There is evidence that volcanoes sometimes erupt under ice, as they do on Earth at times.
 What seems to happen it that much ice melts, the water escapes, and then the surface cracks and collapses.
 These exhibit concentric fractures and large pieces of ground that seemed to have been pulled apart.
 Sites like this may have recently had held liquid water, hence they may be fruitful places to search for evidence of life.
There is evidence that volcanoes sometimes erupt under ice, as they do on Earth at times.  What seems to happen it that much ice melts, the water escapes, and then the surface cracks and collapses.  These exhibit concentric fractures and large pieces of ground that seemed to have been pulled apart.  Sites like this may have recently had held liquid water, hence they may be fruitful places to search for evidence of life.
Ismenius Lacus quadrangle