Refereed Publications
Year Author Word



1992

Clement, B. M. and D. G. Martinson, 1992: A Quantitative Comparison of 2 Paleomagnetic Records of the Cobb Mountain Subchron from North-Atlantic Deep-Sea Sediments. Journal of Geophysical Research-Solid Earth, 97(B2): 1735-1752. ABS
Imbrie, J. , E. Boyle, S. Clemens, A. Duffy, W. Howard, G. Kukla, J. Kutzbach, D. Martinson, A. McIntyre, A. Mix, B. Molfino, J. Morley, L. Peterson, N. Pisias, W. Prell, M. Raymo, N. Shackleton and J. Toggweiler, 1992: On the structure and origin of major glaciation cycles, 1. Linear responses to Milankovitch forcing. Paleoceanography, 7(6): 701-738.
Martinson, D. G. and J. R. Hopper, 1992: Nonlinear Seismic Trace Interpolation. Geophysics, 57(1): 136-145. PDF ABS



Abstracts

Clement, B. M. and D. G. Martinson, 1992: A Quantitative Comparison of 2 Paleomagnetic Records of the Cobb Mountain Subchron from North-Atlantic Deep-Sea Sediments. Journal of Geophysical Research-Solid Earth, 97(B2): 1735-1752.

We present a new paleomagnetic record of the Cobb Mountain Subchron obtained from deep-sea sediments cored at Ocean Drilling Program site 647 in the southern Labrador Sea. The details of the transitional field behavior documented by this record appear to be very similar to those recorded in a previously published record of this subchron obtained at Deep-Sea Drilling Project (DSDP) site 609 in the North Atlantic (Clement and Kent, 1987). We used a quantitative correlation technique (Martinson et al., 1982) to establish statistically the degree of similarity between these two records and thereby constrain the spatial variability in these transitional fields. The error in the alignments is reduced significantly by aligning records of virtual geomagnetic pole positions rather than directions, indicating that these records document such large scale changes in the fields that we can not distinguish them from dipolar changes, given the proximity of these two sites. These replicate records of the Cobb Mountain Subchron provide evidence that deep-sea sediments are capable of providing high resolution records of geomagnetic field behavior. A reexamination of the sequence of polarity transitions recorded at DSDP site 609 in light of these results suggests the presence of two preferred transitional field configurations. The field appears to change from one configuration to the other for several reversals and then back to the original configuration, suggesting that a geographical influence on the reversal process persists through this sequence. The variability in these reversal records provides insights into the response of the geodynamo to this geographical influence.


back to top




Martinson, D. G. and J. R. Hopper, 1992: Nonlinear Seismic Trace Interpolation. Geophysics, 57(1): 136-145.

The nonlinear correlation technique has been used to guide a seismic trace interpolant to fill gaps in seismic surveys, replace noisy traces, and produce evenly spaced arrays. Given an initial alignment (NMO correction for prestack data and manually inserted correlation lines for post-stack data), the correlation aligns corresponding features between adjacent seismic traces and quantifies the traveltime difference between the traces on a point-for-point basis. This information is used to construct synthetic (interpolated) traces, at any arbitrary distance between the correlated traces, which preserve dip and amplitude changes of the individual reflectors, assuming that such dip and amplitude changes occur linearly (or some other specified functional form) between the correlated traces.

back to top




The database was updated today.

Maintained by: Virginia DiBlasi, Lamont-Doherty Earth Observatory of Columbia University