Alternative explanation for intermediate--wavelength magnetic anomalies
Harrison and Carle and others have examined very long profiles of the magnetic field and have calculated one-dimensional power spectra. In these they expect to see, but do not find, a minimum in power at intermediate wavelengths, between 65 and 150 km. Conventional one-dimensional models of the field predict very little power in this band, which lies between the spectral peaks arising from sources in the crust and the core. Mantle sources or high-intensity, long-wavelength magnetizations have been proposed to account for the observations. An alternative, more plausible explanation is that one-dimensional spectra of two-dimensional fields contain contributions from wavenumbers in the perpendicular (i.e., nonsampled) direction. Unless the seafloor spreading anomalies are perfectly lineated at right angles to the profile, some low-wavenumber energy must be attributed to this effect; we propose that such directional aliasing is a major factor in the power spectra. To support this idea we discuss theoretical models and analyze a large-scale marine survey.
- Research Organization:
- Scripps Institution of Oceanography, Institute of Geophysics and Planetary Physics, University of California at San Diego, La Jolla, California 92093
- OSTI ID:
- 5545714
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 86:B12
- Country of Publication:
- United States
- Language:
- English
Similar Records
Northern east Pacific rise: Magnetic anomaly and bathymetric framework
Can remanent magnetization in the deep crust contribute to long wavelength magnetic anomalies