Talk:Marine isotope stage
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OK... who is watching this page? Anyway, an anon added The difference that has puzzled scientists is the current rise in CO2 levels of MIS1, which according to natural trends based on past interglacials should have been steadily decreasing over the last 5000y. This seems a bit odd. I assume its not referring to the last 150y of obviously anthro increase, but its a slightly confused ref to the Ruddiman hypothesis. In which case I think its rather over stated William M. Connolley 20:57, 6 November 2006 (UTC)
Each stage represents a glacial, interglacial, stadial or interstadial. Interglacials are odd-numbered; glacials are even numbered, one for each stage, starting from the present and working backward in time. For example, the Holocene is MIS1, or O-stage 1, or just stage 1. The previous interglacial is MIS5, or O-stage 5, or just stage 5.
Exceptionally, MIS2-4 refers to some middle part of the last glacial, because when initially interpreted MIS3 looked like an interglacial.
Stadials and interstadials are identified by a letter following the corresponding glacial or interglacial: 5a, 5b, etc. The dates of the stages were obtained by calibrating the graph on known dates by other methods.
MIS 11 approximately 400ka is the most similar to MIS 1. A difference is that CO2 levels remained steady or rose during MIS1 (before the industrial era), when by analogy to past interglacials, they should have been steadily decreasing over the last 5000 years. This is the basis of the Early anthropocene hypothesis. DuKu , 26 Jan 2010 Needs cleanup. —Preceding unsigned comment added by DuKu (talk • contribs) 06:45, 26 January 2010 (UTC)
- To add some detail (originally heard from Nick Shackleton in a lecture) for the numbering of isotope stage 3/4: Emiliani had expected the palaeoclimate cycles to be primarily governed by orbital obliquity, with a 41 kyr cyclicity. So when the first marine records were obtained, and there was a warming about 40 kyr before present, it was allocated an "interglacial" stage number (3). Only later, when it became apparent that the oxygen isotope stratigraphy was overall dominated by 100,000 year cyclicity in the late Pleistocene, was the numbering system modified to give the 100,000 year interglacials odd numbers. But the stage 3/4 numbering had already "stuck" by then; and anyway it is not really a problem.Orbitalforam (talk) 14:19, 25 May 2010 (UTC)
In 2010 the Subcommission on Quaternary Stratigraphy (SQS) (http://quaternary.stratigraphy.org/) dumped earlier MIS versions and started using the Lisiecki & Raymo (2005) LR04 Benthic Stack in their ChronoStratigraphical Correlation Table see notes for 2010: http://quaternary.stratigraphy.org/correlation/chart.html, here's the Lisiecki & Raymo (2005) LR04 Stack links page: http://www.lorraine-lisiecki.com/stack.html and the MIS table: http://www.lorraine-lisiecki.com/LR04_MISboundaries.txt think we oughta follow suit and revise the page MIS data and preceding paragraph? Or keep the existing data and add a new table - or what?188.8.131.52 (talk) 02:09, 28 December 2013 (UTC)
- I'd rather add, above the old one. Do you want to do it? Johnbod (talk) 12:48, 28 December 2013 (UTC)
- Done it now. Please check over. Johnbod (talk) 15:22, 28 December 2013 (UTC)
- When somebody next edits this, please take a look at http://www.whoi.edu/pclift/Ruddiman.pdf, or http://hol.sagepub.com/content/21/5/865.full.pdf+html by Ruddiman, Kutzbach, Vavrus in The Holocene Aug 2011. I think they make a pretty good case (or at least, raise some good red flags) about Stage 11 being considered the best analog of Stage 1., but rather being an outlier in multiple ways. JohnMashey (talk) 22:45, 13 January 2014 (UTC)
Unreliability of MIS dates
As stated in the article, the International Commission on Stratigraphy has adopted Lisiecki and Raymo's Benthic Stack for MIS dates, and the article cites the dates on her web site. I was puzzled that it gives 14,000 years ago for the start of the Holocene instead of the generally accepted 11,600, and emailed Lisiecki to query it. She replied that 14,000 is based on less well studied time intervals, and 11,600 is preferable. As Mike Christie has pointed out, this shows the danger of relying on raw data. We really need an up to date reliable secondary source. Can anyone suggest one? Dudley Miles (talk) 18:47, 18 September 2015 (UTC)