# Volcano Watch - Radar Specialist joins Hawaiʻian Volcano Observatory Staff

Release Date:

We welcome to our staff at the U.S. Geological Survey's Hawaiʻian Volcano Observatory our newest volcano watcher, Dr. Michael Poland.

Mike comes to HVO from the Cascades Volcano Observatory (CVO) with expertise in new and exciting ways to monitor volcanic activity and a reputation for baking excellent cookies.

He received his Ph.D. in geology from Arizona State University in Phoenix and went on to a postdoctoral position at CVO. He had been working at CVO for three years when Mount St Helens erupted last September. It was tough to tear him away from the ongoing eruption, but we're thrilled to have lured him out to Hawaii to join the monitoring staff of HVO.

In addition to assisting with our ongoing monitoring and research efforts, he will be adding the exciting new technology of satellite-borne radar to the set of tools that we use to monitor and learn about Hawaiʻian volcanoes.

As we discussed in this column a few weeks ago, the technique of radar interferometry (also known as InSAR) detects changes in the shape of the ground surface by differencing pairs of radar images taken from a satellite. This technology has many and varied applications; for example, it can be used to monitor stability of landslide-prone areas or widespread subsidence of urban areas from pumping of ground water.

On an active volcano, the pattern of ground motion can be interpreted to locate and quantify sub-surface accumulation of magma. The methods of measuring the usually small surface motions associated with magma movement in a volcano are continuously changing and improving, and InSAR is the newest in the evolution of this science.

Mike has had a lot of experience using InSAR on active volcanoes. While at CVO, he worked with radar satellite imagery from many Cascades range volcanoes in Washington and Oregon, Long Valley in California, Yellowstone in Wyoming, and even volcanoes as far away as Africa, such as the recently destructive Nyiragongo volcano.

He didn't just work at his computer in the office, however. Rather, he was actively involved in field campaigns to monitor volcanoes on the ground, using well-established techniques like leveling and GPS. He also measured gravity signals to estimate sub-surface mass changes at deforming volcanoes, such as would occur when magma intrudes into an area.

When Mount St. Helens started erupting last fall, Mike was integrally involved in the crisis response. His main role was measuring and interpreting the changing shape of the volcano's surface in order to better evaluate the eruptive hazard.

In the midst of all this productive activity, he taught an evening geology course at Clarke College in Vancouver, exercising his gift for teaching. He also found time to indulge in his passions for inline hockey and playing bass in a jazz band.

Mike arrived at HVO in time to help with the most recent expansion of our GPS network on Mauna Loa Volcano. Spearheaded by the Pacific GPS Facility at the University of Hawaii at Manoa, the project involved installing 11 new continuously recording GPS instruments on Mauna Loa, almost doubling the number of GPS stations on the volcano. Most of the new sites are located along the northeast and southwest rift zones - the linear ridges dotted with eruptive vents that extend from the summit caldera. The rift zones are usually the preferred pathways from magma reservoirs beneath the summit area to eruptive vents at the surface. The current GPS network is now even better suited to monitor potential magma intrusions into the rift zones as well as the current, ongoing inflation.

Mike's addition to the staff will greatly expand our capability to monitor the volcanoes of Hawaii (and possibly our waistlines if he keeps bringing in those good cookies!). Welcome to HVO, Mike!

### Volcano Activity Update

Eruptive activity at Puu Oo continues. Glow is visible from several vents within the crater on clear nights. The Puu Oo crater web-camera is back online at our website.

The PKK lava tube continues to produce intermittent surface flows from the top of Pulama pali almost to the ocean. No ocean entries have been active since April 13. Since the 18th, lava has been cascading over the sea cliff at East Laeapuki onto the delta below, but hadn't reached the water as of April 21. Surface flows are active on the coastal plain inland of East Laeapuki. This is the closest activity to the end of Chain of Craters Road, in Hawaii Volcanoes National Park, and is located about 4.7 km (3 miles) from the ranger shed. Expect a 2-hour walk each way and bring lots of water. Stay well back from the sea cliff, regardless of whether there is an active ocean entry or not. Heed the National Park warning signs.

During the week ending April 21, 3 earthquakes were felt on Hawaii Island. A magnitude-1.7 quake occurred 14 km (9 miles) southeast of Naalehu at a depth of 40 km (25 miles) at 10:54 a.m. on Saturday, April 16; amazingly, it was felt in Kona. A magnitude-3.2 quake occurred 12 km (8 miles) west of Kīlauea summit at a depth of 3 km (2.0 miles) at 2:18 p.m. on Tuesday, April 19; it was felt at HVO and Volcano Village. A magnitude-3.7 earthquake occurred 4 km southeast of Puu O`o at a depth of 9 km (6 miles) at 6:28 a.m. on Thursday, April 21; it was felt locally in Puna and as far away as Hilo and Honomu.

Mauna Loa is not erupting. During the week ending April 20, 7 earthquakes were recorded beneath the summit area. Two were deep and long-period in nature. Inflation also continues beneath the summit.