A5016795877- Seismic Waves and Analysis
- Earthquake Detection and Analysis
- Seismology and Earthquake Studies
- earthquake and tectonic studies
- Seismic Imaging and Inversion Techniques
- Underwater Acoustics Research
- Geophysical Methods and Applications
- Landslides and related hazards
- Meteorological Phenomena and Simulations
- High-pressure geophysics and materials
- Cryospheric studies and observations
- Geological and Geophysical Studies
- Aerodynamics and Acoustics in Jet Flows
- Geophysics and Sensor Technology
- Methane Hydrates and Related Phenomena
- Radiation Detection and Scintillator Technologies
- Lightning and Electromagnetic Phenomena
- Planetary Science and Exploration
- Geological and Geochemical Analysis
- Acoustic Wave Phenomena Research
- Speech and Audio Processing
- Geology and Paleoclimatology Research
- Maritime and Coastal Archaeology
- Tropical and Extratropical Cyclones Research
- Ionosphere and magnetosphere dynamics
University of California, Santa Barbara
2016-2025
University of California, San Diego
2006-2019
University of Alaska Fairbanks
2016
Scripps Institution of Oceanography
2006-2015
Czech Academy of Sciences, Institute of Geophysics
2015
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2010-2012
CEA DAM Île-de-France
2010-2012
The 15 January 2022 climactic eruption of Hunga volcano, Tonga, produced an explosion in the atmosphere a size that has not been documented modern geophysical record. event generated broad range atmospheric waves observed globally by various ground-based and spaceborne instrumentation networks. Most prominent was surface-guided Lamb wave (≲0.01 hertz), which we propagating for four (plus three antipodal) passages around Earth over 6 days. As measured amplitudes, comparable to 1883 Krakatau...
Abstract We present a new three‐dimensional seismic velocity model of the crustal and upper mantle structure for Mauna Loa Kilauea volcanoes in Hawaii. Our is derived from first‐arrival times compressional shear waves about 53,000 events on near Island Hawaii between 1992 2009 recorded by Hawaiian Volcano Observatory stations. The V p generally agrees with previous studies, showing high‐velocity anomalies calderas rift zones low‐velocity fault systems. most significant difference models / s...
The lowermost section of a Vulcanian or Plinian volcanic eruption column may be thought as momentum‐driven, turbulent, free‐shear jet flow. We propose that large‐amplitude and long‐duration infrasonic (<20 Hz) signals recorded at ranges tens kilometers during powerful eruptions Mount St. Helens, USA, Tungurahua, Ecuador, represent low frequency form noise. A preliminary test this hypothesis is made by comparing the observed spectra to empirically‐derived similarity for pure‐air jets....
[1] The April–May 2010 summit eruption of Eyjafjallajökull, Iceland, was recorded by 14 atmospheric infrasound sensor arrays at ranges between 1,700 and 3,700 km, indicating that from modest-size eruptions can propagate for thousands kilometers in waveguides. Although variations both propagation conditions background noise levels the sensors generate fluctuations signal-to-noise ratios signal detectability, array processing techniques successfully discriminate volcanic ambient coherent...
Multiyear continuous infrasound monitoring with the global International Monitoring System (IMS) demonstrates that microbaroms, generated by nonlinear interaction of opposing oceanic surface waves, are globally observed at equatorial, middle, and high latitudes. Direction arrival microbarom signals systematically estimated all IMS stations. Using a cross‐bearing method, we perform monthly localization worldwide sources. At most stations, detections show clear seasonal trends, driven...
The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation more than 100 flights in North America. generated strong tremor was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including EarthScope Transportable Array. relationship between amplitudes height changes considerably waxing waning portions eruption. Similar hysteresis has been observed river noise discharge during storms, suggesting flow erosional processes both...
Abstract Since the 1919 foundation of International Association Volcanology and Chemistry Earth’s Interior (IAVCEI), fields volcano seismology acoustics have seen dramatic advances in instrumentation techniques, undergone paradigm shifts understanding volcanic seismo-acoustic source processes internal structure. Some early twentieth-century volcanological studies gave equal emphasis to barograph (infrasound acoustic-gravity wave) seismograph observations, but rapidly outpaced became standard...
During the early stages of 2004–2008 Mount St. Helens eruption, source process that produced a sustained sequence repetitive long‐period (LP) seismic events also impulsive broadband infrasonic signals in atmosphere. To assess whether could be generated simply by seismic‐acoustic coupling from shallow LP events, we perform finite difference simulation seismo‐acoustic wavefield using single numerical scheme for elastic ground and The effects topography, velocity structure, wind, configuration...
On 29 May 2006 a large rockfall off the Mount St. Helens lava dome produced an atmospheric plume that was reported by airplane pilots to have risen 6,000 m above sea level and interpreted be result of explosive event. However, subsequent field reconnaissance found no evidence ballistic field, indicating there component. The complex seismic infrasonic signals, with latter recorded at sites 0.6 13.4 km from source. An unusual, very long‐period (50 s) signal recorded, we model as air...
The ability of the International Monitoring System (IMS) infrasound network to detect atmospheric nuclear explosions and other signals interest is strongly dependent on station‐specific ambient noise. This noise includes both incoherent wind real coherent infrasonic waves. Previous models have not distinguished between components. We present a first attempt at statistically systematically characterizing recorded by IMS. perform broadband (0.01–5 Hz) array processing with IMS continuous...
One of the most striking aspects seismicity during 2004–2008 eruption Mount St. Helens (MSH) was precise regularity in occurrence repetitive long‐period (LP) or “drumbeat” events over sustained time periods. However, this not always observed, and at times temporal LP became more random. In addition, accompanying dominant class MSH eruption, there a near‐continuous, randomly occurring series smaller seismic events. These subevents are simply small‐amplitude versions but appear instead to...
A fundamental goal of volcano acoustics is to relate observed infrasonic signals the eruptive processes generating them. link between acoustic power and volcanic gas exit velocity V was proposed by Woulff McGetchin (1976) based upon prevailing jet noise theory at time (acoustic analogy theory). We reexamine this approach in context current understanding noise, using data from a laboratory jet, full‐scale military aircraft, rocket motor. Accurate estimates require good spatial sampling...
Abstract The analysis and interpretation of seismicity from mantle depths to the surface play a key role in understanding how Hawaiian volcanoes work. We present results comprehensive systematic re‐analysis waveforms 130,902 seismic events recorded by U.S. Geological Survey Volcano Observatory permanent network January 1992 March 2009. compute high‐precision relative relocations for 101,390 (77% all considered) using waveform cross correlation cluster analysis, resulting multiyear...
Air-ground and ground-air elastic wave coupling are key processes in the rapidly developing field of seismoacoustics particularly relevant for volcanoes. During a sustained explosive volcanic eruption, it is typical to record broadband signal on seismometers, termed eruption tremor. Eruption tremor usually attributed subsurface seismic source process, such as upward migration magma gases through shallow conduit vent. However, now known that eruptions also generate powerful signals...
Abstract We experiment with a new method to search systematically through multiyear data from the International Monitoring System (IMS) infrasound network identify explosive volcanic eruption signals originating anywhere on Earth. Detecting, quantifying, and cataloging global occurrence of volcanism helps toward several goals in Earth sciences has direct applications hazard mitigation. combine signal association across multiple stations source location using brute‐force, grid‐search,...
Abstract The two major explosive phases of the 22–23 April 2015 eruption Calbuco volcano, Chile, produced powerful seismicity and infrasound. was recorded on seismo‐acoustic stations out to 1,540 km five (IS02, IS08, IS09, IS27, IS49) International Monitoring System (IMS) infrasound network at distances from 1,525 5,122 km. remote IMS provide an accurate explosion chronology consistent with regional local data previous studies lightning plume observations. We use detect locate signals using...
More than 100 separate incidents of interactions between aircraft and volcanic ash were documented 1973 2003. Incidents on international flight paths over remote areas have resulted in engine failures significant damage expense to commercial airlines. To protect from ash, pilots need rapid reliable notification ash‐ generating events. A global infrasound array network, consisting the International Monitoring System (IMS) other national networks, has demonstrated a capability for detection...