The Impact of Seamount Topography on Ocean Currents in the Western Tropical Pacific Ocean

Abstract

This study integrates physical oceanography and marine geology to survey seamounts in the Western Tropical Pacific Ocean near Guam. Seamounts are significant because of their ability to manipulate ocean currents and wave turbulence on both a local and global scale. Seamounts within this region are abundant due to their location on a subduction zone along the Mariana Arc, but there is limited data identifying how their structures influence the regional currents in this area. The objective of this study is to determine the relationship between the slope of a seamount and the surrounding current velocities. I hypothesized that horizontal currents would be faster around seamounts with steeper topographic slopes compared to seamounts with flatter slopes. To analyze fluid flow interactions with seamount topography, this study measured current velocities with an Acoustic Doppler Current Profiler and imaged seafloor bathymetry using multibeam sonar techniques around two seamounts near the Mariana Arc, named NW Rota-1 and Ruby. I found that current speeds around North West Rota-1 were faster than at the other seamount Ruby, but I did not observe a clear relationship between topographic slope and current speed. Although these results suggest that shallower seamounts are associated with stronger flows than deeper seamounts, more observations are needed to understand the impact of seamount slope on the surrounding oceanographic currents.