Kaʻū News Briefs, Friday, September 27, 2019

     Since Sept. 20, HVO scientists have documented what appears to be an influx of water to the pond, with a less cloudy green showing where water is coming in. Circulation of the water can be observed in recent video and time lapse photo compilations. There are at least three places where water appears to coming into the pond.

     Learn more and see updates at volcanoes.usgs.gov/volcanoes/kilauea/multimedia_chronology.html. See time lapse video and a gif of the expansion.

     Even though Kīlauea Volcano's lower East Rift Zone eruption has been over for about a year, steam continues to appear in new places or reappear in old places, and vegetation continues to die because of lingering heat and steam in areas of the 2018 fissures.  

On May 10, 2018, Highway 130 was newly cracked, with steam coming up from the east side of the road due to the  dike – tabular body of magma – that intruded Kīlauea's lower East Rift Zone. The two orange and white road  markers are on slightly uplifted areas of the highway, which are about 100 m (330 ft) apart. Half way between the  uplifted areas, the road is sagging, a result of the magma intrusion beneath the highway. USGS photo by C. Parcheta

     Some residents are concerned about continuing – or potentially new – volcanic activity in the lower East Rift Zone because they are feeling, seeing, and smelling the heat, steam, and odors that remain in the area. In fact, the most common questions for USGS HVO geologists, who work in the LERZ, are, "What is that smell?," "How much gas is still coming out?," and "How deep is the magma below me?"

     HVO's July 18, 2019, Volcano Watcharticle, volcanoes.usgs.gov/observatories/hvo/hvo_volcano_watch.html?vwid=1421, addressed the lingering heat and gas aspect of the story. This week we examine how deep the dike – the intrusive body of magma that fed the 2018 LERZ eruption – might be.

     On May 5 to 7, 2018, when fissures 7 through 12 were opening farther to the west – up rift – of Leilani Estates, the pavement on Highway 130 cracked and began to sag. As it did, the area was immediately engulfed in steam and sulfur dioxide gas, so much so that one could not see across the road.

     A dike is an elongate tabular body – envision a knife blade – that runs parallel to the rift zone. It is fed by magma from deeper within the rift zone core. 

Steam rises from the road in Leilani Estates during the 2018 eruption. HVO photo

     As magma rises in a dike, it pushes the surrounding rock apart to make room for magma to reach the surface. This causes the ground directly above the dike to sink, and ground on either side of the dike to lift.

     As a dike continues moving toward the surface, the sinking, or sagging, above it can progress to form a linear depression with well-defined walls – a feature that geologists call a graben. In 2018, Highway 130 experienced sagging, but a graben did not form across the road.

     As soon as Highway 130 sagged and increased heat and gas were observed, HVO field crews documented and numbered ten major cracks opening across the road. The total extension measured across these ten cracks was 22 cm (8.6 in) over two days. We were unable to continue measuring crack widths when steel plates were placed on top of them to keep the road open and allow the safe flow of traffic.

     Sagging and cracks in the road, as well as increased heat and gas output, meant that magma was rising closer to the surface under Highway 130. At the same time, new fissures were opening closer to the highway.

     Although steel plates concealed the growing cracks, HVO geologists had other ways to determine what was happening below the road. Sagging ground on Highway 130 and in neighboring properties provided valuable information about where the magma was located.

     Theoretical calculations of ground deformation around a dike have been known to volcanologists for decades. Previous modeling shows that the horizontal distance between two uplifted sections of ground above a dike is directly related to dike depth below the surface. 

     On Highway 130, the ground rose slightly in the area of cracks 3 and 8, which were about 100 m (330 ft) apart. Between those two cracks, the ground sagged. Crack 5 was in the middle of the sag, about 50 m (about 165 ft) from crack 8 to the north and crack 3 to the south.

Cracks, outlined in paint, from the 2018 eruption. HVO photo

     Using the aforementioned model, we can determine how close magma came to reaching the surface where Highway 130 cracked and sagged in 2018. Based on a 100 m (330 ft) distance between uplifts on either side of the down-dropped area, the upper edge of the dike must be only 50‒100 m (about 165‒330 ft) below the highway.

     The portion of the 2018 dike below Highway 130 did not have enough energy to reach the surface. Now that the uppermost dike is probably solidified, the 2018 magma just below the surface of the highway and neighboring properties will remain frozen in the ground as solid rock.

     Volcano Activity Updates

     Kῑlauea Volcano is not erupting and its USGS Volcano Alert level remains at NORMAL. Kīlauea deformation and seismicity showed no notable changes over the past week. Sulfur dioxide emission rates are low at the summit and below detection limits at Puʻu ʻŌʻō and the LERZ. The water pond at the bottom of Halema‘uma‘u continues to slowly expand and deepen.

      At or near the 2018 LERZ eruptive fissures, elevated ground temperatures and minor releases of gas (steam, tiny amounts of hydrogen sulfide, and carbon dioxide) persist. These are typical post-eruption conditions and are expected to be long-term.

     Hazards remain at the LERZ and summit of Kīlauea. Closures and warnings in these areas should be heeded. The 2018 lava flows are primarily on private property; please be respectful and do not enter or park on private property.

     Visit volcanoes.usgs.gov/hvofor past Volcano Watch articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake info, and more. Email questions to askHVO@usgs.gov.

REP. TULSI GABBARD NOW SUPPORTS THE IMPEACHMENT INQUIRY into Pres. Donald Trump, to investigate alleged wrongdoing in dealings with the Ukranian government. She was the sole holdout of the four U.S.congresspersons for Hawaiʻi. She told CNN earlier this week that "It's important that Donald Trump be voted out of office by the American people." She released a statement today:

     "Up to this point, I have been opposed to pursuing impeachment because it will further divide our already badly divided country.
     "However, after looking carefully at the transcript of the conversation with Ukraine's President, the whistleblower complaint, the Inspector General memo, and President Trump's comments about the issue, unfortunately, I believe that if we do not proceed with the inquiry, it will set a very dangerous precedent. Future presidents, as well as anyone in positions of power in the government, will conclude that they can abuse their position for personal gain, without fear of accountability or consequences.
     "If we allow the President to abuse his or her power, then our society will rot from top to bottom. We will turn into a banana republic, where people in positions of power – from the president all the way down to the traffic cop – will feel it's okay to abuse their power with no consequences.
     "This is not the kind of country that any of us want to see.
     "So it is unfortunate, but necessary, that I speak in support of the inquiry into the President's alleged abuse of power in relation to his interactions with Ukraine's leaders. This inquiry must be swift, thorough, and narrowly-focused. It cannot be turned into a long, protracted partisan circus that will further divide our country and undermine our democracy."
      State Sen. Kai Kahele, who is running for Gabbard's position in the U.S. House of Representatives, also said he supports the impeachment proceedings.