Inflation resumed at the summit of Kilauea overnight and the lava lake rose close to the rim of its crater, but did not overflow Friday morning, Hawaiian Volcano Observatory scientists said.

On Thursday, the lake level was about one yard below the crater floor and four yards below the new perched rim above the crater floor, created by lava buildup from this week’s overflow.

Scientists said inflation at the summit resumed at about 8 p.m. Thursday, after the summit experienced a period of deflation Thursday morning.

Geologists said the lake level rose slightly and was “very close” to the lava lake rim Friday morning.

The lava lake level generally rises as the summit inflates and falls during periods of deflation. 

The rise in lava levels that started last week is the first time a lake of lava has been visible from the national park visitor overlook since 1974, scientists said. 

The sight of the pulsing lava has attracted crowds of visitors, who sometimes have to wait for a half-hour to get a parking space close to the Jaggar Museum overlook or walk a mile to the crater from other parking areas.

The lava lake and its crater formed on March 19, 2008, but until this week, only the gas plume and nighttime glow from the vent had been visible.

In their weekly Volcano Watch update, Hawaiian Volcano Observatory scientists noted that this is the16th lava lake in Halemaumau Crater since the explosions of May 1924, which doubled the crater’s width and increased its depth to about 450 yards.

The current lava lake has already outlasted previous Halemaumau lava lakes since 1924.

Geologists said the lava lake could continue to overflow its rim intermittently.

During similar lava lake activity at Halemaumau in the 1800s and early 1900s, lava lakes frequently produced overflows, scientists said in a volcano update Wednesday. 

Observatory scientists said Wednesday the current activity is likely due to an increase in magma supply to Kilauea. Higher volumes of magma moving through the summit and upper East Rift Zone could be causing increased earthquake activity and inflation.

“As long as magma supply is elevated, we expect continued high lava lake levels accompanied by additional overflows,” observatory scientists said. “We expect continued rockfalls, intermittent explosions and ash fall, and continued high levels of gas release.”

It’s also possible that a surge of lava will reach the Puu Oo vent, increasing lava flows there. Or a new vent could form at the surface, most likely along a portion of the East Rift Zone between Pauahi Crater and Puu Oo.

“Other outbreaks in the summit area or along either rift zone on Kilauea cannot be ruled out. If a new outbreak or surge in lava to Puu Oo occurs, we will expect a drop in the summit lava lake,” scientists said.