09:45 〜 10:00
[S19-1-06] Investigating the Interior of Icy Worlds with Short Aperture Seismic Arrays
invited
The interiors of the icy outer satellites are currently of great interest as they may support the largest volume of habitable space within the Solar System. A key parameter of this habitability is the presence of liquid water oceans or seas beneath the frozen surface, thus geophysical investigations of the interior are crucial for understanding the structure, dynamics, and evolution of these liquid water reservoirs. Seismology will be the preeminent tool for determining the thickness of ice shells, the depth of oceans, underlying silicate bodies, and assessing Icy Worlds for habitability. Our present understanding of the seismic signals produced by Icy Worlds is limited, with the level of seismic activity at the surfaces (and interiors) likely driven by tidal processes. The harsh operating environments will limit mission observation times, making it is essential that the seismic information returned from a surface mission be of high fidelity in resolving key questions about the internal environment of an Icy World.
Such measurements can be provided by a short aperture seismic array. We define a short aperture array as a deployment of multiple 3-component seismometers, with a separation between instruments of 1-10 meters. The instruments in the array must have a sampling rate and frequency range sensitivity capable of distinguishing between waves arriving at each station. We will present 3-D synthetic modeling and analog field results that demonstrate sensing requirements and the primary advantages of such a seismic array over a single station, including the improved ability to resolve the location of the source through detection of backazimuth and differential timing between stations, ambient noise techniques, as well as the ability to improve the signal to noise ratio by additive methods such as stacking and velocity-slowness analysis. Our results inform future missions to the surfaces of Europa, Enceladus, Titan, and other objects in the outer Solar System.
Such measurements can be provided by a short aperture seismic array. We define a short aperture array as a deployment of multiple 3-component seismometers, with a separation between instruments of 1-10 meters. The instruments in the array must have a sampling rate and frequency range sensitivity capable of distinguishing between waves arriving at each station. We will present 3-D synthetic modeling and analog field results that demonstrate sensing requirements and the primary advantages of such a seismic array over a single station, including the improved ability to resolve the location of the source through detection of backazimuth and differential timing between stations, ambient noise techniques, as well as the ability to improve the signal to noise ratio by additive methods such as stacking and velocity-slowness analysis. Our results inform future missions to the surfaces of Europa, Enceladus, Titan, and other objects in the outer Solar System.