Stormquakes: Tracing the path of ocean storms through the solid earth

We have discovered a new geophysical phenomenon involving the coupling of the atmosphere-ocean and solid Earth using a novel array method. An analysis of ten years of seismic data recorded in the continental United States, mainly at the USArray, shows that large storms such as hurricanes and Nor’easters can excite transient seismic surface waves in the 20–50 s band with amplitudes equivalent to those excited by M3.5 earthquakes. These sources, which we label stormquakes, can produce transcontinental coherent Rayleigh wave packets observable in the time domain and are thus fundamentally different from previously reported atmosphere-ocean solid Earth couplings that produce incoherent seismic noise. We present unique observations and methods to pinpoint the source locations and timing, which clearly shows that these seismic waves are from interactions of seafloor bathymetry and ocean waves that are energized by large storms. Stormquakes migrate along continental shelfbreak, tracking the leading edge of large storms. We have documented features and identified a possible physical mechanism explaining the stormquake excitation. Stormquakes have potential use in oceanography and meteorology as a remote monitoring tool with high spatial and temporal resolution with which to investigate ocean wave dynamics during large storms.