Category Archives: Speleothem

Speleothem Dating

Today I’m doing a short note on nonlinear equation solving of speleothem equations. As a preface to this, I’d like to comment that I’ve not made an overall post placing speleothems in context. And they have some very interesting properties as proxies that should not be lost sight of either in the context of posts […]

Fleitmann 2007: "Observed Anti-Correlation"

Today, I’m going to discuss a couple of points arising out of Fleitmann et al 2007, a discussion of speleothems in western Asia. Most notably, I’m going to discuss a “statistical” calculation made in this article, where the authors relied on a “visual” interpretation of noisy time series, which readily permit an alternative interpretation. (The […]

Five Monsoon O18 Series

Jud Partin observed yesterday that a “fantastic new record” had been recently (early Nov 2008) published from Wanxiang, China. Zhang et al report that their new record is “broadly similar” to the reconstructions of Esper, Mann and Jones 2003 and Moberg as follows: The Wanxiang record, with a d18O range of ~1.3 per mil (‰) […]

Calibrating Tropical Speleothems

Readers have inquired recently about how tropical speleothems are calibrated to temperature. Judd Partin, Kim Cobb (both of Georgia Tech) and associates wrote an excellent article last year (Cobb et al, EPSL 2007) on detailed O18 observations near a Borneo speleothem about which they had published. They introduced the article with the following observation that […]

Gavin Schmidt and "Uniquely" Oriented Speleothems

In our examination of the new Mann proxies, there is a notable increase in the prevalence of speleothem proxies in the MWP network. Craig Loehle used a couple of speleothem proxies in his reconstruction. One was a grey-scale series from Holmgren’s Cold Air Cave, South Africa. Not to be outdone, Mann et al used two […]