Lava inched slightly closer to the Daniel K. Inouye Highway on Wednesday after the main Mauna Loa flow slowed to less than 20 feet per hour.
The U.S. Geological Survey’s Hawaiian Volcano Observatory reported Wednesday afternoon that the leading edge of the lava flow was about 1.8 miles from the highway. On Tuesday, it was 1.9 miles away.
Hawaii County Civil Defense reported Tuesday that the lava was 1.5 miles from the highway, but that report was confirmed Wednesday to be an error.
HVO’s Deputy Scientist in Charge David Phillips on Wednesday said the flow may have been slowed down by a fork that developed about 2.8 miles upslope from the flow front. That fork, which broke out on the east side of the lava channel, could be pulling enough lava from the main flow to reduce its speed, Phillips theorized.
However, Phillips said it is still difficult to make any estimates about when, where or if the flow will reach the highway, or what direction it will go.
But Phillips added that the eruption is still maintaining consistent effusion rates and is still producing ‘a‘a lava, the more viscous and rough type of lava.
Four of the last eight historical eruptions from Mauna Loa’s Northeast Rift Zone averaged about 18 days in length, and all produced ‘a‘a lava.
The other four eruptions produced pahoehoe lava, the smooth and more fluid type of lava, and ranged in duration from 40 to 450 days.
Mayor Mitch Roth on Wednesday urged visitors to remain respectful while viewing the lava. He said that several people have left the Traffic Hazard Mitigation Route on Old Saddle Road to approach the lava on foot, with some even leaving marshmallows near the flow to watch them cook.
Roth reiterated that all of the land south of the mitigation route is managed by the U.S. Army’s Pohakuloa Training Area and is off-limits to civilians. Trespassing, he said, could be charged as a misdemeanor offense, and continual offenses by visitors could lead to the county closing the viewing area.
Roth said that about 17,000 vehicles have traversed the mitigation route.
Later this week, Roth said the Royal Order of Kamehameha will “prepare the way for Madame Pele,” and will clean and conduct ceremonies around the lava viewing area.
Hawaii Police Department spokeswoman Denise Laitinen said there were three parking citations issued Tuesday to vehicles parked on the highway.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.