JPL Planetary Photojournal
http://www.lpi.usra.edu/publications/slidesets/venus.html
http://mountainscenes.com/Images/South%20Cascades%20Images/Mt.%20St.%20Helens%20%20SOU.148.06.H.STHELENS.htm
Comparative planetology: Volcanos.
Venus, Earth, Mars all have volcanos:
JPL Planetary Photojournal
http://www.lpi.usra.edu/publications/slidesets/venus.html
http://mountainscenes.com/Images/South%20Cascades%20Images/Mt.%20St.%20Helens%20%20SOU.148.06.H.STHELENS.htm
Earth's volcanos are currently active. Venus' volcanos are
probably not currently active. Mars' volcanos
are not currently active.
How do we do know how active the volcanos are?