Unexploded ordnance prompts hours-long closure of lava-viewing route
The discovery of an unexploded ordnance Sunday morning prompted the temporary closure of the recently established lava-viewing route along Old Saddle Road.
The ordnance was found in rock being moved away from the road, also known as the Hawaii County Traffic Hazard Mitigation Route, the U.S. Army Garrison Pohakuloa said Sunday. The Army subsequently detonated the item and the route was reopened about 4 p.m.
The Army reminded the public that users of the 4.5-mile lava-viewing route must stay on the road and not wander off into the Army training areas. The route utilizes the Old Saddle Road across from the Gilbert Kahele State Recreation Area to a point just west of Pu‘u Huluhulu near the Maunakea Access Road.
“Enjoy your volcano viewing and please abide by all guidelines – park in the designated area, stay on the road, and do not walk on the lava rocks. This is so our community can continue to enjoy this route in a safe and efficient manner. Mahalo for your kokua,” public affairs officer Amy Phillips wrote in an emailed update.
The Hawaiian Volcano Observatory reported Sunday afternoon that Mauna Loa’s eruption was focused to a single vent, fissure 3, at an elevation of about 11,500 feet along the Northeast Rift Zone. The vent was feeding lava fountains up to 100 feet over the past day, scientists reported.
Lava from the fissure on Sunday continued to flow northward toward the Daniel K. Inouye Highway (Saddle Road). As of noon Sunday, the flow front was located about 2.25 miles from the major thoroughfare. The lava was advancing at a rate of about 40 feet per hour. The rate of the lava’s advance has slowed significantly as of late because the flow is moving over flatter ground. That’s despite no apparent decrease in the supply of lava.
“Advance rates may be highly variable over the coming days and weeks. On the flat ground between Mauna Loa and Mauna Kea, lava flows advance more slowly, spread out, and inflate. Individual lobes may advance quickly, and then stall. Additional breakouts may occur if lava channels get blocked upslope. There are many variables at play and both the direction and timing of flow advances are expected to change over periods of hours to days, making it difficult to estimate when or if the flow will impact Daniel K. Inouye Highway,” the observatory wrote in its Sunday afternoon update.
Tremor (a signal associated with subsurface fluid movement) continued Sunday beneath the active fissure. The observatory stated the tremor indicates that magma is still being supplied to the fissure, and activity is likely to continue until the tremor ceases.
There was no active lava within Moku’aweoweo caldera nor the Southwest Rift Zone as of Sunday afternoon.
Also Sunday, officials lowered the aviation color code for Mauna Loa from red (warning) to orange (watch) noting that while the eruption from fissure 3 continues, the threat to aviation of significant volcanic ash emission into the atmosphere has passed.
A temporary flight restriction issued by the FAA extending from the surface to 1,500 feet above ground level in the eruption area remains in effect.
The ground-based volcano alert level remains at warning, reflecting the ongoing hazards of the fissure 3 lava flow, the observatory said.
Meanwhile, sulfur dioxide emission rates remain elevated, scientists said. As of Dec. 1, the rate was about 180,000 tonnes per day. The volcanic gas is being carried at high altitudes toward the west, generating vog (volcanic air pollution) in areas downwind.
