# Southern Indian Ocean G. bulloides Core-top Area Density Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # Template Version 4.0 # Encoding: UTF-8 # NOTE: Please cite original publication, online resource and date accessed when using this 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/33332 # 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-ocean-33332.json # Study_Level_JSON_Description: JSON metadata of this data file's parent study, which includes all study metadata. # # Data_Type: Paleoceanography # # Dataset_DOI: 10.25921/b0e1-3v98 # # Science_Keywords: #--------------------------------------- # Resource_Links # # Data_Download_Resource: https://www.ncei.noaa.gov/pub/data/paleo/contributions_by_author/umling2021/umling2021-ctd.txt # Data_Download_Description: NOAA Template File; TT1811 CTD Data # #--------------------------------------- # Contribution_Date # Date: 2021-05-06 #--------------------------------------- # File_Last_Modified_Date # Date: 2025-06-02 #--------------------------------------- # Title # Study_Name: Southern Indian Ocean G. bulloides Core-top Area Density Data #--------------------------------------- # Investigators # Investigators: Umling, N.E.; Saad, B.; Sikes, E.; Goodkin, N.F. #--------------------------------------- # Description_Notes_and_Keywords # Description: Water depths range from 1796 to 3825 m #--------------------------------------- # Publication # Authors: Umling, N.E., B. Saad, E. Sikes, and N.F. Goodkin # Published_Date_or_Year: 2021 # Published_Title: Proximity to undersaturation and the influences on G. bulloides area-density in southern Indian Ocean marine sediments # Journal_Name: Paleoceanography and Paleoclimatology # Volume: 36 # Edition: # Issue: 6 # Pages: # Report_Number: e2021PA004249 # DOI: 10.1029/2021PA004249 # Online_Resource: # Full_Citation: # Abstract: The area density proxy of foraminiferal shell thickness and calcification intensity has the potential to provide information about past ocean CO2 content and has the benefit of small sample requirements, simple analytical techniques, and the ability to re-use the analyzed foraminifera for other paleo-proxies. Using a series of multicore core-tops collected from the southeastern Indian Ocean (1.8–3.8 km water depth), we evaluate the reliability of utilizing area density values of Globigerina bulloides from sediment cores to estimate surface ocean carbonate parameters. Because foraminifera in marine sediments can rarely be considered “pristine†(or “glassyâ€), we grouped area density measurements of shells to designate various stages of diagenesis. Visual signs of alteration were apparent at area density values as low as ∼0.122 × 104 µg/µm2, with deviations from the “pristine†endmember beginning at area density values of ∼0.087 × 104 µg/µm2. We find that increases in area density overprint the surface ocean carbonate signature in thicker (>0.122 × 104 µg/µm2 shells), but small increases associated with marine sedimentary burial and diagenesis can be accounted for, allowing this proxy to be applied back in time. Reconstructing the distribution of area density values in a given sample has the potential to provide valuable information on overall sample preservation by estimating the percent of well-preserved shells (<0.122 × 104 µg/µm2; %wp) in a given sample. Our %wp metric has the potential for use as a proxy for lysocline variability in addition to assessing the suitability of marine sediment samples for surface ocean reconstructions. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OCE-2002630, OCE-1559080 #--------------------------------------- # Site_Information # Site_Name: TT1811 # Location: Indian Ocean # Northernmost_Latitude: -32.26 # Southernmost_Latitude: -42.481 # Easternmost_Longitude: 85.942 # Westernmost_Longitude: 77.129 # Elevation_m: #--------------------------------------- # Data_Collection # Collection_Name: TT1811 CTD Umling2021 # First_Year: # Last_Year: # Time_Unit: # Core_Length_m: # Parameter_Keywords: physical properties # Notes: TT1811 multicore core-top area density data set #--------------------------------------- # 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) # ## Cruise sample identification,,,,,paleoceanography,,,C,sampling cruise identifier ## core sample identification,,,,,paleoceanography,,,C,relevent core site ## Lat_core latitude ,,,degree north,,paleoceanography,,,N,latitude of core site ## Lon_core longitude,,,degree east,,paleoceanography,,,N,longitude of core site ## water_depth collection water depth,,,meter,,paleoceanography,,,N, ## surface_CTD sample identification,,,,,instrumental,,,C,referenced CTD for surface ocean values ## Lat_surfCTD latitude ,,,degree north,,instrumental,,,N,latitude surface CTD ## Lon_surfCTD longitude,,,degree east,,instrumental,,,N,longitude surface CTD ## deep_CTD sample identification,,,,,instrumental,,,C,referenced CTD for deep ocean values ## Lat_deepCTD latitude ,,,degree north,,instrumental,,,N,latitude deep ocean CTD ## Lon_deepCTD longitude,,,degree east,,instrumental,,,N,longitude deep ocean CTD ## depth depth,,,meter,,instrumental,,,N,CTD depth; contains some averaged CTD depths ## CO3_surface carbonate ion,sea surface,,micromole per kilogram,,instrumental,,,N,surface ocean carbonate ion concentration ## CO3_deep carbonate ion,sea water,,micromole per kilogram,,instrumental,,,N,bottom water carbonate ion concentration ## deep_omega calcite saturation state,sea water,,dimensionless,,instrumental,,,N,bottom water omega value ## DIC dissolved inorganic carbon,sea water,,micromole per kilogram,,instrumental,,,N,bottom water DIC ## Alk alkalinity,sea water,,micromole per kilogram,,instrumental,,,N,bottom water Alkalinity ## pH pH,sea water,,dimensionless,,instrumental,,,N,bottom water pH ## notes notes,,,,,instrumental,,,C, #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NaN Cruise core Lat_core Lon_core water_depth surface_CTD Lat_surfCTD Lon_surfCTD deep_CTD Lat_deepCTD Lon_deepCTD depth CO3_surface CO3_deep deep_omega DIC Alk pH notes TT1811 31MC -42.481 80.590 2981 29CTD 80.64 -42.20567696 29CTD 80.64 -42.21 2950 152.73 72.67 0.94 2164.64 2251.37 7.80 TT1811 32MC -41.717 80.161 3174 33CTD 80.09 -41.64604769 33CTD 80.09 -41.65 3200 144.27 52.56 0.64 2168.62 2213.24 7.65 TT1811 36MC -40.745 79.928 3035 33CTD 80.09 -41.64604769 33CTD 80.09 -41.65 2950 144.27 52.49 0.68 2163.75 2207.57 7.66 *averaged CTD depths TT1811 38MC -40.156 79.055 2845 33CTD 80.09 -41.64604769 33CTD 80.09 -41.65 2700 144.27 52.43 0.71 2158.88 2201.90 7.67 TT1811 40MC -39.663 78.775 2954 33CTD 80.09 -41.64604769 33CTD 80.09 -41.65 2950 144.27 52.49 0.68 2163.75 2207.57 7.66 *averaged CTD depths TT1811 43MC -38.150 79.105 1796 46CTD 78.75 -38.47620967 46CTD 78.75 -38.48 1800 198.97 47.82 0.78 2155.98 2185.61 7.64 TT1811 45MC -38.475 78.745 2034 46CTD 78.75 -38.47620967 46CTD 78.75 -38.48 2000 198.97 48.42 0.76 2175.30 2206.15 7.64 TT1811 60MC -38.301 77.424 1930 54CTD 77.13 -38.3397152 54CTD 77.13 -38.34 2000 183.41 46.40 0.73 2156.42 2183.27 7.63 *averaged CTD depths TT1811 65MC -38.339 77.129 2568 54CTD 77.13 -38.3397152 54CTD 77.13 -38.34 2540 183.41 46.15 0.65 2178.58 2205.73 7.61 TT1811 74MC -34.011 82.352 3512 69CTD 80.43 -35.75322202 75CTD 85.08 -32.71 3500 242.13 52.07 0.60 2177.39 2221.49 7.64 TT1811 77MC -32.260 85.942 3825 75CTD 85.08 -32.71337229 80CTD 85.94 -32.26 3800 249.09 52.47 0.57 2178.47 2224.40 7.64