# 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-hs1layer-noaa.txt # Data_Download_Description: NOAA Template File; Layer Thickness Data from Core 1 # #-------------------- # 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 layer thickness # First_Year: 1835 # Last_Year: 1993 # Time_Unit: CE # Core_Length_m: # Parameter_Keywords: annual layer thickness (meters) # 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,start of Aug-Jul thermal year ## age_end_CE ice age at sample end,,,year Common Era,,ice cores,,,N,end of Aug-Jul thermal year ## depth_bot_m depth at sample start,,,meter,,ice cores,,,N,Core depth bottom ## thickness layer thickness,bulk ice,,meter,Aug-Jul,ice cores,,,N, ## density density,bulk ice,,unspecified unit,Aug-Jul,ice cores,,,N,mean density ## IED_bot_m depth,,,meter,,ice cores,,,N,ice equivalent depth bottom ## IED_thick layer thickness,bulk ice,,meter,Aug-Jul,ice cores,,,N,ice equivalent depth layer thickness #-------------------- # 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 depth_bot_m thickness density IED_bot_m IED_thick 1992 1993 3.37 3.37 0.388 1.600 1.600 1991 1992 5.51 2.14 0.486 2.785 1.185 1990 1991 8.29 2.78 0.533 4.473 1.687 1989 1990 10.27 1.98 0.584 5.764 1.291 1988 1989 12.89 2.62 0.616 7.573 1.810 1987 1988 14.45 1.56 0.655 8.704 1.130 1986 1987 16.27 1.82 0.678 10.071 1.367 1985 1986 17.67 1.40 0.704 11.158 1.087 1984 1985 19.27 1.60 0.724 12.437 1.280 1983 1984 21.17 1.90 0.747 14.008 1.571 1982 1983 22.73 1.56 0.774 15.339 1.331 1981 1982 24.05 1.32 0.795 16.493 1.154 1980 1981 25.25 1.20 0.813 17.563 1.070 1979 1980 26.19 0.94 0.828 18.415 0.852 1978 1979 27.70 1.51 0.840 19.808 1.393 1977 1978 28.72 1.02 0.857 20.765 0.957 1976 1977 29.51 0.79 0.868 21.514 0.749 1975 1976 30.74 1.23 0.876 22.692 1.179 1974 1975 31.81 1.07 0.887 23.729 1.037 1973 1974 33.12 1.31 0.896 25.011 1.282 1972 1973 34.19 1.07 0.905 26.067 1.056 1971 1972 35.59 1.40 0.910 27.457 1.390 1970 1971 37.07 1.48 0.916 28.933 1.477 1969 1970 38.42 1.35 0.920 30.283 1.350 1968 1969 39.84 1.42 0.920 31.703 1.420 1967 1968 41.17 1.33 0.920 33.033 1.330 1966 1967 42.98 1.81 0.920 34.843 1.810 1965 1966 44.13 1.15 0.920 35.993 1.150 1964 1965 45.21 1.08 0.920 37.073 1.080 1963 1964 46.19 0.98 0.920 38.053 0.980 1962 1963 47.01 0.82 0.920 38.873 0.820 1961 1962 48.16 1.15 0.920 40.023 1.150 1960 1961 49.53 1.37 0.920 41.393 1.370 1959 1960 50.83 1.30 0.920 42.693 1.300 1958 1959 51.90 1.07 0.920 43.763 1.070 1957 1958 52.88 0.98 0.920 44.743 0.980 1956 1957 53.71 0.83 0.920 45.573 0.830 1955 1956 54.47 0.76 0.920 46.333 0.760 1954 1955 55.69 1.22 0.920 47.553 1.220 1953 1954 56.75 1.06 0.920 48.613 1.060 1952 1953 57.61 0.86 0.920 49.473 0.860 1951 1952 58.46 0.85 0.920 50.323 0.850 1950 1951 59.39 0.93 0.920 51.253 0.930 1949 1950 60.04 0.65 0.920 51.903 0.650 1948 1949 60.79 0.75 0.920 52.653 0.750 1947 1948 61.54 0.75 0.920 53.403 0.750 1946 1947 62.42 0.88 0.920 54.283 0.880 1945 1946 63.28 0.86 0.920 55.143 0.860 1944 1945 64.29 1.01 0.920 56.153 1.010 1943 1944 65.24 0.95 0.920 57.103 0.950 1942 1943 66.38 1.14 0.920 58.243 1.140 1941 1942 68.50 2.12 0.920 60.363 2.120 1940 1941 69.43 0.93 0.920 61.293 0.930 1939 1940 70.40 0.97 0.920 62.263 0.970 1938 1939 71.70 1.30 0.920 63.563 1.300 1937 1938 72.55 0.85 0.920 64.413 0.850 1936 1937 73.52 0.97 0.920 65.383 0.970 1935 1936 74.42 0.90 0.920 66.283 0.900 1934 1935 75.07 0.65 0.920 66.933 0.650 1933 1934 75.94 0.87 0.920 67.803 0.870 1932 1933 76.67 0.73 0.920 68.533 0.730 1931 1932 77.10 0.43 0.920 68.963 0.430 1930 1931 77.66 0.56 0.920 69.523 0.560 1929 1930 78.38 0.72 0.920 70.243 0.720 1928 1929 79.09 0.71 0.920 70.953 0.710 1927 1928 79.65 0.56 0.920 71.513 0.560 1926 1927 80.89 1.24 0.920 72.753 1.240 1925 1926 82.80 1.91 0.920 74.663 1.910 1924 1925 84.40 1.60 0.920 76.263 1.600 1923 1924 85.15 0.75 0.920 77.013 0.750 1922 1923 86.03 0.88 0.920 77.893 0.880 1921 1922 87.20 1.17 0.920 79.063 1.170 1920 1921 87.95 0.75 0.920 79.813 0.750 1919 1920 88.72 0.77 0.920 80.583 0.770 1918 1919 89.34 0.62 0.920 81.203 0.620 1917 1918 90.68 1.34 0.920 82.543 1.340 1916 1917 91.49 0.81 0.920 83.353 0.810 1915 1916 92.86 1.37 0.920 84.723 1.370 1914 1915 93.61 0.75 0.920 85.473 0.750 1913 1914 94.38 0.77 0.920 86.243 0.770 1912 1913 95.07 0.69 0.920 86.933 0.690 1911 1912 95.84 0.77 0.920 87.703 0.770 1910 1911 97.03 1.19 0.920 88.893 1.190 1909 1910 98.07 1.04 0.920 89.933 1.040 1908 1909 98.76 0.69 0.920 90.623 0.690 1907 1908 99.83 1.07 0.920 91.693 1.070 1906 1907 100.57 0.74 0.920 92.433 0.740 1905 1906 101.11 0.54 0.920 92.973 0.540 1904 1905 101.53 0.42 0.920 93.393 0.420 1903 1904 102.09 0.56 0.920 93.953 0.560 1902 1903 102.48 0.39 0.920 94.343 0.390 1901 1902 102.94 0.46 0.920 94.803 0.460 1900 1901 103.50 0.56 0.920 95.363 0.560 1899 1900 104.14 0.64 0.920 96.003 0.640 1898 1899 104.98 0.84 0.920 96.843 0.840 1897 1898 105.47 0.49 0.920 97.333 0.490 1896 1897 106.09 0.62 0.920 97.953 0.620 1895 1896 106.64 0.55 0.920 98.503 0.550 1894 1895 107.07 0.43 0.920 98.933 0.430 1893 1894 107.63 0.56 0.920 99.493 0.560 1892 1893 107.98 0.35 0.920 99.843 0.350 1891 1892 108.32 0.34 0.920 100.183 0.340 1890 1891 108.71 0.39 0.920 100.573 0.390 1889 1890 109.00 0.29 0.920 100.863 0.290 1888 1889 109.23 0.23 0.920 101.093 0.230 1887 1888 109.47 0.24 0.920 101.333 0.240 1886 1887 109.80 0.33 0.920 101.663 0.330 1885 1886 110.15 0.35 0.920 102.013 0.350 1884 1885 110.49 0.34 0.920 102.353 0.340 1883 1884 110.89 0.40 0.920 102.753 0.400 1882 1883 111.21 0.32 0.920 103.073 0.320 1881 1882 111.50 0.29 0.920 103.363 0.290 1880 1881 111.68 0.18 0.920 103.543 0.180 1879 1880 111.93 0.25 0.920 103.793 0.250 1878 1879 112.12 0.19 0.920 103.983 0.190 1877 1878 112.30 0.18 0.920 104.163 0.180 1876 1877 112.45 0.15 0.920 104.313 0.150 1875 1876 112.64 0.19 0.920 104.503 0.190 1874 1875 112.90 0.26 0.920 104.763 0.260 1873 1874 113.12 0.22 0.920 104.983 0.220 1872 1873 113.41 0.29 0.920 105.273 0.290 1871 1872 113.60 0.19 0.920 105.463 0.190 1870 1871 113.76 0.16 0.920 105.623 0.160 1869 1870 113.90 0.14 0.920 105.763 0.140 1868 1869 114.03 0.13 0.920 105.893 0.130 1867 1868 114.17 0.14 0.920 106.033 0.140 1866 1867 114.28 0.11 0.920 106.143 0.110 1865 1866 114.41 0.13 0.920 106.273 0.130 1864 1865 114.52 0.11 0.920 106.383 0.110 1863 1864 114.67 0.15 0.920 106.533 0.150 1862 1863 114.82 0.15 0.920 106.683 0.150 1861 1862 115.01 0.19 0.920 106.873 0.190 1860 1861 115.145 0.135 0.920 107.008 0.135 1859 1860 115.240 0.095 0.920 107.103 0.095 1858 1859 115.335 0.095 0.920 107.198 0.095 1857 1858 115.415 0.080 0.920 107.278 0.080 1856 1857 115.490 0.075 0.920 107.353 0.075 1855 1856 115.555 0.065 0.920 107.418 0.065 1854 1855 115.670 0.115 0.920 107.533 0.115 1853 1854 115.785 0.115 0.920 107.648 0.115 1852 1853 115.885 0.100 0.920 107.748 0.100 1851 1852 115.960 0.075 0.920 107.823 0.075 1850 1851 116.025 0.065 0.920 107.888 0.065 1849 1850 116.095 0.070 0.920 107.958 0.070 1848 1849 116.150 0.055 0.920 108.013 0.055 1847 1848 116.215 0.065 0.920 108.078 0.065 1846 1847 116.310 0.095 0.920 108.173 0.095 1845 1846 116.395 0.085 0.920 108.258 0.085 1844 1845 116.490 0.095 0.920 108.353 0.095 1843 1844 116.605 0.115 0.920 108.468 0.115 1842 1843 116.695 0.090 0.920 108.558 0.090 1841 1842 116.780 0.085 0.920 108.643 0.085 1840 1841 116.880 0.100 0.920 108.743 0.100 1839 1840 116.965 0.085 0.920 108.828 0.085 1838 1839 117.055 0.090 0.920 108.918 0.090 1837 1838 117.135 0.080 0.920 108.998 0.080 1836 1837 117.205 0.070 0.920 109.068 0.070 1835 1836 117.300 0.095 0.920 109.163 0.095