[RadioAstronomer]

I'm not much on geology, so, wouldn't an eruption of this magnitude, with no other eruptions across the surface indicate an impact cause?

I also am not a planetary geologist, however, I believe that the internal elasticity and the tidal forces could cause such an erruption.

I will defer to the geologists. :-)

[Aracelis]

I believe that the internal elasticity and the tidal forces could cause such an erruption.

Indeed they can...and do. I do not have the image readily accessible, but there was another famous photo (a side view) of an eruption in progress on Io.

No doubt PH could come up with the photo :-)