The Aloha Cabled Observatory: New Insights into hurricane generation of the seismo-acoustic noise spectrum

Abstract

The close passage of Hurricane Lester near the Hawaiian Islands in September 2016 afforded an in-depth, close-up study of storm generation of the largest background vibrations observed planet wide. The observations at the ALOHA Cabled Observatory on the seafloor below the Hurricane, coupled with seismic sensors on Oahu, and ocean wave buoys off shore, present a detailed picture connecting the storm to the ocean and Earth. Wave interactions from a distant typhoon near Japan play an important role. Vibration energy levels observed on Oahu closely match those on the sea floor 100 km north of Oahu, where ALOHA Cabled Observatory is the world’s deepest seafloor observatory at 4,728 m depth. Characteristic vibrations generated radially from the Hurricane were observed, along with unexpected transverse motions perpendicular to the radial waves. This latter observation is consistent with a broad source region extending from Hurricane Lester and generating the vibrations. Evidence for substantial scattering of the...