Holocene evolution of sea-surface temperature and salinity in the Gulf of Mexico

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Thirumalai, Kaustubh, Richey, Julie N., Quinn, Terrence M., and Reynolds, Caitlin E., 20210507, Holocene evolution of sea-surface temperature and salinity in the Gulf of Mexico: U.S. Geological Survey Data Release doi:10.5066/P9Q5L9VU, U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

   Online Links:

   • https://doi.org/10.5066/P9Q5L9VU

   This is part of the following larger work.
   Thirumalai, Kaustubh, Richey, Julie N., and Quinn, Terrence M., Unknown, Holocene evolution of sea-surface temperature and salinity in the Gulf of Mexico: Paleoceanography and Paleoclimatology: Paleoceanography and Paleoclimatology Unknown, American Geophysical Union, Washington, D.C..

   Online Links:

   • Unknown

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -93.92
   East_Bounding_Coordinate: -93.92
   North_Bounding_Coordinate: 27.67
   South_Bounding_Coordinate: 27.67
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 11-Apr-2010

   Ending_Date: 20-Apr-2010

   Currentness_Reference:

   ground condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Tabular digital data
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      
   2. What coordinate system is used to represent geographic features?
      
7. How does the data set describe geographic features?

   Radiocarbon_dates.csv, Radiocarbon_dates.xlsx

   Comma-separated values (.csv) and Microsoft Excel (.xlsx) files containing core samples, depths, materials, and uncalibrated 14C Age attribute information for the mixed planktic samples collected from Garrison Basin in the Gulf of Mexico in 2010. (Source: USGS)

   SI. No.

   Sample number given to each sample measured. (Source: USGS)

   Range of values
   Minimum:	1
   Maximum:	14

   Core Sample

   Name of each core sample taken. (Source: USGS) Refers to the specific year, basin, core type collected and depth.

   Depth lower (cm)

   Depth in centimeters (cm) the core was collected. Lower refers to the lowest interval collected in the sample (0). (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	250

   Depth upper (cm)

   Depth in centimeters (cm) the core was collected. Upper refers to the highest interval collected in the sample (.5). (Source: USGS)

   Range of values
   Minimum:	0.5
   Maximum:	250.5

   mid-Depth (cm)

   Depth in centimeters (cm) the core was collected. Mid refers to the middle interval collected in the sample (.25). (Source: USGS)

   Range of values
   Minimum:	0.25
   Maximum:	250.25

   Material

   The type of material used to get radiocarbon date. (Source: USGS)

   Value	Definition
   Mixed Planktics	Mixed planktic were used for radiocarbon dating.

   Uncalibrated ¹⁴C Age

   Uncalibrated ¹⁴C Age in years before present (B.P.) that was determined using radiocarbon dating techniques. (Source: USGS)

   Range of values
   Minimum:	805
   Maximum:	18480

   Error

   Error related to Uncalibrated ¹⁴C Age in years before present (B.P) that was determined using radiocarbon dating techniques. (Source: USGS)

   Range of values
   Minimum:	25
   Maximum:	40

   Foram_geochemistry.csv, Foram_geochemistry.xlsx

   Comma-separated values (.csv) and Microsoft Excel (.xlsx) files containing foraminifera (Globigerinoides ruber (white variety)) geochemistry data attribute information associated with sediment core 2010-GB2-GC1 (Source: USGS)

   Depth

   Depth in centimeters (cm) the sample was collected. (Source: USGS)

   Range of values
   Minimum:	0.25
   Maximum:	127.75

   Age

   Calibrated Radiocarbon age in years before present (B.P.) (Source: USGS)

   Range of values
   Minimum:	526.80
   Maximum:	11720.88

   Mg/Ca

   Measured Mg/Ca in mmol/mol (Source: USGS)

   Range of values
   Minimum:	3.13
   Maximum:	4.44

   δ18 O

   Measured δ18O of carbonate. Value of “nan” represents no data collected. (Source: USGS)

   Range of values
   Minimum:	-2.19
   Maximum:	-0.23

   δ13 C

   Measured δ13C of carbonate. Value of “nan” represents no data collected. (Source: USGS)

   Range of values
   Minimum:	-0.26
   Maximum:	1.75

   Entity_and_Attribute_Overview:

   The entity and attribute information provided here describes the tabular data associated with the dataset. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset.

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Kaustubh Thirumalai
   • Julie N. Richey
   • Terrence M. Quinn
   • Caitlin E. Reynolds
2. Who also contributed to the data set?

   U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center

3. To whom should users address questions about the data?

Why was the data set created?

The larger goal of this project is to use paleoceanographic reconstructions from the Gulf of Mexico and surrounding regions to better understand what mechanisms are forcing climate variability on decadal to centennial time-scales. The sediment core was collected during U.S. Geological Survey (USGS) field activity number (FAN) 10CEV05. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/fan_info.php?fan=10CEV05.

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 2018 (process 1 of 1)

   Planktic foraminiferal geochemistry was used to reconstruct Holocene SST and δ18Osw variations in the northwestern GoM. Marine sediment core 2010-GB2-GC1 was raised from the Garrison Basin (26.67°N, 93.92°W) at a water depth of 1776 meters (m), aboard the R/V Cape Hatteras in April 2010. An age model was built using a Monte Carlo approach on the Bayesian posterior ages from 15 radiocarbon measurements on upper-ocean planktic foraminifera. Researchers measured the δ18O (number (n) = 265) and magnesium to-calcium (Mg/Ca) ratio (n = 275) composition in the calcareous shells of the white variety of planktic foraminifera Globigerinoides ruber (hereafter G. ruber). For this study, researchers did not discriminate between different morphotypes of G. ruber. Approximately 70-100 individual shells were picked from 0.5 centimeter (cm) sediment intervals (corresponding to an average time resolution of ∼45 years (yrs) per sample), after which they were gently crushed and homogenized. A large fraction of this mixture was kept aside for trace metal analysis whereas the remnant portion was used for stable isotope analysis, which was performed on an isotope ratio mass spectrometer housed at the University of Texas at Austin. All δ18O values are reported in permil relative to the Vienna Pee Dee Belemnite standard notation (‰, VPDB). Based on an external standard, NBS-19 (n = 89), the 1σ analytical precision was ±0.03‰ for δ13C and ±0.06‰ for δ18O, consistent with the long-term precision of the instrumental setup (0.06‰ for δ13C and 0.08‰ for δ18O). Note that reconstructed and observed δ18Osw values are reported in permil relative to the Vienna Standard Mean Ocean Water notation (‰, VSMOW). Elemental ratios were measured at the USGS St. Petersburg Coastal and Marine Science Center (SPCMSC) following established foraminiferal cleaning techniques (Barker and others, 2003; note that the reductive cleaning step was not used). Mg/Ca analysis was performed using inductively coupled plasma optical emission spectrometry utilizing protocols similar to those reported in Thirumalai and others (2018). Along with an internal gravimetric standard which was used to monitor drift and accuracy, repeat measurements on external, matrix-matched standards yielded an analytical precision of ±0.15% (1σ = 0.02 mmol mol−1). Researchers inferred sampling uncertainty from replicate measurements of different sets of G. ruber tests from the same sample depth (n = 30), which was ±3% (0.10 mmol/mol) and ±0.08‰ respectively for Mg/Ca and δ18O analysis. Both analytical and sampling uncertainty were taken into account while computing SST and δ18Osw.

3. What similar or related data should the user be aware of?
   S, Barker, M, Grieves, and H, Elderfield, 20030905, A study of cleaning procedures used for foraminiferal Mg/Ca paleothermometry: Geochemistry, Geophysics, Geosystems Volume 4, Issue 9.

   Online Links:

   • https://doi.org/10.1029/2003GC000559

   Other_Citation_Details: Pages 1-20
   

   K, Thirumalai, TM, Quinn, Y, Okumura, JN, Richey, JW, Partin, RZ, Poore, and E, Moreno-Chamarro, 20180126, Pronounced centennial-scale Atlantic Ocean climate variability correlated with Western Hemisphere hydroclimate: Nature Communications Volume 9, Issue 1.

   Online Links:

   • https://doi.org/10.1038/s41467-018-02846-4

   Other_Citation_Details: Pages 1-11
   

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   No formal attribute accuracy tests were conducted.
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the data set has not been conducted.
3. How accurate are the heights or depths?
   A formal accuracy assessment of the vertical positional information in the dataset has either not been conducted or is not applicable.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:

Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests that it be acknowledged as the originator of this dataset in any future products or research derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey St. Petersburg Coastal and Marine Science Center

   Attn: Julie Richey

   Geologist

   600 4th Street South

   St. Petersburg, FL
   

   USA

   (727) 502-8123 (voice)

   jrichey@usgs.gov
2. What's the catalog number I need to order this data set? Radiocarbon_dates.csv, Radiocarbon_dates.xlsx, Foram_geochemistry.csv, Foram_geochemsitry.xlsx
3. What legal disclaimers am I supposed to read?

   Distributor assumes no liability for misuse of data. This publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	CSV, XLSX
     Network links:	https://coastal.er.usgs.gov/data-release/doi-P9Q5L9VU/data/Radiocarbon_dates.zip https://coastal.er.usgs.gov/data-release/doi-P9Q5L9VU/data/Foram_geochemistry.zip

   • Cost to order the data: None. No fees are applicable for obtaining the dataset.

Who wrote the metadata?

Dates:

Last modified: 22-Sep-2021

Metadata author:

U.S. Geological Survey

Attn: Julie Richey

Research Geologist

600 4th Street South

St. Petersburg, FL

USA

727-502-8123 (voice)

jrichey@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)