  The search for extrasolar rocky planets has already found the first
transiting rocky super-Earth, Corot 7b, with a surface temperature that allows
for magma oceans. Here we ask if we could distinguish rocky planets with recent
major volcanism by remote observation. We develop a model for volcanic
eruptions on an Earth-like exoplanet based on the present day Earth, derive the
observable features in emergent and transmission spectra for multiple scenarios
of gas distribution and cloudcover. We calculate the observation time needed to
detect explosive volcanism on exoplanets in primary as well as secondary
eclipse and discuss the likelihood of observing volcanism on transiting Earth
to super-Earth sized exoplanets. We find that sulfur dioxide from large
explosive eruptions does present a spectral signal that is remotely detectable
especially for secondary eclipse measurements around the closest stars using
ground based telescopes, and report the frequency and magnitude of the expected
signatures. Transit probability of planet in the habitable zone decreases with
distance to the host star, making small, close by host stars the best targets
