Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 119-121).Through-going muon events are analyzed as a function of their direction of travel through the Sudbury Neutrino Observatory. Based on simulations and previous measurements, muons with a zenith angle of 1 0:33 at the 90% confidence level. In addition, the flux of atmospheric neutrinos is measured in 1-D with a 68% confidence level to be 1:24+0:11 0:10 times the prediction of the BARTOL group based on SNO data alone, and 1:27+/-0.09 times the prediction when the oscillation parameters are constrained by the Super Kamiokande and Minos results.by Thomas John Sonley.Ph.D