A5055979975- earthquake and tectonic studies
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Seismic Waves and Analysis
- Earthquake Detection and Analysis
- Seismology and Earthquake Studies
- Seismic Imaging and Inversion Techniques
- Geophysics and Sensor Technology
- Geological and Geophysical Studies
- Methane Hydrates and Related Phenomena
- Geological and Tectonic Studies in Latin America
- Geophysics and Gravity Measurements
- Geological Studies and Exploration
- Geomagnetism and Paleomagnetism Studies
- Earthquake and Tsunami Effects
- Astro and Planetary Science
- GNSS positioning and interference
- Coastal and Marine Dynamics
- Geology and Paleoclimatology Research
- Disaster Management and Resilience
- Geophysical Methods and Applications
- Reservoir Engineering and Simulation Methods
- Geological Modeling and Analysis
- Planetary Science and Exploration
- Geological and Geophysical Studies Worldwide
University of California, Santa Cruz
2016-2025
ORCID
2023
Planetary Science Institute
2005-2019
Pacific Northwest National Laboratory
2014
Rutgers, The State University of New Jersey
2014
Laboratoire de Météorologie Dynamique
2014
Sorbonne Université
2014
Centre National de la Recherche Scientifique
2014
University of Alaska Fairbanks
2006-2013
American Geophysical Union
2013
The two largest earthquakes of the past 40 years ruptured a 1600-kilometer-long portion fault boundary between Indo-Australian and southeastern Eurasian plates on 26 December 2004 [seismic moment magnitude (Mw) = 9.1 to 9.3] 28 March 2005 (Mw 8.6). first event generated tsunami that caused more than 283,000 deaths. Fault slip up 15 meters occurred near Banda Aceh, Sumatra, but north, along Nicobar Andaman Islands, rapid was much smaller. Tsunami geodetic observations indicate additional slow...
PrefaceCh. 1Historical Introduction3Ch. 2Continuum Mechanics25Ch. 3Equations of Motion56Ch. 4Normal Modes109Ch. 5Seismic Source Representation146Ch. 6Anelasticity and Attenuation193Ch. 7Rayleigh-Ritz Method237Ch. 8Spheroidal Toroidal Oscillations257Ch. 9Elastic Anelastic Perturbations327Ch. 10Synthetic Seismograms363Ch. 11Love Rayleigh Waves405Ch. 12Mode-Ray Duality451Ch. 13Perturbation Theory537Ch. 14Mode Splitting Coupling596Ch. 15Body-Wave Ray Theory669Ch. 16Surface-Wave JWKB...
The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then expanded at of about 2.5 kilometers per second toward north northwest, extending 1200 1300 along Andaman trough. Peak displacements reached approximately 15 meters 600-kilometer segment plate boundary offshore northwestern Sumatra southern Nicobar islands. Slip was less in northern 400 500 aftershock zone, least some that region may have occurred on...
Subduction zone plate boundary megathrust faults accommodate relative motions with spatially varying sliding behavior. The 2004 Sumatra‐Andaman (M w 9.2), 2010 Chile 8.8), and 2011 Tohoku 9.0) great earthquakes had similar depth variations in seismic wave radiation across their wide rupture zones – coherent teleseismic short‐period preferentially emanated from the deeper portion of megathrusts whereas largest fault displacements occurred at shallower depths but produced relatively little...
A lower mantle S-wave triplication detected with short- and long-period WWSSN CSN recordings indicates a substantial shear velocity discontinuity near 280 km above the core—mantle boundary. The can be observed in rotated SH seismograms from intermediate deep focus events throughout distance range 70° to 95°. Three distinct source region—receiver array combinations that have been investigated detail demonstrate consistent travel time relative amplitude behaviour of triplication, slight...
The 11 March 2011 off the Pacific coast of Tohoku (Mw 9.0) Earthquake ruptured a 200 km wide megathrust fault, with average displacements ~15–20 m. Early estimates co-seismic slip distribution using seismic, geodetic and tsunami observations vary significantly in placement slip, particularly vicinity trench. All methods have difficulty resolving up-dip extent rupture; onshore inversions limited sensitivity to far offshore, seismic instabilities moment estimation as subfault segments get very...
The 11 March 2011 Tohoku Earthquake ruptured the interplate boundary off-shore of east Japan, with fault displacements up to 40 m and a rupture duration 150–160 s. W-phase inversion indicates moment 3.9 × 1022 N (Mw 9.0) centroid time 71 We invert teleseismic P waves broadband Rayleigh wave observations high-rate GPS recordings from Japan characterize rupture. resulting model begins steady increase rate for first 80 s, speed 1.5 km/s. Then expands southwestward at about 2.5 model's primary...
Abstract Source parameter scaling for major and great thrust‐faulting events on circum‐Pacific megathrusts is examined using uniformly processed finite‐fault inversions radiated energy estimates 114 M w ≥ 7.0 earthquakes. To address the limited resolution of source spatial extent rupture expansion velocity ( V r ) from teleseismic observations, are subdivided into either group 1 (18 events) having independent constraints prior studies or 2 (96 lacking constraints. For 2, with = 2.0, 2.5, 3.0...
Two major earthquakes (MW 7.8 and MW 7.7) ruptured left-lateral strike-slip faults of the East Anatolian Fault Zone (EAFZ) on February 6, 2023, causing >59,000 fatalities ~$119B in damage southeastern Türkiye northwestern Syria. Here we derived kinematic rupture models for two events by inverting extensive seismic geodetic observations using complex 5-6 segment fault constrained satellite relocated aftershocks. The larger event nucleated a splay fault, then propagated bilaterally ~350 km...
Abstract The 1938 M S 8.3 and 2021 W 8.2 earthquakes both ruptured within the Semidi segment of Aleutian‐Alaska subduction zone. large‐slip distribution event is well constrained depth range 25–45 km, with seaward tsunami observations excluding significant shallower coseismic slip. slip more uncertain. Regional far‐field tide gauge for are modeled to constrain location large largest (2.0 m) located below continental shelf on a 180‐km‐long portion rupture extending further northeast than...
The 75 year history of the American Geophysical Union has accompanied great advances in our understanding physics and chemistry transition zone between Earth's core mantle. core‐mantle boundary (CMB) is most significant internal within planet, buried at remote depths probably forever hidden from direct observation; yet this region very important to dynamic Earth system. thermal chemical processes operating near CMB have intimate relationships fundamental events history, such as formation,...
Temperature gradients in a low-shear-velocity province the lowermost mantle (D'' region) beneath central Pacific Ocean were inferred from observation of rapid S-wave velocity increase overlying decrease. These paired seismic discontinuities are attributed to phase change perovskite post-perovskite and then back as temperature increases with depth. Iron enrichment could explain occurrence several hundred kilometers above core-mantle boundary this warm, chemically distinct province. The double...
Tsunami earthquakes, shallow events that produce larger tsunamis than expected given their surface wave magnitudes (M s ), typically have long durations and a source spectrum depleted in short period energy. Seven cases of underthrusting tsunami earthquakes provide information on the rupture processes, but little constraint geographic distribution or frequency. We compare characteristics with smaller magnitude circum‐Pacific interplate thrust faults. Comparable moment release time histories...
Seismic body waves which were excited by the May 18, 1980, eruption of Mount St. Helens and recorded Global Digital Seismographic Network stations are analyzed to determine nature time sequence events associated with eruption. The polarity teleseismic p (period ∼20 s ) is identical at six stations, distributed over a wide azimuthal range. This observation, together very small S P amplitude ratio (at 20 s), suggests that source nearly vertical single force. A simple model shows for seismic...
The 27 February 2010 Chile (M w 8.8) earthquake is the fifth largest to strike during age of seismological instrumentation. faulting geometry, slip distribution, seismic moment, and moment‐rate function are estimated from broadband teleseismic P, SH, Rayleigh wave signals. We explore some trade‐offs in rupture‐process estimation due model parameterizations, limited sampling phase velocities, uncertainty fault geometry. average over ∼81,500 km 2 rupture area about 5 m, with concentrations...
The 17 July 2006 Java earthquake involved thrust faulting in the trench and excited a deadly tsunami (∼5–8 m) that inundated southern coast of Java. earthquake's size estimates vary significantly with seismic wave period: very long‐period signals (300–500+ s) indicate moment 6.7 × 10 20 Nm (M w = 7.8), M S (∼20 7.2, m b (∼1 6.2, while shaking intensities (3–10 Hz) were ≤ MMIV. large relative to characterizes this event as earthquake. Like previous earthquakes, had an unusually low rupture...