Publication Date:
2017-04-04
Description:
We use the Empirical Mode Decomposition (EMD) method to study the decadal variations in polar motion and its long-term trend since year 1900. The existence of the so-called “Markowitz wobble”, a multidecadal fluctuation of the mean pole of rotation whose nature has long been debated since its discovery in 1960, is confirmed. In the EMD approach, the Markowitz wobble naturally arises as an empirical oscillatory term in polar motion, showing significant amplitude variations and a period of approximately 3 decades. The path of the time-averaged, non-cyclic component of polar motion matches the results of previous investigations based on classical spectral methods. However, our analysis also reveals previously unnoticed steep variations (change points) in the rate and the direction of secular polar motion.
Description:
Published
Description:
200–211
Description:
1T. Geodinamica e interno della Terra
Description:
JCR Journal
Description:
reserved
Keywords:
secular polar motion
;
markowitz wobble
;
04. Solid Earth::04.03. Geodesy::04.03.02. Earth rotation
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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