SIGNAL SEPARATION TO REVEAL SUBTLE FEATURES IN GRAVITY AND MAGNETIC DATA FROM THE BELLEFONTAINE OUTLIER, OHIO

Fidler, Michael L. Jr and Noltimier, Hallan C., 2006, Signal separation to review subtle features in gravity and magnetic data from the Bellefontaine outlier, Ohio [poster]: Geological Society of America North-Central Section 40th Annual Meeting, 2006, Session 38, Paper 38-2. Abstract published: Geological Society of America, Abstracts with Programs, Vol. 38, No. 4, p. 76; http://gsa.confex.com/gsa/2006NC/finalprogram/abstract_103533.htm At previous GSA meetings the general basement topography and structure of the Bellefontaine Outlier region of Ohio has been presented in poster format based upon our own detailed gravity and magnetic survey data and the COCORP Ohio #1 seismic survey which crossed the region. Recent experimentation with signal separation has brought new structural details to light. By removing the major gravity and magnetic signals from their respective data sets and re-normalizing the resulting data to isolate small scale variations, many features become visible. Correlation of these new details hidden within the gravity and magnetic survey data sets is presented as well as correlation with surface topographic features. For example: A north-east trending basement fault correlates with surface topography

UC-56 Rendeview

Rendeview is a mobile application designed to allow users to find a physical meeting location equitable for 3+ people, taking into account drive time and traffic conditions.Advisors(s): Dr. Reza PariziTopic(s): Software EngineeringSWE 472

Antarctic Mapping Mission Planning Aids

On November 4, 1995, the Canadian RADARSAT was carried aloft by a NASA rocket launched from Vandenburg Air Force Base. Radarsat is equipped with a C-band Synthetic Aperture Radar (SAR) capable of acquiring high resolution (25 m) images of Earth's surface day or night and under all weather conditions. Along with the attributes familiar to researchers working with SAR data from the European Space Agency's Earth Remote Sensing Satellite and the Japanese Earth Resources Satellite, RADARSAT will have enhanced flexibility to collect data using a variety of swath widths, incidence angles and resolutions. Most importantly, for scientists interested in Antarctica, the agreement for a U.S. launch of RADARSAT includes a provision for rotating in orbit the normally right-looking SAR to a left-looking mode. This 'Antarctic Mode' will provide for the first time a nearly instantaneous, high resolution view of the entirety of Antarctica on each of two proposed mappings separated by 2 years. This is an unprecedented opportunity to finish mapping one of the few remaining uncharted regions of the Earth. The completed maps will also provide two important benchmarks for gauging changes of Antarctica's ice cover. The preparation of a digital mosaic of Antarctica is being conducted under a NASA Pathfinder Project awarded to the Byrd Polar Research Center of The Ohio State University. The primary goal of this proposal is to compile digital SAR mosaics of the entire Antarctic continent using a combination of standard and extended beams during the "Antarctic Mode" of the Radarsat Mission. Agreements with the Canadian Space Agency call for the first Antarctic Mapping Manuever to occur in September, 1997. A mission plan to coordinate that complex acquisition and downlinking of Antarctic data has been developed by NASA's Jet Propulsion Laboratory. The Alaska SAR Facility (ASF) will be used as the primary data collection site supported by collections at the Canadian Gatineau and Prince Albert Ground Stations. ASF will process data into images which will be sent to OSU for compositing into map products using state-of-the-art equipment to be designed by Vexcel Corporation of Boulder Colorado. Imaging geometry will be constrained over the Antarctic using active radar transponders constructed by the Environmental Research Institute of Michigan and by corner reflectors deployed by the British Antarctic Survey. Additional ground control is being supplied by the National Imagery and Mapping Agency. Final products will be distributed through the ASF and the National Snow and Ice Data Center which are both NASA Data Archive Centers. The mosaics and ancillary information will be prepared on CDROM and will be made available to the science community through NASA DAACs. Science opportunities envisioned for the program are summarized on the accompanying table. These include studying the dynamics and variability of the Antarctic Ice Sheet including studies of regions like the Wordie Ice Shelf and the Larsen Ice Shelf which have recently experienced unexplained and nearly catastropic retreat. Geologic applications include large scale mapping of faults, volcanic features, and mountain building processes (particularly the Transantarctic Mountains). Finally, there is simply the unprecedented opportunity to use these digital maps in studies of many previously unexplored areas of the Southern Continent.NASACanadian Space Agenc

Derived Backscatter Values from JERS-1 Digital Number Distributions Over Ross Island, Antarctica (McMurdo Station).

This report examines the derived backscatter values for different physical properties from one JERS-1 image over Hut Point Peninsula on Ross Island in the McMurdo Station area. The results discussed in this report will be used to determine a suitable location for transponder testing for the Radarsat Antarctic Mapping Project. Histograms of digital number (DN) values (0-255) were created to determine the DN distribution and approximate backscatter value for five locations on a single JERS-1 image. Two locations were chosen over first year sea ice, and one location each over glacial ice, exposed rock, and the McMurdo Station. From published backscatter values for first year ice of -15dB and a DN of 40, estimated from histograms, an approximation of the calibration constant K was calculated and subsequent backscatter coefficients were computed for the remaining locations. Digital numbers peaked at 255 for both glacial ice and McMurdo Station indicating that an area outside of McMurdo Station would be preferable for transponder testing

Experimental deformation of synthetic magnetite-bearing calcite sandstones: effects on remanence, bulk magnetic properties, and magnetic anisotropy

NSF EAR 88-04820 and NSERC A686

Geological Analysis of ERS-1 SAR Mosaic: Impilcations for the Tectonic Segmentation of the Antarctic Peninsula

The Antarctic Peninsula (AP) is a Mesozoic-Cenozoic Andean-type magmatic arc resulting from subduction of Pacific Ocean lithosphere beneath its western margin. During the past 60 million years discrete segments of the Pacific-Phoenix spreading ridge have successively collided with the western margin of the AP diachronously from south to north in a series of ridge-crest collision episodes. Previous work suggested that the AP (upper plate) was tectonically segmented due to subduction of discrete ridge-crest segments, with segments bounded by the projection of oceanic fracture zones. This work interpreted an apparent left-lateral offset of the Pacific Margin Anomaly (PMA) visible in aeromagnetic anomaly data as evidence for a component of left lateral strike-slip motion along segment boundaries. An ERS-l SAR mosaic was created of the entire AP and combined with aeromagnetic anomaly data and mapped geologic data to study how the process of fracture zone subduction modified AP structure. Our approach was to compare lineaments derived from the SAR mosaic with aeromagnetic lineations and mapped geologic structure. Good correlation of SAR lineament trends and mapped fault trends on Alexander Island provide evidence that some of the SAR lineaments are structurally controlled. Based on this relation, the Graham Land-Palmer Land Transition Zone (TZ) was examined in detail. Correlation between the SAR and aeromagnetic lineaments suggests both mark crustal structures in the TZ. Differences between trends of mapped geologic features and SAR lineaments within the TZ and to the north of the TZ argue that the TZ is structurally unique within the AP. A model invoking left lateral fault motion can explain the lineament patterns. Correlation between lineament trends and fracture zone traces suggests that faulting reflects the response of the AP crust to fracture zone subduction.European Space Agency for the ERS-1 SAR data.This project was supported by a grant from the Antarctic Geology and Geophysics Program, Office of Polar Programs, National Science Foundation

Variations in Radar Backscatter Across the Great Ice Sheets

Radar backscatter over the great ice sheets is modulated by the near surface properties of polar firn. These properties (grain size, density, stratigraphy, wetness) change in time and from region to region. Information was compiled on the spatial variation in backscatter across selected parts of Antarctica and Greenland from ERS-l SAR data. This SAR-derived backscatter information is compared to similar data, collected in situ and from the ERS-l scatterometer, obtained from literature. These results will be used to refine processing schemes for the Radarsat Antarctic Mapping Project

A model for the horst and graben structure of Midocean ridge crests based upon spreading velocity and basalt delivery to the Oceanic crust

La cresta de la dorsal del Pacifico oriental entre los 17° N a los 40° S se caracteriza por un horst central. Este rasgo se atribuye a! producto estacionario de una deriva constante en torno a la cresta, en que la varianza de la velocidad de inyección es menor que la varianza de la velocidad de deformación horizontal. Se elabora un modelo basado en estos dos parámetros, con el que se logra explicar tanto la topografía del horst central como de un graben central. Este último ocurre cuando en el modelo se postula una velocidad del fondo marino suficientemente baja, de modo que la varianza de la velocidad de inyección vertical es mayor que la varianza de la velocidad de deformación horizontal. Se supone que esto ocurrirá solamente cuando la deriva es intermitente, debido a la solidificación y ruptura alternada de la zona central de intrusión. Por lo tanto, la configuración del horst central sería la "normal". Dicho de otra manera, hay formación de graben central cuando el material asciende por la cresta sobre distancias mayores que las necesarias para acelerar el material de la cresta desde una velocidad horizontal nula hasta la velocidad de dispersión. De lo contrario, se forma un horst central