Imagine, it is 50 years in the future and there are numerous seismic monitoring stations on Mars. A marsquake (earthquake, but on Mars) originates at Olympus Mons, the blue triangle on the map. Both S and P waves from the marsquake are detected everywhere there is a green on the map. But neither S nor P waves are detected where there are red x signs on the map. What does this tell the future scientists about Mars