Paltay
e
4600
48
Aerial photos (left) and satellite imagery
(above) were used to map glacier extent in
1962 and 1997. Digital glacier surfaces
were reconstructed with photogrammetry
and differential GPS. Contour map (upper
right, interval = 200m) of the glacierized
areas on the Queshque massif (photos of 3
glaciers to left). Three tones of shading
represent: 1999 glacier areas of the
glaciers (light grey); the 1962 areas
mapped from aerial photography (blue);
and other areas mapped from 1997 SPOT
imagery (dark grey). Dots represent GPSmapped surface elevations from 1999
survey. Dashed lines are ridges separating
the major drainages. Digital elevation
model (DEM) generated from digitized
1:25,000 contour lines (lower right).
00
48
00
40
Negra1
40
0
40
-1.0
1960
1970
1980
1990
5688
00
1980
1990
5400
5300
-11° S
(SW)
Queshque Main
(E)
Queshque East
(S)
Mururaju
5200
(Left): Hypsometric curves for
the Queshque glaciers, showing
area with altitude. The
Queshque Main glacier has
more mass exposed at lower
elevation.
5100
°C 5000
per decade
4900
4800
4700
4600
0
0.5
1
300
Moraine
Ice2
L. Casercocha
Ice3
4450 ± 45
Modern Ice
10
10,362 ± 73
0
250
Queshque
East (E)
255
260
2830 ± 70
328 ± 46
13,380 ± 150
Cordillera Vilcanota
Lakes
20
Kil
Ausengate
(6372 m)
om
ete
rs
Glacier
Rivers
Nevado
Ausengate
(6372 m)
Quelccaya
Ice Cap
235
Huancane
Valley
230
1.5
Glacier area (km2 ) 2)
2
2.5
Quesh Main (SW)
SW
E
S
3
-
Cl
24 +
SO
+
2-
+
-
Cl
CO3 + HCO3
Na + K
-
120
small
large
small
large
100
200
80
150
60
100
40
DEM
volume
change
1962-99
mean area
3
3
2
Quesh East (E)
Mururaju (S)
2
(5645 m)
0
2
4
8
10 Kilometers
(10 m )
(m)
48951
2215
5441
2197
407
1079
22
5
5
Lake
H1
12,230 ± 180
-2
Winter Solstice Wm
6600 - 7500
6200 - 6600
5800 - 6200
5500 - 5800
5100 - 5500
4600 - 5100
4100 - 4600
3500 - 4100
2800 - 3500
1000 - 2800
No Data
Summer Solstice Wm
7900 - 8700
7600 - 7900
7400 - 7600
7100 - 7400
6700 - 7100
6300 - 6700
5800 - 6300
5300 - 5800
4600 - 5300
2800 - 4600
No Data
N
W
E
S
-2
(Above): Mean annual solar radiation flux (Wm )
verses average surface lowering (m) calculated for
the 3 Queshque glaciers, identified by name.
A 30m DEM was generated from 1:25,000 and
1:100,000 maps and used to model insolation
receipt to the surface. Integrated clear-sky values
of global radiation for winter and summer solstices
(right) show seasonal shading differences. A
simple transmittivity model using the DEM
indicates solar radiation related to altered
cloudiness was not a predominant climatic forcing
of mass loss.
(Right, top): Mean annual clear sky solar radiation
flux (Wm-2) averaged over the 3 different areas for
each of the glaciers, representing the surface
areas for both 1962 and 1999, as well as the area
vacated by the ice between these dates (1962-99).
The mean annual total radiation is greatest over
the east-facing glacier.
0
Moraine
H2
Stream
View of Ausengate and the Cordillera Vilcanota from the
Upismayo valley (below). Landsat image draped over
DEM of the Vilcanota, viewed from NW (above).
H3
270 ± 80
Modern Ice
10,910 ± 160
10,870 ± 72
-2
+0.4
6
0
6
12 Kilometers
ey
e
ll
Va
L. Acconcancha
an
L. Paco Cocha
nc
Qu
Ha
elc
ca
ya
Ice
Ca
p
2670 ± 95
9980 ± 255
1
0
1
2
3
ice3
Glacier
Volume
(km3)
Upismayo Valley
ice3
1.17
ice2
0.74
ice1
0.55
mod
0.14
Huancané Valley
H3
0.43
H2
0.34
H1
0.19
mod
0.14
ice2
H3
ice1
H2
Deglacial Volume (km3)
Deglacial Interval (yrs)
(small)
(large)
Qori Kalis glacier
H1
Deglacial Rate (10-5 km3/yr)
(small)
(large)
(small)
5150 4400 3746 12073 11605 10950
2504 2135 1823 4986 4651 4472
489 384 279
0.43
0.19
0.55
1.31
0.88
0.69
3.56
3.71
3.81
4.09
112.47 143.23
3778 2400 1511
1806 700 617
492 290
0.09
0.34
0.19
0.57
0.48
0.33
2.38
3.47
38.62
250
(large)
3.93
4.25
197.13
25.44
35.14
141.10
29.77
41.22
179.69
34.97
48.27
247.31
5.96
4.18
---
15.09
26.58
67.07
23.75
68.57
113.79
37.72
77.80
---
4
5 Kilometers
12,240 ± 170
11,183 ± 109
200
150
9787
9130
8133
3.75
3.72
65.52
Moraine chronology in the Upismayo and Huancané valleys allows for a rates of deglaciation to be calculated using
paleoglacier volumes estimated from a digital elevation model (DEM). Radiocarbon ages for moraine features are shown in
the site maps above (from Goodman et al., 2001). Three paleoglacier volumes were reconstructed for each valley, as
shown with contour lines in figures to left (Mark et al., 2002). The estimated rates are tabulated above, and shown in bar
graphs, as explained below.
Huancané Valley
1962-99
surface
lowering
(10 m )
20
50
0
240
Queshque Main
Queshque East
Mururaju
2+
Ca
(Above) Piper plot of major ion chemistry from the averaged end-members in the Callejon de
Huaylas watershed. The Rio Santa is on a mixing line between the glacierized Cordillera
Blanca tributaries and non-glacierized Cordillera Negra tributaries, with a relative contribution of
66% from the Cordillera Blanca. The size of each symbol is proportionate to TDS.
250
L. Comercocha
10
Upismayo Valley
1962 area
1999 area
1962-99 area
-2
5600
5500
Ice1
DEM (1:25,000)
245
3
60
ismayo
255
Aspect
20
40
Glacierized area (%)
Q. Up
250
Glacier
2-
Stream
2000
Year
Ele v ation (m )
ºC
0.0
-1.0
1970
Lake
225
1.0
1960
E
S
Pleistocene moraines,
Cordillera Blanca
5
(Left): Annual deviation of
temperature from the
1961-1990 average from
29 Peruvian stations
located between 9-12 S
latitude, ranging in
elevation from 20 - 4600 m
a.s.l. The trends are based
on ordinary least squares
regression, and the
vertical bars extend 2
standard errors of the
mean on either side of the
annual average.
SO4
Part 3: Glacial moraine chronology provides a basis for evaluating the timing and rates of deglaciation for late glacial and Holocene paleoglaciers in the
Peruvian Andes. Rates of deglaciation were calculated for paleoglacier volumes on both the western side of the Quelccaya Ice Cap and the northwest side
of the Cordillera Vilcanota, Perú. The late glacial episode of deglaciation on the west side of Quelccaya is coincident with rapid deglaciation in the Cordillera
Blanca of north central Perú that occurred during the Younger Dryas interval, out of phase with glaciation in the North Atlantic region (Rodbell and Seltzer,
2000). The fastest rates of deglaciation were calculated for the youngest paleoglaciers, corresponding to the last few centuries. These rates fall within the
range of modern rates measured on the Quelccaya Ice Cap, interpreted as evidence of enhanced atmospheric temperatures (Thompson, 2000). Applying
the maximum modern deglacial rates to the late glacial ice volumes results in deglaciation over a few centuries, consistent with lake-core evidence. These
results imply that rates of deglaciation may fluctuate significantly over time, and that high rates of deglaciation may not be exclusive to the late 20th century.
Mururaju
(S)
Solar radiation (Wm -2)
2.0
-2.0
1950
Glacierized % (1962) (1997)
Paron
55
52
Llanganuco
41
36
Cedros
22
18
Chancos
25
22
Colcas
20
18
Olleros
12
10
Querococha
6
3
2
Upismayo Valley
10
Year
0
N
Queshque
Main (SW)
245
2+
(Above) Hydrological and climatological data from the successively larger
catchments of the case study (see Fig. 1): (a) observational data from the Yanamarey
glacier catchment, including monthly measurements of specific discharge (Qt) (mm)
from YAN plotted with the monthly precipitation totals (P) (mm) and monthly average
temperature (T) (degrees C) sampled over the 1998-99 hydrological year, plotted with
the glacier melt (Melt) calculated from a simplified hydrological mass balance; (b)
specific discharge data from locations in the Querococha watershed plotted with
monthly precipitation at the Querococha gauge (both in mm), on the same scale as
(a); (c) magnitude and variation of annual stream discharge with percentage of
glacierized area in the Río Santa tributaries, shown by ratio of maximum monthly
discharge to mean monthly discharge (max Q / mean Q); labeled data points
correspond to gauge locations shown on map.
80 km
5400
265
0
240
2000
-
0.0
(Above) Case study location maps of successively larger scale: Callejon de Huaylas, a watershed of ~5000 km draining the Cordillera Blanca, Perú, to the upper Rio Santa.
2
2
Stream gauge and sample locations are identified; Querococha watershed, 60 km , showing the discharge and water sampling points; Yanamarey catchment, 1.3 km
between 4600 m and 5300 m, 75% of which is covered by glacier ice. The shaded region shows the outline of Glaciar Yanamarey in 1982, with contours and a center-line to
show distance from headwall with 100 m intervals (after Hastenrath and Ames, 1995a). Terminus positions are mapped onto a common datum, based on surveys for 1939,
1948, 1962, 1973, 1982, 1988, 1997, 1998, and 1999. The latter three positions were mapped using differential GPS. The cumulative terminus recession from the 1939
position is shown (m) on the inset graph as solid line, with solid rectangles for years with corresponding terminus position mapped (data from A. Ames, personal
communication, 1998), along with average recession rate between years with mapped termini (in meters/year). Asterix marks the location of a weather station, where daily
•1999 glacier surface from
temperature and monthly precipitation were recorded discontinuously from 1982.
W
Mururaju (S)
-2.0
1950
Cl
Paron
Mg
3. Tributaries of Rio Santa
Tuco
CONOCOCHA
-
R2 = 0.65
Querococha
3980
Q3
discharge
SANTA1
Negra2
72°W
+ HCO
0.5
44
80°W
2-
Chancos
1.0
4400
00
16°S
Queshque
East (E)
260
15
Q1
discharge
cha
0.0
Max Q
Mean Q
44
Q2
discharge
CO
differential GPS survey
25
20
Olleros
1.5
laco
mm
1.0
Querococha
2.0
Q. Ja
(Left): Normalized anomalies
of annual precipitation totals
(mm) from 45 Peruvian
stations above 3000 m a.s.l.
Between 1953-1998. Vertical
bars extend 2 standard errors
of the mean on either side of
the annual averaged anomaly.
5197
00
Pachacoto
Wm
2.0
Surface lowering (m)
Mururaju (S)
2.5
Llanganuco
9°50'
5000
Queshque Main (SW)
c. Callejon de Huaylas
48
Yanayacu
Lima
+
Na + K
Cord Blanca
Rio Santa
Cord Negra
08- 06- 10- 19- 19- 28- 29- 04- 05- 23- 02- 25Jun- Jul- Aug- Sep- Oct- Nov-Dec- Feb- Mar- Apr- Jun- Jun98 98 98 98 98 98 98 99 99 99 99 99
2. Downstream confluence
00
77°00'
Q3
Cordillera
Vilcanota
YAN
discharge
5322
Olleros
+
2+
(Above) Piper plot of major ion chemistry from the YAN-Querococha watershed. Q3 is on a mixing
line between the glacial snout and Q1, with a relative contribution of 50% from each end member.
The size of each symbol is proportional to TDS.
0
Glaciar
Yanamarey
6395
SANTA2
Ca
-4
100
4 km
5237
-3
Q1
Q2
Q3
2+
hqu
2
-2
b. Querococha
300
Contour interval = 200 m
-1
400
-400
g
+M
ues
0
2
4000
sQ
*
73
62
2-
2+
a
una
0
P
Melt
Qt (YAN)
T
500
-300
Quilcay
Cordillera
Blanca
1
800
0
600
-200
82
SO4
2
900
100
700
-100
88
2+
Ca
gr
Ne
Lag
3
Queshque
Main
(SW)
3
Querococha watershed
6162
Huaraz
1100
300
200
50 00
Queshque East (E)
1. Glacier watershed
1939
ca 5000
Marcara
8°S
5403
Mururaju
(5688)
1990
4
Mg
Cl -
1970
400
97
48
Anta
JANGAS
1950
5
1000
200
00
99
98
10
5
0
2010
6
500
+
6125
00
9°10'
15
an
30
ra
ille
4000
rd
Buin
-700
1930
20
Bl
5000
Co
PERU
ra
6768
Ranrahirca
0°S
ille
Llanganuco
-550
25
Terminus
recession
(m)
(m/yr)
(m/yr)
(m)
rd
6395 Kinzl
Equator 0
77°20'
Co
Paron
-400
5000
78°00'
4000
Llullan
South America
and differential GPS mapping to quantify the volume of ice lost between AD
1962 and 1999 from 3 glaciers of different aspect. A heuristic sensitivity analysis
-2
indicates the 9.3 Wm required to melt the observed ice loss can be explained
-1
by a 1K rise in temperature and 0.14 gkg increase in specific humidity.
Queshque
(5680)
Glaciar
Yanamarey
48
7
600
2-
-100
-250
6259
a. Yanamarey
700
00
50
40
35
>4000 m in elevation
(SPOT image 1997)
5237
400 m
30
Colcas
Negra Low
SANTA LOW
Part 1: We use a combination of aerial photogrammetry, satellite imagery,
5680
200
4
00
Huallanca
0
200
SO
Lake
Watershed
Glacierized
20
3000
8°50'
Tropical glaciers are intriguing and presently rapidly disappearing components of the cryosphere that
literally crown a vast ecosystem of global significance. They are highly sensitive to climate changes
over different temporal and spatial scales and are important hydrological resources in tropical
highlands. Moreover, an accurate understanding of the dynamics and climate response of tropical
glaciers in the past is a crucial source of paleoclimatic information for the validation and comparison
of global climate models. We have studied both present-day glacier recession and field evidence of
past episodes of deglaciation in Perú to test hypotheses related to this important climatically forced
process in the developing Andean region. Modern glacier recession raises the issues of the nature of
climatic forcing and the impact on surface water runoff. While rates of contemporary glacier recession
appear to be accelerating, careful analysis of the timing and volumetric extent of deglaciation from
Late Glacial and Holocene moraine positions provides a historical comparison with important
implications for understanding glacial-to-interglacial transitions. Our research incorporates three
specific parts: (1) an analysis of the spatial variability and climatic forcing of late 20th century glacier
recession in the Queshque massif of the southern Cordillera Blanca, Peru; (2) an evaluation of the
hydrological significance of glacial meltwater with respect to streamflow in the Cordillera Blanca
region; and (3) an evaluation of the rate and extent of deglaciation during the late-Pleistocene and
Holocene compared to modern glacier recession in the Cordillera Vilcanota/Quelccaya. We review
our results in the context of outlining a vision for using glacial-environmental assessment as a focal
point to investigate both physical and human dimensions of climate change.
Yanamarey catchment
Contour interval = 1000 m
a
(C)
nt
(mm)
Callejon de Huaylas
4000
Sa
2+
o
g
+M
Ri
(1) The Ohio State University, Department of Geography & Byrd Polar Research Center, Columbus, OH 43210, mark.9@osu.edu
(2) Syracuse University, Department of Earth Sciences, Syracuse, NY 13210, jmmckenz@syr.edu
Yan Glac
YAN
Q2
Q1
Q3
Below Quero
2+
Bryan G. Mark (1) & Jefferey M. McKenzie (2)
Part 2: Understanding the impact that melting glaciers are having on water resources in the Callejon de
Huaylas requires quantifying the annual impact of glacier mass loss to the main river channel. We have
traced melt water hydrochemically from the small Yanamarey glacier catchment through the Querococha
watershed and in the downstream tributaries of the Rio Santa with different degrees of glacier coverage.
Ca
Tropical Peruvian glaciers in a changing climate:
Forcing, rates of change, and impact to water supply
3
Volume (km ) of each reconstructed paleoglacier is calculated using gridded-model surfaces and the DEM. Modern glacier
1.36
volume ('mod') was estimated from surface area by the formula V=28.5 S (after Chen and Ohmura, 1990). Deglacial
interval (yrs) represents the conceivable time range over which the paleoglacier deglaciated from successively less
extensive end moraine positions. The interval is presented as a mean surrounded by the one-sigma range in calibrated
radiocarbon ages. Where available radiocarbon dates include more than one constraining age for a moraine, the maximum
3
and minimum possible intervals are provided as 'large' and 'small' intervals respectively. Deglacial volume (km ) represents
the volume lost from the paleoglacier in 2 possible deglacial scenarios: a 'large' volume from complete deglaciation; and a
-5
3
-1
'small' volume considering only the volume lost between successive moraine positions. Deglacial rate (10 km yr ) is
calculated by dividing the deglacial volume by the deglacial interval, such that the 'small' rate equals 'small' volume divided
by 'large' interval, and 'large' rate equals 'large' volume divided by 'small' interval.
100
50
0
1963-1978
1978-1983
1983-1991
Accelerating rates of deglaciation for the Qori Kalis
-5
3
-1
glacier (photo above) in 10 km yr , calculated
from terrestrial and aerial photogrammetry
(Brecher and Thomas, 1993).
Paleoglacier
Upismayo Valley
H3
H2
Huancané Valley
Ice3
Ice2
Volume needed
(x modeled)
Time needed
(yrs)
5-8
20-40
210-370
130-230
3-5
20-25
500-630
110-150
The increments in volume (multiple of the modeled volume) and deglacial interval (number of years) needed for the modeled
paleoglaciers to equal the most recent rates of deglaciation are tabulated to right.
References
Brecher, H. and L. G. Thompson, 1993: Measurement of the retreat of Qori Kalis glacier in the tropical Andes of Peru by terrestrial photogrammetry.
Photogrammetric Engineering & Remote Sensing 59(6), 1017-1022.
Chen, J., and A. Ohmura, 1990: Estimation of alpine glacier water resources and their change since the 1870s. Hydrology in Mountainous Regions. IHydrological Measurements; the Water Cycle (Proceedings of two Lausanne Symposia, August, 1990). IAHS Publ. No. 193, 127-135.
Hastenrath, S., Ames, A., 1995. Recession of Yanamarey Glacier in Cordillera Blanca, Peru, during the 20th century. Journal of Glaciology 41(137), 191-196.
Goodman, A.Y., Rodbell, D.T., Seltzer, G.O., Mark, B.G., 2001. Subdivision of glacial deposits in southeastern Peru based on pedogenic development and
radiometric ages. Quaternary Research 56(1), 31-50.
Mark, B.G., Seltzer, G.O., Rodbell, D.T., Goodman, A.Y., 2002. Rates of deglaciation during the last glaciation and Holocene in the Cordillera VilcanotaQuelccaya Ice Cap region, Southeastern Perú. Quaternary Research 57(3), 287-298.
Mark, B.G., Seltzer, G.O., 2003. Tropical glacier meltwater contribution to stream discharge: a case study in the Cordillera Blanca, Peru. Journal of
Glaciology 49(165), 271-281.
Mark, B.G., Seltzer, G.O., 2005. Recent glacial recession in the Cordillera Blanca, Peru (AD 1962-1999). Quaternary Science Reviews, in press.
Rodbell, D. T. and Seltzer, G. O. (2000). Rapid Ice Margin Fluctuations during the Younger Dryas in the TropicalAndes. Quaternary Research 54, 328-338.
Thompson, L. G., 2000: Ice core evidence for climate change in the Tropics: implications for our future. Quaternary Science Reviews 19, 19-35.
Acknowledgments
Kathy Welch, Anne Carey
and Berry Lyons are
gratefully acknowledged for
facilitating laboratory
analyses at Ohio State
University. Don Siegel
supported laboratory work at
Syracuse University. Initial
field work was conducted
while BGM was supported
on a U.S. Fulbright
Scholarship, 1997-98.