Applications of time series analysis to geophysical data
Chave, Alan D.
MetadataShow full item record
South Atlantic Ocean
KeywordGeomagnetism; Electromagnetic fields; Marine sediments; Paleomagnetism; Geophysics; Marine geophysics; Atlantis II (Ship : 1963-) Cruise AII94
This thesis consists of three papers applying the techniques of time series analysis to geophysical data. Surface wave dispersion along the Walvis Ridge, South Atlantic Ocean, is obtained by bandpass filtering the recorded seismogram in the frequency domain. The group velocity is anomalously low in the period range of 15-50 s, and formal inversion of the data indicates both crustal thickening to 12.5 km and low shear velocity (4.25-4.35 km/s) to depths of 40-50 km. The electromagnetic induction fields at a deep ocean site northeast of Hawaii were used to determine the electrical conductivity of the earth to 400 km depth. Singular value decomposition of the data matrix indicates three degrees of freedom, suggesting source field complications and a two dimensional conductive structure. Inversion of one of the principal terms in the response function shows an abrupt rise in electrical conductivity to 0.05 mho/m near 160 km with no resolvable decrease below this. A model study suggests that moving source fields influence the induction appreciably in the other principal response tunction. A set of piston cores from the northeast Atlantic Ocean are used to construct paleomagnetic time series covering the interval 25-127 kybp. Stratigraphic control is provided by counts of planktonic toraminifera, and empirical orthogonal function analysis shows a significant decrease in sedimentation rate at the interglaciai/glacial transition. The sediments are magnetically stable and reliable relative paleointensity measurements could be obtained. Spectral analysis of the directions reveals a predominant 10 ky periodicity and no dominant looping direction.
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June, 1980
Showing items related by title, author, creator and subject.
Marine sedimentary organic matter : delineation of marine and terrestrial sources through radiocarbon dating; and the role of organic sulfur in early petroleum generation Benitez-Nelson, Bryan C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-05)This thesis details two years of research conducted with the guidance and support of three advisors: Dr. J. K. Whelan, Dr. J. S. Seewald and Dr. T. I. Eglinton. Each of the three chapters represents a different, ...
Dynamic energy budgets and bioaccumulation : a model for marine mammals and marine mammal populations Klanjscek, Tin (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-06)Energy intake of individuals affects growth of organisms and, therefore, populations. Persistent lipophilic toxicants acquired with the energy can bioaccumulate and harm individuals. Marine mammals are particularly ...
Developing a national marine electronics agenda : proceedings of the Marine Instrumentation Panel meeting, September 12-14, 1989 Gaines, Arthur G.; Lindborg, Kristina L. C. (Woods Hole Oceanographic Institution, 1990-12)Thirteen short papers address aspects of competitiveness in the marine electronics instrumentation industry. Topics include activity and status of government initiatives in Japan and Europe to promote this industry; and ...