Date of Award

Spring 2012

Project Type

Thesis

Program or Major

Earth Sciences

Degree Name

Master of Science

First Advisor

David Monahan

Abstract

In this study we evaluate the differences between six publicly available bathymetry grids in different regions of the Arctic. The independent, high-resolution and accuracy multibeam sonar derived grids are used as a ground truth against which the analyzed grids are compared. The specific bathymetry grids assessed, IBCAO, GEBCO 1 minute, GEBCO_08, ETOPO1, SRTM30_Plus, and Smith and Sandwell, are separated into two major Types: Type A, grids based solely on sounding data sources, and Type B, grids based on sounding data combined with gravity data. The differences were evaluated in terms of source data accuracy, depth accuracy, internal consistency, presence of artifacts, interpolation accuracy, registration issues and resolution of the coastline. These parameters were chosen as quality metrics important for the choice of the grid for any given purpose. We find that Type A bathymetry grids (in particular GEBCO_08) perform better than Type B grids in terms of internal consistency, and have higher accuracy in the different morphological provinces, especially the continental shelf, mainly due to the better source data coverage. Type B grids, on the other hand, have pronounced artifacts and have low accuracy on the shelf due to the scarcity of source data in the region and, in general, the poor performance of gravity prediction in shallow areas and high latitudes. Finally, we propose qualitative metrics that are important when choosing a bathymetry grid and support these metrics with a quality model to guide the choice of the most appropriate grid.

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