Chilean engineer Christian Hepp of Chile's National Agriculture Institute takes samples of volcanic ash in Futaleufu. Experts believe the volcano could continue belching out vast clouds of ash for months, but distraught people evacuated from nearby towns say they yearn to return as soon as possible. Ash that has reached as far as Argentina continued to spew for a seventh day on Thursday, disrupting flights to the southern Patagonia region with no sign of let-up.