[PPS05-P10] Possible tidal resonance of the Martian paleo-ocean
Keywords:Mars, Ocean, Tide, Resonance
We assumed that the paleo-ocean have a polar basin of a constant depth (h) with no bottom friction.The eigen-angular velocity of the ocean (σ) is determined by the basin radius(θ in colatitude), the angular velocity of the Martian rotation (Ω), and the gravity acceleration of the Mars. We calculated the eigen-angular velocity of S1 and S2 tides for the representative values of the parameters, applying the approximation by Goldsbrough (1915). Calculations for h = 400 m and θ = 45 - 60 degrees show that S2 tide has the eigen-angular velocity of σ/2Ω ~ 1 for Ω = Ωp - 2Ωp (Ωp , the present angular velocity of the Martian rotation). This implies that the paleo-ocean might be under the tidal resonance of S2 for a long time if the rotation rate of the early Mars was larger than at the present. For S1 tide, the eigen-angular velocity is much smaller than at the present. Thus S2 tidal resonance may possibly be taken into account for the study on the Martian rotation in the early time, although the tidal torque due to the bottom friction should be examined.