PERIODIC VARIATION OF DELTA-O-18 VALUES FROM V28-239 PACIFIC-OCEAN DEEP-SEA CORE

Citation
J. Xanthakis et al., PERIODIC VARIATION OF DELTA-O-18 VALUES FROM V28-239 PACIFIC-OCEAN DEEP-SEA CORE, Earth, moon, and planets, 66(3), 1994, pp. 253-278
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Astronomy & Astrophysics","Geosciences, Interdisciplinary
Journal title
ISSN journal
0167-9295
Volume
66
Issue
3
Year of publication
1994
Pages
253 - 278
Database
ISI
SICI code
0167-9295(1994)66:3<253:PVODVF>2.0.ZU;2-S
Abstract
Spectral analysis of delta(18)O values from V28-239 pacific ocean deep -sea core has revealed periodicities which correspond to those calcula ted for the eccentricity (400 and 100 Kyrs), the obliquity (41 Kyrs) a nd the climatic precession (23 and 19 Kyrs) as well as secondary ones spanning between 16 Kyrs to 1 million years. The methods of spectrum a nalysis applied were the maximum entropy, fourier and the successive a pproximations, where the periodicities are located and their amplitude defined. The significance and stationarity of the detected periods wa s examined by various tests as well as employing an evolutionary pseud osonogram. The dominant 100 Kyrs and 50 Kyrs periods are present throu ghout all the interval, the 30 Kyrs is at low variance during 1.2 to 2 million years interval, the precessional signal is not stationary and appears at about 600 Kyrs to 1820 Kyrs. This study shows the necessit y of applying various spectral analysis techniques and several tests t o extract the optimum of spectral information and also to test the sta tionarity of certain periodicities, especially when implied mechanisms of climatic cause and variability are involved.