Part 2: Understanding the impact that melting glaciers are having on water resources in the Callejon de Yan Glac Tropical Peruvian glaciers in a changing climate: YAN - Huaylas requires quantifying the annual impact of glacier mass loss to the main river channel. We have l C C traced melt water hydrochemically from the small Yanamarey glacier catchment through the Querococha Q2 a 2+ 2- + + watershed and in the downstream tributaries of the Rio Santa with different degrees of glacier coverage. Q1 4 Forcing, rates of change, and impact to water supply O M Q3 S g Below Quero 2+ Bryan G. Mark (1) & Jefferey M. McKenzie (2) Rio (1) The Ohio State University, Department of Geography & Byrd Polar Research Center, Columbus, OH 43210, [email protected] 4000 5237 Santa Callejon de Huaylas Yanamarey catchment 700 a. Yanamarey 7 2+ (2) Syracuse University, Department of Earth Sciences, Syracuse, NY 13210, [email protected] Mg 2- Contour interval = 1000 m 200 0 200 400 m 600 6 SO4 3000 5000 500 5 2000 Lake Watershed 400 4 40 Glaciar Huallanca Glacierized -100 35 1100300 3 8 50'° 4000 30 4800Yanamarey 1000200 2 -250 25 5000 ° Colcas Terminus 900100 1 6259 20 99 (m) 78 00' recession Negra Low (C) Tropical glaciers are intriguing and presently rapidly disappearing components of the cryosphere that Cordillera Blanca -400 (m/yr) 15 98 1. Glacier watershed (mm) 8000 0 Paron (m) literally crown a vast ecosystem of global significance. They are highly sensitive to climate changes SANTA LOW (m/yr) 10 97 700 Llullan -550 -100 P -1 88 ° 5 over different temporal and spatial scales and are important hydrological resources in tropical 6395 Kinzl -200600 Melt -2 South America Llanganuco 77 20' -700 0 82 Qt (YAN) -300500 -3 highlands. Moreover, an accurate understanding of the dynamics and climate response of tropical 1930 1950 1970 1990 2010 73 T 2+ + + 2- - - Equator 0 6768 9 10'° glaciers in the past is a crucial source of paleoclimatic information for the validation and comparison CordilleraRanrahirca Negra 62 * -400400 -4 Ca Na +K CO +HCO Cl 5000 48 of global climate models. We have studied both present-day glacier recession and field evidence of 1939 300 b. Querococha (Above) Piper plot of major ion chemistry from the YAN-Querococha watershed. Q3 is on a mixing 4000 Q1 Buin 200 line between the glacial snout and Q1, with a relative contribution of 50% from each end member. 6125 Q2 The size of each symbol is proportional to TDS. past episodes of deglaciation in Perú to test hypotheses related to this important climatically forced 3000 Querococha watershed 100 Q3 process in the developing Andean region. Modern glacier recession raises the issues of the nature of Marcara 2 0 2 4km 0 Anta 5000 climatic forcing and the impact on surface water runoff. While rates of contemporary glacier recession Paltay 08- 06- 10- 19- 19- 28- 29- 04- 05- 23- 02- 25- Cord Blanca JANGAS Contour interval = 200 m Jun- Jul- Aug-Sep- Oct- Nov-Dec- Feb-Mar- Apr- Jun- Jun- appear to be accelerating, careful analysis of the timing and volumetric extent of deglaciation from 0S° 6162 5237 Glaciar - C Yanamarey 98 98 98 98 98 98 98 99 99 99 99 99 l a 2+ Rio Santa C Late Glacial and Holocene moraine positions provides a historical comparison with important Quilcay 2. Downstream confluence c. Callejon de Huaylas + + Huaraz 6395 Cord Negra 2- implications for understanding glacial-to-interglacial transitions. Our research incorporates three PERU 2.5 M Querococha 4 Cordillera 4800 g specific parts:(1) an analysis of the spatial variability and climatic forcing of late 20th century glacier O 2+ Blanca YAN 5197 Olleros S recession in the Queshque massif of the southern Cordillera Blanca, Peru;(2) an evaluation of the SANTA2 5322 discharge 2.0 Chancos 8S° Olleros Llanganuco hydrological significance of glacial meltwater with respect to streamflow in the Cordillera Blanca Q3 ° 4400 1.5 Paron Q 77 00' region; and(3) an evaluation of the rate and extent of deglaciation during the late-Pleistocene and Cordillera Q Vilcanota Yanayacu 9 50'° 4800 2+ 2- Lima Q2 Q1 Max 1.0 Holocene compared to modern glacier recession in the Cordillera Vilcanota/Quelccaya. We review Mean Mg SO4 4000 our results in the context of outlining a vision for using glacial-environmental assessment as a focal Pachacoto discharge discharge 0.5 point to investigate both physical and human dimensions of climate change. 16° S 4400 R2 =0.65 4400 >4000 m in elevation 4000 0.0 Querococha SANTA1 0204060 80° W 72° W Negra2 3980 Q3 Part 1: We use a combination of aerial photogrammetry, satellite imagery, discharge 3. Tributaries of Rio Santa Glacierized area (%) Negra1 Tuco and differential GPS mapping to quantify the volume of ice lost between AD 40 0 40 80 km (Above) Hydrological and climatological data from the successively larger CONOCOCHA catchments of the case study (see Fig. 1): (a) observational data from the Yanamarey 1962 and 1999 from 3 glaciers of different aspect. A heuristic sensitivity analysis Glacierized % (1962) (1997) glacier catchment, including monthly measurements of specific discharge (Qt) (mm) -2 Paron 55 52 from YAN plotted with the monthly precipitation totals (P) (mm) and monthly average 2+ + + 2- - - indicates the 9.3 Wm required to melt the observed ice loss can be explained 2 temperature (T) (degrees C) sampled over the 1998-99 hydrological year, plotted with -1 (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. Llanganuco 41 36 CO +HCO Cl 2 2 Ca Na +K 3 3 by a 1K rise in temperature and 0.14 gkg increase in specific humidity. Stream gauge and sample locations are identified; Querococha watershed, 60 km , showing the discharge and water sampling points; Yanamarey catchment, 1.3 km the glacier melt (Melt) calculated from a simplified hydrological mass balance; (b) Cedros 22 18 specific discharge data from locations in the Querococha watershed plotted with 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 Chancos 25 22 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, monthly precipitation at the Querococha gauge (both in mm), on the same scale as 5680 (Above) Piper plot of major ion chemistry from the averaged end-members in the Callejon de (SPOT image 1997) 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 Colcas 20 18 (a); (c) magnitude and variation of annual stream discharge with percentage of Queshque Huaylas watershed. The Rio Santa is on a mixing line between the glacierized Cordillera 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 glacierized area in the Río Santa tributaries, shown by ratio of maximum monthly East (E) Olleros 12 10 Blanca tributaries and non-glacierized Cordillera Negra tributaries, with a relative contribution of Queshque 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 discharge to mean monthly discharge (max Q / mean Q); labeled data points Querococha 6 3 66% from the Cordillera Blanca. The size of each symbol is proportionate to TDS. (5680) temperature and monthly precipitation were recorded discontinuously from 1982.•1999 glacier surface from correspond to gauge locations shown on map. 5403 differential GPS survey 0 Glacial moraine chronology provides a basis for evaluating the timing and rates of deglaciation for late glacial and Holocene paleoglaciers in the 00 Part 3: 5 Peruvian Andes. Rates of deglaciation were calculated for paleoglacier volumes on both the western side of the Quelccaya Ice Cap and the northwest side Mururaju Mururaju Queshque East (E) (5688) 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 Queshque (S) Main 5688 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, 0 0 5 2000). The fastest rates of deglaciation were calculated for the youngest paleoglaciers, corresponding to the last few centuries. These rates fall within the 00 8 400 46 (SW) 4 Lagunas Queshque 3 range of modern rates measured on the Quelccaya Ice Cap, interpreted as evidence of enhanced atmospheric temperatures (Thompson, 2000). Applying 5000 the maximum modern deglacial rates to the late glacial ice volumes results in deglaciation over a few centuries, consistent with lake-core evidence. These Aerial photos (left) and satellite imagery 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. (above) were used to map glacier extent in 1962 and 1997. Digital glacier surfaces Queshque Main (SW) were reconstructed with photogrammetry N 300 120 L. Casercocha small small and differential GPS. Contour map (upper Upismayo Valley large large right, interval = 200m) of the glacierized 250 100 areas on the Queshque massif (photos of 3 glaciers to left). Three tones of shading W E Lake Ice1 200 80 represent: 1999 glacier areas of the Moraine Ice2 glaciers (light grey); the 1962 areas Stream Ice3 150 60 mapped from aerial photography (blue); Modern Ice 4450 ± 45 and other areas mapped from 1997 SPOT Pleistocene moraines, S 10 imagery (dark grey).