# Rwenzori Mountains Cosmogenic Nuclide Beryllium-10 Data of Glacial Features over the Past 30 ka
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#               World Data Service for Paleoclimatology, Boulder
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#                      NOAA Paleoclimatology Program
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# 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.
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# Description/Documentation lines begin with '#' followed by a space
# Data lines have no '#'
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# 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.
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# Data_Type: Other Collections
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# Dataset_DOI: 10.25921/5d2y-n304
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# Science_Keywords: Glaciers and Ice Sheets Reconstruction, Last Glacial Maximum, Tropics
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# Resource_Links
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# Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/contributions_by_author/kelly2019/kelly2019-moulyambouli_10-be.txt
#   Data_Download_Description: NOAA Template File; 10-Be Data
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# Contribution_Date
#   Date: 2022-12-30
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# File_Last_Modified_Date
#   Date: 2023-03-10
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# Title
#   Study_Name: Rwenzori Mountains Cosmogenic Nuclide Beryllium-10 Data of Glacial Features over the Past 30 ka
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# Investigators
#   Investigators: Kelly, Meredith (https://orcid.org/0000-0001-8163-3907); Jackson, Margaret (https://orcid.org/0000-0001-7613-752X)
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# 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.  
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# 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.
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# 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.
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# 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.
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# Funding_Agency
#   Funding_Agency_Name: National Science Foundation
#   Grant: EAR-1222705, GSS-1558358, EAR-1702293
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# Funding_Agency
#   Funding_Agency_Name: Comer Family Foundation
#   Grant: CP103, CCF1
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# Site_Information
#   Site_Name: Moulyambouli Valley, Rwenzori Mountains
#   Location: Uganda
#   Northernmost_Latitude: 0.26167
#   Southernmost_Latitude: 0.25812
#   Easternmost_Longitude: 29.94724
#   Westernmost_Longitude: 29.94410
#   Elevation_m: 
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# Data_Collection
#   Collection_Name: Moulyambouli_10-Be
#   First_Year: 
#   Last_Year: 
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#   Core_Length_m: 
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#   Notes: 
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# Chronology_Information 
# Chronology: 
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# 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)
# RZ-12-46 	Moraine Boulder	Moulyambouli, Left lateral	Jackson et al.  (2019)	0.26167	29.94410	2883	1.00	2.65	0.966	283882	6007	2012	BE37994	3.0320	0.1628	1.335	5.93E-14	1.25E-15	BE37998	4.38E-16	1.49E-16
# RZ-12-47 	Moraine Boulder	Moulyambouli, Left lateral	Jackson et al.  (2019)	0.26152	29.94438	2872	4.21	2.65	0.962	269035	5787	2012	BE37995	3.0322	0.1625	1.335	5.63E-14	1.21E-15	BE37998	4.38E-16	1.49E-16
# RZ-12-50 	Moraine Boulder	Moulyambouli, Left lateral	Jackson et al.  (2019)	0.26089	29.94524	2848	1.64	2.65	0.972	283626	6202	2012	BE37996	3.0417	0.1631	1.335	5.93E-14	1.30E-15	BE37998	4.38E-16	1.49E-16
# RZ-12-54 	Moraine Boulder	Moulyambouli, Left lateral	Jackson et al.  (2019)	0.25812	29.94724	2777	3.00	2.65	0.983	262419	6232	2012	BE37997	3.0733	0.1625	1.335	5.56E-14	1.32E-15	BE37998	4.38E-16	1.49E-16
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# Cronus Earth Format
# 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)
# RZ-12-46 	0.26167	29.94410	2883	std	1.00	2.65	0.966	0	2012;	RZ-12-46 	Be-10	Quartz	283882	6007	07KNSTD;
# RZ-12-47 	0.26152	29.94438	2872	std	4.21	2.65	0.962	0	2012;	RZ-12-47 	Be-10	Quartz	269035	5787	07KNSTD;
# RZ-12-50 	0.26089	29.94524	2848	std	1.64	2.65	0.972	0	2012;	RZ-12-50 	Be-10	Quartz	283626	6202	07KNSTD;
# RZ-12-54 	0.25812	29.94724	2777	std	3.00	2.65	0.983	0	2012;	RZ-12-54 	Be-10	Quartz	262419	6232	07KNSTD;			
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# 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.
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# 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)
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# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing_Values: