85

Bulletin of Glaciological Research ,- (,**0) 2/ῌ3ῌJapanese Society of Snow and Ice

Preliminary observations of sub-surface and shallow ice core at July +st Glacier,
China in ,**,ῌ,**.
Jun UETAKE+, Akiko SAKAI,, Yoshihiro MATSUDA,, Koji FUJITA,, Hideki NARITA-,
Sumito MATOBA-, Keqin DUAN., Masayoshi NAKAWO/ and Tandong YAO 0+ Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo +/,ῌ2//+ Japan, Graduate School of Environmental Studies, Nagoya University, Nagoya .0.ῌ20*+ Japan- Institute of Low Temperature Science, Hokkaido University, Sapporo *0*ῌ*2+3, Japan. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 1-****, China/ Research Institute for Humanity and Nature, Kyoto 0*,ῌ*212, Japan
0 Institute of Tibetan Plateau, Beijing +***2/, China(Received October 1, ,**/; revised manuscript accepted November +., ,**/)

Abstract
The albedo reduction on glacier surfaces in past summers due to microbiological activities andmineral particles should be considered to reconstruct precise ﬂuctuation of glacier mass balance.
However, there is little knowledge on preservation of the microorganisms and the mineral particles inglacier ice. In particular, inﬂuence of superimposed ice formation on these preservations is unknown.
As the ﬁrst step to understand the albedo reduction process and to reconstruct surface albedo changes
on glaciers in northwestern China, where superimposed ice formation has an impact on glacier massbalance, we report the glacier surface level changes, seasonal and annual changes of stratigraphy andanalyzed results of short ice cores at upper parts of the July +st Glacier from ,**, to ,**.. Surface
melting on the glacier was accelerated by dark-colored materials composed of cryoconite and mineralparticles. The glacier surface level was lowered year by year and ELA (Equilibrium Line Altitude) wasmuch higher than that in the +31*s and +32*s. An ice core of +.2, m length included ﬁve cyanobacterial
layers. As cyanobacteria grow during summer, these layers may be useful as markers for summer
layers and allow to infer surface albedo changes in the past. Average annual snow mass balance
estimated from the cyanobacterial peaks in the core is -+- mm, which corresponds to the annual
precipitation observed near the terminus of the July +st Glacier. These results would open up the
possibilities that we could reconstruct past mass balance and albedo e#ects.

+.

Introduction

Glaciers in arid and semi-arid regions of central
Asia are the most important sources of fresh water.
However, glaciers in Qilian Mountains of China havebeen retreating and shrinking rapidly. Moreover, theshrinkage has been accelerated in the recent few decades (Liu, et al., +33,, ,**-; Sakai et al., ,**.). One of its
reasons would be the temperature increasing, since
Liu and Chen (,***) revealed that the recent air temperature increases were larger at higher altitudes in
the Tibetan Plateau.
The Qilian Mountains are located in -0ῌ-3ῌN, 3.ῌ
+*.ῌE, with length of about 2/* km and width of ,**ῌ-** km, in the northwestern Qinghai-Tibetan Plateau
of west China. There are ,2+/ glaciers, most of which
are located on the north facing slopes, and the entire

glaciated area was +-3*..3 km, in +32* (Wu, +32/).
July +st Glacier is located on the western part of
the Qilian Mountains. Many observations have been
carried out since +3/2 in glaciology, hydrology andmeteorology (Lanzhou Institute of Glaciology andGeocryology, +32/, +33,; Shi et al., +322; Matsuda et al.,,**.; Sakai et al., ,**0). Some portion of the meltwater should refreeze in snow layer and form thesuperimposed ice. It is, therefore, necessary to take
into account the refrozen amounts in order to estimate the mass balance of a glacier (Fujita et al., +330;
Fujita and Ageta, ,***).
During winter, continental air makes this region
dry and cold. On the other hand, in summer, southwesterly and southeasterly monsoons from Indianand Paciﬁc Oceans provide the moisture to this region.
Therefore, precipitation is concentrated in the summer season (from June to September), and snow accu-

86Bulletin of Glaciological Research

mulation and melting on the glaciers coincide during
the summer season. There is relatively high precipitation (more than -** mm yrῌ+) at high elevations (morethan -*** m a.s.l.) in these mountainous areas (Dingand Kang, +32/; Zhu and Wang, +330), while there islittle precipitation (less than /* mm yrῌ+) downstream(Ding and Kang, +32/; Wang and Cheng, +333).
The Japan-China joint research team has carriedout many observations on the July +st Glacier from
June ,**, to September ,**/. The observations on theglacier surfaces suggested that mud-like materials
composed by microbiological activities during summer reduced the albedo, would accelerate the surface
melting, and would a#ect the mass balance (Takeuchi
et al., ,**/). And recent shrinkage estimated from thealtitudinal proﬁles of the mass balance (Matsuda et al.,,**.) would be a#ected by the microbiological activities. However, determination of annual layers in ice
cores obtained from superimposed ice zone has still
been di$cult. Moreover, inﬂuence of superimposed ice
formation on preservation of microorganisms andmineral particles is unknown. As the ﬁrst step tounderstand the albedo reduction process and to reconstruct the past surface albedo on glaciers from ice
cores composed by superimposed ice in northwestern
China, we present preliminary results regarding glacier surface level changes, seasonal and annual changes of stratigraphy near the surface, and analyses ofshort ice cores at the upper parts of July +st Glacierfrom ,**, to ,**..

,.

Physical setting of July +st Glacier

The July +st Glacier is located at -3῍+/ῌN, 31῍./ῌE,
in the Qilian Mountains, northwestern QinghaiTibetan Plateau of west China. The altitude of thisglacier is .,3/ῌ/*22 m a.s.l. and its length is -.2 km (Liuet al., +33,). Dyurgerov (,**,) showed that the ELA
was .//*ῌ.1+* m a.s.l. in the mid-+31*s and +32*s.
The glacier is polar type (Huang, +33*), and theinstant ice temperature data at 0 m depth in August
showed ῌ0῎ during the +31*s (Xie et al., +32/). Someportion of the melt-water should refreeze in snow
layer. It is, therefore, necessary to take into accountthe refrozen amount in order to estimate the massbalance of the glacier (Fujita et al., +330; Fujita andAgeta, ,***).

-.

Observations and analysis methods

Meteorological observation, pit work and ice coredrilling were carried out in ,**,ῌ,**. at ST2-, (.0+- m
a.s.l.) and ST+* (.2,. m a.s.l.) in the upper part of thisglacier (Fig. +). In the situations during the +31*s and+32*s, the locations of ST2-, and ST+* were around theequilibrium line altitude and in the accumulationarea, respectively.

Fig. +. Location map of July +st Glacier (upper) andcontour map of the July +st Glacier (lower)
produced by Shi et al. (+322). Solid circles in thelower map show locations of the observation sitesof ST2-, and ST+*.

Automatic weather stations (AWS) were installed
at ST2-, and ST+* to measure air temperature andsurface level. Ice temperature was measured at ST2-,
from Jun ,**, to Jul ,**..
Pit works were carried out at ST+* from +0 Jun to-* Aug in ,**, with intervals of +ῌ, weeks to observe
stratigraphy and surface level changes. On +1 Sep.
,**-, an ice core of +.2, m length was taken by hand
drilling at ST+*, and stratigraphy, ice crystal size andthe major axis of bubble were observed on site. In,**., we carried out surface snow pit surveys and ice
core sampling on -* May and , June at ST2-, and ST+*. There was a snow layer on the ice with depth of*.,0 m on -* May at ST2-,. A shallow ice core of -.*0 m
length was obtained by using an ice auger after removing the entire surface snow cover. On the other
hand, at ST+*, an ice core was obtained by removing
surface snow of *.-0 m thickness and its length was a,.*1 m. Stratigraphies of both the ice cores and the pits
were observed on site. Snow densities were also measured at the pits.
The core samples were cut by pre-cleaned ceramic

Uetake et al.

87

knifes into each *.*/ῌ*.+* m length. The core surface
was scraped o# by thickness of +* mm with precleaned ceramic knifes on site in order to eliminate
contamination. These samples were packed into sterilized plastic bags. After melting, all samples were dispensed into clean plastic bottles for biological andisotopic analysis. Oxygen isotopes in the ice core samples were measured with a dual-inlet isotope mass
spectrometer Finnigan Delta Plus at the Hydrospheric
Atmospheric Research Center, Nagoya University.
The biological samples were added with formalin of-ῌ in the sample volume for preservation. For analysis of microorganisms, sample of *.*-ῌ*.+* ml volume
was ﬁltered on hydrophilic polytetraﬂuoroethylene(PTFE) membrane ﬁlters (JHWP*+-**: pore size *.,mm, +- mm diameter; Millipore, USA), and cells of microorganisms on the ﬁlters were counted by using a
ﬂuorescent microscope (NIKON: E-0**). Microbiological density was determined by the counted cell numbers in samples and expressed in the unit of “cellsmLῌ+”. Mean cell volume (mm- cellῌ+) was estimated bymeasuring their dimensions with the microscope. Total biomass of microorganisms in the sample wasrepresented by total cell volume (mm- mLῌ+), which
was the product of the microbiological density andthe mean cell volume.

..

Results and discussion

Surface level changes in ,**,ῌ,**.
Figure ,a shows surface level variations at ST2-,
measured with the stake during three periods (Jun +/-Sep ., ,**,; Aug +.-Sep ,+, ,**-; and May ,2-Sep +*,,**.) and with a snow depth meter from Sep. ,,, ,**to Sep. 3, ,**.. The glacier surface level was loweredby about -./ m over the - summer seasons although
our site was in the upper part of the glacier. Especiallyduring the summers of ,**, and ,**., the surface
lowering was severe. Moreover, snow accumulation isrelatively small throughout the observation period.
Figure ,b shows surface level variations at ST+* measured with a stake between Jun +- and Sep ., ,**,, andwith a snow depth meter from Sep /, ,**, to Aug -,,**.. In the ,**- summer, this instrument did notwork temporarily. At this site, the glacier surface level
was similarly lowered by about ,./ m for the - summer
seasons. Some amounts of snow accumulated in eachspring, but the accumulated snow melted in the subsequent summer. In the mid-+31*s, the altitudes of ST2-,(.0+- m a.s.l.) and ST+* (.2,. m a.s.l.) were above ELA(Dyurgerov, ,**,). However, our observations revealthat ELA was above ST+* in ,**., because the snow
surface level continued lowering.
..+.

..,.

Seasonal change of sub-surface stratigraphy in,**,
Figure - shows the sub-surface stratigraphicalFig. ,. Surface level changes at ST2-, (a) and ST+* (b)from ,**, to ,**.. Solid line indicates the datameasured by snow depth meter. Triangles andsquares show manual observations of surface level
and ice level, respectively. Dotted lines (b) show
the date of ice core sampling in ,**- and ,**..

changes in pits excavated during the ,**, summer at
ST+*. The surface level on the ordinate has the origin
at that on +0 June. The surface level was lowered by+.+2 m from +0 Jun to -* Aug. In June and July, theglacier was covered with compacted snow with a thindirt layer. The snow cover was gradually thinningfrom ,3 Jun, while internal ice layer was thickening.
Moreover, mean ice temperature in June ,**. was ῌ
0.0῍ at *.0,ῌ+.** m depth and ῌ-.,῍ at *..-ῌ*.0, m
depth. These suggest that superimposed ice would
accumulate because internal layer was cold enough torefreeze melt water. By 0 August, the surface snow
layer has completely melted and the surface level has
been signiﬁcantly lowered. Moreover, bare ice surface
was covered with dark-colored dirt that contained
cryoconite and mineral particles, and the glacier surface was changed to black color (Fig. .). During +,ῌ+/Aug, new snow covered the dirty ice surface due tosnow accumulation. The AWS near the glacier terminus recorded precipitation at the same time (Sakai etal., ,**0). On ,- August, dirty ice was exposed atsurface because of the snow melting, and then thesurface level started lowering again.

88

Bulletin of Glaciological Research

Fig. -. Changes of surface snow stratigraphy (column) and albedo changes (solid line) at ST+* from +0 Jun to -* Aug,,**,. Diamonds on the solid line mean that the albedo was measured on the same day as the stratigraphicalobservation, and the triangles mean that the dates were di#erent. The marks of ‘d’ show dirt layers which could beobserved visually.

Fig. .. Photograph of glacier surface at ST+* on 0
Aug, ,**, when the dirt layer and ice layer
appeared on the surface.

Albedo change at ST+* in ,**,
Solid line in Fig. - shows surface albedo change
from ,3 June to ,/ August ,**, at ST+*. The surface
albedo was measured when a sub-surface pit survey
was carried out (Fig. -). The albedo was relatively
high (*..,ῌ*.22) from Jun to mid-Jul, and then changed
relatively low (*.+*ῌ*.,+) except on +, August. Albedo
of clean ice surface and dry snow is generally *..* and*.2., respectively according to Paterson (+33.). The
observed albedo is lower than those general values
after mid-Jul. The di#erences would arise from thesurface conditions. Once dark-colored bare ice ap-

peared on the surface and coloration turned to blackat the beginning of August, the albedo decreased quickly. However, on +, August, the glacier was covered
with snow (Sakai et al., ,**0), and the albedo wasrelatively high. Therefore, the dark-colored bare ice
would reduce the albedo. Cryoconite in dark-coloredbare ice is known to reduce surface albedo on glaciersbecause the cryoconite has dark color and contains
many kinds of microorganisms (Kohshima +323;
Takeuchi et al. ,**+a, ,**+b, ,**/; Takeuchi, ,**,).
These studies suggest that not only mineral particles
but also microbiological activities in glaciers play
important roles in albedo reduction. To reconstruct
the past ﬂuctuation of the July +st Glacier, we need toknow albedo value, which is determined by these two
factors, exactly. Therefore, dirt layers containing mineral particles and/or microorganisms in ice cores may
enable to reconstruct past albedo ﬂuctuation.

..-.

.... Snow pit and ice core in ,**- and ,**.
....+. Cyanobacteria in July +st GlacierThree species of cyanobacteria were observed inpit and ice core samples in ,**-. Similar kinds ofcyanobacteria were reported from glaciers in Alaska,
Patagonia and China (Takeuchi, ,**+; Takeuchi and
Kohshima, ,**.; Takeuchi et al., ,**/). These cyanobacteria are contained in the cryoconite and are one ofits main components. A description of the three species is as follows.
Oscillatriaceae cyanobacteria. + (Fig. /a): Trichomes areUetake et al.

,ῌ/ mm in width, and / mm in length. Total length is+,./ῌ/** mm.
Oscillatriaceae cyanobacteria. , (Fig. /b): Trichomes
are +./ mm in width, and ,./ mm in length. Total lengthis 1/ῌ-** mm.
Oscillatriaceae cyanobacteria. - (Fig. /c): Trichomes
are ,./ mm in width, ,./ mm in length, and all cells areround. Total length is ,/ῌ+** mm.
....,. Analyses of the Ice core at ST+* in ,**Figure 0 shows the vertical proﬁle of stratigraphy, cyanobacterial biomass, oxygen isotope ratio (d+2O), major axis length of bubble and ice crystal size of

Fig. /. a) Oscillatriaceae cyanobacteria +, b) Oscillatriaceae cyanobacteria ,, c) Oscillatriaceae cyanobacteria -. All bars show +* mm.

89

a +.2, m depth ice core from ST+* in ,**-. Glaciersurface is covered with snow of *.+ m thickness, whichaccumulated during the ,**- summer. The ice below
surface snow must have formed before ,**, because
the surface level continued to be lowered from June,**, (Fig. ,b). This ice core contains one dense dirty
layer at *./1ῌ*.1, m depth and three cryoconite grainrich layers at *.+3ῌ*.,0, *..1ῌ*..2 and *.1,ῌ+.- m depth.
In the proﬁle of cyanobacterial biomass, ﬁve peaks arefound at *.+/ῌ*.,0, *./,ῌ*./1, *.00ῌ*.2,, +.*,ῌ+., and +..ῌ+./ m depth in Fig. 0b and the peaks at *.+/ῌ*.,0 and*.00ῌ*.2, m depth correspond to the cryoconite grainrich layer and the dirt layer, respectively. In Himalayan and Patagonian glaciers, snow microorganisms
are reported to be useful for an annual marker in theglacier strata (Yoshimura et al., ,***; Shiraiwa et al.,,**+), because microbiological activities increase during summer due to high temperature and existence ofmelt water. Also in the July +st Glacier, microbiological activities increased during summer, because weobserved an enormous amount of cyanobacteria growing on the summer surface by conﬁrming the darkcolored surface. Furthermore, a large-sized particle(ex. pollen) is more di$cult to move by melt water
than chemical ions and isotopes, due to its size
(Nakazawa et al., ,**.), and the length of cyanobacteria cells (+,./ῌ/** mm) is greater than the diameter ofpollen (+*ῌ+/* mm). Cyanobacteria rich layers in thisice core, therefore, would be markers of summer layers. However, the glacier surface level continued to belowered during recent years, which indicates that re-Fig. 0. Proﬁles of ice core at ST+* taken in ,**-. a) Stratigraphy, b) Biomass of cyanobacteria, c)d+2 O, d) major axis of
bubbles, e) ice crystal size. Solid line and dashed line show the maximum and minimum sizes, respectively.

90

Bulletin of Glaciological Researchcent year’s accumulation would have melted completely and not be preserved. For this reason, we cannot
decide the date of each layer in the ice core. However,this ice core appears to contain ﬁve summer layers
from biological analysis. These layers were formed inpast years when the drilling site was in accumulation
area and colder than present, because the estimatedsummer layers were not disturbed. Then, as melting
water should have been accumulated on superimposed
ice and hardly run o#, mass balance would be similar
to precipitation. Therefore, average annual mass balance estimated from the cyanobacterial peak is -+- mm
over four years dated by the peak of the biomass, thevalue of which agrees with the annual precipitation(-.*ῌ-1* mm) observed in the July +st Glacier in ,**and in ,**. (Sakai et al., ,**0). This result implies thatsummer layers and past mass balance ﬂuctuations
could be detected by the marker of cyanobacteria.
Dust layers, which contains much dusts and corresponds here to the dirt layer, may be also formed in
the ice core from spring to summer, because a dust
storm was mainly observed from March to June +33+
ῌ+33, in Zhangye, located at the foot of the Qilian
Mountains (Kai et al., +331). Sakai et al. (,**0) also
reported a dust storm at July +st Glacier in July ,**..
A dust layer would be normally observed at least once
every year, but we observed only one dirt layer in theice core containing / annual layers, the dating of
which was determined by the biomass peak. Accumulation of aerosol would change year by year because
the frequency and intensity of dust storms will change depending on climate. In this study, we used only
visual observations and can identify only a layer caused by a relatively large dust storm. As further studies, we will analyze the particle size of samples, thenwe may detect other dust layers.
The vertical proﬁle of d+2 O is relatively high at *ῌ*.+ and *./,ῌ*.1, m depth. Tian, et al. (,**-) showedthat d+2 O in precipitation depends on temperature in
the northern Tibetan Plateau, and summer precipitation has high d+2 O. Actually, the summer surface snow
in ,**- had high d+2 O at ST+*. Therefore, if there is no
melting, a high value of d+2 O will be a marker of asummer layer. Below *.+ m depth, d+2 O is high aroundthe summer layers estimated from biological analysis.
However, the peaks of high d+2 O were not remarkable.
In temperate regions, the proﬁles of isotope ratios area#ected by melt water and often disturbed (Iizuka etal., ,***). Therefore, it is di$cult to identify the summer layer only by isotope signals, but combination ofpeaks of d+2 O and cyanobacteria may support morereliable dating.
At *./1ῌ*.00 m depth, a peak in the proﬁle of the
major axis of bubbles corresponds to the dirt layer(Fig. 0d). However, we cannot understand process ofthe bubble formation at present, because we do nothave su$cient information.

At *.,1ῌ*.00 and +.1,ῌ+.2, m depths, ice crystal size
is relatively large (Fig. 0e). The ice crystal size insuperimposed ice should be small because the melt
water comes down into contact with a cold ice layer
and refreezes rapidly, and while the size should become larger when the meltwater refreezes slowly according to Wakahama and Hasemi (+31.). However,
we do not have su$cient information on ice temperature of this glacier and cannot understand the process.
Further study will reveal the formation processes of
bubbles and crystal size.
....-. Analyses of the Ice cores and snow pits in ,**.
Figures 1a and 1b show the stratigraphy of theTable +. Densities in snow pits at ST2-, and ST+* in
Jun ,**.. Each sample is numbered by portion in
the stratigraphy in Fig. 2b.
Sampling No.

Depth fromsnow surface (m)Density(kg mῌ-)st2ῌ,ῌ+st2ῌ,ῌ,st2ῌ,ῌst2ῌ,ῌ.
st2ῌ,ῌ/

*4*+0
*4*10
*4++0
*4+10
*4,-+

-4,,
-4/0
,4,,4+0-4/+

st+*ῌ+
st+*ῌ,
st+*ῌst+*ῌ.
st+*ῌ/
st+*ῌ0st+*ῌ1

*4*+.
*4*/3
*4+*0
*4+/+
*4+3+
*4,-0
*4,02

-4,1
,40+
,43,
,40/
-4*.
,41+
,4.1

Fig. 1. Stratigraphy of snow pits at ST2-, (a) and ST+* (b) in June ,**.. Squares (size: *.*.1῍*.*/3 m)show sampling portions for density measurement,
and their numbers correspond to those in Table +.

Uetake et al.

91

Fig. 2. Stratigraphy of ice core taken at ST2-, (a) and ST+* (b) in June ,**. andST+* in September ,**- (c). Ice cores in ,**. are excavated below the bottomof snow pits. Dashed lines between b) and c) show the same layers in ourestimation.

snow pits at ST2-, and ST+* on -* May and , Jun ,**.,
respectively, and sampling positions for density measurements. The surface was covered with ﬁrn snow by*.,0 m at ST2-, and by *.-0 m at ST+*. All density data
are summarized in Table +, which range from ,.+0 to-./0 kg mῌ-. Ice core samples were excavated below
the bottom of the ﬁrn at both sites of ST2-, and ST+*.
Figures 2a and 2b show the stratigraphy of the coresfrom ST2-, and ST+*, respectively. The stratigraphyof the core from ST+* in ,**- is also shown in Figure
2c. The ice core of -.*0 m depth from ST2-, site contains ﬁve dense dirty layers (*.0ῌ*.1/, *.13ῌ*.22, +.*/ῌ
+.*2, ,.+1ῌ,.+3 and ,.3/ῌ-.*+ m depth) and two layerswith red colored grains (*.1/ῌ*.13 and *.3ῌ*.33 m depth).
Red materials were also found in the ice core at ST+*in ,**-, and they were cryoconites which were composed of snow microorganisms and mineral particles.
On the other hand, the ice core from ST+* site in ,**.
contained , dense dirty layers (*..+ῌ*..2 and +.10ῌ+.13
m depth). The surface level of the ST+* ice core in ,**.
corresponded to the *.+, m depth of the ,**- ice corefrom the snow depth meter record (Figures ,b, 2b and2c). Therefore, the dirt layer at *..+ῌ*..2 m depth would
correspond with the dirt layer at *.0+ῌ*.1 m depth of inthe ,**- ice core (Fig. 2c), and the lower dirt layer inthe core taken in ,**. was not observed in the ,**- icecore, since the ice core in ,**- was not deep enough.
These results suggest that the ,**- ice core corresponds well with the ,**. ice core. In that ice core, as
the glacier surface was melted and lowered drastically, annual dating of recent years is impossible.
However, we conﬁrmed by visual observations thatthe glacier strata in further upstream part than ST+*
had been kept clearly. Therefore, an ice core from thissite may provide the past climatic information such as
surface albedo.

/.

Conclusion

The surface levels of July +st Glacier was loweredby about -./ and ,./ m at ST2 and ST+*, respectively,from Jun ,**, to September/August ,**.. These surface lowering would be accelerated by albedo reduction due to exposure of bare ice with dark-coloredmaterials during summer. The dark-colored bare ice
contained mineral particles and cryoconites. In the ice
core, we observed cyanobacterial layers. As cyanobacteria grow during the summer, these layers should be92

Bulletin of Glaciological Research

formed during summer and seem to be markers forsummer layers. Relatively high values of d+2 O, whichindicates summer layer, also corresponded with thepeaks of cyanobacteria, although the seasonal cycles
in d+2 O value were ambiguous at the lower parts.
Average annual mass balance in the ice core estimated from the cyanobacterial peak was -+- mm,
which corresponded to the annual precipitation observed near the terminus of the July +st Glacier. Detecting summer layers in the ice core by using the
cyanobacteria peaks would open up the possibilities
of reconstructing the past albedo.

Acknowledgments
The ﬁeld research and data analyses were funded
by a Grant-in-Aid for Scientiﬁc Research (Project No.
+.,*3*,*) from the Ministry of Education, Culture,
Sports, Science and Technology of Japan and theSumitomo Foundation. This paper is a contribution to
the Oasis Project (Historical evolution of adaptability
in an oasis region to water resource changes), promoted by the Research Institute for Humanity andNature (RIHN). This study was partly supported by
the Center Research Project of Hydrospheric Atmospheric Research Center, Nagoya University.

References
Ding, L. and Kang, X. (+32/): Climatic conditions for thedevelopment of glacier and their e#ect on the characteristics of glaciers in Qilian Mountains (in Chinese). Memoirs of Lanzhou Institute of Glaciology and Geocryology,
Chinese Academy of Sciences, No. /, 3ῌ+/.
Dyurgerov, M. (,**,): Glacier mass balance and regime. In
Meier, M. and Armstrong, R. (eds.), Data of Measurement
and Analysis, University of Colorado, Institute of Arctic
and Alpine Research, Occasional Paper No. //, 22 pp.
Fujita, K. and Ageta, Y. (,***): E#ect of summer accumulation on glacier mass balance on the Tibetan Plateau
revealed by mass-balance model. J. Glaciol., .0 (+/-), ,..ῌ,/,.
Fujita, K., Seko, K., Ageta, Y., Pu, J. and Yao, T. (+330):
Superimposed ice in glacier mass balance on the Tibetan
Plateau. J. Glaciol., ., (+.,) ./.ῌ.0*.
Huang, M. (+33*): On the temperature distribution of glacierson China. J. Glaciol., -0 (+,-), ,+*ῌ,+/.
Iizuka, Y., Igarashi, M., Watanabe, K., Kamiyama, K. and
Watanabe, O. (,***): Re-distribution of chemical compositions in the snowpack at the dome of Austfonna ice
cap, Svalbard (in Japanese with English abstract). Seppyo, 0,, ,./ῌ,/..
Kai, K., Huang, Z. C., Shiobara, M., Shen, Z. and Mitsuta, Y.
(+331): Seasonal variation of aerosol optical thickness
over the Zhangye oasis in the Hexi Corridor, China. J.
Meteor. Soc. Japan, 1/ (0), ++//ῌ++0-.
Kohshima, S. (+323): Glaciological importance of microorganisms in the surface mud-like materials and dirt layer
particles of Chongce Ice Cap and Gozha Glacier, West
Kunlun Mountains, China. Bull. Glacier Res., 1, /3ῌ0/.
Lanzhou Institute of Glaciology and Geocryology (ed.) (+32/):
Glacier variations and utilizations in Qilian Mountains(in Chinese). Memoirs of Lanzhou Institute of Glaciology
and Geocryology, Chinese Academy of Sciences, No. /,Science Press, Beijing, +2/ pp.
Lanzhou Institute of Glaciology and Geocryology (ed.) (+33,):
The monitoring of glacier, climate, runo# changes andresearch of cold region hydrology in Qilian Mountains(in Chinese with English abstract). Memoirs of Lanzhou
Institute of Glaciology and Geocryology, Chinese Academy of Sciences, No. 1, Science Press, Beijing, +.1 pp.
Liu, C., Song, G. and Jin, M. (+33,): Recent change and trend
prediction of glacier in Qilian Mountain (in Chinese withEnglish abstract). Memoirs of Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences.
No. 1, +ῌ3.
Liu, S., Sun, W., Shen, Y. and Li, G. (,**-): Glacier changes
since the Little Ice Age maximum in the western Qilian
Shan, northwest China, and consequences of glacier discharge for water supply. J. Glaciol., .3 (+0.), ++1ῌ+,..
Liu, X. and Chen, B. (,***): Climatic warming in the Tibetan
Plateau during recent decades. International Journal of
Climatology, ,*, +1,3ῌ+1.,.
Matsuda, Y., Sakai, A., Fujita, K., Nakawo, M., Duan, K., Pu, J.
and Yao, T. (,**.): Glaciological observations on July +st
Glacier in Qilian Mountains of west China during summer ,**,. Bull. Glaciological Res., ,+, -+ῌ-0.
Nakazawa, F., Fujita, K., Uetake, J., Kohno, M., Fujiki, T.,
Arkhipov, S. M., Kameda, T., Suzuki, K. and Fujii, Y.
(,**.): Application of pollen analysis to dating of ice
cores from lower-latitude glaciers. J. Geophy. Res., +*3 (F.), F*.**+, doi: +*.+*,3/,**. JF***+,/.
Paterson, W. S. B. (+33.): The Physics of Glaciers, -rd edition.
Pergamon, Oxford, .2* pp.
Sakai, A., Fujita, K. Matsuda, Y., Kubota, J., Duan, K., Pu, J.,
Nakawo, M. and Yao, T. (,**.): Five decades of shrinkageof the July +st Glacier in the Qilian Mountains of China.
The .th international symposium on the Tibetan Plateau, Lhasa, China.
Sakai, A., Matsuda, Y., Fujita, K., Matoba, S., Uetake, J.,
Satow, K., Duan, K., Pu, J., Nakawo, M. and Yao, T. (,**0):
Meteorological observation at July +st Glacier in northwest China from ,**, to ,**/. Bull. Glaciological Res., ,-,(in this issue).
Shi, Y., Huang, M., Ren, B., Bai, C., Deng, Y., Wang, P., Xie, Z.,
Yang, Z. and Zhang, J. (+322): An introduction to theglaciers in China (in Chinese). Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Science,
Science Press, Beijing, ,.- pp.
Shiraiwa. T., Kohshima, S., Uemura, R., Yoshida, N., Matoba,
S., Uetake, J. and Godoi, A. M. (,**+): High net accumulation rates at the Southern Patagonia Iceﬁeld revealed byanalysis of a ./.31-m-long ice core. Ann. Glaciol., -/, 2.ῌ3*.
Takeuchi, N. (,**+): The altitudinal distribution of snow algae on an Alaska glacier (Gulkana Glacier in the Alaska
range). Hydrol. Proc., +/, -..1ῌ-./3.
Takeuchi, N. (,**,): Surface albedo and characteristics of
cryoconite (biogenic surface dust) on an Alaska glacier,Gulkana Glacier in Alaska Ranage. Bull. GlaciologicalRes., +3, 0-ῌ1*.
Takeuchi, N. and Kohshima, S. (,**.): A snow algal community on a Patagonian glacier, Tyndall Glacier in theSouthern Patagonia Iceﬁeld. Arctic, Antarctic and Alpine Res., -0, 3,ῌ33.
Takeuchi, N., Kohshima, S. and Seko, K. (,**+a): Structure,formation, and darkening process of albedo-reduction
material (cryoconite) on Himalayan glacier: granular algal mat growing on the glacier. Arctic, Antarctic and
Alpine Res., --, ++/ῌ+,,.
Takeuchi, N., Kohshima, S., Shiraiwa, T. and Kubota, K. (,**+b): Characteristics of cryoconite (surface dust on glaciers) and surface albedo of Patagonian glacier, Tyndall
Glacier, Southern Patagonia Iceﬁeld. Bull. GlaciologicalRes., +2, 0/ῌ03.
Takeuchi, N., Matsuda, Y., Sakai, A. and Fujita, K. (,**/): A
large amount of biogenic surface dust (cryoconite) on a

Uetake et al.

glacier in the Qilian Mountains, China. Bull. Glaciological Res., ,,, +ῌ2.
Tian, L., Yao, T., Schuster, P. F., White, J. W. C., Ichiyanagi, K.,
Pendall, E., Pu, J. and Yu, W. (,**-): Oxygen-+2 concentrations in recent precipitation and ice cores on the
Tibetan Plateau. J. Geophys. Res., +*2 (D3), .,3-, doi:+*.+*,3/,**,JD**,+1-.
Wakahama, G. and Hasemi, T. (+31.): Formation of superimposed ice in sub-polar glaciers. Laboratory experiments
and numerical simulations. Low Temperature Science,
Ser. A, -,, +0+ῌ+1..
Wang, G. and Cheng, G. (+333): Water resource development
and its inﬂuence on the environment in arid areas ofChina-the case of the Hei River basin. Journal of Arid
Environments, .-, +,+ῌ+-+.

93

Wu, G. (+32/): Glacier water resources and e#ect of glacierwater in stream runo# in Qilian Mountains (in Chinese).
Memoirs of Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences, No. /, +ῌ2.
Xie, Z., Wu, G., Wang, L. and Wang, Z. (+32/): Ice formation of
glaciers in Qilian mountains (in Chinese). Memoirs ofLanzhou Institute of Glaciology and Cryopedology, Chinese Academy of Sciences, No. /, ,1ῌ.*.
Yoshimura, Y., Kohshima, S., Takeuchi, N., Seko, K. andFujita, K. (,***): Himalayan ice core dating with snow
algae. J. Glaciol., .0, --/ῌ-.*.
Zhu, S. and Wang, Q. (+330): Temporal-spatial distributions
and recent changes of precipitation in the northern slopes of the Qilian Mountains. Journal of Glaciology andGeocryology, +2, Special Issue, ,30ῌ-*..