The PACIFIC project (Passive seismic techniques for environmentally friendly and cost efficient mineral exploration) will develop a new, low-cost and environmentally friendly tool for exploring for mineral deposits beneath the surface. The approach will build on the "traditional" passive seismic method, which is capable of providing useful broad-brush background information about the geological and structural setting of mineralised regions, but lacks the resolution needed for reliable identification of ore bodies. Two radically new developments are planned; reflection passive seismics, which is appropriate from greenfields exploration, and the multi-array method, which will typically be deployed during drilling or in brownfields exploration. Both techniques have major advantages over current techniques, namely relatively low cost and minor impact on the environment.