# Volcano Watch - New Year - New Volcano Watcher

Release Date:

At this new calendar year, we welcome to our staff at the U S Geological Survey's Hawaiian Volcano Observatory our newest volcano watcher, Dr. Peter Cervelli.

Peter Cervelli inspects a permanent GPS station on the flank of Mauna Loa. Kīlauea Caldera is in the background.

(Public domain.)

Peter comes to HVO from California, where he received his Ph.D. in Geophysics at Stanford University. He joins our staff to help lead our geodetic monitoring and develop models of the processes occurring within the volcanoes that give rise to change that we measure at the Earth's surface.

Perhaps more formally, this activity is termed "volcano geodesy," but it is commonly referred to as ground deformation. As magma moves within the volcanoes and as the Earth responds to that and other sources of deformation, such as earthquakes, points on the Earth's surface will move. The task at hand is to try to measure such changes at or near the surface and to associate these changes with mathematical models of the causative process.

At Stanford, Peter's Ph.D. research focused on deformation studies of Kilauea Volcano using many types of geodetic measurements. With his Stanford research colleagues and our deformation team at HVO, Peter helped build up a rather comprehensive deformation monitoring network for Kilauea, based on a set of Global Positioning System (GPS) stations in more-or-less continuous operation since 1996. In that sense, he is not really a new volcano watcher, but his addition to the staff will truly enhance our deformation studies.

The continuous GPS monitor differs from earlier campaign-style approaches to volcano deformation. Rather than mobilizing a campaign to measure changes following significant events such as eruptions or large earthquakes, the continuous GPS provides a record of the ongoing changes or evolution of the surface deformations. This offers an unprecedented view of volcanic process.

With these enriched sources of information come the technical and scientific challenges of handling large amounts of data and developing models and interpretations that will account for the measurements. At Stanford, Peter worked on techniques to optimize the search for a mathematical model of the volcano which best fits the deformation data. He also began to incorporate more realistic physical properties into these models. No doubt these capabilities will be added here and our understanding of the volcano further refined.

A very interesting and important aspect of Kilauea's deformation is the relatively steady and ongoing southeastward movement of Kilauea's south flank. This has been discussed in earlier "Volcano Watch" articles. It is clear that, while we experience many south flank earthquakes, the majority of the current flank movement is aseismic, that is, not produced by earthquakes.

Earthquakes, including the devastating South Hawaii earthquakes in 1868, 1975, and future large earthquakes that we can expect to occur, are very significant and rapid deformation events. It is now evident that, between such earthquakes, there are slower flank deformations also taking place. With the quality of information afforded by the continuous GPS, it is also possible to begin to explore the sources of these deformations.

An exciting recent finding derived from the GPS data by Peter and co-workers is that previously unrecognized sources of deformation within Kilauea might be quite active. Earlier studies of the volcano have shaped our views of where faults and magma bodies might lie. The GPS data must be studied in conjunction with other data and observations to add detail and constraints where possible. For now, the continuous GPS data suggest that the aseismic deformation sources may be shallower than accounted for in the traditional and possibly prevalent views.

Before becoming a geophysicist, Peter received both a Bachelor's and a Master's degree in philosophy. We don't know exactly how these will factor into HVO, but they will. Welcome, Peter Cervelli, to HVO.

### Volcano Activity Update

Eruptive activity of Kilauea Volcano continued unabated at the Puu Oo vent during the past week. Lava moves away from the vent toward the ocean in a network of tubes and descends Pulama pali in several separate tubes. Breakouts of the main tube system supply active flows above the pali. Many surface flows, mainly from breakouts of the Kamoamoa tube, are observed on the pali and in the coastal flats. Lava enters the ocean at Kamoamoa and the area east of Kupapa`u.

The public is reminded that the benches of the ocean entries are very hazardous, with possible collapses of the unstable new land. The steam clouds are extremely hot, highly acidic, and laced with glass particles. Swimming at the black sand beaches of the benches can be a blistering or even deadly venture.

There were no earthquakes reported felt during the week ending on January 10.