# Nevado Huascarán - Oxygen Isotope, NO3, Layer Thickness, and Particle Data #---------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #---------------------------------------------------- # Template Version 4.0 # Encoding: UTF-8 # NOTE: Please cite original publication, NOAA Landing Page URL, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, study title, NOAA Landing Page URL, and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # NOAA_Landing_Page: https://www.ncei.noaa.gov/access/paleo-search/study/2447 # Landing_Page_Description: NOAA Landing Page of this file's parent study, which includes all study metadata. # # Study_Level_JSON_Metadata: https://www.ncei.noaa.gov/pub/data/metadata/published/paleo/json/noaa-icecore-2447.json # Study_Level_JSON_Description: JSON metadata of this data file's parent study, which includes all study metadata. # # Data_Type: Ice Cores # # Dataset_DOI: 10.25921/swwy-sg59 # # Science_Keywords: PAGES LOTRED SA2k, PAGES 2k Network #-------------------- # Resource_Links # # Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/icecore/trop/huascaran/thompson1995-anions-noaa.txt # Data_Download_Description: NOAA Template File; Anion Data from Core 2 # #-------------------- # Contribution_Date # Date: 2001-01-30 #-------------------- # File_Last_Modified_Date # Date: 2023-07-06 #-------------------- # Title # Study_Name: Nevado Huascarán - Oxygen Isotope, NO3, Layer Thickness, and Particle Data #-------------------- # Investigators # Investigators: Thompson, L.G.(https://orcid.org/0000-0001-5371-2579); Mosley-Thompson, E.(https://orcid.org/0000-0002-9665-3705); Davis, M.E.(https://orcid.org/0000-0003-1049-5935); Lin, P-N.(https://orcid.org/0000-0001-6006-0716); Henderson, K.A.; Cole-Dai, J.(https://orcid.org/0000-0003-0921-5916); Bolzan, J.F.; Liu, K.-B.(https://orcid.org/0000-0002-0038-2198) #-------------------- # Description_Notes_and_Keywords # Description: General Information about the Huascarán Ice Cores # # Site Description and Analysis: # # In July-August 1993, two ice cores to bedrock were recovered from the col between the north and south peaks of Nevado Huascarán, Peru (9°S, 77°30'W, col elevation 6050 m) and were subsequently transported back to the cold room facility at the Byrd Polar Research Center (BPRC). Core 1 (HSC1, 160.40 m) was sectioned in the field into 2677 samples decreasing in thickness from 13 cm at the top to 3 cm at the base, which were then melted and poured into 2 or 4 oz. plastic (HDPE) bottles, and sealed with wax. Core 2 (HSC2, 166.08 m), drilled approximately 100 m from the HSC1 site, was returned frozen in 1 m sections. Ice motion vectors determined from stake movements from 1991-93 indicate that the drill sites are proximal to the divide between ice flow towards the east and west outlets of the col. Visible observations and borehole temperatures indicate that the glacier is 'polar' type, i.e., it remains frozen to the bed (Thompson et al., Science, v.269, 1995, p. 46-50). # # Each ice sample from HSC2 was prepared in a Class 100 clean room environment, and analyzed for major anion concentrations (Cl-, NO3-, and SO42-) on a Dionex 2010i ion chromatograph, d18O on a Finnigan Mat mass spectrometer (Craig, 1957), and for particulate concentration and size distribution using a Coulter TA-II particle counter (Thompson, OSU IPS Report 46, 1973). A complete d18O profile was also produced from the bottled samples from HSC1. Contamination during field preparation and transport of these samples precluded the development of a second complete record of particles and anion concentrations. # # For display purposes, variable averaging on the core depth scale was utilized to show the major large-scale events in the record without the confusion of the large annual variations superimposed upon the upper portion. Hence, for HSC2, 5-m integrated averages were calculated for between the surface and 140 meters depth and then 50-cm averages were generated between 140 and 160 meters. Between 160 and 166 meters, every sample value was plotted. A similar scheme was used for HSC1 (all values plotted for 155-160.4 m). These data are included in hs12-5m.txt in this data archive, and the graph can be seen in Thompson et al., 1995 (Fig. 3). # # Development of the time/depth relationship: # # Tropical South American climate is marked by annual dry seasons (July-October) which were identifiable in the ice core record as elevated values in all relevant measurements. The nitrate (NO3-) record from the Huascarán ice core provided the most definitive seasonal marker, but the final time scale was constructed from a comparison of four major parameters (NO3-, d18O, dust and SO42-). Each annual maximum corresponds to the middle of the dry season, assumed to occur on the 1st of August. The rapid layer-thinning below 120 m limited annual resolution to the most recent 270 years. However, the high accumulation and strong preservation of seasonal cycles also made possible the subannual resolution of d18O variations for a period of at least 100 years (1894-1993). # # The accuracy of the time scale is of paramount importance in the development of relationships between ice core proxy data and tropical climate conditions. Several horizons in recent times were useful for confirming the layer counting as a reliable method, and indicate almost certain ages for the uppermost 50 years. In 1980, during the original reconnaissance expedition to Huascarán, a 10 m firn core was extracted and analyzed for d18O at BPRC (Thompson et al., JGR, v. 89d3, 1984, p. 4638-4646). Aside from minor accumulation variation and slight signal attenuation, the 1993 cores duplicated the earlier stable isotope profile over the common portion, and confirmed the layer counting to 1980 as absolute. Additionally, a magnitude 7.7 earthquake struck coastal Peru in May 1970, generating large mud flows following the collapse of a large portion of the Huascarán glacier from the north peak. The event was recognized in the ice core by a sharp two-year rise in particulates from the newly-created sediment source. A third time horizon was provided by the HSC2 36Cl profile (Synal et al., Glaciers From the Alps, Paul Scherrer Inst., 1997, p. 99-102), a substance produced by neutron activation during the explosion of atomic devices in the presence of a 35Cl source, such as sea water. An abrupt >100-fold rise in 36Cl concentration occurred at ~54 m depth, which dates (by layer counting) to 1951-53. This was in direct response to the October 31, 1952 U.S. 'Ivy' surface test of an experimental nuclear device on the Eniwetok Atoll in the Pacific Ocean (11°N, 162°E) (Carter and Moghissi, Health Physics, v. 33, 1977, p. 55-71). Finally, in both HSC1 and HSC2, the 1883 eruption of Krakatau, Indonesia (6°S, 105°30'E) was identified by an anomalous sulfate concentration of ~400 ppb at 110 m depth, more than twice the level of any other local (within 10 m) event. A date of mid-year 1884 was thus considered to be an absolute time marker for both cores within the error of the time lag (less than one year). #-------------------- # Publication # Authors: Thompson, L.G., E. Mosley-Thompson, M.E. Davis, P-N. Lin, K.A. Henderson, J. Cole-Dai, J.F. Bolzan and K-b. Liu # Journal_Name: Science # Published_Title: Late Glacial Stage and Holocene tropical ice core records from Huascarán, Peru # Published_Date_or_Year: 1995 # Volume: 269 # Pages: 46-50 # Issue: # Report_Number: # DOI: 10.1126/science.269.5220.46 # Full_Citation: # Abstract: Two ice cores from the col of Huascarán in the north-central Andes of Peru contain a paleoclimatic history extending well into the Wisconsinan (Würm) Glacial Stage and include evidence of the Younger Dryas cool phase. Glacial stage conditions at high elevations in the tropics appear to have been as much as 8° to 12°C cooler than today, the atmosphere contained about 200 times as much dust, and the Amazon Basin forest cover may have been much less extensive. Differences in both the oxygen isotope ratio d18O (8 per mil) and the deuterium excess (4.5 per mil) from the Late Glacial Stage to the Holocene are comparable with polar ice core records. These data imply that the tropical Atlantic was possibly 5° to 6°C cooler during the Late Glacial Stage, that the climate was warmest from 8400 to 5200 years before present, and that it cooled gradually, culminating with the Little Ice Age (200 to 500 years before present). A strong warming has dominated the last two centuries. #-------------------- # Funding_Agency # Funding_Agency_Name: # Grant: #-------------------- # Site_Information # Site_Name: Nevado Huascarán # Location: Peru # Northernmost_Latitude: -9.0 # Southernmost_Latitude: -9.0 # Easternmost_Longitude: -77.5 # Westernmost_Longitude: -77.5 # Elevation_m: 6050 #-------------------- # Data_Collection # Collection_Name: Huascarán 1995 Core 2 anions # First_Year: 200 # Last_Year: 1992 # Time_Unit: CE # Core_Length_m: 160 # Parameter_Keywords: chemistry # Notes: #-------------------- # Chronology_Information # Chronology: #-------------------- # Variables # PaST_Thesaurus_Download_Resource: https://www.ncei.noaa.gov/access/paleo-search/skos/past-thesaurus.rdf # PaST_Thesaurus_Download_Description: Paleoenvironmental Standard Terms (PaST) Thesaurus terms, definitions, and relationships in SKOS format. # # Data variables follow that are preceded by '##' in columns one and two. # Variables list, one per line, shortname-tab-var components: what, material, error, units, seasonality, data type, detail, method, C or N for Character or Numeric data) # ## age_start_CE ice age at sample start,,,year Common Era,,ice cores,,,N,First thermal year of decade ## age_end_CE ice age at sample end,,,year Common Era,,ice cores,,,N,Last thermal year of decade ## Chloride chloride,bulk ice,,parts per billion,,ice cores,averaged,ion chromatography,N, ## Nitrate nitrate,bulk ice,,parts per billion,,ice cores,averaged,ion chromatography,N, ## Sulfate sulfate,bulk ice,,parts per billion,,ice cores,averaged,ion chromatography,N, #-------------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: age_start_CE age_end_CE Chloride Nitrate Sulfate 1990 1992 37.17 112.15 142.52 1980 1989 44.54 109.68 153.02 1970 1979 41.98 100.35 163.58 1960 1969 21.13 99.16 142.18 1950 1959 23.43 94.42 109.23 1940 1949 21.82 87.83 95.43 1930 1939 9.86 84.03 86.90 1920 1929 9.85 79.97 108.59 1910 1919 7.63 83.44 139.56 1900 1909 8.52 87.90 94.90 1890 1899 6.85 76.75 54.09 1880 1889 10.15 113.52 72.04 1870 1879 9.92 99.49 62.85 1860 1869 8.87 92.65 101.15 1850 1859 9.61 91.20 75.91 1840 1849 8.50 85.07 83.08 1830 1839 8.24 104.06 62.45 1820 1829 12.46 96.65 85.43 1810 1819 9.70 101.57 61.03 1800 1809 13.50 118.63 80.94 1790 1799 8.87 96.15 64.56 1780 1789 13.11 129.87 69.42 1770 1779 6.83 78.88 42.13 1760 1769 9.03 94.35 44.86 1750 1759 7.72 102.79 52.69 1740 1749 9.03 90.55 49.14 1730 1739 8.70 79.95 41.13 1720 1729 6.46 76.58 44.26 1710 1719 9.70 85.65 56.22 1700 1709 9.32 97.49 56.20 1690 1699 9.83 93.79 51.07 1680 1689 9.39 95.64 47.80 1670 1679 7.21 86.33 43.69 1660 1669 8.97 87.38 40.39 1650 1659 6.87 83.55 39.32 1640 1649 6.78 81.13 38.75 1630 1639 5.79 79.73 34.52 1620 1629 6.15 80.05 35.74 1610 1619 6.76 89.06 40.16 1600 1609 6.02 76.17 35.29 1590 1599 7.04 93.42 43.92 1580 1589 6.75 82.91 35.81 1570 1579 6.14 77.93 37.67 1560 1569 5.78 78.39 37.06 1550 1559 7.70 90.43 42.16 1540 1549 6.18 77.11 36.21 1530 1539 7.31 81.33 37.26 1520 1529 10.56 88.62 41.39 1510 1519 6.99 76.29 34.29 1500 1509 8.02 86.00 50.12 1490 1499 6.48 77.44 34.89 1480 1489 5.82 72.49 34.96 1470 1479 5.76 76.58 33.80 1460 1469 6.15 80.65 35.85 1450 1459 5.96 83.33 37.73 1440 1449 6.06 77.14 35.96 1430 1439 7.26 78.51 42.24 1420 1429 6.47 82.89 38.99 1410 1419 7.34 78.21 36.13 1400 1409 6.31 80.28 38.28 1390 1399 7.15 86.87 41.65 1380 1389 7.23 81.80 41.20 1370 1379 7.44 88.26 43.81 1360 1369 7.21 91.40 44.56 1350 1359 7.02 83.93 41.60 1340 1349 7.35 86.17 45.35 1330 1339 7.04 86.57 41.66 1320 1329 8.75 94.20 46.86 1310 1319 7.23 88.26 46.37 1300 1309 8.10 89.91 45.56 1290 1299 8.02 85.08 44.48 1280 1289 7.20 86.57 42.53 1270 1279 7.36 93.75 43.26 1260 1269 7.58 100.00 45.89 1250 1259 8.39 107.96 48.96 1241 1249 7.98 100.26 48.58 1230 1240 7.24 101.80 46.54 1220 1229 7.22 97.14 46.68 1210 1219 7.18 97.36 45.32 1200 1209 7.62 101.76 48.97 1190 1199 8.31 107.61 54.43 1180 1189 9.95 111.36 60.34 1170 1179 12.47 121.62 55.26 1160 1169 8.75 115.05 53.19 1151 1159 9.01 128.79 55.18 1140 1150 7.31 110.68 49.08 1131 1139 7.68 113.16 54.85 1120 1130 7.16 112.07 53.61 1110 1119 6.87 105.51 52.71 1100 1109 7.63 107.53 53.21 1090 1099 8.34 108.46 57.65 1080 1089 8.44 110.13 59.51 1070 1079 11.59 120.51 61.13 1060 1069 10.41 119.84 68.90 1050 1059 9.77 114.71 61.94 1041 1049 9.18 116.37 56.43 1030 1040 8.46 111.09 56.60 1020 1029 8.11 110.36 66.99 1010 1019 8.32 111.12 60.18 1000 1009 9.60 118.30 69.60 991 999 8.83 113.10 67.75 980 990 8.61 115.01 62.76 970 979 8.69 113.09 57.41 960 969 8.37 116.33 69.67 951 959 8.55 109.58 61.10 940 950 8.40 113.70 83.54 930 939 8.68 111.47 62.82 920 929 9.62 113.38 66.18 911 919 11.08 104.58 78.20 901 910 11.40 120.02 62.76 891 900 11.78 112.02 70.44 881 890 11.92 112.78 83.92 871 880 10.52 116.28 75.46 860 870 12.63 111.83 99.15 850 859 10.42 106.30 62.80 840 849 9.12 102.30 50.34 830 839 10.12 107.30 44.72 821 829 10.68 106.25 54.95 811 820 10.17 103.13 46.67 800 810 9.38 101.00 45.35 790 799 17.45 126.13 52.60 780 789 11.88 104.78 43.23 770 779 10.37 106.00 48.47 760 769 12.17 108.85 45.93 751 759 10.40 101.64 43.26 740 750 10.58 102.20 47.48 731 739 9.55 104.90 50.08 719 730 8.08 96.83 46.13 710 718 9.15 101.13 47.68 701 709 11.05 109.03 49.30 691 700 9.75 109.75 45.73 681 690 11.23 114.60 55.80 670 680 10.16 100.52 52.04 661 669 9.40 102.85 53.78 651 660 11.95 109.75 48.63 639 650 9.10 104.76 48.26 629 638 10.40 122.45 49.23 619 628 10.55 111.33 51.38 609 618 9.97 99.60 51.50 601 608 9.50 94.83 52.00 590 600 12.33 106.55 59.65 582 589 11.07 111.07 48.47 571 581 12.65 108.93 46.83 563 570 12.30 112.13 52.67 551 562 20.20 106.35 50.88 540 550 10.68 108.68 46.95 531 539 11.37 108.50 52.90 520 530 11.55 108.10 62.78 511 519 15.07 107.27 61.77 499 510 15.03 110.23 55.95 489 498 14.90 111.55 48.30 480 488 18.37 106.90 50.67 471 479 14.00 106.93 44.47 462 470 13.60 107.93 45.70 452 461 14.63 106.67 44.30 440 451 14.70 112.73 47.18 430 439 15.03 113.13 55.03 420 429 15.73 111.40 56.90 410 419 15.03 118.23 59.67 401 409 12.17 115.83 50.47 391 400 13.40 112.73 54.07 381 390 12.93 113.67 52.53 371 380 12.43 111.80 47.67 361 370 12.73 109.97 46.50 351 360 12.73 110.77 44.87 340 350 14.33 115.97 62.97 330 339 12.17 108.37 52.40 323 329 20.75 118.35 69.75 313 322 14.80 107.70 53.57 303 312 11.43 108.47 51.37 289 302 20.90 118.83 64.90 279 288 12.77 124.03 54.83 272 278 11.50 112.00 52.45 261 271 11.03 107.07 48.00 250 260 9.40 107.37 47.73 238 249 10.20 116.67 64.77 231 237 9.60 109.60 55.10 223 230 9.50 109.40 58.95 212 222 11.33 107.43 56.33 200 211 9.60 113.13 51.30