Even with decades of experience studying volcanoes, Christina (Tina) Neal had never seen anything quite like last year’s massive Kilauea eruption.

“I’ve never been through anything like last summer,” said Neal, the scientist-in- charge at the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO).

“It was the protracted nature, the length of the activity, the sustained crisis response, and of course the impact on the people on the ground … having lava erupt within a residential neighborhood and having the potential for lava flows to go through other neighborhoods,” Neal said.

Neal, a geologist, developed a love for science as a young girl following the Gemini and Apollo space missions. She worked at HVO from 1983 to 1989, then spent nearly 25 years at the Alaska Volcano Observatory before returning in 2015 to lead HVO. For Neal and her team, last year’s event was a challenge like no other.

The violent eruption, which began May 3, 2018, after the collapse of the Pu‘u ‘O‘o crater on April 30, lasted for months and covered more than 6,000 acres of land in Lower Puna. More than 700 homes in the Leilani Estates and Kapoho areas were destroyed. Thousands of people had to evacuate, including Neal — she had “a couple of hours” to gather up what she could from her rented house in Hawaii Volcanoes National Park.

“There’s that moment of, how do I choose?” she said. “What do I take? It was a little bit surreal. Of course, it’s a lesson I’ve been preaching for years and years to always be ready to go, and I think I saw that myself.”

Also displaced was HVO, which had to abandon its badly damaged headquarters on the rim of Kilauea’s summit caldera after more than a century of presence within the park. Earlier this month Congress approved about $70 million in funding to build a new HVO headquarters as well as retrofit temporary facilities, now set up at the Hilo Ironworks Building and a warehouse in Keaau. Preliminary planning for the new facility is underway, weighing factors such as proximity to HVO’s partners and natural hazards.

Still, leaving the park was hard for the HVO staff.

“It was a blow,” Neal said. “We miss being up there.”

Question: What is the current outlook for activity at Kilauea and Mauna Loa?

Answer: It is impossible to say with certainty … but for the moment, based on 24/7 monitoring data and a review of past activity, our volcanoes are fairly quiet. The most likely outlook for Kilauea is months to years of continuing quiet, then a return of lava to the summit area, perhaps return of a lava lake, and then some years later another outbreak on one of the rift zones. But this is by no means a certainty, and that is why we continue to monitor the volcano closely and intensely.

Mauna Loa Volcano is showing signs, again, of magma accumulation in the shallow magmatic system, but at rates that are not yet alarming. We had a period of similar behavior from about 2014 to 2017-18 and no eruption occurred, so this may be another slight increase in unrest that quiets down again. There is some evidence that when Kilauea is quiet, the possibility of an eruption at Mauna Loa increases, so we have to keep that in mind. It has been 35 years since Mauna Loa erupted, and over the past several hundred years, it has averaged an eruption every seven years or so.

Despite the apparent quiet, we have been in active eruption at Kilauea or Mauna Loa during 72 of the last 100 calendar years. That isn’t a specific predictive statement, but it should underscore the most important thing residents, visitors and officials should remember: We live on active volcanoes and need to be ready for eruptions at all times. With monitoring, we should be able to give warning of weeks to days, but as last May’s lower East Rift Zone outbreak demonstrated, even a few days of warning is a very short time to prepare.

Q: How has the technology of studying volcanic activity evolved?

A: There have been so many advances, but a few that come to mind are: 1. new space-based imaging systems such as satellite radar. By comparing successive radar images, we can detect extremely small ground elevation changes that reflect accumulation or migration of shallow magma or the motion of parts of the volcano; 2. GPS technology, which also allows essentially near real-time tracking of precise positions of the ground surface, so we can see quickly deformation that may indicate hazardous changes or an imminent eruption; 3. miniaturized high-resolution visual and thermal cameras; 4. UAS (unmanned aerial systems) that can carry small sensors and cameras to sample and measure gas, and basically go where it is unsafe for people to go; 5. new laboratory analytical instrumentation that allows geochemists to probe ever smaller crystals and trapped gas bubbles in lava samples to understand what happens below the ground before and during eruptions; 6. geographic information systems and new computer- based models that can replicate how lava flows move across the ground, helping us to forecast the most likely path of lava once it is erupted.

Q: Given technological advances, does the new HVO facility need to be in or close to Hawaii Volcanoes National Park?

A: Technology does allow us to do a great deal remotely, and that is a great asset. During last year’s eruption, colleagues on the mainland were watching monitoring data during the night from Washington, California, Alaska, so that HVO staff could sleep. However, there is still much we do that requires us to visit our volcanoes on a near-daily basis, depending greatly on what is happening at the volcano. Examples include installing and maintaining ground-based monitoring equipment, making direct observations of activity as we did at the Kilauea summit during the years of the lava lake, conducting field studies of deposits, developing and testing new equipment. All of these activities require HVO scientists, technicians and collaborating scientists from around the world to spend time on the volcano, including inside the National Park.

Another important point we must address is, where are we best situated to support future crisis response? The National Park and the summit of Kilauea (or Mauna Loa) are the most likely locations for the next eruption crisis: We absolutely want HVO staff to be on site without delay.

Finally, Kilauea and Mauna Loa volcanoes are world-renowned laboratories for volcano research by scientists from all over the planet, including those from HVO. To participate and engage in this work, we need to think about the best facility or facilities to support ongoing research.

Q: Did the 2018 eruption advance our knowledge of how volcanic eruptions work?

A: Although other rift zone eruptions and caldera collapse events have been witnessed and studied in recent history, this is one of the most well-documented. Many, many M.S. (master’s degree in science) and Ph.D. theses will be written! So far, just a very few insights and hypotheses in play:

>> Kilauea Volcano is capable of long-duration, high-discharge eruptions, and this may be more characteristic of low-elevation eruptions along the rift zones due to the significant pressure difference between the summit and lower-rift zone vents. Prior to 2018, rates of lava effusion exceeding 100 cubic meters per second were seen only for brief periods of time during other recent historical eruptions. The 1840 eruption of the lower East Rift Zone may be the closest analog.

>> During vigorous eruptions, the Kilauea summit magma reservoir system can be extremely well-connected to distant vents along its rift zones; we know this in part because following individual caldera collapse events last summer, increases in lava output at Fissure 8, 25 miles away, were detected within minutes and peaked between two to four hours after the collapse. This behavior may apply to other basaltic shield volcanoes and could help with forecasting lava flow hazards over short periods of time during future events.

>> Explosions of ash and blocks can occur from Kilauea’s summit caldera even without the interaction of groundwater with hot rocks within the volcano. We have so far found no evidence of that (interaction) in 2018, so must revisit our ideas about the role of water versus magmatic gas in producing summit explosions.

Q: What was it like working at HVO during the eruption?

A: I was so impressed with everybody on the staff, all the visiting scientists who came in from other observatories, that they just did what we had to do and worked around the clock; people rarely took a break. There were times when the uncertainty of what was happening and the concern that emergency managers obviously had for these various scenarios were stressful to deal with, but we just tried to stay focused and gather the critical information and give people the range of possibilities.