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Tectonic history of the Greater Ontong Java Plateau and errata-based correction of marine geophysical trackline data

Posted on:2012-03-03Degree:Ph.DType:Thesis
University:University of Hawai'i at ManoaCandidate:Chandler, Michael ThomasFull Text:PDF
GTID:2450390008495760Subject:Geology
Abstract/Summary:
The plate tectonic revolution of the 1960s and 1970s is said to mark the Earth Sciences' transition from data-driven discovery to hypothesis testing. This is largely the case in marine geoscience as modern research expeditions focus on isolated study areas rather than globe spanning surveys typical of the past. Although the onus among scientists is generally to explore new problems by gathering new sets of data, I contend that we have not yet fully digested existing data sets. During my doctoral studies, I engaged in researches that examined large amounts of previously collected data. I utilized paleolatitude measurements in my attempts to constrain the past movements of the Ontong Java, Manihiki and Hikurangi oceanic plateaus. Through my resultant familiarity, I was able to discover a pattern within the paleolatitudes that suggested significant rotation of the plateaus. This rotation may explain why Ontong Java's paleo-pole does not agree with other coeval Pacific paleo-poles and with the Pacific apparent polar wander path in general. This inference further implies that Ontong Java may have been decoupled from the Pacific plate during the past or that, speculatively, the entire Pacific plate was rotated by ∼30°--50° to coincide with Ontong Java's paleo-orientation. I further immersed myself in the entirety of the National Geophysical Data Center's marine geophysical trackline archive in an effort to identify and correct large-scale and systematic errors in marine gravity, magnetic, and single/center beam depth measurements. I produced 5,203 "E77" correction tables pertaining to along-track analysis of each of the archived surveys. Initial inspection of discrepancies at intersecting tracks indicates improvements in median crossover errors from 27.3 m to 24.0 m, 6.0 mGal to 4.4 mGal, and 81.6 nT to 29.6 nT for depths, free air gravity anomalies, and residual magnetic anomalies, respectively.
Keywords/Search Tags:Data, Ontong java, Plate, Marine, Geophysical
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