We present both FFT and wavelet spectral analysis of the environmental magnetic parameters obtained at IMAGES Sites MD012380 covering the time 0-780 ka. These parameters, representing the abundance of magnetic minerals, include magnetic susceptibility (χ), anhysteretic remanent magnetization (ARM), and saturated isothermal remanent magnetization (SIRM).The FFT spectral results show clear peak of power at the frequency corresponding to the Earth eccentricity (100 ka). However there are several frequencies that we do not know their meanings yet in the spectral results. In order to distinguish the temporal discontinuities and the non- stationary signals in our data, we alternatively use the wavelet analysis. All these parameters present obvious periods corresponding to the eccentricity (100 ka) and precession (23 ka). Besides, as same as the FFT spectral result,and SIRM also show clear signal at ~160 ka period while ARM shows a period of ~66 ka. Furthermore we apply these parameters to cross spectral with Oxygen isotope (δ18O) and clear frequencies corresponding to the Earth orbital parameters (Eccentricity, obliqyity, precession) have been found. It indicates that magnetic parameters are good indexes to provide informations for paleo-environment study. One of the factors that affects the paleo-environment variation in the Banda Sea area may be contributed by the orbital forces.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- 1500 GEOMAGNETISM AND PALEOMAGNETISM;
- 1512 Environmental magnetism