdrillingprogramatMount Loganwas origi−
nallyplanedtoclarifyl）anthropogenicimpactonthe

Pacific sector of the Arctic，2）decadalandinter−decadalclimatechangesintheNorthPacific，and3）

dynamicalbehavior of cold mountain glaciers．We
decidedtodrillanicecorewithinthemassifofMount

Logan（5959ma．s．1．），theCanada shighestmountain，

to extract records from planetary boundary layer
Which are thought to belocated at muchlower alti−

resolutions．Holdsworth et al．（1992）and Holdsworth tude thantheprevious drillingsite at5340m（Hold−
SWOrthetal．，1991；1992）．Wewillreporthereourfield（2001）relatedtheaccumulationtime−SeriesofMount
LoganwithJapaneseprecipitation．Mooreetal．（2001）
activities conducting the radio−eCho soundings，Shal−

1ater interpreted this teleconnection as an extraT
tropicalresponse of ENSO to the higherlatitude．

While Shiraiwaand Yamaguchi（2002）attempted toCOmpare the Logan accumulation・time series
mentionedabovewiththatobtainedfromUshkovsky

VOIcano，Kamchatka，and found that the two are

lowice−COre drilling，borehole thermometry，andinstallationofastrainnetatKingCol（60035 20 N，140836 15 W；4135m）ofMountLogan．Theoverview
OfthewholeprojectisreportedbyGoto・Azumaetal．
（2003）andisnotgivenhere．

5g

BulletinofGlaciologicalResearch

2．Geographicalsetting
The drilling and the related observations wereconducted at King Col which was a saddle between

MountLoganandKingPeak（5173m）（Figs．1and2）．

Thesiteislocatedjustnorthoftheworld−1argesticefield，Bagleyice field and Seward Glacier complex．

The King Col itself constitutes the highest point of
QuintinoSellaGlacier．Itisnearlyflatsaddleconfined
bytwoicefalls，Onefrom Mount Logantothenorth
andtheotherfromSchoeningridgetothesouth．The
iceinthesaddleismainlydrainedintoQuintinoSella
Glacier to thewest，butpart of theiceis collapsing
fromthebigwallofSchoeningridgetotheeast．

Topographical survey of the micro relief at theKing Colindicates that the flattest placeislocatedbetweenthetwo ridgesfromnorth andsouth ofthe

COl（Fig．3）．ThesurfaceoftheKingCoIwascovered
With wind・erOded structures such as sastrugi andduneswithO．1−0．2mhighwhenwefirstarrivedatthe

King Colin Apri130．It was flattenedlaterin the
beginningofMayduemainlytosnowfall．Itbecame
bumpy again in the middle of May but finally
flattenedbysubstantialamountofsnowfallintheend
OfMay．Thesechangesinthesnowsurfacearecausedby accumulation andwind−erOSion during the opera−tion anditis best displayedin the record of snow
Stakenetwork coverlngthecentralpart oftheKing
Col（Fig．4）．

一140

Fig．1．AerialviewoftheKingCol（4135m）takenfromthe
helicopternear thesummit of Mount Logan（5959m）．
PiramidalpeakbehindtheKingColisKingPeak（5173
脚E∴

−120

−100

−80 −60 −40
Distance（m）−20

Fig．3．Topographicalmapofthemicro−reliefatKingCol（contourinterval：0．2m）．Thecontourlinewasdrawnon
the basis of our survey with the controlpoint at the
distancesof（0，0）．Cross，Openandsoliddotsindicatethe
SurVeyedpoints，SnOWStakesandtheradar−eChosound−ingsites，reSpeCtively．Gothic3digitnumbersindicate
the thickness（m）of theice sounded with theice−penetratingradar．

6718500

06718000

寸 6717500○−
凸A
卜 6717000
∑
ト
n
ひ
已
T

6716500﹈ 6716000︼
OZ

6715500
520500521500522500523500Easting UTM 7VD−04（m）

Fig．2．TopographicalmapoftheKingColregion（contour
interval：50m）．Originaldigitalelevation data wasprovidedbyDr．MichaelDemuthofGeologicalSurvey
OfCanada，DottedsquareatthecentralpartoftheKing
ColissurveyedmoreindetailasshowninFig．3．

号
O
u
∽
亡
一
∈
0
︶
監
u
眉
0
0
篤
t
n
の
○
基
巾
一
コ
∈
コ
0

■
8

0
0
0

■
■0
J
0

40
3

0
0

2
1
や

ゃ

や

や
a

M y

h
ザ

￠

せ

せ

や

や

ヽ
Ju

ヽ

Fig．4．Change of the snow surface during the drilling
Operation from May12toJune4．The stakes were
installedinsidetheareashowninFig．3．

βタ

Shiraiwa（2fαJ．

Wedidnotmonitorairtemperaturecontinuously．
Intermittent temperature measurement and visual
Observationonthesnowsurfaceindicatethatmelting
atsnowsurfacewasneverobservedduringourstayat

Thedrillingsitewasdecidedinordertofillthe

followingtworequirements：1）obtainingtheoldesticeatthesiteand2）recoveringtheicewhichhasexperi−

enced the sil11plest strain sinceits deposition．We
have，therefore，Selected one of the flattest place

Wherewebelievedwecoulddrilltothebottombyour

l

0

l

0

︵5
U
n
V
O

Oneoftheauthors（Goto−Azuma）studiedthissitein
theyearsof2000and2001andfoundthattbeaccumひ3．Determination ofthe drj ingsite

5

n
V
ハ
5
U

tionswereconductedattheplacesandallofthedata
indicatethattheKingColislocatedatdrysnowzone
andsummermeltingisnearlyzeroorlimitedintime．

ma−1inwater（Goto−Azuma et alリ2003）．

000KingColfromM野8toJune12．Severalpitobserva−

1ationrateatthissitewashighlyvariablefromyear
to year，and the estimated accumulation rate bymeansofpitstratigraphyfrom2001to2002wasO．60

1

l
l
O
O

0

︵5
U

︵
と
論
題
璧
r

l
1

0
0

0

5

0

n
V

0
1
1
0

5
︵
U
O
5
0
5
0
0
5

−
■

drillingsystem．

Icethicknesswassounded by anice−penetratingradarsystem．Thesystemiscomposedofanimpulse
transmitterandasetofatransnlissionandareceiving
antennas at the centralfrequency of5MHz．Time
Seriesofreceivedvoltageweredigitizedandstacked
withaportableoscilloscope．8Mbitdigitizedvaluesare
acquired for aset of received signalsin a personal
COmputer．

ThecentralpartoftheKingCoIwasgriddedwith
SnOW Stakes by50m and the radio−eCho soundings−▲＿1 0 1 Z 3 4 5Time叫S）

Fig．5．Time
series of received radio waves at fiveloca・−−
tions（a：Borehole；b：Kingcoll；C：Kingco12；d：Kingco1

3；e：Kingco14asshowninFig．3）．Arrowsindicatethereflection from the bedrock．

WereCOnductedat4gridslabeledasKingcoll，2，3，and4（Fig，3）．Thecentralgridwasalsosoundedwith
receivingantennasof30m，tbetbicknessoftbeiced
the most careful＼＼▼a）rS With so ea11ed common−mid
can becalculated as follows（Matsuoka（；f（7l．，1999）；
pointmethod，tbatis，Changirlgthetra王1Smittingand︼

receiving antennas separationswith the fixedmid
point．AIsowechangedthe antenna orientationwith
every45degreesandobtainedthereceivedsignalsat

fourantennaorientations．Usingthesetwoways，WeCOtlfirmedthat thereeeivedsignalsdidnotdependon
antenna separations and orientations significantly．
This means that the received signals were basicallycomposed of reflected radio waves beneath the sur‑
Veyed site and surrounding surface and subglacial
peaksarenotcritical．
Figure5sわowstbetjmeserie＄Oftわeradiowaves
atthefivesites（a：Borehole；b：Kingco11；C：Kingco1
2；d：Kingco13；e：Kingco14asshowninFig．3）．Each−

Whereレ（mps￣1）isavelocityoftheradiowave，T毎s）a delay time，2エ（m〉tbe arltenna Separation

distance．The average density of the glacier wa

Calculatedas800kgm▼3bythebulkdensitymeasure・

mentsoftheicecoreasmentionedbelow，SOtheradio

WaVeVelocityiノWaSCalculatedas179mjLS，1byusing
I．ooyenga、s equation（Glen and Paren，1975）aIld

assumirlgthepermittivityofpureiceattemperature

Of…18．5凸C as3．17（Matzler and Wegmiiller，1987）．

Ofthewaveswasobtainedwithantennaseparationof

Thethicknessoftheglacierattheboreholewasthus
Calculated as 222 m．The other four points were

Consideringtheseparationofthetransmittingandthe

gridasourdrillingsite．

Calculatedas230m（Kingcoll），269m（Kingcol礼225
30m，butwithdifferentantermaorierrtations（aandb：m（Kingco13）and191m（Kingco14），reSpeCtively（Fig．
east・WeSt；CtOe：nOrth・SOuth）．Thefivewavesshowed
Clearreflectionsindicatedby arrowsat2．48（a），2．57 3）．Becausethelengthofourwinchcablewas220mat
themaximum，Wehaveselectedthecentralpartofthe（b），3．01（c），2．52（d），and2．14（e）JLS，reSpeCtively．

BlユIletinofGiaciologicalResearch甜

4．kecoredr‖jngandtheice＜OrePrOPertiesA鉦erinstailingthe drillingsystemin a drilii喝
tentfromMaylO≠12，WeStartedtheice−COringinMay

13andendedinMay30．Wedrilledtheicecoremainly

indaytimefrom9：00to18：00．

The dri11ing system we used were the electro−
mechanicalice−COring drilldeveloped by Takahashi（1996）（Fig．6）．Unfortunatel）∴We COuld not hit the

bedrockduetotheshortageofthewinchcable．ThereWaSnOClearindicationinthebottom・iceTCOreSimply・

ingwhetherthedepthisclosetothebedrockornot．

Shooting，WeCOntinuedthedrilling．Thedrillingspeed

becameasslowasO．9mperhourbelow150mtillthe
end．Therelativelyslowdrillingspeedwasrnainlydue

tothehardnessoftbeicevhicbwasnearly−1S℃

throughtheborehole．
Icecoreof94mmindiameterand70cminlength
isconstantlyrecoveredirleaChdrillingrun．Thanksto
the slower dri11ing speed，We COtlld recover a goodqualityoficecく）reSuntiltbedeptbof200mくFig．8）．

Thisisunusualfortheicecoredrillingatmountain−
glacier＄OrSmallicecapswhereabrittleiceusuallyappearsbelowthedepthoflOOto150m（Takahashi，
1996；Koci，2002）．Wecannotspecifythereasonwhy

We bave sucb a brittieice only below280m，Tbe
brittieicebelow200mmayindicatethatthebedrock
WaSnOtfarfromthedepthof220．52m．
Leng也（Cm）

0 20 40 60 80 100
0

20
40
60
80
′岬ヽ 100
凰

音120

n 140

Fig．6．Photographofthedrillingsystemweusedforthe
driⅢng．

Figure7sbowsctlmtliativedrilli‡唱time恥ラマersus
depth（m）atKingCol．Ittook195hoursintotaitodrill
icecoresdownto220．52m．Averagedrillingspeedwas

l．6mperhourfortheupper140mwherewehada

180
200
220

0 2 4 6 8 10
NumberofcorepleCeS
Fig．8．Profilesoftbeiengthofeacbc（）re（cm：b王ack cir・Cles）aTld the piecesof払eice core obtained for eac王1drillingrun（opensquare）．

しThe drilled ice cores were subjected to visual
ObservationofstratigraphyinasnowcavejustafterF〜

troublewiththedrilling．Afterthreedaysoftrouble−

1（iOtberecoveriロg．Stratigrapbicfeaturesiikegrainsize

andbubblesize／shapeasweiiassequencesoflayers
Were Carefully checked with aluminescencelight．
Bulk densitymeasurementswere also made forpre−
1iminary assessment of the average density of theglacierforthecalculationofradio−WaVeS（Fig．9）．The

要
0

50

100

150

200

T血￠（hour）

Fig，7．Cumulative drilling time（h）versus depth（rn）at
Ki喝Col．

densityprofileshowsthatthedensificationatthissite
is purely controlled by dry snow densification andmelting−freezing processisinsignificant at this alti−

tudeoftheglacier．Theporecloseoffdepthwasfoundatapproximately50】60mdeep．

6J

Shiraiwa et al.

2 9

8uIkdonsity（Mgm■3）

0．3

0．5

0．7

0．g

2 7
︵
∈
エ
〇
一
︶
0
0
亡
疇
l
の
扇
○
∝

2
2

■
−
︶

◆10m 一■−

2

3

Om
80m

1

20m

0

2000 4000 6000 8000
T血e（S）

Fig．10．Examples of the resistance（temperature）varia−
tionswithtimeatsix depths．

Figure 11 shows the profile of the 2 hours‑
temperatures along the borehole．Variation of thetemperatureissurprisinglysmallfrom−18．00CatlO．
00m to−17．70C at220．52m depths．In a top of

Fig．9．Bulkdensityprofilefromthesurfacetothebottom
ofthe borehole．

accumulation area，temperature prOfile generally
takestheformofcoldesttemperatureatthesurface
andthewarmestatthebottom．Thisisnotthecaseat

KingCol：theupperlOOmhasareversegradient．This

maybeexplainedeitheroneofthefollowings（ortheboth）：1）recentincreaseinairtemperatureand／or2）

5．Boreholethermometryand strain gridsurvey
Temperatureoftheboreholewallwasmeasured

aftertheice・COredrillingfromMay31toJunel．The

Wal1temperaturewasmeasuredbyathermistorsen−

SOr（modelBYE・64，Techno−SeVenCo．Ltd．）whichwas

placedindirectcontactwiththewalloftheborehole

byleafsprings（Kamedaetal．，1993）．Theresistanceof
thesensor（12kohmatODC）withthedrillingcable（18advectionofcoldicefromupperpart oftheglacier．
Thesecondpossibilitycannotberejectedbecausethe
icefalltothenorthcantransporticetotheKingCol．
Thisquestioncanbeansweredifwecouldobtaindata
Onflowfieldoftheglacier．

Rosはtan￠○（kohm）
29．5 29 28．5 28 27．5 27

0hm at O DC）was measured by a digitalmultimeter

WitharesolutionoflO ohm．Dueto thelargediffer−ence in the resistances between the sensor and theCable，thecableresistancewasfoundtobenegligible．

The finalaccuracy of the measurementin this case

was±0．10C．

The sensor wasinsertedin the borehole andStOpped for measurement at every20m from thesurface to the bottom of theborehole．Thewalltem−

peratures were measured after the system was
StOpped at certain depths．Readings of the digital

multimeter were made at O，1，5，10，30，60and120
minutesaftertheinstallation．FigurelOshowsexam−

一1l．0 −1●．6 −1lJO −116

佃昨）

Fig．11．Temperatureprofileofthewalloftheborehole．

plesoftemperaturevariationswithtimeatsixdepths．
In each case，temperatureS decreased with time
becausethefrictionheatgeneratedbythemovement

pointsinJunel．Surveypolesof3mwereinstalledat

peratures．Although such a equilibrium state can

Ofthepoleswerelocatedrelativetotheboreholewith

WaSdissipatedtoreachtheso−Calledequilibriumtem−
neverbeattainedin2hours，the2−hourstemperature

SeemStObenearlyequaltotheequilibriumtempera−

turewithina range ofaccuracy ofmeasurement（±
0．lOC）．

As a finalfield activity，Weinsta11ed strain−grid5points：borehole，Kingcoll，2，3and4（Fig．3）．Each

apairofGPSreceivers（TOPCONmodelGP−SXl）byrapid static method．By re−SurVeying the strain・gridpointsintheyearof2003，WeeXpeCttOreVealtheflow
fieldatKingCol．

62

BulletinofGlaciologicalResearch

6．Depth・age rerationshipYears beIore2002
0

The220．52−micecorewastransportedtoJapan

Within2monthsandstoredinthecoldlaboratoryof■

perature Science．Prior to the cutting for various

Chemical，physicalandbiologicalanalyses，Weneeded

depthandageoftheicecore．Thisisonlyavailable，atthe moment，if we apply a simple modelfor age−determination．We applied ルe time scale （Nye，1963）becauseitrequirestwoparametersonly，i．e．，ice
equivalentthickness oftheglacier h（m）and annual
ice accumulation rate c（m a￣1）when the following

assumptions are fulfilled：COnStant Verticalthinningandfrozenbed．Thetemperatureprofileoftheglacier（Fig．11）andthesoundeddepthoftheglacier（≒222m）

Clearlyindicatethatthebottomoftheglacierismost
probably frozen to bedrock．The first assumptionis

debatable，however．Wecannotexcludetheinfluence

OftheflowfromtheicefallontheicebeneaththeKing
Col．Iftheicefalltransports a significant amount of
ice to the centralpart of the King Col，the first
assumptionmaycollapse．
An average annual ice accumulation rate has
never been obtained at this site．We attempted toestimate this parameter from the relationshipbetweenannualaccumulationrateandverticalprofile

Offirndensity．HerronandLangway（1980）proposed

an empirical equation showing the relationshipbetween annualaccumulation rate A（m a￣1）anddensityprofileasexpressedbyconstant C ；A＝（争）2，
Where ptisthedensityofpureice（0．917Mgm3），kL

the Arrhenius−type rate COnStant dependent only on
temperature and takes the value of O．0249for the1000 1500￣l＝Ot40

temperatureat−200CattheInstitute ofLowTem−

to know the preliminary relationship between the

500

6 0
8 0

︵
E
︶
≡
d
O
凸

1
1

▲ 0
U 0

2
140

160
180
200
220

Fig．12．Depth−age relationships estimated by ne

SCalewiththreedifferenticeaccumulationrates（OA，0．5
andl．O m a▼1）．

yearsof2000and2001，Wetentativelycalculatedthe
relationshipsbyuslngtWOmOredifferenticeaccumu−

1ationrates ofO．50andl．00m a￣1．Inthecase of c＝0．40，thebottomageisnearly1300yearsandthecase
Of c＝1．00，itisabout500years．

7．Concludingremarks
AnicecorewasdrilledatKingCol，aSaddlenear

Mount Logan（5959m），inordertobetterunderstandl）anthropogenicimpact onthe Pacific sector ofthe

Arctic，2）decadalandinterdecadalclimatechangesin
the NorthPacific，and3）dynamicalbehaviorofcold
mountainglaciers．Firstly，WeCOnductedaradio−eChoSOundingwithanimpulseice−penetratingradaratfive
Sites anddetailedtopographicalsurveyto determine

the drilling site．Anice core dri11ing down to220．52

temperatureof−18OC．Constant C canbeobtained
mTdeep，temperature meaSurementS along the bore−
fromdepthgradientofln［p（pi．P）］inFig．9forthe hole，andinstallationofastrain−gridnetwork atthe
densityrangebetweenO．55andO．80Mgm￣3andtakes
KingCol，WereCOnductedsubsequently．Thethickness
the value of O．0378．Annualaccumulation rate Ais Oftheglacier was estimated as190to270m at thetherefore calculated as O．36m a￣1in water．For theCenterOftheKingCol，Whilethesurfaceisnearlyflat
Nyetimescale，WeCOnVertedthesoundeddepthofthe
withminorridgesextendingfromnorthtosouth．The
glacier（d＝222min firn andice mixture）and theice core was good in quality and showed that the
CalculatedannualaccumulationrateA（0．36m a1in
drilling site was categorizedin dry snow zone．The
Water）intoice−equivalentvaluesas200（h：m）andO．40
glacieris nearlyisothermalfrom −18．O OC atlO
（c：ma「1），reSpeCtively．Thetime tatdepthzisnow
m−depth to−17．7OC at the bottom of the borehole．

givenby；f＝1。
CThe坤e time scaleindicates that the age oftheice

COre Varies from approx．500 to1300 years with

VarylnglCe aCCumulationratesfroml．OtoO．4ma」．

Figure12shows the depth−age relationships as
Calculated by the equation．Because the annualice

Acknowledgments

small with respect to the snow pits observations

Thule Outfitters，Mr．Doug Makkonen of Trans−
NorthHelicopters，and Vostok BobofAklakAir

accumulation rate of OAO m a1is considered to be

COnductedbyoneoftheauthors（Goto−Azuma）forthe

Wewouldliketothank Mr．PaulClausofUltima

Shiraiwa et al．

6ヲ（Eds．），Routledge，London，pp．483−504．
for their excellent flight operations．We thank Drs．
Holdsworth，G．（2001）：Atmosphericteleconnection between
David Fisher，Roy Koerner，MichaelDemuth，Chris−
JapanandtheSaintEliasMountains，Yukon．Mem．Natl．
tianZdanowicz，CameronWake and Lonnie Thomp−

Inst．PolarRes．Spec．Issue，54，161−168．
Kameda，T．，Takahashi，S．，Goto−Azuma，KりKohshima，S．，
Watanabe，0．and Hagen，J．0．（1993）：First report ofice
COre analyses and borehole temperatures on the highest
icefieldonwesternSpitsbergenin1992．Bull．Glaciol．Res．，
Whomwearegreatlyacknowledged．Technicalcom−
11，5161．
ments from Mrs．Kunio Shinbori，AkiyoshiTakaha−Koci，B．（2002）：Areviewofhigh−altitudedrilling．Mem．Natl．
Shi，Drs．HideakiMotoyamaandOkitsuguWatanabeInst．PolarRes．Spec．Issue，56，1−4．
were essential for the success of the drilling and we
Matsuoka，K．，Horikawa，S．，Shiraiwa，T．，Muravyev，Salamatin，A．N．，Ovsyannikov，A．AリMaeno，lL and Ohi，
Wish to express our sincere gratitude to them．This
M．（1999）：Radioechosoundingatthesummiticecapofthe
Study was financially supportedby Grant−in Aid for
UshkovskyvoIcano，Kamchatka．InNaruse，R．（ed．）Cryos−
Scientific Research on Priority Areas（B）（PI：Dr．
phericStudiesinKamchatkaII，InstituteofLowTempera−
Kumiko Goto・Azuma），and Grant−in・Aidfor Creative
tureScience，HokkaidoUniversity，Sapporo，20−24．
Scientific Research（Project no．14GSO202；PI：Prof． M盟tzler，C．andWegmtiller，U．（1987）：Dielectricpropertiesof
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Science，Sports，CultureandTechnology，Japan．
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TakaoKamedaofKitamiInstituteofTechnologyto