Rocketquake Seismology with a Falcon 9 Rocket Source

TL;DR

This study explores using rocket launches as seismic sources to image planetary subsurface structures, demonstrating the potential for planetary exploration and hazard detection through rocketquake seismology.

Contribution

It introduces the concept of rocketquake seismology, applying seismic inversion techniques to data from Falcon 9 launches for planetary subsurface imaging.

Findings

Coherent body waves recorded at less than 7 km from launch site

Rayleigh waves inverted to S-velocity profile to 60 m depth

No detectable signals at 15 km distance from launch site

Abstract

We investigate the feasibility of using rocket launches, specifically rocketquakes, as a seismic source to image subsurface velocity and geology of planetary bodies. Toward this goal, we record the seismic vibrations excited by a Falcon 9 rocket launch from Vandenberg Space Force Base (SFB) near Lompoc, California. Nine passive three-component (3C) seismometers were deployed every 18.75 meters along a 45-degree line from the launch site starting at the offset of about 7 km kilometers from the launch pad. Results show that coherent body waves can be recorded with a P-velocity of more than 2.0 km/s and a penetration depth of 1 km or deeper. Stronger Rayleigh waves were also recorded and inverted to give an S-velocity profile to a depth of 60 m. Notably, a 3C recorder placed approximately 15 km from the launch site did not capture any discernible body wave arrivals. The imaging techniques employed for rocketquake seismology integrate inversion methods from earthquake and exploration seismology, yielding the P- and S-velocity profiles of the subsurface. These results suggest that rocket launches as seismic sources will provide unprecedented opportunities for identifying the subsurface hazards, faults, tunnels, water ice, and mineral deposits of planetary bodies and their moons.