Errors carbon 14 dating
The output is along the bottom axis; it is a trimodal graph, with peaks at around 710 AD, 740 AD, and 760 AD.
Again, the ranges within the 1σ confidence range are in dark grey, and the ranges within the 2σ confidence range are in light grey.
Example t, in red on the graph, shows this situation: a radiocarbon age range of about 1260 BP to 1280 BP converts to three separate ranges between about 1190 BP and 1260 BP.
The curve showed two types of variation from the straight line: a long term fluctuation with a period of about 9,000 years, and a shorter term variation, often referred to as "wiggles", with a period of decades.
Suess said he drew the line showing the wiggles by "cosmic schwung" – freehand, in other words.
A normal distribution is shown at left; this is the input data, in radiocarbon years.
The central darker part of the normal curve is the range within one standard deviation of the mean; the lighter grey area shows the range within two standard deviations of the mean.