Bryksina, N.A. and Last, W.M. 2005. Fractal analysis of the gray-scale intensity data of finely laminated sediments from Bainbridge Crater Lake, Galápagos. Mathematical Geology 37: 327-335.
What was done
The Galápagos Archipelago is a small group of volcanic islands located about 1000 km off the coast of Ecuador within the core of the El Niño/Southern Oscillation (ENSO) region, and as such is home to numerous studies of ENSO phenomena. In the present study, Bryksina and Last examined the laminations in a sediment core retrieved from Bainbridge Crater Lake (91°34'W, 0°21'S) in the Galápagos as a proxy for ENSO over the past 6200 years.
What was learned
After dividing the sediment record into two time periods (6200 to 3000 yr BP and 3000 yr BP to the present), the authors determined that "ENSO fluctuation before 3000 yr BP had a persistent behavior on a time-scale up to 26 years, while the more recent El Niño occurrences have a persistent behavior on a time-scale up to 5.6 years," where "decreasing time scale of persistent behavior ... indicates increasing frequencies of ENSO activity."
What it means
Climate alarmists typically claim that ENSO events become more frequent as a result of global warming. However, the data from this study suggest just the opposite. During the latter part of the Holocene Climatic Optimum (6200 to 3000 yr BP), when it was much warmer than it was over the following 3000 years, ENSO persistent behavior was fully four times greater than what was experienced subsequently, indicative of a significantly lower frequency of ENSO occurrence during that earlier period of greater warmth. Thus, if the warming that the earth experienced in recovering from the global chill of the Little Ice Age continues into the future, we can probably expect ENSO frequency to decline a bit.