# 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-annualt-noaa.txt # Data_Download_Description: NOAA Template File; Annual-average (Thermal Year; Aug-Jul) Data from Cores 1 and 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 1+2 therm avg # First_Year: 1894 # Last_Year: 1993 # Time_Unit: CE # Core_Length_m: # Parameter_Keywords: chemistry, delta 18O PDB (per mille), particle concentration (number per milliliter) # 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_CE ice age,,,year Common Era,,ice cores,,,N,thermal year previous Aug - current Jul ## d18O_HScore2 delta 18O,bulk ice,,per mil SMOW,Aug-Jul,ice cores,averaged,isotope ratio mass spectrometry,N,thermal year average previous Aug - current Jul; HS Core2 ## part>2_HScore2 particles,bulk ice,,count,Aug-Jul,ice cores,averaged,electric sensing particle size analysis,N,particles > 2 micrometers; thermal year average previous Aug - current Jul; HS Core2 ## part>0.63_HScore2 particles,bulk ice,,count,Aug-Jul,ice cores,averaged,electric sensing particle size analysis,N,particles > 0.63 micrometers; thermal year average previous Aug - current Jul; HS Core2 ## NO3_HScore2 nitrate,bulk ice,,parts per billion,Aug-Jul,ice cores,averaged,ion chromatography,N,thermal year average previous Aug- current Jul; HS Core2 ## d18O_HScore1 delta 18O,bulk ice,,per mil SMOW,Aug-Jul,ice cores,averaged,isotope ratio mass spectrometry,N,thermal year average previous Aug - current Jul; HS Core1 #-------------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: age_CE d18O_HScore2 part>2_HScore2 part>0.63_HScore2 NO3_HScore2 d18O_HScore1 1993 -17.83 1432 14896 88.6 -14.91 1992 -12.81 3271 33333 155.8 -14.42 1991 -16.82 2076 29901 120.0 -17.35 1990 -14.63 3459 43928 99.1 -14.79 1989 -18.07 1552 23190 107.0 -18.97 1988 -16.47 1878 19814 113.8 -15.24 1987 -16.24 1730 19691 108.4 -16.59 1986 -18.22 2353 22951 97.7 -18.61 1985 -16.50 1895 19809 112.7 -16.29 1984 -21.20 1693 15489 96.0 -19.81 1983 -14.60 2650 26273 104.3 -15.60 1982 -16.78 2504 27143 145.7 -17.51 1981 -18.11 1849 24423 78.7 -17.81 1980 -15.37 3914 26483 152.9 -15.10 1979 -17.26 3165 16268 169.3 -17.45 1978 -16.14 2213 11913 108.8 -15.97 1977 -16.94 2549 12180 133.0 -17.25 1976 -19.91 2143 11616 103.5 -19.56 1975 -18.63 1487 9407 62.1 -18.42 1974 -18.52 2365 17584 90.0 -19.22 1973 -19.78 1933 32966 68.4 -18.60 1972 -18.90 3472 33023 89.7 -19.91 1971 -17.82 3904 24443 99.7 -18.78 1970 -17.67 2052 15410 79.6 -18.03 1969 -13.79 3229 19143 126.8 -15.10 1968 -15.37 2346 15602 100.7 -14.96 1967 -17.77 1914 13976 86.2 -17.85 1966 -15.69 2186 9560 90.6 -15.57 1965 -16.21 2432 16294 77.9 -15.54 1964 -14.02 2707 15845 89.9 -15.09 1963 -14.96 2141 12663 121.2 -13.96 1962 -18.55 3023 19360 100.5 -18.87 1961 -18.80 1727 13182 101.1 -18.15 1960 -16.91 2272 14509 97.4 -17.26 1959 -16.82 2044 13073 120.4 -17.26 1958 -17.49 3842 31810 84.8 -17.23 1957 -15.08 2463 11647 116.9 -15.56 1956 -14.38 2561 19080 101.2 -14.93 1955 -19.75 1503 11430 123.5 -17.97 1954 -18.56 1266 10093 90.0 -19.58 1953 -18.55 1935 15016 98.7 -18.79 1952 -18.19 1497 13230 68.2 -19.57 1951 -18.86 1005 7293 64.0 -18.07 1950 -19.76 1444 14360 81.9 -20.06 1949 -19.08 1524 12622 94.5 -19.14 1948 -15.93 2387 14731 97.4 -16.31 1947 -15.94 2200 16234 87.0 -14.92 1946 -14.73 1600 14709 77.4 -14.93 1945 -18.41 1797 12439 102.1 -18.89 1944 -16.94 2094 17854 78.2 -17.18 1943 -17.31 1716 11203 93.4 -18.03 1942 -19.17 1748 11625 83.5 -18.21 1941 -15.76 2619 17012 100.3 -16.15 1940 -17.18 2018 13865 63.3 -17.27 1939 -15.75 1451 9053 67.6 -16.78 1938 -17.23 2169 13477 81.3 -17.58 1937 -15.50 2013 13646 111.9 -15.98 1936 -15.71 2009 14267 109.4 -16.72 1935 -14.86 2879 15833 104.7 -15.16 1934 -16.15 2176 14469 77.9 -16.89 1933 -19.24 1838 10269 89.7 -19.60 1932 -20.30 1557 10252 57.7 -19.88 1931 -16.32 1320 9433 76.9 -16.55 1930 -18.67 1876 13821 59.4 -18.95 1929 -17.04 1980 13846 89.5 -17.98 1928 -14.65 3032 20769 101.4 -14.74 1927 -15.38 2169 11771 77.2 -19.38 1926 -17.48 1395 8831 78.8 -17.70 1925 -16.64 2268 13500 86.4 -18.25 1924 -17.99 1987 11819 79.5 -19.72 1923 -16.58 1477 9806 72.4 -15.60 1922 -21.28 1826 10622 82.9 -19.54 1921 -18.33 1912 9825 83.2 -16.77 1920 -18.02 927 6005 62.6 -19.09 1919 -18.41 1719 7571 80.4 -19.23 1918 -17.57 4160 19600 100.3 -20.23 1917 -18.92 2157 13688 77.7 -18.91 1916 -17.07 1824 9657 82.8 -17.66 1915 -18.48 1423 7401 87.6 -17.46 1914 -15.79 2237 10248 98.3 -17.54 1913 -17.99 1208 6602 91.8 -18.20 1912 -17.59 2781 13391 92.3 -16.24 1911 -18.33 2113 11776 73.0 -18.23 1910 -18.41 1816 10315 73.5 -18.27 1909 -15.86 2788 14330 93.0 -15.17 1908 -18.77 1473 8467 100.0 -19.25 1907 -21.37 1480 8275 80.3 -20.35 1906 -17.83 1168 7220 62.4 -19.06 1905 -17.52 1943 10158 104.7 -17.98 1904 -14.53 2643 18977 95.6 -14.49 1903 -15.93 2358 14747 82.0 -12.77 1902 -21.17 1081 6597 78.9 -20.49 1901 -15.02 2230 18036 91.5 -17.00 1900 -19.54 1558 10839 88.9 -18.00 1899 -16.86 2380 15253 83.4 -16.77 1898 -17.08 1518 9449 64.6 -15.60 1897 -22.63 1087 7181 64.7 -19.92 1896 -20.20 1435 8873 75.2 -18.81 1895 -16.80 1947 10440 64.5 -15.86 1894 -20.23 1074 6421 71.6 -18.91