# Rwenzori Mountains Cosmogenic Nuclide Beryllium-10 Data of Glacial Features over the Past 30 ka #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # 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 '#' followed by a space # Data lines have no '#' # # NOAA_Landing_Page: https://www.ncei.noaa.gov/access/paleo-search/study/37178 # 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-other-37178.json # Study_Level_JSON_Description: JSON metadata of this data file's parent study, which includes all study metadata. # # Data_Type: Other Collections # # Dataset_DOI: 10.25921/5d2y-n304 # # Science_Keywords: Glaciers and Ice Sheets Reconstruction, Last Glacial Maximum, Tropics #--------------------------------------- # Resource_Links # # Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/contributions_by_author/kelly2019/kelly2019-lamia_10-be.txt # Data_Download_Description: NOAA Template File; 10-Be Data # #--------------------------------------- # Contribution_Date # Date: 2022-12-30 #--------------------------------------- # File_Last_Modified_Date # Date: 2023-03-10 #--------------------------------------- # Title # Study_Name: Rwenzori Mountains Cosmogenic Nuclide Beryllium-10 Data of Glacial Features over the Past 30 ka #--------------------------------------- # Investigators # Investigators: Kelly, Meredith (https://orcid.org/0000-0001-8163-3907); Jackson, Margaret (https://orcid.org/0000-0001-7613-752X) #--------------------------------------- # Description_Notes_and_Keywords # Description: Metadata for 115 samples for surface exposure dating using the cosmogenic nuclide berylllium-10 (10Be) of glacial features in the Rwenzori Mountains, Uganda. The samples were collected from 2009-2019. #--------------------------------------- # Publication # Authors: Jackson MS, Kelly MA, Russell JM, Doughty AM, Howley JA, Chipman JW, Cavagnaro D, Nakileza B, Zimmerman SH # Published_Date_or_Year: 2019-12-11 # Published_Title: High-latitude warming initiated the onset of the last deglaciation in the tropics # Journal_Name: Science Advances # Volume: 5 # Edition: # Issue: 12 # Pages: eaaw2610 # Report_Number: # DOI: 10.1126/sciadv.aaw2610 # Online_Resource: # Full_Citation: # Abstract: Atmospheric greenhouse gas concentrations are thought to have synchronized global temperatures during Pleistocene glacial–interglacial cycles, yet their impact relative to changes in high-latitude insolation and ice-sheet extent remains poorly constrained. Here, we use tropical glacial fluctuations to assess the timing of low-latitude temperature changes relative to global climate forcings. We report 10Be ages of moraines in tropical East Africa and South America and show that glaciers reached their maxima at ~29 to 20 ka, during the global Last Glacial Maximum. Tropical glacial recession was underway by 20 ka, before the rapid CO2 rise at ~18.2 ka. This “early” tropical warming was influenced by rising high-latitude insolation and coincident ice-sheet recession in both polar regions, which lowered the meridional thermal gradient and reduced tropical heat export to the high latitudes. #--------------------------------------- # Publication # Authors: Jackson MS, Kelly MA, Russell JM, Doughty AM, Howley JA, Chipman JW, Cavagnaro DA, Baber MB, Zimmerman SRH, Nakileza B # Published_Date_or_Year: 2020-09-01 # Published_Title: Glacial fluctuations in tropical Africa during the last glacial termination and implications for tropical climate following the Last Glacial Maximum # Journal_Name: Quaternary Science Reviews # Volume: 243 # Edition: # Issue: # Pages: # Report_Number: 106455 # DOI: 10.1016/j.quascirev.2020.106455 # Online_Resource: # Full_Citation: # Abstract: The tropics are a dynamic component of the global climate system and exert a profound influence on modern climate variability. Yet the role of the tropics in past climate changes, for example during the last glacial termination, is uncertain. This uncertainty is due in part to the relative paucity of terrestrial temperature records from the tropics, which hinders efforts to understand the mechanisms that influenced deglacial warming and abrupt climate events. Tropical glaciers are sensitive to changes in climate, and mapping and dating past tropical glacial fluctuations provides a valuable record of terrestrial climate changes in the low latitudes.We report a chronology of past glacial extents in the Rwenzori Mountains of Uganda (0.3°N, 29.9°E) based on 51 beryllium-10 (10Be) surface-exposure ages from three separate glacial catchments. Results indicate that Rwenzori glaciers retreated considerably during Heinrich Stadial 1. The rate of net glacial recession slowed between ~15 and 11 ka, although glaciers continued to retreat during this period. Rwenzori glaciers then retreated more rapidly during the early Holocene. The Rwenzori glacial chronology is broadly similar to glacial chronologies reconstructed elsewhere in East Africa and in tropical South America. We suggest that this similarity may reflect coherent, tropics-wide temperature fluctuations during the last deglaciation. The Rwenzori glacial chronology provides crucial information on the global footprint of deglacial warming and abrupt climate events and, thus, the potential mechanisms that influenced tropical climate during the last glacial termination. #--------------------------------------- # Publication # Authors: Vickers AC, Shakun JD, Goehring BM, Gorin A, Kelly MA, Jackson MS, Doughty AD, Russell JM # Published_Date_or_Year: 2021-02-01 # Published_Title: Similar Holocene glaciation histories in tropical South America and Africa # Journal_Name: Geology # Volume: 49 # Edition: # Issue: 2 # Pages: 140-144 # Report_Number: # DOI: 10.1130/G48059.1 # Online_Resource: # Full_Citation: # Abstract: Tropical glaciers have retreated alongside warming temperatures over the past century, yet the way in which these trends fit into a long-term geological context is largely unclear. Here, we present reconstructions of Holocene glacier extents relative to today from the Quelccaya ice cap (Peru) and the Rwenzori Mountains (Uganda) based on measurements of in situ 14C and 10Be from recently exposed bedrock. Ice-extent histories are similar at both sites and suggest that ice was generally smaller than today during the first half of the Holocene and larger than today for most, if not all, of the past several millennia. The similar glaciation history in South America and Africa suggests that large-scale warming followed by cooling of the tropics during the late Holocene primarily drove ice extent, rather than regional changes in precipitation. Our results also imply that recent tropical ice retreat is anomalous in a multimillennial context. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: EAR-1222705, GSS-1558358, EAR-1702293 #--------------------------------------- # Funding_Agency # Funding_Agency_Name: Comer Family Foundation # Grant: CP103, CCF1 #--------------------------------------- # Site_Information # Site_Name: Lamia Valley, Rwenzori Mountains # Location: Uganda # Northernmost_Latitude: 0.47563 # Southernmost_Latitude: 0.46913 # Easternmost_Longitude: 29.9846 # Westernmost_Longitude: 29.98147 # Elevation_m: #--------------------------------------- # Data_Collection # Collection_Name: Lamia_10-Be # First_Year: # Last_Year: # Time_Unit: # Core_Length_m: # Parameter_Keywords: # Notes: #--------------------------------------- # Chronology_Information # Chronology: # # Sample_ID Sample_type Associated_landform Publication Latitude(DD) Longitude(DD) Elev(m) Thickness(cm) Density(g/cm3) Shielding 10-Be(atoms/g) 10-Be_error(atoms/g) Year Cathode_ID Quartz(g) Carrier_wt(mg) Carrier_conc(ppm) Sample(10-Be/9-Be) Sample_error(10-Be/9-Be) Process Blank Blank(10-Be/9-Be) Blank_error(10-Be/9-Be) # RWZ-18-15 Moraine Boulder Lamia, Left lateral inner Unpublished 0.47355 29.983267 3179 4.4505 2.65 0.981 317160 6076 2018 BE49867 4.6474 0.2074 0.96 1.11E-13 2.12E-15 BE49873 1.00E-15 1.67E-16 # RWZ-18-16 Moraine Boulder Lamia, Left lateral inner Unpublished 0.47355 29.983267 3179 3.8128 2.65 0.982 599340 11907 2018 BE49868 5.2518 0.2072 0.96 2.37E-13 4.70E-15 BE49873 1.00E-15 1.67E-16 # RWZ-18-19 Moraine Boulder Lamia, Left lateral inner Unpublished 0.472067 29.981683 3240 2.6212 2.65 0.996 317976 5701 2018 BE49869 5.2388 0.2052 0.96 1.27E-13 2.27E-15 BE49873 1.00E-15 1.67E-16 # RWZ-18-20 Moraine Boulder Lamia, Left lateral inner Unpublished 0.472 29.98158 3239 2.4275 2.65 0.995 337502 8350 2018 BE50405 5.2206 0.2039 0.961 1.35E-13 3.33E-15 BE50413 1.04E-15 1.44E-16 # RWZ-18-21 Moraine Boulder Lamia, Left lateral inner Unpublished 0.47172 29.98147 3242 3.3889 2.65 0.995 313648 7415 2018 BE50406 5.2368 0.204 0.961 1.25E-13 2.96E-15 BE50413 1.04E-15 1.44E-16 # RWZ-18-22 Moraine Boulder Lamia, Left lateral outer Unpublished 0.47563 29.98243 3151 3.3526 2.65 0.992 286295 7066 2018 BE50407 5.4099 0.2046 0.961 1.18E-13 2.91E-15 BE50413 1.04E-15 1.44E-16 # RWZ-18-23 Moraine Boulder Lamia, Left lateral outer Unpublished 0.47542 29.98235 3154 3.1684 2.65 0.992 310834 5812 2018 BE50893 5.04 0.2052 0.962 1.19E-13 2.22E-15 BE50899 7.12E-16 1.37E-16 # RWZ-18-24 Moraine Boulder Lamia, Left lateral outer Unpublished 0.47532 29.98237 3152 3.8469 2.65 0.992 270348 5051 2018 BE50894 5.0675 0.205 0.962 1.04E-13 1.94E-15 BE50899 7.12E-16 1.37E-16 # RWZ-18-25 Moraine Boulder Lamia, Right lateral inner Unpublished 0.46913 29.98438 3249 10.6571 2.65 0.993 308252 4973 2018 BE50895 5.0544 0.2033 0.962 1.19E-13 1.92E-15 BE50899 7.12E-16 1.37E-16 # RWZ-18-28 Moraine Boulder Lamia, Right lateral inner Unpublished 0.46993 29.9846 3258 3.4133 2.65 0.993 316515 5890 2018 BE50896 5.0899 0.2029 0.962 1.24E-13 2.30E-15 BE50899 7.12E-16 1.37E-16 # # Cronus Earth Formatted # Sample_ID Latitude(DD) Longitude(DD) Elev(m) Pressure Thickness(cm) Density(g/cm3) Shielding Erosion_Rate(cm/yr) Year Process_Blank(Cathode_ID) Nuclide Mineral 10-Be_Conc 10-Be_Uncert(atoms/g) Standard(atoms/g) # RWZ-18-15 0.47355 29.983267 3179 std 4.4505 2.65 0.981 0 2018; RWZ-18-15 Be-10 quartz 317160 6076 07KNSTD; # RWZ-18-16 0.47355 29.983267 3179 std 3.8128 2.65 0.982 0 2018; RWZ-18-16 Be-10 quartz 599340 11907 07KNSTD; # RWZ-18-19 0.472067 29.981683 3240 std 2.6212 2.65 0.996 0 2018; RWZ-18-19 Be-10 quartz 317976 5701 07KNSTD; # RWZ-18-20 0.472 29.98158 3239 std 2.4275 2.65 0.995 0 2018; RWZ-18-20 Be-10 quartz 337502 8350 07KNSTD; # RWZ-18-21 0.47172 29.98147 3242 std 3.3889 2.65 0.995 0 2018; RWZ-18-21 Be-10 quartz 313648 7415 07KNSTD; # RWZ-18-22 0.47563 29.98243 3151 std 3.3526 2.65 0.992 0 2018; RWZ-18-22 Be-10 quartz 286295 7066 07KNSTD; # RWZ-18-23 0.47542 29.98235 3154 std 3.1684 2.65 0.992 0 2018; RWZ-18-23 Be-10 quartz 310834 5812 07KNSTD; # RWZ-18-24 0.47532 29.98237 3152 std 3.8469 2.65 0.992 0 2018; RWZ-18-24 Be-10 quartz 270348 5051 07KNSTD; # RWZ-18-25 0.46913 29.98438 3249 std 10.6571 2.65 0.993 0 2018; RWZ-18-25 Be-10 quartz 308252 4973 07KNSTD; # RWZ-18-28 0.46993 29.9846 3258 std 3.4133 2.65 0.993 0 2018; RWZ-18-28 Be-10 quartz 316515 5890 07KNSTD; # #--------------------------------------- # 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) # #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: