Like a moving jigsaw puzzle, the lava lake at the summit of Kilauea Volcano continues to glow and gurgle, while the Puu Oo vent is feeding a flow largely hidden from public view.

The lava lake level rose steadily Tuesday and on Wednesday was about 160 feet below the floor of Halemaumau Crater, the U.S. Geological Survey reported.

Spatter cones on the floor of Puu Oo Crater are glowing persistently, with the northeast spatter cone hosting an active lava pond, according to the agency’s Hawaiian Volcano Observatory. A satellite image on Sunday showed the Kahaualea 2 lava flow burning through forest 3 to 4.2 miles northeast of Puu Oo.

Meanwhile, 15 earthquakes were strong enough to be located beneath Kilauea Volcano on Tuesday and Wednesday, including two near Kaoiki Pali, five around the summit, one on the east rift zone, one on the southwest rift zone and six on the south flank.

Kilauea has been erupting continuously through various incarnations since Jan. 3, 1983.

Most of the flow field is within the closed-access Kahaualea Natural Area Reserve or the Wao Kele o Puna Forest Reserve and can be viewed only from the air.

From a public safety standpoint, that’s a plus, the observatory says.

Potentially lethal concentrations of sulfur dioxide gas may be present within 1,100 yards downwind of vent areas, the observatory warns on its website. Active lava flows within forests also can produce methane blasts that propel rocks and other debris into the air.