Discipline: Ecology Environmental and Earth Sciences
Subcategory: Geosciences and Earth Sciences
Ayanna Overton - North Carolina A&T State University
Co-Author(s): Charlie Nelson, Kentucky State University, KY Kamberlin King, Mississippi Valley State University, MS
The Ross Ice Shelf, located on the southwestern coast of Antarctica, is the largest ice shelf in Antarctica. In West Antarctica, more than 20 km3 of ice is discharged every year due to the drainage from West Antarctica into the Ross Ice Shelf. The speeds of glaciers, which have advanced up to eight times more over an 18-month period, have also impacted ice sheet balance. With the many changes that have occurred over the years a validation was needed for the Antarctic Snow Accumulation and Ice Discharge (ASAID) basal stress boundary (BSB) created in 2003. Research was conducted on validation of the ABSB vs. natural basal stress boundary (NBSB) using three comparison sets of Level 1, Band 2 Landsat images: years 1988 and 2014 of path 32 and row 115, years 1999 and 2003 of path 30 and row 116, and years 2000 and 2014 of path 32 and row 116. The use of the path and row allowed for observation of the Ross Ice Shelf at the line of equinox to the southwest-most border of the ice shelf. Observation of the ice shelf spanned a total of 25 years. Images were collected using the United States Geological Survey (USGS) Global Visualization Viewer (GloVis). Level 1 products were used because it allowed multiple bands to be chosen from to detect any deviations of the BSB. Exelis Visual Information Solutions (ENVI) Classic 4.7 was used to view a text file of the entire Antarctica Peninsula, which was modified to include only the BSB. Images were warped to improve the accuracy of older images so that they could be used in comparison to more recent Landsat images. ENVI Classic, along with ENVI 5.0, was used to geo-reference images. New warped images were viewed in ENVI Classic and the ASAID BSB was superimposed onto the warped image. By utilizing the standard zoom of ~x4 of the ENVI Classic zoom window feature, it was concluded that there had been a misplacement of the NBSB along the Ross Ice Shelf. The deviations of the NBSB were documented in a data table with the change that occurred along with the latitude and longitude geographic coordinates. Future research includes providing each ice shelf with an ASAID BSB text and ENVI vector file in a unique file. This would create a new file that could be used to decrease the time spent identifying sections around the map of Antarctica.
References: E. Rignot, J. L. Bamber, M. R. van den Broeke, C. Davis, L. Yonghong, W. J. van deBerg, et al, “Recent Antarctic ice mass loss from radar interferometry and regional climate modeling.” Nature Geoscience, vol. 1, pp. 106 – 110, 2008.
Funder Acknowledgement(s): Dr. Linda Hayden, Center for Remote Sensing of Ice Sheets (CReSIS), and National Science Foundation (NSF).
Faculty Advisor: Michael Jefferson Jr.,