John Lyons Email & Phone Number

Anchorage, Alaska Area

Alaska Volcano Observatory

Quito, Ecuador

I am currently completing a microseismicity study of a potential geothermal energy field in the Chacana caldera. Once this project is completed, I will be installing seismic stations in the nascent national seismic network in Ecuador, as well as pursing geophysical research into the active volcanoes in Ecuador and beyond.

Tokyo, Japan

Dr. Ichihara and I investigated the transmission of harmonic tremor generated in the volcanic conduit into the atmosphere. We designed a built a model volcanic conduit in the laboratory, and ran experiments. The experimental apparatus generated a harmonic signal in a closed conduit, which was passed through a tank of viscoelastic gel (our magma analogue). The harmonic signals were recorded in the conduit and the atmosphere with pressure sensors and the experimental runs were captured on high speed camera. The results have provided valuable insights into how infrasonic and seismic tremor are linked in natural volcanic systems, and why sometimes we observe only seismic tremor, while other times we record both seismic and infrasonic tremor. We are currently working on a paper describing our results and linking the experimental results to observations at Shinmoe-dake volcano, Japan and Fuego volcano, Guatemala.

My PhD work focused on developing a more comprehensive understanding of explosive degassing at Fuego volcano, Guatemala through observations and analysis of geophysical data collected in 2005 – 2009. A pattern of eruptive activity was observed during 2005 – 2007 and quantified with seismic and infrasound, satellite thermal and gas measurements, and lava flow lengths. Eruptive styles are related to variable magma flux and accumulation of gas. Explosive degassing was recorded on broadband seismic and infrasound sensors in 2008 and 2009. Explosion energy partitioning between the ground and the atmosphere shows an increase in acoustic energy from 2008 to 2009, indicating a shift toward increased gas pressure in the conduit. Very-long-period (VLP) seismic signals are associated with the strongest explosions recorded in 2009 and waveform modeling in the 10 – 30 s band produces a best-fit source location 300 m west and 300 m below the summit crater. The calculated moment tensor indicates a volumetric source, which is modeled as a dike feeding a SW-dipping (35°) sill. The sill is the dominant component and its projection to the surface nearly intersects the summit crater. The deformation history of the sill is interpreted as: 1) an initial inflation due to pressurization, followed by 2) a rapid deflation as overpressure is explosively release, and finally 3) a reinflation as fresh magma flows into the sill and degasses. Tilt signals are derived from the horizontal components of the seismometer and show repetitive inflation– deflation cycles with a 25 minute period coincident with strong explosions. These cycles represent the pressurization of the shallow conduit and explosive venting of overpressure that develops beneath a partially crystallized plug of magma. In summary, Fuego is becoming more gas charged and its summit centered vent is shifting to the west - serious hazard consequences are likely.

In addition to conducting research for my dissertation, I am also recruiting students for MTU's Peace Corps Masters International Program (http://peacecorps.mtu.edu/).

Doctor Of Philosophy (Phd), Volcano Geophysics

M.S., Geolgoy

B.S., Geology

High School