ISSN:
1573-0794
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract Spectral analysis ofδ 18O values from V28–239 pacific ocean deep-sea core has revealed periodicities which correspond to those calculated for the eccentricity (400 and 100 Kyrs), the obliquity (41 Kyrs) and the climatic precession (23 and 19 Kyrs) as well as secondary ones spanning between 16 Kyrs to 1 million years. The methods of spectrum analysis applied were the maximum entropy, fourier and the successive approximations, where the periodicities are located and their amplitude defined. The significance and stationarity of the detected periods was examined by various tests as well as employing an evolutionary pseudosonogram. The dominant 100 Kyrs and 50 Kyrs periods are present throughout 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 necessity of applying various spectral analysis techniques and several tests to extract the optimum of spectral information and also to test the stationarity of certain periodicities, especially when implied mechanisms of climatic cause and variability are involved.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00579465
