Alert level raised for Hawaii volcano due to rumbles, quakes

An eruption of Mauna Loa, the world's largest active volcano, did not appear to be imminent.The increased seismic activity indicated a shift in the "shallow magma storage system" under the mountain, the Hawaii Volcano Observatory (HVO) said in an advisory.Yellow is the second level on the Hawaii Volcano Observatory's color-coded alert chart, above green, which is used to indicate "background, non-eruptive state." Orange signifies a volcano exhibiting "heightened or escalating unrest with increas