TABLE OF CONTENTS

This specific investigation focuses on bed state variability and bed state evolution in-fluenced by free surface gravity waves. Observations of seabed geometry were obtained at the O. H. Hinsdale Wave Research Laboratory large scale wave flume at Oregon State Uni-versity in 2005. Flow field and seabed geometry data was collected using a submersible Particle Image Velocimetry (PIV) system. Sea bed geometry measurements include: ripple height (η), wavelength (λ), and radius of curvature (RC). The seabed is determined by the centroid of the maximum light reflection captured by a submerged camera when the bed is illuminated by a laser sheet in the PIV system. Observations were obtained under random wave conditions using a TMA spectrum with significant wave heights ranging from 30 to 50 cm and wave periods in the range of 4 to 8 seconds. The resulting bed geometries ranged from flat to rippled. Over temporal scales as short as one wave period, significant trans-formations in geometry were recorded. Bedform ripple height was found to be dependent on root-mean-square velocity for wave peak periods of 6 and 8 seconds, and independent of root-mean-square velocity for relatively small peak periods of 4 seconds. Radius of curva