Category:Chronologies Working Group

From Linked Earth Wiki
Revision as of 12:53, 15 September 2016 by Jeg (Talk | contribs) (Specific tasks)

Jump to: navigation, search
( Pages with a poll, Working Group )
An imaginary chronology based on U/Th dates, generated via Bchron
Credit: Julien Emile-Geay (Own work)


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 chronologies, and aims to formulate a set of recommendations for such a standard.

This WG needs to work closely with other WGs, as constraints will vary by archive. Nevertheless, some aspects are common enough that it is worth pursuing some general recommendations, and devise ad hoc adjustments for individual archives if need be. It is recommended that every WG coordinator join this WG to keep track of discussions.

Specific tasks

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

For each chronology 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 age models themselves - the chronological measurements (data table)

  • provide an ideal chronology table, so the community knows what to report and how to report it.
  • provide separate recommendations for new and legacy datasets

While it is recognized that most real-word chronologies are of mixed types (e.g. a Holocene lake sediment chronology may blend radiocarbon dates, 210Pb dates, and volcanic ash markers), it is critical to first define guidelines for how to report pure chronologies. Once the foundations are sound, they will be easier to compose together.

Tie-point chronologies


link to existing standards/templates


no known existing standard/template


Layer-counted chronologies

Comboul et al[1] argue that it is critical to report uncertainties in layer-counted chronologies, and that these can be expressed in terms of an undercounting and overcounting rate. However, there needs to be agreement about how to measure and report this rate for various archives.


Growth rings

Trees, corals, speleothems

Ice layers

Role of flow models.


Here are polls that the group might want to consider:

For NEW DATASETS: (this is a dummy poll; please update)

What is your favorite chronology poll?
You are not entitled to vote.
You are not entitled to view results of this poll.
There were 3 votes since the poll was created on 13:59, 14 September 2016.
poll-id 04877B968E307B8838FF8E7EF3E5EACD


What should we do with legacy chronologies?
You are not entitled to vote.
You are not entitled to view results of this poll.
There were 6 votes since the poll was created on 14:02, 14 September 2016.
poll-id 621063422906BC7406116D6A2614B7F2


  1. Comboul, M., J. Emile-Geay, M. N. Evans, N. Mirnateghi, K. M. Cobb, and D. M. Thompson (2014), A probabilistic model of chronological errors in layer-counted climate proxies: applications to annually banded coral archives, Climate of the Past, 10(2), 825–841, doi:10.5194/cp-10-825-2014

Pages in category "Chronologies Working Group"

This category contains only the following page.