BulletinofGlaciologicalResearch22（2005）109−119J〃9◎JapanescSocietyofSnowandIce

OverviewofGlaciologicalResearchProjectinPatagonia2003
MasamuAMYAl．KazuhideSATOW2．pedroSKVARCA3．RyoANMAl．TatsutoAOKl4．
TakanobuSAWAGAKl5．TomonoriTANIKAWA6，RenjiNARUSE7．NeilGLASSERB

andStephanHARRISON9

1GraduateSchoolofLifeandEnvironmentalSciences，UniversityofTsukuba，Ibaraki305L8572，Japan
2NagaokaNationalCo11egeofTechnology，Nagaoka940／8532，Japan
3InstitutoAntまrticoArgentino，Serrito1248，ClOlOAAZBuenosAires，Argentina
4DepartmentofGeography，KanazawaUniversity，Kanazawa9201192，Japan
5GraduateSchoolofEnvironmentalEarthSciences，HokkaidoUniversity，SapporoO60LO810，Japan
6GraduateStudent，GraduateSchoolofLifeandEnvironmentalSciences，UniversityofTsukuba，Ibaraki3058572，Japan
7InstituteofLowTemperatureScience，HokkaidoUniversity，SapporoO600819，Japan
8CentreforGlaciology，InstituteofGeographyandEarthSciences，UniversityofWales，Aberystwyth，Aberystwyth，UK
90ⅩfordUniversityCentrefortheEnvironment，MansfieldRoad，Oxford，UK（ReceivedOctober6，2004；RevisedmanuscriptreceivedOctober29，2004）

Abstract

GlaciologicalResearchProjectinPatagonia2003isthefirstyearofthethree−yearprOJeCtentitled

HoloceneEnvironmentalChangesinPatagoniaIcefield，SouthAmerica fundedbytheMinistry of
Education，Science，SportsandCulture，Japan・Inthisreport，WeOutlinedtheaimoftheproJeCtand
purposesofthe2003activities．ThreefieldpartiesweresenttoPatagonia；（1）geomorphologicalandglaciologicalgrouptoGlaciarExploradores，theNorthernPatagoniaIcefield，（2）glaciologicalgroupto
GlaciarPeritoMoreno，theSouthernPatagoniaIcefield，and（3）geologicalgrouptothevoIcanicfield
and alpineglaciersofPatagonia・Activitiesoftheeachgrouparedescribed andsomepreliminary
results are summarized．

1．lntroduction
Glacio10gicalResearchProjectin Patagonia2003（hereafterGRPPO3）wasthefirstyearofthethree−year
proJeCtentitled HoloceneEnvironmentalChangesin
PatagoniaIcefield，South America． The main objec−

tivesofthisproJeCtaretO：

and（3）preliminarygeomorphologicalinvestigationof
the Patagonian voIcanicfield，and of South Andean

alpineglaciers．Figurelshowstheareaofourinterest．

2．Studyarea
2J．GJαCgαγ且ゆわγαdoγeS，〟PⅣ

1etglaciers，

The HPNislocated around 470s and 73030′w
With an area ofabout4200km2in1974（Aniya，1988，
Fig．2）．It has the highest mountainin Patagonia，Monte San Valentin（3910m）at the northeastern cor−neroftheIcefield．Theicefieldhas280utletglaciers，OfCiers，and

Variations since1944to1999（Aniya，2001）．Of these，in the Middle Miocene‑Holocene igneous rocks andsediments．

GRPPs since1983（e．g．，Nakajima，1985，1987；Aniya
and Naruse，2001）．This time Glaciar Exploradores，（1）establish the Holocene glacialchronology of the
HieloPatag6nicoNorte（HPN），（2）continuemonitoringofvariationoftheHPNout−（3）elucidate calving mechanism ofPatagonian gla−
（4）establish paleomagnetic characteristics recorded

The research themesin 2003consisted of threemajor topics；（1）geomorphologicaland glaciologicalresearchatGlaciarExploradores，HPN（HieloPatag6n−
ico Norte or Northern PatagoniaIce貝eld）；（2）glaci−

0loglCalinvestigation atGlaciarPerito Moreno，HPS（HieloPatag6nicoSur，OrSouthernPatagoniaIcefield）；

which 21 major glaciers have been studied for theil‑

Glaciar Soler has been extensively studied by thelocated at the northeast corner of theice負eld on thenorthflank of Monte San Valentin，WaS Chosen forgeomorphologicaland glaciologicalstudies．The gla−

Cierhasanareaofabout95km2withalengthof20．3

km and the AAR was O．66in1974（Aniya，1988）．The

glacieris nourished on the northflank ofMonte San

BulletinofGlaciologicalResearch

Fig．1．Map of the southern part of South America−
Patagonia．Major areas ofinterestin this paper
indicated．

Valentinwithtwobranches．Thereisabig，COnSPicu−

OuS，elongated continuous morainein front of thepresent glacier snout．Thisis the only terminalmo−raine formed by Glaciar Exploradores that can berecognizedinthevalleyofRioExploradores（Harrison

Fig．2．Landsat ETMimage of the HPN（March 8，
2001），indicating thelocation of Glaciar Explor

radores．

etal．，2004）．Ifwecan datetheageofthismoraine，WemaybeabletoestablishapartoftheHoloceneglacial
ChronologyoftheHPN，becausetherearesimilarmoLand the glacier has been fairly stable since the 1940s

え2．CJαCよαγP（Zγよわ肋γe乃0，〃f誓

ご．．●J．7ソJ（、八J／（ぺ■りJJ山JJJ・り／（…JJ（・．信一／（7∫ r川（′ 打んJ（、J（−J■∫（J／

raines at otherglacierssuch as Grosse，Reicher，Gua− despitethegeneraltrendofglacierrecessioninPatago，
1as，Nef，Coloniatonamebutafew．AIsonoglaciologi−nia（Aniya and Skvarca，1992；Aniya etal．，1997）、In
Calstudy has been carried out at Glaciar Explora−
2003，the glacier had advanced，thereby dammingup
Brazo Rico−Sur for thefirst time since1988．Theice−dores，despite relatively easy access from Pto．Tran−dam waseventually rupturedon March13，2004．
quilo．

Glaciar Perito Morenoislocatedin the HPS，On

theeasternsideinArgentinaat53030′sand73000′w．

CeγγOSαれ⊥0γeれZOα乃dCeγmダよ臨月0γ

The Miocene−Pleistocene voIcanic rocks（Fig．1；
Kayetal．，1993）ofthePatagonianvoIcanic頁eldcover
AAR of O．73in1986（Aniya etal．，1996，Fig．3）．The
VaSt area behind the Andean arc system．Wevisited

Ithasanareaof258km2andalengthof30kmwithan

GRPPshavebeenstudyingthisglaciersince1990andhaveaccumulatedawealthofglaciologicalandmete−

most Mesetas aligned along thelongitude700win
Figurel．
Andean alpine glaciers are developed on the top

OrOlogicalinformation（e．g．，Naruse and Aniya，1992；
Aniyaetalり1992；Aniyaand Skvarca，1992；Naruseet
Of Miocene plutons distributed along back−arC plu−
tonicchainbehindtheAndesandtheHieiosPatag6n−al．，1992；Naruse and Aniya，1995；Naruseetal．，1995a；
icos Norteand Sur．Among them，famousmountains
1995b；Takeuchietal．，1996；delValleetal．，1995；Skv−arcaandNaruse，1997），aSWe11asfewstudiesbyothers SuCh as Cerro（Co．；Mount，Mt）San Lorenzo（6．6Ma；
SuarezandDelaCruz，2001），Co．FitzRoy（18Ma；Kay（e．g，Warren，1994；Rottetalリ1998；MichelandRignot，etal．，1993）and TorresdelPaine（12〜13Ma；Halpern，
1999）．Glaciar Perito Moreno has been known for the
repeated advances and consequent damming up of1973）massifs areincluded（Fig．1）．Co．San Lorenzo
lake BrazoRicoLSur tothesouth（Mercer，1962；1968）（3，706m）islocated on the border between Chile andAniyaetal，

Fig．3．Landsat TMimage of Glaciar Perito Moreno（January14，1986）．Inset：Landsat ETM mosaic of
the HPS（Marchll，2001），indicating thelocation of
Glaciar Perito Moreno．

Argentina atlatitude47．60s，tO the southeast ofthe
HPN，and Co．Fitz Roy（3，405m）islocated on theeasternedgeoftheHPSatlatitude49．30s，tOthenorth
OfGlaciar Viedma，thesecondlargestglacierin Pata−

gonia．

3．Fieldwork
3．ノ．CJαCgβγ且ゆわγαdoγeSα乃d〜ゐe〃PⅣ／∫■／

Fig，4．Landsat ETMimage of Glaciar Exploradores（Apri12，2003），On Which sampling points for］1c
dating materials and GPS points for glacierflow
measurements areindicated．

WaS One Of the best spot for viewing the mountain．
Thelocation of BC was not convenient，because we
hadtocrossabranchoftheoutletstream，about20m

Wideandknee−thighdeep，tOgOtOglaciereverytime．

（1）Glacierflow

Initially we planned to carry out the measurc−
ment of glacier flows with a GPS and an Electronic

Distance Meter（EDM）in the ablation area of theglacier．However，We COuld not use the EDM．The

Schedule：November28TDecember13，2003
primary reason was that the glacier was too big toMember：M．Aniya，T．Aoki，T．Sawagaki，T．Tanikawa
establishcontroIpoints onlateralmorainesoneither
and G．Barcaza
Side of the glacier（about2．7km wide），and going to
Activities：Measurementsofglacierflow，COllectionof
lateralmorainesrequiredcrossingmarginalstreams／
materialsfor14cdating，andmeasurementsofglacierpond，Whichwaspractica11yimpossible．
Surfacealbedoand roughness．
Insteadofusingstakes，WeChoseprominentboul−
The weather in November and December 2003
dersforthedifferentialGPS measurement，andestat）−

was exceptionally bad in the HPN area and of two
Weeksinthefieldwehadonlytwodayswithoutrain．

1ished six GPS stations from near the debris covered

highestmountaininPatagonia，althoughthecampsite

ments are shownin Tablel．The notable results are

We could neversee Monte San Valentin（3910m），the

SnOut tO dirt mounds on cleanice about7km uI）−
Stream（Fig．4）．Preliminary results of these measureT

Bulletin ofGlaciologlCalResearch

JJ2

Table．1．Flow speed ofGlaciarExploradores（movements bydifferentialGPS）．
Horizontal VerticalAzimuth Number of

（m）

1
2
3

0
0
0
0
0
0

5
7
8
6
6
9

8

1

3
3
7
1

1
0

ハ
U

G

days

Daily movement
H（cm） V（cm）

1

E28．7

6．5

14．5

9

ElO．O

8．1

11

E7．9

9．3

W40．O

8．5

0．9

W3．5

8．4

−2．3

WlO．5

11．4

1

一 0
一

6

8
9

13．3

−2．2

0
∩
︶

Table2．14cDatingResults．

G SampleNo，

G

9

＜ 0
U 1

8

5

G

3
2

4

G

（degree）（m）

03120601
O312080l
O3121201
O3121202

Material
woodorganic sedimentorganic sediment1eavesYear（calibrated）

1900BP±50（Beta188284）

108．9BP±0．7pMC
115．3BP±0．3pMC（Beta188283）（Beta188282）

122．6BP±0．2pMC（Beta188285）

G

upward movementoftheglaciernearthesnout．The

CreVaSSeWereabout7mand22m，reSpeCtively，underCaying，therebybecomingpitted topographyand has（3）Moraines

debris−COVered area of the snout has been slowly de−been considered deadice（Aniya，2001）：however，Ourtheassumptionofthehemispheroidformofcrevasses．

We have collected four samples for 14C dating

measurements revealed active forward and upwardfrom the moraines；One piece of wood and three or−
ganicmaterials（Fig．4）．TheresultsarelistedinTable

urementsofablation，Whichwas about20cm ormore
inafewdays．Iftheglacierwerenotactiveinupward
movement，the surface would havelowered rapidly
Withthisrateofmeltingduringsummer．

depressionin the moraine surface．A piece of wood

movements．These movements explain why the de−bris−COVered part hasexisted foralong time，atleast
2．Theorganicsampleswerecollectedfrom theunder
Since1946．Whilein thefield，Wemadecursory meas− the top surface of moraine（cliff）orsedimentsin the（2）Solarradiation，glaciersurfacealbedoandglacierSurfaceroughness
We carried out measurements of solar radiation
andglaciersurfacealbedobyalbedometerinthemid−dle of white expanse of the ablation area．Since theWeatherhadbeenunusuallybadwhenwewereinthe

且eld，the measurements were notideal．The broad−bandalbedointhesolarspectralregion（3003000nm）

WaS meaSured using albedometer（EKOInstruments（03120601）wasrecoveredfromtheproximalsideofthe
WeStern Part Of the prominent moraine（Fig．4）．The

lakeinfrontofthismoraine hasbeenslowlyexpand−ing since1974．Thereis a cluster of wood pieces em−
beddedabout5mabovethepresentlakelevel．Appar−

ently these wood pieces were entrapped in debris on
glacier and carried down here．Therefore the age ofthis piece of woodindicates thelowerlimit of themoraine formation，Whichis1900BP±50（calibrated）．

Thethreeorganicsamplesyieldedmodernages．Fromthese data，We Only know that the prominent，elon−

gated continuous moraine was formed some time af−

Trading Co．，Ltd，Japan）．The broadband albedo was ter1900BP or about 50AD．Within this time con−
Straint，tWOOrthreeglaciationshavebeenrecognizedSampled everylsecond andlO−SeCOnd averaged val−in the HPN（Aniya and Naruse，1999；Glasser etal．，
ueswerestoredinadatalogger．Tokeeptheobserva−
tionalconditionuniform，Weanalyzed onlydataclos− 2002）．Therefore，before we can assign the certain
age to this moraine in order to establish the glacial
est to thelocalsolar noon（13：0014：00LT）．The al−

bedo was approximately O．74under the cloudy sky（cloudcover7／8）．Thisisrelativelylowascomparedto

newsnow，Whichmay beaccountedforby wetsnow（granularsnow）on theglaciersurfacewithscatteredtiny−debriscover．

The roughness of glacier surface was estimatedfortheradarbackscatter，by measuringtwotraverselineswithahandyaltimeterandarangefinderinthe
middle of theablation area．The width andlengthof

ChronologyoftheHPN，Wehavetocollectsomemore

data．

（4）Environmentalchange−reCent Warming？
While walking around the big，prOminent mo−raine，We Observed a fewinteresting phenomena．We

SaW SeVeralspots at the base ofproximalsideofthemoraine，Where water was seeping out／flowing out，
thereby forming a pond（Fig．5）．Submerged trees（di−ameteratbreastheight，uptO20cmorso）arecommon

Aniyaetal．

ノJ、ノCharacteristics of a typICalice−COred slope．At one
SpOt，WeSaWtheexposureofcore−iceatthebaseofthebigmoraine．Betweenthisprominentmoraineandthe

debris−COVered snout，there are many moraines cov−
ered withtreesand／orgrasses．Tosupporttrees，SOilmusthavedeveloped，Whichrequiressomestabilityof

the surface．However，We SaW quite a few morainesthat are covered withlarge／dense trees，yet Whose

Surface has gotten cracked open and became soggy

due to core−ice melting（Fig．6）．The thickness of top

SOillayerisabout20cmormore，SuggeStingthatfora
long time，the environment had been stable so thatFig．5．Pond formed and fed by recent core−ice
melting and convex slope above the pond．Note：
Submerged treesin the pond．The convex slopeis
the result of bulging caused by flowage due toCOre−ice melting．Many trees on this slope havetilted（Photo Dec．6，2003）．Location，near the
SamplingpointO312080lofFig．4．

SOildeveloped and trees have grown；however，COre−icehasstartedmeltingrecently，PrObablyduetotem−

Peraturerise．

（5）Aerialsurvey
We planned to make two aerialsurveys：Circum−

ferentialflightoftheHPNtotakesnoutphotosofthe

Outlet glaciers to update the variation（Aniya，1987；
1992；2001；Wada and Aniya，1995；Aniya and Wakao，

1997）and verticalphotographs ofGlaciers Soler andExploradores．However，duetotheexceptionallybad

Weatherin December，We COuld barelyfly once for
Oblique photographs oftheoutletglaciers．Although
the vertical photographs of Glaciar Exploradores
Wereimportantfordetailed topographic mapplng Of
the glacier for fieldwork and we established someground controlpoints（GCPs），We had togiveupthis
time．

BasedontheresultsandexperienceoftheDecemq
ber2003fieldwork，We discussed about thefieldworkin2004／2005，inwhichweplantoinclude hydrometeN
OrOlogicalobservationsandice−radarthicknessmeas−
urements．In the course of discussion，We Came up

With theidea of going there during australwinter（JulyTAugust）to avoid excessive melt waterin theglacier forice−radar measurements．AIso Aniya has

beencontemplatingforsometimeanaerialsurveyof
the HPNin winter，because he has postulated that

Winter precipitation may not be asimportant／domi−

nantasnormallythoughttonourishandmaintainthe
HPN glacier（Aniya，unpublished）．

Fig．6．Surface deformation due to recent core−ice
melting．Top：Vegetatedsurfacewithsoilabout20
30cm thick．Whitelineindicates surface．The

height of the step about50cm（Dec．8，by Aniya）．
Location，near the sampling pointO312060lofFig．
4．Bottom：StepPed surface covered with moss，right next to the older moraine（probably of LIA）
（Dec．l，by Aniya）．A stick as scale．Location，near
GlofFig．4．

in such ponds．Normally，above such spot／pondis
located uneven，COnVeX Slope with cracks and small
Cliffs（a few cm or more）with tilted trees，Which areConsequently，Aniya went back to Patagoniain
July 2004 for aerial survey and reconnaissance of
GlaciarExploradoresinwinter．HeflewonJuly25in
OneOfthetwobestweatherconditionsin20yearsof

hisaerialsurveyexperience，Withnowindatall．The

resultwaswhatAniyaanticipatedfortheHPNwinterCOndition，thatis，nOtmuChsnowingeneral，although

there are regionaldifferences．ThoseglacierslocatedOn the northand westsidesoftheHPNweremostly

SnOW−free on thelower part of glaciers（Glaciers Ex−
ploradores，Grosse，Reicher，Gualas，San Rafael，San
Quintin，Benito，HPNl，HPN2，HPN3）．Evenproglaciallakesarenotfrozen，aSWellassomesupraglaciallakes

On these glaciers．In particular，the valley of Rio Ex−

ploradoreslooksasgreenasinsummer，Withoutsnow

BulletinofGlaciologlCalResearch

Jノ4

at all．

Exploradoresseemsvery feasible．Thebig advantage

Thetemperatureduringthenightwasonly−20Cdue

temperature during the night may below，between

peraturewewouldexperienceisprobablyintheneigh−borhoodof10to r150c whentheskyisclear．The

ヱ2．GJαCよeγPeγわ0ルわγe乃0，ガf誓

The roads to Glaciar Exploradores were mostly

Ofwinter丘eldworkistheweather，i．e．，thereisaspell
SnOW／ice−freeandwevisitedtheglacieronJuly2627． Of sunny days without winds at all，although thetocloudcover．Previouseveningthetemperaturedrop− StOrmS．With the sunshine during the daytime，field−
WOrkshouldbenoproblem withproperattire．
ped to −50C before becoming cloudy．So the tem−

Schedule：November27−December19，2003
SCenerylS almostasgreen asinsummer：Onlydiffer−
Members：K．Satow，P．Skvarca，R．Naruse，E．Isenk
ence was that plant Nalcas were dead and rotten
among evergreen plants such as Nothofagus andand C．M．Paterlini
Calafate，0fferingeasypassagethroughdensebush． Activities：meaSurementS Ofglacier且ow，glacierpro−
The glacier surface on which we walked around in
file，bathymetry oflake and sedimentthickness，and

December2003wascompletelysnow−freeandasdirty

as and strewn with debrisjust asin summer（Fig．7）．
Proglacialand supraglacialponds are notfrozen，eX−
Ceptforverysmallones，andwaterwasflowing．

With running water readily available and with−out snow and winds，貞eldworkin winter at Glaciar

Supraglacialstreaminvestigation．
We have conducted the fo1lowing measurements
andobservationsatGlaciarPeritoMorenooftheHPS，
inanattempttoshedlightonthecalvingmechanism，Whilewewereinthefield，OneOfthemostinteresting
phenomena at Glaciar Perito Moreno was occurring，

thatis，damming up of thelake to the south，Brazo
RicoTSur（Fig．8）．Thisprovided uswitharareoppor−

tunity to observe and measure the glacial processes
SuChasnowspeedandcalvingduringthedamming−
up．

（1）Glacierflow

Glacierflowspeedatthe terminuswasmeasured
WithanEDMeverydayortwo，andalsowithtaking
astereoTpalrOfphotostwiceaday．Wealsomeasured
the height of seracs above the lake surface near theterminus．Duringtheobservationperiod，theaverage
flow speed was2．3md1at the terminus，With thefrontalheight of about52m．Theflow speed at up−

Fig．7．Winter aeriaIview of Glaciar Exploradores（July 25，2004，by Aniya）．No snow at a1lon theablation area of the glacier．The elevation of theglacier surface in the photograph is about 240400
m a．m．s．1．

Stream Where the glacier entersinto thelake wasmeasured to be5mdl．comparing withthose meas−
urementsin1999（Naruseetal．，2001），the貝owspeedin

2003wasfaster，althoughtheglacierheightabovethe
lake surface was about the same．

Fig．8．Glaciar Perito Moreno，Showing theice dam that had separated Brazo RicoTSur（farside）from CanaldelosT占mpanos（nearside）．（Nov，28，2003，bySatow）．

Aniyaetal．

〃5

Fig．9．Calving front of Glaciar Perito Moreno，Showing that the tip ofice has reached the opposite bank，
thereby blocking waterflowbetweentwolakes．NearsidelakeisBrazoRico−Sur，andthefarsideisCanaldelosT昌mpanos．Normallywater貝owsfromBrazoRico−SurtoCanaldelosT昌mpanos．（Dec．13，2003，by
Skvarca）．

（2）Calvingevents
We set up a water−level（pressure）gaugein thelake that recorded every2seconds，from which weestimated the frequency and magnitude of calving

sediments was made at Brazo Ricoin December2003．
Measurements were carried out continuously almost

events．During the observation period，the average

alloverthelakefrom asemi−rigid rubberboat，uSing
a high−reSOlutionseismicreflectionsystem（EPCBoo−mer）．ThetotalsurveydistancereachedaboutlOOkm，

than 7 0f the1999 0bservation（Iizuka etal．，2001）．
However，again，there seems no correlation between

wasfoundtobearoundlOOm．Warren（1994）reporte〔lnumberofdaily calving was25，Whichis muchmore

thenumberofdai1ycalvingeventsor hourly calving
events and temperature variations．Comparing with
the1999data，Row speed was slightly faster and thenumberofcalvingeventswasmuchmore，Whichmay
beinterpreted as the effectofincreased buoyancyor
reflectingchangein theglacierflow system．

（3）Cross−prOfileofglaciersurface
At the mid−SeCtion of the glacier，We meaSured a

CrOSS−PrOfile of the glacier surface with an EDM（whichisgoingtobeanalyzedsoon）．We haverepeat−
edly measured the profi1e since1990（Naruse etal．，
1995a；Skvarca and Naruse，1997），and found out thattheperiod19901999wasverystablewithoutthicken−

ingorthinning．However，between1999and2002，theglacier was found to be thickening（Skvarca etal．，
2004）．From2002to2003，theglacierwasalmoststeady．

We think that the thickening trend in the middle
reach between19992002may have effected the ad−

and thethicknessofsedimentsrangesfrom5m to3O
m．A meandepthofBrazoRiconeartheglacierfront

thedepthabout170mbyspotmeasurements，andthe
differenceisprobablyduetothedifferenceinmeasur−
ingsites．
（7）Water，leveloflake BrazoRico−Sur

Sincetheaustralspring2003，theglacierfronthas

reached the opposite bank，thereby blocking the wa−

terflow from Brazo Rico−Sur to Canaldelos Tem−

panos，CauSingwater−levelrise．ByDecember14，2003，
the waterlevelhad risen by4．2m．

Dammingupprocessin2003isasfollows（Skvarca

etal．，unpublished）．The tunnelin the glacier front，through which water had been drained from Braz（）
Rico−Sur to Canaldelos T6mpanos，has closed ofF
probablyin September／October2003，thereby com−pletely separating Brazo Rico−Sur from CanaldelosTempanos（Fig．9）．The waterlevelcontinued to risc

byseveralcmperdayuntilMarchllwhenthewaterlevelreached the highest at9．3m above the normal．
VanCein 2003 for damming up of Brazo Rico−Sur；
TheareaofBrazoRico−Surexpandedfrom125km2to
however，mOredetailed mechanism mustbeclarified． 170km2withthewidthof2．5kmandalengthof48km．
Then water started to drain through cracks in the（4）Supraglacialhydrology
Atthemid−SeCtionandterminusoftheglacier，We glacierorsubglacialwaterchannels，andonMarch13，
thefrontalpartoftheice−dam（severaltensofmeters
mapped the distribution ofsupraglacialstreams，andhighandseveraltensofmeterswide）almostinstanta−measured waterflow−SPeed and temperature，and thedepthofmoulins．

neouslycollapsed，therebydischarglngaboutlO9m30f
WaterintoCanaldelosTempanos．

uredtemperatureandsolarradiationwithadatalog−

3．3．PαJαgO乃Zα乃〃OJcα乃わカβJdαれd Ceγm Sαれエore乃Z（）ger．

α乃d CeγγOFgね月0γ

In order to study the past evolution of Glaciar
Perito Moreno，a SurVey Of thickness distribution ofand S．Ike（5）Meteorology
At the terminus and the mid−SeCtion，We meaS−（6）Bathymetryandsoundingoflakesediments

Schedule：February26−March28，2004
Members：R．Anma，A．Veloso，R．Endo，S．Yamamoto，BulletinofGlaciologicalResearch

ノノβ

Fig．10．ViewofaridgesystemthatencirclesMesetanearTamelAikeat48．70s（Mar．18，2004，byAnma）．
Activities：Sampling rocks and sediments and recon−

naissanceofmorainesofsomealpineglaciers．

（1）Geomorphologicalinvestigation of the Patago−
nian voIcanic丘eld

The Patagonian voIcanic field，ratherflat withdeeplyerodedMesetas，prOVidesanexcellentopportu−

nitytoobservecrosssectionsofpilesoflavaflowsand
allows sequential sampling of oriented samples foranalyses．The younger Pliocene−Pleistocene voIcanic

rocks form a horizontalthin sheet ofless than4m

thick．Theyhavefi11edintheareaoftopographiclow．
In contrast，the older Miocene voIcanic rocks are dis−tributedinhigherelevations，formingalmosthorizon−
talterrace of the Mesetas（Fig．10）．They comprise apileoflavaflowsthatreaches40min totalthickness，
with eachless thanlOmin thickness．The base of
theselavaflowsis exclusively covered withloose

COnglomerateand／OrSand．Suchloosesedimentswere

Observedthroughoutthisareaandmaybeofice−Sheet
related deposit．Furthersystematicinvestigation wi11

benecessarytoclarifytheorlgin．Noeskerorsandur−

1ike structure was recognized during this reconnais−
SanCe．Itis noteworthy that a thick pile of Miocene

lavaflowsis normally faulted and slid（Fig．10）or

toppledalongedgesoftheMesetaduetodeeplnCisionby the drainage system，and forms a series of ridge
SyStemSthatfringetheMeseta．Wecollectedoriented
rock samples only from the cliff walls or top of theterraces toavoid theeffectoflater block rotation due

togravitysliding．

（2）Alpine glaciers and moraines of Cerro San Lo−

renzo and Cerro Fitz Roy
Figurellis based on the geologicalmap by

Fig．11．Map showing the distribution of glaciersaround Co．San Lorenzo．Brokenline，nationalboundary：Darkpattern，1ake．

raineridgesinthefieldtoreachthefootoftheeasternridgeofCo．SanLorenzo（3706m）．Detailedmappingof

SuChsmalltopographicalfeaturesmayleadustofur−
ther understanding of behavior of alplne glaciers，Whichis sensitive to small−SCale environmentalcha−
nges．In the valley of Rio Tanquilo，threelevels of
lateralmorainescanberecognized（Fig．13）．Thelow−

estlateralmoraineisclearlyvisibleintheupstreamto

the right（south），While the highestlateralmoraineis

Welkneretal．（2002）．WetraveledalongRioTanquilo traceablein the middlepart ofFigure13andcontin−
uestotheleft，Whichisinterruptedbyalandslide．The

and Rio San Lorenzo．The valley head of Rio San
Lorenzois covered by a smallglacier（indicated bytrimline of theintermediatelateralmoraine can be

GSLinFig．11），Whichhasaseriesofterminalmoraines recognized，althoughweak，inthemiddleofthe high−With a glacia11ake and ablation valleys（Fig．12）．At
estmoraineslope；butisobliteratedbyfandepositsin
least，tWOlateralmorainesarerecognizablefrom thisthecenter．Agesofthesemorainesarenotyetknown．
photograph．Inaddition，WeCrOSSedseveralsma11mo−
Figure 14 was drawn based on a trekking map

Aniyaetal．

Jノ7

Fig・12・Co・San Lorenzo seen from Rio San Lorenzo，in whichlateralmoraines are recognizable（Mar．11，2004，by
Anma）．

Fig・13・Lateralmoraines developed along Rio Tranquilo．A hugelandslideinterrupts the highest Lateralmoraine that
COntinuesfrom righttoleftofthephotograph．Thefootofthislandslideiscoveredbyfandepositinthecenter（Mar．
9，2004，byAnma），（Zagier＆Urrutypublications，2004）．Co．FitzRoy（3405m）is composed of a Miocene plutonintrudedinto

basementrocksoftheJurassicage．Theregionalgla−

Cialchronology of this area since the Late−glacial

periodissummarizedbyWenzensandWenzens（1997）．

We visited Lago Torre and also approached Co．Fitz

Roy from Rio Electrico．In the Rio Electrico area，abriefobservation wasmadeonasmallglacier（GEinFig．14）of Co．Gui11aumet．The glaciers Torre andGrandemergeand貝owintoLagoTorretothesouth

Of Co．Fitz Roy，arOund which two closely−SpaCed
terminalmoraineswereclearlyobserved．Theyoung−er moraine forms Lago Torre．In between，ablation

morainesin the shape of smallcones are scattered．
Agesofthesemorainesarenotknown．

（3）LacustrinedepositaroundLagoGeneralCarrera

We tookashortvisittoanoutcropoflacustrine
sediments deposited around Lago General Carrera

near Puerto（Pto．）Fachinal（see Fig．1）．Medium tofine−grained sand and siltweredeposited here，formTing rhythmiclayers．Orientedsampleswerecollected
fromthisoutcrop．Nomicrofossilswerefoundbybrief
microscopICObservations．

4．List of membersin GlacioIogicalResearch
Projectin Patagoniain2003
The affiliation and title are those at the time ofparticipation
Principal Investigator

Fig．14．Map showing the distribution of glaciersaroundCo．FitzRoy．

MasamuAniya，Dr．（Geomorphologist），Professor

Graduate Schoolof Life and Environmental

Sciences，University of Tsukuba，Ibaraki，

Japan

〃β

Bu11etin ofGlaciologlCalResearch

Co−Investigator

Student

TakanoriNakano，Dr．（Geologist），Associateprofessor

Graduate Schoolof Life and Environmental

Graduate Schoolof Life and Environmental

Sciences，University of Tsukuba，Ibaraki，

Sciences，University of Tsukuba，Ibaraki，

Japan

RyoAnma，Dr．（Geologist），Assistantprofessor

Graduate Schoolof Life and Environmental

Sciences，University of Tsukuba，Ibaraki，

Japan

Japan
ShinjiYamamoto，Mr．（Geologist），Doctoraistudent
Graduate Schoolof Science，TokyoInstitute
OfTechnology，Tokyo，Japan
Shin−ichiIke，Mr．（Geologist），Undergraduatestudent
Co11ege of NaturalSciences，University of

Tatsuto Aoki，Dr．（GeornOrphologist），Associate

professor
Department of Geography，Kanazawa

University，Kanazawa，Japan
Kazuhide Sato，Dr．（Glaciologist），Professor

Nagaoka NationalCollege of Technology，Nagaoka，Japan

TakanobuSawagaki，Dr．（Geomorphologist），Research
assistant

Graduate Schoolof EnvironmentalEarth

Sciences，Hokkaido University，Sapporo，Japan

Tsukuba，Ibaraki，Japan
Acknowledgments：
Sr．Roberto Le6n of Transportes Aereos
CarlosDon

LTDAinCoyhaique，Chile，prOVidedinforma−tion on winter condition of the HPN and Glaciar
Exploradores，Which prompted Aniya to go therein
Winter．Asalways，hemadeexcellentflightsforaerial
SurVey Of the HPN outlet glaciersin December2003
andJuly2004．

Pedro Skvarca，Lic．（Glaciologist），HeadofGlaciology References
Division

Instituto Antartico Argentino，Buenos Aires，Aniya，M．（1987）：Aerialsurveys over the PatagoniaIce頁eld．
Bull．GlacierRes．，4，157p16l．
Aniya，M．（1988）：GlacierinventoryfortheNortherr］Patago−
NeilGlasser，Dr．（GlacialGeomorphologist），Seniorlec−
niaIcefield，Chile，and variations1944／45 to1985／86．
turer
Arct．Alp．Res．，20，179187．
Aniya，M．（1992）：GlaciervariationintheNorthernPatagonia
CentreforGlaciology，InstituteofGeography
Icefield，Chile，between1985／86and1990／9l．Bull．Glacierand Earth Sciences，University of Wales，Res．，10，83−90．
Aberystwyth，Aberystwyth，UK
Aniya，M．and Skvarca，P．（1992）：Characteristics and varia−
Stephan Harrison，Dr．（Geomorphologist），SeniortionsofUpsalaandMorenoglaciers，SOuthernPatagonia．
Bull．GlacierRes．，10，39−53．
researcher
Aniya，M．，Naruse，R．，Shizukuishi，M．，Skvarca，P．
OxfordUniversityCentrefortheEnvironment，Casassa，G．（1992）：Monitoringrecentglaciervariationsin
Mansfield Road，0Ⅹford，UK
theSouthernPatagoniaIcefield，utilizingremotesensing
data．InternationalArch，Photogramm．RemoteSensing，
Field Members

Argentina

RenjiNaruse，Dr．（Glaciologist），Associate professor

29（B7），8「ト94．

Aniya，M．，Sato，H．，Naruse，R，．Skvarca，P．and Casassa，Institute of Low Temperature Science，（1996）：Remotesensingapplication toinventoryinggla−
Hokkaido University，Sapporo，Japan
Ciersin alarge，remOte area・Southern PatagoniaIce−
field．Photogramm．Eng．RemoteSensing．，62，136ト1369．
TomonoriTanikawa，Mr．（Glaciologist），Doctoral
Aniya，M．，Sato，H．，Naruse，R，．Skvarca，P．and Casassa，student（1997）：RecentglaciervariationsintheSouthernPatago−
Graduate Student，Graduate Schoolof Life
niaIcefield，SouthAmerica，Arct．Alp．Res．，29，112．
and EnvironmentalSciences，University of
Aniya，M．and Wakao，Y．（1997）：Glacier variations of Hielo
Patag6nico Norte，Chile，between1944／45and1995／96．
Tsukuba，Ibaraki，Japan
Bull，GiacierRes．，15，1−8．
EvgeniIsenko，Mr．（Glaciologist），Doctoralstudent
Aniya，M．and Naruse，R．（1999）：Late−Holocene glacialad−
Graduate Schoolof EnvironmentalEarth
VanCeS at Glaciar Soler，Hielo Patag6nico Norte，SouthAmerica．Trans，Japanese．Geomorph．Union，20，6983．
Sciences，Hokkaido University，Sapporo，Aniya，M．（2001）：Glacier variations of Hielo Patag6nico
Japan
Norte，ChileanPatagonia，Since1944／45，Withspecialref−
CarlosMarceloPaterlini，Mr．（Geographer），Ingeniero
erencetovariationsbetween1995／96and1999／2000．Bull．
Geodesta y Geofisico，Comisi6n Nationaldel
GlacierRes．，18，55−63．
Aniya，M．and Naruse，R．（2001）：Overview of glaciological
Limite Exterior de la Plataforma Continental
researchproJeCtinPatagoniain1998and1999：Holocene
GonzaloBarcaza，Mr．（Geographer）
glacier variations and their mechanism．Bull．GlacierSelf，employed，Santiago，ChileRes．，18，7178．
RyotaEndo，Mr．（Geologist），Doctoralstudent
delValle，R．，Skvarca，P．，Mancini，M．andLusky，J．（1995）：A
preliminary study of sediment cores from Lago
Graduate Schoolof Life and Environmental
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Sciences，University of Tsukuba，Ibaraki，Patagonia．Bull．Glacier．Res．，13，121126．
Japan
Iizuka，Y．，Kobayashi，S．and Naruse，R．（2004）：Watersurface
WaVeSinduced by calvingeventsatPeritoMorenoGla−
Andr6s Eugenio Veloso，Mr，（Geologist），Doctoral〃タAniya（ZgαJ．

Cier，SOuthern Patagonia．Bull．Glaciol．Res．，21，9卜96． 1yses and numericalexperiments．Ann．Glaciol．，21，297−
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Naruse，R．，Skvarca，P．and Kobayashi，S．（2001）：Measurc−
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Bull．Glaciol．Res．，21，45−48．
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SearCh，JapaneseSocietyofSnowandIce，133p．
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thern PatagoniaIcefield between1990／91and1993／94．
Bull，GlacierResリ13，111119，
SocietyofSnowandIce，175p．
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glCadeChile，29，315．
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K．（1995a）：Thickness change andshort−termflow varia−
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tion ofMorenoGlacier，Patagonia．Bull．GlacierRes．，13，
gonia，Argentina）．Zbl．Geol．Palaont．TeilI，H．36，593−
2ト28．

608．

Naruse，R．，Aniya，M．，Skvarca，P．and Casassa，G．（1995b）：
Zagier＆Urruty Publications（2004）：Patagonian SouthIce−
RecentvariationsofcalvingglaciersinPatagonia，South
field trekking−mOuntaineering map（1：50，000）．Zagier＆America，reVealedbygroundsurveys，Satellite−dataana−
Urruty Publications，BuenosAires，Argentina．