Category:Marine Sediment Working Group

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Revision as of 03:16, 8 March 2017 by Jeg (Talk | contribs) (Types of Data)

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A marine sediment core
Credit: Hannes Grobe (Own work) CC BY 3.0, via Wikimedia Commons

Overview

In the Linked Earth context, a working group (WG) is a self-organized coalition of knowledgeable experts, whose activities are governed herewith. This page is dedicated to the discussion of data and metadata standards for marine sedimentary archives (see this page for a definition of Marine Sediment Archive), and aims to formulate a set of recommendations for such a standard.

Members

The group currently has one coordinator, Julie Richey (USGS)

Specific tasks

We recommend that discussions focus on the following considerations, and explore potential commonalities.

For each observation type, we recommend:

  • structuring discussions around what scientific questions one would want to ask of the data
  • listing essential, recommended, and optional information for:
    • the measurements themselves
    • any inference made from the measurements (e.g. calibration to temperature)
    • the underlying uncertainties, and what those numbers correspond to (e.g. 1-sigma or 2-sigma?)
  • providing an ideal data table, so the community knows what to report and how to report it.
  • providing separate recommendations for new and legacy datasets, and for how to label measured and inferred variable (e.g. Mg/Ca is measured, temperature is inferred)
  • thinking about how the rest of the paleoscience community, or other (non)scientists may make use of the data you describe.

Marine sediments are a very ubiquitous archive on which many types of observations are made, and involving thousands of people around the world. It seems wise for this WG to rally around sub-groups start dedicated to data standards about the following sensors/observation types.

Previous standardization efforts

A discussion regarding paleoclimate data standards was started during the PMIP Ocean Workshop: Understanding changes since the Last Glacial Maximum (hereafter, PMIP_LGM) in Corvallis, OR in December 2013. Given the expertise of the working group members, the discussion focus on sedimentary archives. Meeting notes can be found here and summarized in the sections below.

The recommendations made at the workshop concerned new datasets only. It was recognized that different sets of standards would be necessary for legacy datasets.

Types of Data

There are three principle types of data that are relevant for the paleoceanography/paleoclimatology community:

Original data values

this would include raw values of all variables measured or otherwise determined on the substrate of interest, recorded against an unambiguous sample identifier (for instance, depth in the archive). This includes age control points (ACP) used to derive the age model of the paleo-time series, including radioisotopes (14C, excess 210Pb), and benthic stack comparison. All data that are reported for the first time in a scientific publication should be treated as original. The procedure of obtaining original data should be documented such as to allow full replication of the results. In the LinkedEarth Ontology, the original data values are referred as Category:MeasuredVariable_©.

Should the "unique sample identifier" identified at the PMIP_LGM workshop be:
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There were 7 votes since the poll was created on 23:13, 7 March 2017.
poll-id 36C56A4F3693990E0936AB6AC7F8F158

At the PMIP_LGM workshop, it was proposed that the unique sample identifier consists of the name, geographical coordinates, water depth of the sediment core in addition to the position of the analyses sediment segment in the core. Is this labelling:
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There were 7 votes since the poll was created on 23:27, 7 March 2017.
poll-id 14714BE25ABC4C1A7B14ED87FE6B20B1

Depth can be problematic as a unique identifier since there are several to calculate or report depth in a sample (i.e., top-depth, mid-depth, depth interval.) and IODP uses several depth scales.

In the case where depth is reported for sediment cores, should we report:
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poll-id 27DAE87F3370E83700CE16B6457F9284

Deborah Khider (talk) 15:29, 7 March 2017 (PST): I probably forgot ways of expressing depth, please add comments below.

  • Derived data values – this category refers to values of variables derived from other variables, derived or raw, original or compiled, reported against an unambiguous sample identifier and accompanied with a documentation of the derivation procedure such as to allow full replication of the result. This category includes algorithms of any kind relating depth to age that have been used to assign ages to values of raw or derived variables. In the LinkedEarth Ontology, derived data values are referred to as Category:InferredVariable_©.

The derivation procedure is contained in the Category: CalibrationModel_©.

For marine sediment cores, should the calibration model be:
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There were 7 votes since the poll was created on 00:30, 8 March 2017.
poll-id 7C4AE17FE47EA87830F1BA07B51F59C9

Should the code used in the calibration of marine sedimentary records be:
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There were 8 votes since the poll was created on 00:30, 8 March 2017.
poll-id AB5F5404199B91D8313625A32343B5A2

====Compilation of data values==== this refers to raw values of all variables from published sources, gathered for the purpose of quantitative treatment, recorded against an unambiguous sample identifier and labelled with an unambiguous reference to the publication where such data were originally presented. Reporting of data compilations is required wherever these are used to derive patterns or variables from the data other than those reported in the original publication.

Should compilation of previous work involving marine sediment records report:
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There were 8 votes since the poll was created on 00:31, 8 March 2017.
poll-id 54ACE3242CF87B5F02B413BD62B72E8D

LinkedEarth identifies each series using Property:hasID_©

Archiving

The following recommendations were made at the PMIP_LGM workshop:

The data should be archived in easily accessible database administered by an editorial board. The database should included on on-line system for (1) the reporting of errors, (2) a community-driven quality flag system, and (3) the update of datasets as new data become available. Updates to a particular dataset should be assigned a version number with a link to the old and new references. The editorial board should also be tasked in identifying and archiving older datasets.

For versioning of datasets, see the proposed LinkedEarth standard here and use the Discussion page to comment.

Marine Sediment Standards

Table 1: Essential/Recommended/Desired Metadata for marine sediments
Metadata Essential (E)/ Recommended (R) / Desired (D) Reason Added by (optional)
Collection Method: Gear Type D Some coring techniques are known to stretch/compress the cores (i.e. Marion Dufresne piston core) Deborah Khider (talk) 16:17, 7 March 2017 (PST)
Collection method: Volume of sediment analyzed D May not be useful for all types of data measured on sediment cores. If deemed recommend or essential, insert comment/poll in appropriate section Deborah Khider (talk) 16:17, 7 March 2017 (PST)
Collection method: Sampling methods D u-channel, syringe, slice Deborah Khider (talk) 16:17, 7 March 2017 (PST)
Instrumentation D How were the MeasuredVariables measured? Desired for standard analytical techniques. Should be essential/recommended for new techniques Deborah Khider (talk) 16:23, 7 March 2017 (PST)

Geochemical Data

Foraminiferal Geochemistry

For foraminiferal geochemistry work, should information about the taxonomy being followed on top of the genus/species information be:
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There were 4 votes since the poll was created on 00:25, 8 March 2017.
poll-id 0A5106C96F47C17DC1B065830CA5D1B6

Stable isotopes

In the following table, enter the metadata that you'd wish every member of the stable isotope community would enter to make their data reproducible. To add more lines, follow this guide. For a definition of Essential (E)/ Recommended (R)/ Desired (D), see this page.

Table 2: Essential/Recommended/Desired Metadata for foraminiferal stable isotopes
Metadata Essential (E)/ Recommended (R) / Desired (D) Reason Added by (optional)
Category: Location_© (Lat, Lon) E Location is a must Kau (talk) 13:34, 7 March 2017 (PST)
Property:Wgs84:Alt © (Depth) R Especially for deep-sea drilling sediments, water depths can be important to assess various biogeochemical properties and parameters of stable isotopic parameters Kau (talk) 13:34, 7 March 2017 (PST)
Property:SensorGenus_© Property:SensorSpecies_© E Species information needed to infer which section of the water column is being recorded Kau (talk) 13:34, 7 March 2017 (PST)
Cleaning Methodology R Useful to correct for offsets, especially for compilation work although a quick plot can often help figure out the cleaning methodology Kau (talk) 13:34, 7 March 2017 (PST)
Sample Depth E Positional information needed to relate the samples back to the archive Kau (talk) 13:34, 7 March 2017 (PST)
ChonDataTable E for new datasets/ R for legacy datasets The raw radiocarbon, tie points, 210Pb measurements should be made available so that age models can be updated in light of new calibration curves or new age modeling techniques Kau (talk) 13:34, 7 March 2017 (PST)
Number of specimens utilized per sample R The number of foraminiferal tests used per sample can be used to understand the sampling uncertainity associated with the measurements based on the signal-to-noise ratio of the climate signal at the location (planktic foraminifera live for 2-4 weeks) Kau (talk) 13:34, 7 March 2017 (PST)
Property:Standard © E The standard against which the measurements are reported (especially for d18O). VBDP vs VSMOW Deborah Khider (talk) 13:41, 7 March 2017 (PST)
Analytical Precision R The machine precision based on reproducability of standards Kau (talk) 13:49, 7 March 2017 (PST)
Size Fraction R Stable isotopes ratios have been shown to vary by size fraction in several studies Deborah Khider (talk) 15:48, 7 March 2017 (PST)
Method of sediment disintegration and washing D Brought up at the PMIP_LGM meeting Deborah Khider (talk) 16:19, 7 March 2017 (PST)
Correction applied R For instance, correction for offsets in benthic species (critical for compilation work) Deborah Khider (talk) 16:27, 7 March 2017 (PST)

To gather rapid feedback on whether the proposed metadata should be essential, recommended or optional, answer the polls below:

For stable isotopes in foraminifera, should the location information (and water depth) be:
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There were 6 votes since the poll was created on 21:45, 7 March 2017.
poll-id 45FF02339429C6C462C391EC3CEE963C

For stable isotopes in foraminifera, should the sensor genus/species information be:
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There were 5 votes since the poll was created on 21:45, 7 March 2017.
poll-id F4DAE98FBB4889111B360750A225B6C6


For stable isotopes in foraminifera, should the depth (position of the measurement in the archive) information be:
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There were 6 votes since the poll was created on 21:45, 7 March 2017.
poll-id 9C0329A43D83FE74AB4BBFAF34E3676B

For stable isotopes in foraminifera, should the ChonMeasurementTable information be:
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There were 4 votes since the poll was created on 21:45, 7 March 2017.
poll-id 9E1154CAC198A5C2E9756598EC5FB134

For stable isotopes in foraminifera, should the numbers of specimens utilized be:
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There were 4 votes since the poll was created on 21:45, 7 March 2017.
poll-id E46F4CC0B5B309E1DD2E2019C99AD8E2

For stable isotopes in foraminifera, should the property standard reported be:
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There were 4 votes since the poll was created on 21:52, 7 March 2017.
poll-id 2F10B4A70435835B8464A443435D56CF

For stable isotopes in foraminifera, should the analytical precision reported be:
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There were 4 votes since the poll was created on 21:52, 7 March 2017.
poll-id E198E4FAF1A9E8358CE0BBA841C3BA4F

For stable isotopes in foraminifera, should size fraction be:
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There were 4 votes since the poll was created on 23:48, 7 March 2017.
poll-id 8ED5D3D55F5D5E0D577F05470CA3D485

Trace Metals

Mg/Ca

In the following table, enter the metadata that you'd wish every member of the Mg/Ca community would enter to make their data reproducible. To add more lines, follow this guide. For a definition of Essential (E)/ Recommended (R)/ Desired (D), see this page.

Table 3: Essential/Recommended/Desired Metadata for foraminiferal Mg/Ca
Metadata Essential (E)/ Recommended (R) / Desired (D) Reason Added by (optional)
Category: Location_© (Lat, Lon) E Location is a must Deborah Khider (talk) 12:37, 17 February 2017 (PST)
Property:Wgs84:Alt © (Depth) E Water depth can be useful to get an idea of dissolution in the core. Especially for deep-sea drilling sediments, water depths can be important to assess various biogeochemical properties and parameters of stable isotopic parameters Kau (talk) 13:39, 7 March 2017 (PST)
Property:SensorGenus_© Property:SensorSpecies_© E Species information needed to infer which section of the water column is being recorded Deborah Khider (talk) 12:37, 17 February 2017 (PST)
Cleaning Methodology R Useful to correct for offsets, especially for compilation work although a quick plot can often help figure out the cleaning methodology Deborah Khider (talk) 12:37, 17 February 2017 (PST)
Sample Depth E Positional information needed to relate the samples back to the archive Deborah Khider (talk) 12:37, 17 February 2017 (PST)
ChonDataTable E for new datasets/ R for legacy datasets The raw radiocarbon, tie points, 210Pb measurements should be made available so that age models can be updated in light of new calibration curves or new age modeling techniques Deborah Khider (talk) 12:37, 17 February 2017 (PST)
Number of specimens utilized per sample R The number of foraminiferal tests used per sample can be used to understand the sampling uncertainity associated with the measurements based on the signal-to-noise ratio of the climate signal at the location (planktic foraminifera live for 2-4 weeks) Kau (talk) 13:17, 7 March 2017 (PST)
Analytical Precision D Uncertainty in the measurements Deborah Khider (talk) 13:51, 7 March 2017 (PST)
Size fraction R Mg/Ca and other trace element ratios have been shown to vary with specimens size Deborah Khider (talk) 15:49, 7 March 2017 (PST)
Method of sediment disintegration and washing D Brought up at the PMIP_LGM workshop Deborah Khider (talk) 16:20, 7 March 2017 (PST)
Correction applied R For instance, correction for offsets for cleaning methodologies (critical for compilation work) Deborah Khider (talk) 16:27, 7 March 2017 (PST)

To gather rapid feedback on whether the proposed metadata should be essential, recommended or optional, answer the polls below:

For Mg/Ca in foraminifera, should the location information (especially in relation to water depth) be:
You are not entitled to vote.
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There were 5 votes since the poll was created on 21:26, 7 March 2017.
poll-id 30B1E1BEA2083F7429E59527F2DBF8A8

For Mg/Ca in foraminifera, should the sensor genus/species information be:
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There were 5 votes since the poll was created on 21:26, 7 March 2017.
poll-id 036FE79A6C27842348B489B982D516D8

Should the cleaning methodology be considered:
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There were 7 votes since the poll was created on 20:07, 7 November 2016.
poll-id 5D88039254CA2FE4746A7A2515CDDBCA

For Mg/Ca in foraminifera, should the depth (position of the measurement in the archive) information be:
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There were 5 votes since the poll was created on 21:26, 7 March 2017.
poll-id 5E204D0FB2EBB8A0B8A78A229261EC4E

For Mg/Ca in foraminifera, should the ChonMeasurementTable information be:
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There were 5 votes since the poll was created on 21:26, 7 March 2017.
poll-id 40ECF6DB8C722909F39479BD19C3F2CD

For Mg/Ca in foraminifera, should the numbers of specimens utilized be:
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There were 4 votes since the poll was created on 21:46, 7 March 2017.
poll-id 9D1700879FA581737C1F779C8C0BAB9E

For Mg/Ca in foraminifera, should the analytical precision reported be:
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There were 4 votes since the poll was created on 23:49, 7 March 2017.
poll-id E59628A325A1D182243A5EAF06D70679

For Mg/Ca in foraminifera, should the size fraction be:
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There were 4 votes since the poll was created on 23:49, 7 March 2017.
poll-id 775A08139E4A98D799AA31AA05C7D200

Organic Geochemistry

Alkenones

GDGTs

Should raw peak areas (as opposed to just TEX86 index) be:
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There were 4 votes since the poll was created on 19:20, 21 November 2016.
poll-id 661DF66A537B28E6EBFFACB0E845D584

Compound specific isotopes

Physical Data

Grain Size

Micropaleontological Data

  • Report raw counts if available. If not available, then at least report minimum number of specimens counted
  • Minimum number of specimens counted
  • Size fraction

If the data were used to infer temperature or sea ice concentration, then the method (MAT, WA-PLS, etc) and the training set should be mentioned/required metadata.

For Micropaleontological Data , should raw counts be:
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There were 3 votes since the poll was created on 23:53, 7 March 2017.
poll-id 7A33C91948DB228ECA30F04A172545F2

For Micropaleontological Data , should the number of specimens counted be:
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There were 3 votes since the poll was created on 23:53, 7 March 2017.
poll-id C9A7C884503C82BD1523BC97FF29A258

For Micropaleontological Data, should size fraction be:
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There were 3 votes since the poll was created on 23:54, 7 March 2017.
poll-id 6DB2FF5E82BDB47B27497680D9290BEE

Pages in category "Marine Sediment Working Group"

This category contains only the following page.

O