{"id":800,"date":"2010-07-21T13:47:08","date_gmt":"2010-07-21T17:47:08","guid":{"rendered":"http:\/\/blogs.law.harvard.edu\/kotrc\/?p=800"},"modified":"2010-07-26T09:46:32","modified_gmt":"2010-07-26T13:46:32","slug":"fruitless-fibbing","status":"publish","type":"post","link":"https:\/\/archive.blogs.harvard.edu\/kotrc\/2010\/07\/21\/fruitless-fibbing\/","title":{"rendered":"Fruitless FIBbing"},"content":{"rendered":"
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Spent the morning on the FIB trying my hand, once again, at cutting open the little buggers. No success this time\u2014I was trying to cut up a very large Cretaceous form, for which I decided to use a very large (45 nA) current probe. The end result, after over an hour of milling time, was dismal: the beam had barely made a dent in the carbon tape and done almost nothing to the frustule at all. I consulted Nicholas, and learned that FIB probes need to be aligned, stigmated, and focussed\u2014none of which had been performed on this probe. So, it wasn’t my mistake directly. I scheduled time with Nicholas to learn how to do this next week. I had felt very frustrated at the end of the morning, but when I found out that it was just a matter of learning to set up the tool in the right way, I felt better.<\/p>\n

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Back at the office, the window a\/c unit struggling to keep the temperature at a halfway humane level, I turned my attention back to those fossil diatom samples yet to be ordered. The first thing I needed to do was to figure out the exact age of the samples I already have. To do this I downloaded the corresponding age model data from Chronos, and then sought to use the AgeDepthPlot java implementation to calculate a corresponding age. I then realized that I’d forgotten how to convert from the curatorial sample designation to an mbsf depth… Yikes! Spent some time digging through ODP publications, as well as my own notes from MSc days, trying to remember how I’d done it.<\/p>\n

I’m confused as fuck. It seems cores are usually 9.5m long, with each section 1.5 m. But then it seems (from the ADP manual) that there are core-depth data associated with each hole that give the depths of the top of each core, so that it’s not as easy as simply adding complete cores times 9.5 to complete sections times 1.5 and the sample depth in cm… Aaargh! What a frustrating day. Yes, I could just e-mail Dave to ask him about this, but I feel like a total retard, given that I already learned this\u2014from him\u2014only a few years ago. Fuckity fuck fuck. Yeah, I think that’s right. I found some of my old spreadsheets where I calculated depths in mbsf, and they all require obtaining “coretop” depths, i.e. depths from the seafloor to the top of the cored interval. From this depth you can then calculate total mbsf. This means for each sample I’m considering, I’m going to have to dig through the DSDP or ODP initial results volume and determine the coretop depth for that particular core, in order to be able to calculate the depth in mbsf, in order to be able to calculate the age (after downloading or, if not available, constructing an age model), in order to be able to determine whether it’ll be a suitable candidate at all for sampling.<\/p>\n

Yay. How I love this project.<\/p>\n

Well, it took a little time, but I did it\u2014determined the mbsf depths for the Cenozoic samples held. Then, with a bit of wizardry, worked out the age of the first sample… a small victory. Then, I thought I’d breeze through and do the others: but, alas, Chronos has no age models stored for the other holes. So, I end the day on another disappointment. Crawling along at a glacial pace…<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Spent the morning on the FIB trying my hand, once again, at cutting open the little buggers. No success this time\u2014I was trying to cut up a very large Cretaceous form, for which I decided to use a very large (45 nA) current probe. The end result, after over an hour of milling time, was […]<\/p>\n","protected":false},"author":2222,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[16287],"class_list":["post-800","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-fossil-diatom-fib"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/posts\/800","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/users\/2222"}],"replies":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/comments?post=800"}],"version-history":[{"count":9,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/posts\/800\/revisions"}],"predecessor-version":[{"id":802,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/posts\/800\/revisions\/802"}],"wp:attachment":[{"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/media?parent=800"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/categories?post=800"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/kotrc\/wp-json\/wp\/v2\/tags?post=800"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}