Evaluation of the ASHE Project, Ecuador. M. Garcés 1 , D. Fee 1 , and A. Steffke 1 D. McCormack 2 and R. Servranckx 3 H. Bass 4 and C. Hetzer 4 M. Hedlin 5 and R. Matoza 5 H. Yepes 6 and P. Ramon 6 1 Infrasound Laboratory, University of Hawaii at Manoa
M. Garcés1, D. Fee1, and A. Steffke1
D. McCormack2 and R. Servranckx3
H. Bass4 and C. Hetzer4
M. Hedlin5 and R. Matoza5
H. Yepes6 and P. Ramon6
1Infrasound Laboratory, University of Hawaii at Manoa
2Geological Survey of Canada, 1 Observatory Crescent, Ottawa K1A 0Y3 Ontario, Canada
3Montréal Volcanic Ash Advisory Centre, Canadian Meteorological Centre, Meteorological Service of Canada
4University of Mississippi
5University of California, San Diego
6Instituto Geofísico, Escuela Politécnica Nacional,Quito, Ecuador
ITW, Bermuda, 2008
Bolides – low mass, hypersonic (10’s of km/s) short duration, broad band, moving source(s) distributed in space (line)
Microbaroms - high mass (moving swaths of ocean), low velocity (m/s), nearly continuous, narrow band, multiple moving sources distributed in space (areas).
Surf – medium mass, low velocity (10’s m/s), sustained over periods of days, broadband, multiple moving sources distributed over coastal areas.
Volcanoes – high mass (erupted volumes of cubic km), medium to high speeds (up to ~Mach 1), impulsive to continuous durations, narrow and broadband signals, well localized surface source (point). Stationary in space, but very nonstationary in time.
Due to substantially different physics, energy estimates for ocean and volcanic processes do not lend themselves well to equivalent yield scaling. Propose use of Watts and Joules for continuous and impulsive events, respectively. Well suited energy units for comparison with satellite methodologies. Acoustic to electrical energy efficiency for speakers is typically ~1-10%.
Explosions - impulsive, bipolar pulses with durations of seconds.
Long Period events - possibly emergent events sustained for seconds to minutes. Spectral peaks in 0.5-5 Hz band.
Very Long Period Events - pulses in the 0.5 – 0.001 Hz band
Near continuous oscillation sustained for minutes to years.
Range of 5 km, 40 km, and 250 km.
Near field data courtesy of
Kumagai and Molina, 2008
Using thermospheric arrivals for LITE and direct path for RIOE
mean error (km) = 2.5518
Mean delta lat = 0.0086
Mean delta lon = -0.0051
Using stratospheric arrivals for LITE and direct path for RIOE
Mean error (km) = 6.7821
Mean delta lat = 0.0534
Mean delta lon = 0.0281
Growing list of case studies compare satellite-derived ash heights with acoustic signal intensity and character derived from arrays. Used fine-scale atmospheric specifications typically used for sound propagation studies.
Spectrogram for the Plinian phase of the 8/16 eruption. Note the increase in energy and decrease in frequency of the signal around 0530 UTC. The frequency axis is plotted on a logarithmic scale.
Used coarse atmosphere
ASHE Activity Notification
ASHE Explosion Notification
5-minute notification latency!
ASHE system demonstrated capability to reliably monitor volcanoes at regional distances, with an automatic eruption notification latency of 5 minutes or less for arrays deployed within 40 km. Although sufficiently mature, in the US this technology is not yet integrated into operational environments.