Taking its name from the 50-foot effigy burned every year by a hysterical mob during the Fiestas De Santa Fe in Santa Fe, New Mexico, Zozobra is the brainchild of Cave In/Old Man Gloom bassist Caleb Scofield. “Harmonic Tremors” deftly traverses the far-flung fields of transcendental space rock and explosive dirge metal with alternately snarling and oscillating riffery, crippling bass quakes, and apocalyptic proclamations hurled end over end toward the cosmic unconsciousness.