Yes, if the bottom of the iceberg-hole is below sea level. If the mantle at the bottom of this new bore-hole is under pressure and liquid, then it will go up t

Yes, if the bottom of the iceberg-hole is below sea level. If the mantle at the bottom of this new bore-hole is under pressure and liquid, then it will go up the bore hole until the pressure above it equals the pressure below. If the bottom of the bore-hole hits a part of a liquid mantle with a lot of pressure, then we might get a volcano. Hence, Moria.