Volcano already has erupted twice this week . It has spewed ash to a depth of 60 centimeters in some places , Chilean officials say . Authorities issue an alert for two towns , and there 's a 12-mile exclusion zone .
Volcano already has erupted twice this week . It has spewed ash to a depth of about 23½ inches in some places , Chilean officials say . Authorities issue an alert for two towns , and there 's a 12-mile exclusion zone .