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Full-Text Articles in Geophysics and Seismology

Primary Versus Secondary Gravity Wave Responses At F-Region Heights Generated By A Convective Source, C. J. Heale, P. A. Inchin, J. B. Snively Dec 2021

Primary Versus Secondary Gravity Wave Responses At F-Region Heights Generated By A Convective Source, C. J. Heale, P. A. Inchin, J. B. Snively

Publications

A 2D nonlinear, compressible model is used to simulate the acoustic-gravity wave (AGW, i.e., encompassing the spectrum of acoustic and gravity waves) response to a thunderstorm squall-line type source. We investigate the primary and secondary neutral AGW response in the thermosphere, consistent with waves that can couple to the F-region ionospheric plasma, and manifest as Traveling Ionospheric Disturbances (TIDs). We find that primary waves at z = 240 km altitude have wavelengths and phase speeds in the range 170–270 km, and 180–320 m/s, respectively. The secondary waves generated have wavelengths ranging from ∼100 to 600 km, and phase speeds from …


The Dynamics Of Nonlinear Atmospheric Acoustic-Gravity Waves Generated By Tsunamis Over Realistic Bathymetry, P. A. Inchin, C. J. Heale, J. B. Snively, M. D. Zettergren Nov 2020

The Dynamics Of Nonlinear Atmospheric Acoustic-Gravity Waves Generated By Tsunamis Over Realistic Bathymetry, P. A. Inchin, C. J. Heale, J. B. Snively, M. D. Zettergren

Publications

The investigation of atmospheric tsunamigenic acoustic and gravity wave (TAGW) dynamics, from the ocean surface to the thermosphere, is performed through the numerical computations of the 3D compressible nonlinear Navier-Stokes equations. Tsunami propagation is first simulated using a nonlinear shallow water model, which incorporates instantaneous or temporal evolutions of initial tsunami distributions (ITD). Ocean surface dynamics are then imposed as a boundary condition to excite TAGWs into the atmosphere from the ground level. We perform a case study of a large tsunami associated with the 2011 M9.1 Tohuku-Oki earthquake and parametric studies with simplified and demonstrative bathymetry and ITD. Our …


Toward Near‐Field Tsunami Forecasting Along The Cascadia Subduction Zone Using Rapid Gnss Source Models, Amy L. Williamson, Diego Melgar, Brendan W. Crowell, Diego Argas, Timothy I. Melbourne, Yong Wei, Kevin Kwong Aug 2020

Toward Near‐Field Tsunami Forecasting Along The Cascadia Subduction Zone Using Rapid Gnss Source Models, Amy L. Williamson, Diego Melgar, Brendan W. Crowell, Diego Argas, Timothy I. Melbourne, Yong Wei, Kevin Kwong

Geological Sciences Faculty Scholarship

Over the past 15 years and through multiple large and devastating earthquakes, tsunami warning systems have grown considerably in their efficacy in providing timely and accurate forecasts to affected communities. However, one part of tsunami warning that still needs improvement is forecasts catered to local, near‐field communities in the time after an earthquake rupture but before coastal inundation. In this study, we test a rapid, Global Navigation Satellite Systems (GNSS)‐driven earthquake characterization model using a large data set of synthetic megathrust ruptures for its near‐field tsunami forecasting potential. We also provide a framework for tsunami forecasting that focuses on the …


Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes, P. A. Inchin, J. B. Snively, J. Aguilar Guerrero, M. D. Zettergren, A. Williamson, D. Melgar May 2020

Mesopause Airglow Disturbances Driven By Nonlinear Infrasonic Acoustic Waves Generated By Large Earthquakes, P. A. Inchin, J. B. Snively, J. Aguilar Guerrero, M. D. Zettergren, A. Williamson, D. Melgar

Publications

Near-epicentral mesopause airglow perturbations, driven by infrasonic acoustic waves (AWs) during a nighttime analog of the 2011 M9.1 Tohoku-Oki earthquake, are simulated through the direct numerical computation of the 3D nonlinear Navier-Stokes equations. Surface dynamics from a forward seismic wave propagation simulation, initialized with a kinematic slip model and performed with the SPECFEM3D_GLOBE model, are used to excite AWs into the atmosphere from ground level. Simulated mesopause airglow perturbations include steep oscillations and persistent nonlinear depletions up to 50% and 70% from the background state, respectively, for the hydroxyl OH(3,1) and oxygen O(1S) 557.7-nm emissions. Results suggest that …


Tsunamigenic Potential Of The Baiyun Slide Complex In The South China Sea, Linlin Li, Fengyan Shi, Gangfeng Ma, Qiang Qiu Jan 2019

Tsunamigenic Potential Of The Baiyun Slide Complex In The South China Sea, Linlin Li, Fengyan Shi, Gangfeng Ma, Qiang Qiu

Civil & Environmental Engineering Faculty Publications

The Baiyun slide complex contains geological evidence for some of the largest landslide ever discovered in the continental slopes of the South China Sea. High-resolution seismic data suggest that a variety of landslides with varied scales have occurred repeatedly in this area. The largest landslide reconstructed from bathymetric and seismic data has an estimated spatial coverage of ~5,500 km2 and a conservative volume of ~1,035 km3. Here, using geomorphological and geotechnical data, we construct a series of probable landslide scenarios and assess their tsunamigenic capacity. By treating the slides as deformable mudflows, we simulate the dynamics of …


Defining Historical Earthquake Rupture Parameters And Proposed Slip Distributions Through Tsunami Modeling In South-Central Chile, Alexander Dolcimascolo Jan 2019

Defining Historical Earthquake Rupture Parameters And Proposed Slip Distributions Through Tsunami Modeling In South-Central Chile, Alexander Dolcimascolo

All Master's Theses

Reliable tsunami early warning forecasts rely on accurate initial modeling conditions and interpretations of subduction zone behavior in a multi-century perspective. GPS and seismologic data were introduced this past century to study rupture dynamics in detail, however limited information is known about ruptures that pre-date the 20th century. I propose a methodology that uses statistics to better understand these pre-20th century ruptures. This methodology applies the historical and geologic tsunami record as a means to select a suite of tsunami simulations from earthquake source solutions. I chose south-central Chile (46°S to 30°S) to test this new methodology; it …


2015 Gsa International Distinguished Lecturer Tours Key Locations In Central And South America, Lisa L. Ely Jul 2016

2015 Gsa International Distinguished Lecturer Tours Key Locations In Central And South America, Lisa L. Ely

Geological Sciences Faculty Scholarship

As the International Lecturer from North America, I visited 11 destinations in Ecuador, Peru, Chile, Costa Rica, Mexico, and Puerto Rico. The tour was designed to include locations where the topic of my presentation, “Following in the Footsteps of Darwin:
Combining Geological and Historical Evidence to Assess Earthquakes and Tsunami Hazards,” would have direct relevance.


Did A Submarine Landslide Contribute To The 2011 Tohoku Tsunami?, David R. Tappin, Stephan T. Grilli, Jeffrey C. Harris, Robert J. Geller, Timothy Masterlark, James T. Kirby, Fengyan Shi, Gangfeng Ma, K.K.S. Thingbaijam, P. Martin Mai Jan 2014

Did A Submarine Landslide Contribute To The 2011 Tohoku Tsunami?, David R. Tappin, Stephan T. Grilli, Jeffrey C. Harris, Robert J. Geller, Timothy Masterlark, James T. Kirby, Fengyan Shi, Gangfeng Ma, K.K.S. Thingbaijam, P. Martin Mai

Civil & Environmental Engineering Faculty Publications

Many studies have modeled the Tohoku tsunami of March 11, 2011 as being due entirely to slip on an earthquake fault, but the following discrepancies suggest that further research is warranted. (1) Published models of tsunami propagation and coastal impact underpredict the observed runup heights of up to 40. m measured along the coast of the Sanriku district in the northeast part of Honshu Island. (2) Published models cannot reproduce the timing and high-frequency content of tsunami waves recorded at three nearshore buoys off Sanriku, nor the timing and dispersion properties of the waveforms at offshore DART buoy #21418. (3) …


Detection Of The 2010 Chilean Tsunami Using Satellite Altimetry, B. D. Hamlington, R. R. Leben, O. A. Godin, J. F. Legeais, E. Gica, V. V. Titov Jan 2011

Detection Of The 2010 Chilean Tsunami Using Satellite Altimetry, B. D. Hamlington, R. R. Leben, O. A. Godin, J. F. Legeais, E. Gica, V. V. Titov

CCPO Publications

Tsunamis are difficult to detect and measure in the open ocean because the wave amplitude is much smaller than it is closer to shore. An effective early warning system, however, must be able to observe an impending tsunami threat far away from the shore in order to provide the necessary lead-time for coastal inhabitants to find safety. Given the expansiveness of the ocean, sensors capable of detecting the tsunami must also have very broad areal coverage. The 2004 Sumatra-Andaman tsunami was definitively detected in the open ocean from both sea surface height and sea surface roughness measurements provided by satellite …