HR: 0800h
AN: IN51B-0406    [Abstracts]
TI: Improving Marine Geophysical Data Quality
AU: * Chandler, M T
EM: mtchandl@hawaii.edu
AF: SOEST, Dept. of Geology & Geophysics, 1680 East-West Rd. Ste. 813, Honolulu, HI 96822, United States
AU: Wessel, P
EM: pwessel@hawaii.edu
AF: SOEST, Dept. of Geology & Geophysics, 1680 East-West Rd. Ste. 813, Honolulu, HI 96822, United States
AB: The 4,918 marine geophysics cruises currently archived at the National Geophysical Data Center's trackline archive comprise the primary global database for marine gravity, bathymetry, and magnetics. Many of these cruises fed the plate tectonic revolution of the 1960s and 1970s and remain valuable today as the cost of seagoing research continues to rise without alternative methods for obtaining comparable resolution. Although these data are of tremendous value to scientists, their affective use is limited by a significant amount of error within the archive. To ensure the continued use of these data we have completed a thorough along-track analysis of the archive. We find ~5-10% of marine gravity and bathymetry records erroneous and estimate that magnetic errors may exceed twice this proportion. By flagging extreme navigation errors, systematic errors such as invalid metadata and incorrectly scaled or offset data, temporary instrument malfunctions, and by recomputing invalid free-air and magnetic anomalies, we obtain an "internally consistent" data set suitable for more rigorous Crossover Error (COE) analysis. Rather than overwrite original cruise files, we compile extreme problems detected along-track into "E77" errata tables which we generate for each cruise. E77 tables will be made available via the web to facilitate sharing of corrections amongst scientists. Upon removal of extreme internal errors, we perform updated global COE analyses of marine gravity and bathymetry as well as the first global COE analysis of marine magnetics to date. Whereas E77 tables are static and may be easily shared and updated when necessary, COE tables are ephemeral and evolve as new cruises are added. Here we report preliminary COE findings and present examples of obvious errors correctable using COE correction tables.
DE: 0520 Data analysis: algorithms and implementation
DE: 0910 Data processing
DE: 3005 Marine magnetics and paleomagnetics (1550)
DE: 3010 Gravity and isostasy (1218, 1222)
SC: Earth and Space Science Informatics [IN]
MN: 2007 Fall Meeting