Map of flows from Pu`u `O`o: 9 April 2004

Map shows lava flows erupted during 1983-present activity of Pu`u `O`o and Kupaianaha.

Shades of red denote Mother's Day flow, which began erupting on May 12, 2002 and continues to the present. Darkest shade indicates lava flows erupted in November 2003-9 April 2004. Yellow stars indicate centers of recently active rootless shields built along lava tube in Mother's Day flow. As of April 9, no shields were active except for Okita shield, uppermost in the rootless shield complex. As of April 9, most activity was located south of the rootless shield complex and was fed by breakouts from the Mother's Day tube, which now carries lava beneath the shields to the breakout points.

Through September and into early October 2003, lava was moving along the east and west sides of the Mother's Day flow. The east-side lava (known as the August 9 breakout) came from the August 9 rootless shield, itself fed by the main Mother's Day tube from Pu`u `O`o. The west side lava, known as the Kohola arm of the Mother's Day flow, branched off the tube system below the rootless shield.

In early October 2003, the August 9 breakout stopped moving, the Kohola died back to a trickle, and the one labeled rootless shield gained prominence. By October 16, however, the shield had partly collapsed, leaving several drained perched ponds behind. Upstream from the shield, many hornitos and small flows formed over the Mother's Day tube. Soon thereafter, other rootless shields began to form over the Mother's Day, August 9, and Kohola tubes.

New vents opened at the southern base of Pu`u `O`o on January 19 and fed Martin Luther King (MLK) flows, which remained active until March 5. Several small vents formed during this time. On March 20, Prince Kuhio Kalaniana`ole (PKK) flow originated from two vents, main one about 250 m south of base of Pu`u `O`o. That flow was sluggishly active when map was made on April 9.

Vents in West Gap Pit became active in early October, were quiet for 3 weeks, and then resumed intermittent activity that continued well into December. Other vents were also sporadically active in Puka Nui (near West Gap Pit) and in the crater of Pu`u `O`o.