09:15 〜 09:30
[S19-1-04] Planetary Seismology Using Infrasound and Airglow Signatures on Venus
The planetary evolution and structure of Venus remain uncertain more than half a century after the first visit by a robotic spacecraft. To understand how Venus evolved it is necessary to detect the signs of seismic activity. Due to the adverse surface conditions on Venus, with extremely high temperature and pressure, it is infeasible to place seismometers on the surface for an extended period of time. Due to dynamic coupling between the solid planet and the atmosphere, the waves generated by quakes propagate and can be detected in the atmosphere itself.
JPL in collaboration with ISAE and Caltech Campus is in a process of developing an instrument to measure seismic activity on Venus by in-situ measurements of infrasonic waves in the atmosphere. The overall objective of this research is to demonstrate the feasibility of sensitive barometers to detect infrasonic signals from seismic and explosive activity on Venus from a balloon platform. The seismic signals are known to couple about 60 times more efficiently into the atmosphere on Venus than on Earth, which might allow the detection of small regional quakes (magnitude ~3). We will report results on the first flight experiment that will focus on using the barometer instruments on a tethered helium-filled balloon. The results of the experiments are intended to validate the two-barometer signal processing approach using a well-characterized point signal source.
In addition, we will present another mission concept VAMOS (Venus Airglow Measurement and Orbiter for Seismicity) measuring atmospheric perturbations from an orbiting platform that could provide a breakthrough in detecting seismicity on Venus and in monitoring of seismic surface wave propagation. In contrary to the in-situ balloon strategy, VAMOS will be based on remote airglow monitoring from orbit and might allow to track the propagation of the surface waves and to determine group velocities providing key constrains on crustal and upper mantle structures.
JPL in collaboration with ISAE and Caltech Campus is in a process of developing an instrument to measure seismic activity on Venus by in-situ measurements of infrasonic waves in the atmosphere. The overall objective of this research is to demonstrate the feasibility of sensitive barometers to detect infrasonic signals from seismic and explosive activity on Venus from a balloon platform. The seismic signals are known to couple about 60 times more efficiently into the atmosphere on Venus than on Earth, which might allow the detection of small regional quakes (magnitude ~3). We will report results on the first flight experiment that will focus on using the barometer instruments on a tethered helium-filled balloon. The results of the experiments are intended to validate the two-barometer signal processing approach using a well-characterized point signal source.
In addition, we will present another mission concept VAMOS (Venus Airglow Measurement and Orbiter for Seismicity) measuring atmospheric perturbations from an orbiting platform that could provide a breakthrough in detecting seismicity on Venus and in monitoring of seismic surface wave propagation. In contrary to the in-situ balloon strategy, VAMOS will be based on remote airglow monitoring from orbit and might allow to track the propagation of the surface waves and to determine group velocities providing key constrains on crustal and upper mantle structures.