Tag Archives: marcott

Bent Their Core Tops In

In today’s post, I’m going to show Marcott-Shakun redating in several relevant cases. The problem, as I’ve said on numerous occasions, has nothing to do with the very slight recalibration of radiocarbon dates from CALIB 6.0.1 (essentially negligible in the modern period in discussion here), but with Marcott-Shakun core top redating.

Hiding the Decline: MD01-2421

As noted in my previous post, Marcott, Shakun, Clark and Mix disappeared two alkenone cores from the 1940 population, both of which were highly negative. In addition, they made some surprising additions to the 1940 population, including three cores whose coretops were dated by competent specialists 500-1000 years earlier. While the article says that ages […]

The Marcott-Shakun Dating Service

Marcott, Shakun, Clark and Mix did not use the published dates for ocean cores, instead substituting their own dates. The validity of Marcott-Shakun re-dating will be discussed below, but first, to show that the re-dating “matters” (TM-climate science), here is a graph showing reconstructions using alkenones (31 of 73 proxies) in Marcott style, comparing the […]

How Marcottian Upticks Arise

I’m working towards a post on the effect of Marcott re-dating, but first I want to document some points on the methodology of Marcott et al 2013 and to remove some speculation on the Marcott upticks, which do not arise from any of the main speculations. In the graphic below, I’ve plotted Marcott’s NHX reconstruction […]

Marcott’s Zonal Reconstructions

I’m going to do a detailed post on my diagnosis of the Marcott uptick, but before I do so, I want to comment on the reconstructions for NH and SH extratropics, neither of which have attracted sufficient notice though both are very remarkable. In a substantive sense, because orbital changes have different effects on NH […]

No Uptick in Marcott Thesis

Reader ^ drew our attention to Marcott’s thesis (see chapter 4 here. Marcott’s thesis has a series of diagrams in an identical style as the Science article. The proxy datasets are identical. However, as Jean S alertly observed, the diagrams in the thesis lack the closing uptick of the Science. Other aspects of the modern […]

Marcott Mystery #1

Marcott et al 2013 has received lots of publicity, mainly because of its supposed vindication of the Stick. A number of commenters have observed that they are unable to figure out how Marcott got the Stick portion of his graph from his data set. Add me to that group. The uptick occurs in the final […]


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