We report on the discovery of a new Galactic supershell , GSH 006 - 15+7 , from the Galactic All Sky Survey data .
Observed and derived properties are presented and we find that GSH 006 - 15+7 is one of the nearest physically large supershells known , with dimensions of \sim 780 \times 520 pc at a distance of \sim 1.5 kpc .
The shell wall appears in H i emission at b \lesssim - 6.5 ^ { \circ } and in H i self-absorption ( H i SA ) at b \gtrsim - 6.5 ^ { \circ } .
We use this feature along with H i SA diagnostics to estimate an optical depth of \tau~ { } \sim 3 , a spin temperature of \sim 40 K and a swept-up mass of M \sim 3 \times 10 ^ { 6 } ~ { } \mathrm { M } _ { \odot } .
We also investigate the origin of GSH 006 - 15+7 , assessing the energy contribution of candidate powering sources and finding evidence in favour of a formation energy of \sim 10 ^ { 52 } ergs .
We find that this structure provides evidence for the transfer of mass and energy from the Galactic disk into the halo .