Volcano observatory welcomes radar expert
A new volcano watcher has joined the staff at the Hawaiian Volcano Observatory (HVO). Dr. Michael Poland, fresh from the Cascades Volcano Observatory (CVO), returns to Hawaii and brings with him expertise in new and exciting ways to monitor volcanic activity… and a reputation for baking excellent cookies.
Poland 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. The HVO monitoring staff say it was tough to tear him away from the ongoing eruption, but that they were ultimately able to lured him out to the islands.
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 Hawaiian volcanoes.
As discussed in “Volcano Watch” 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 the observatory’s GPS network on Mauna Loa Volcano. Spearheaded by the Pacific GPS Facility at the University of Hawai`i 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.
Poland’s addition to the staff will greatly expand the HVO’s capability to monitor the volcanoes of Hawai`i (and possibly its staffmembers’ waistlines, if he keeps bringing in his famous cookies).
Activity Update
Eruptive activity at Pu`u `O`o continues. Glow is visible from several vents within the crater on clear nights. The Pu`u `O`o crater web-camera is back online at the HVO 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 Lae`apuki 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 Lae`apuki. This is the closest activity to the end of Chain of Craters Road, in Hawai`i 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 Hawai`i Island. A magnitude-1.7 quake occurred 14 km (9 miles) southeast of Na`alehu 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 Kilauea 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 Pu`u `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.
This article was written by scientists at the U.S. Geological Survey’s Hawaii Volcano Observatory and is republished by HawaiiNews.com with permission.
