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Halyomorpha halys (Stal), the brown marmorated stink bug, is a globally invasive stink bug species. Its first major outbreak was in the United States, where it has caused millions of dollars in damage, threatened livelihoods of specialty crop growers and impacted row crop growers, and become an extreme nuisance pest in and around dwellings. The BMSB IPM Working Group, funded by the Northeastern IPM Center, was central to providing a mechanism to form a multidisciplinary team and develop initial and subsequent research, Extension, regulatory and consumer priorities. Ultimately, a project team consisting of over 50 scientists from 11 institutions in 10 states obtained the largest ever USDA-NIFA Specialty Crop Research Initiative CAP grant, totaling over $10.7 million, to tackle this crisis over a 5-yr period (2011-2016). Researchers and Extension educators integrated stakeholder feedback throughout the course of the project, and priorities evolved according to needs of affected growers and public stakeholders. Initially, the team focused on identification of H. halys, its damage symptoms and crop-specific risks, and short-term mitigation strategies for crop protection. Subsequently, work focused on its biology, ecology, and behavior leading to the development of potential longer-term IPM tactics and landscape level management solutions, including biological control. This work continues under a second SCRI CAP grant (2016-2021). The information from the initial team reached an estimated 22,000 specialty crop stakeholder contacts via Extension efforts, and over 600 million people via mainstream media. We highlight the main lessons learned from coordinating a national response to the threat posed by H. halys to agriculture in the United States.

Growth of major populated cities near active faults (e.g., Los Angeles and San Francisco in USA, Tokyo and Osaka in Japan) has significantly elevated the seismic hazards. Understanding complex paradigm of near-fault ground motions is crucial in order to mitigate seismic hazards. Since the 1994 Mw 6.7 Northridge earthquake, there has been much discussion about the adequacy of building code and a term of “pulse”. The engineering effects of near-fault pulse-like ground motions were strikingly exhibited in the 1994 Northridge earthquake in which great seismic damage was attributed to the large impulsive ground shaking of this type. Such near-fault pulselike ground motions with high intensity and damage potentials are hypothetically associated to either pulse-like rupture on fault or the rupture directivity. These mechanisms will be introduced and studied.In Chapter 2, we study far-field effects of a self-healing pulse-like rupture mode with dynamic weakening. Pulse-like rupture leads to development of a second corner frequency, and the intermediate spectral slope is approximately 2 in most cases. The focal-sphere-averaged lower P and S wave corner frequencies are systematically higher for pulse-like models than crack models of comparable rupture velocity. The slip-weighted stress drop exceeds the moment-based stress drop for pulse-like ruptures, with the ratio ranging from about 1.3 to 1.65, while they are equal for the crack-like case. The transition from arresting- to growing-pulse rupture is accompanied by a large (factor of 1.6) increase in the radiation ratio. Thus, variations in rupture mode may account for the portion of the scatter in observational spectral estimates ofsource parameters.In Chapter 3, we confirm the pulse-like ground motion in the 2015 Nepal Gorkha earthquake is related to the causing fault geometry of the Main Himalayan Thrust (MHT). Our dynamic rupture simulations in an elastoplastic medium yield earthquake parameters comparable to those deduce

In this dissertation, I study two fundamental topics in seismology, tidal triggering of earthquakes and attenuation and scattering structure. Studies of tidal triggering help constrain earthquake nucleation models and relate to earthquake predicability and forecasting. Resolvingattenuation and scattering behavior can provide more physically realistic models for strong ground motion prediction equations (GMPEs) and improve our understanding of the physical properties of rocks in the lithosphere. Chapter 1 is an introduction, providing background and motivation for each of the following chapters. Chapters 2 & 3 focus on the topic of tidal triggering of earthquakes. Chapter 2 studies tidal triggering in the central Japan region using M>3 earthquakes and finds no clear evidence for tidal triggering. Chapter 3 analyzes seismicity in the Coso region of California and finds strong tidal triggering but an absence of remote triggering at the Coso geothermal field, constraining earthquake triggering sensitivities at different time scales of stress perturbations. Chapters 4-6 study the inelastic properties of the crust and upper mantle in southern California using both coda and direct-wave observations. Chapter 4 stacks coda envelope functions across southern California and synthesizes them using a two-layer model, composed of a shallow crustallayer with strong wide-angle scattering and high P and S intrinsic attenuation and a deeper layer with weaker scattering and lower intrinsic attenuation. Chapter 5 describes improvements to the conventional coda-Q method to solve for coda attenuation, site amplification and source radiated energy simultaneously. Chapter 6 models focal-sphere-dependent S/P amplitudes assuming awhole-space intrinsic and scattering attenuation model around the San Bernardino region.

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Solid Earth 123 (2018): 3147-3159, doi:10.1002/2018JB015573., Teleseismic records of the 2012 Mw 7.2 Sumatra earthquake contain prominent phases in the P wave train, arriving about 50 to 100 s after the direct P arrival. Azimuthal variations in these arrivals, together with back‐projection analysis, led Fan and Shearer (2016a, https://doi.org/10.1002/2016GL067785) to conclude that they originated from early aftershock(s), located ∼150 km northeast of the mainshock and landward of the trench. However, recently, Yue et al. (2017, https://doi.org/10.1002/2017GL073254) argued that the anomalous arrivals are more likely water reverberations from the mainshock, based mostly on empirical Green's function analysis of a M6 earthquake near the mainshock and a water phase synthetic test. Here we present detailed back‐projection and waveform analyses of three M6 earthquakes within 100 km of the Mw 7.2 earthquake, including the empirical Green's function event analyzed in Yue et al. (2017, https://doi.org/10.1002/2017GL073254). In addition, we examine the waveforms of three M5.5 reverse‐faulting earthquakes close to the inferred early aftershock location in Fan and Shearer (2016a, https://doi.org/10.1002/2016GL067785). These results suggest that the reverberatory character of the anomalous arrivals in the mainshock coda is consistent with water reverberations, but the origin of this energy is more likely an early aftershock rather than delayed and displaced water reverberations from the mainshock., National Science Foundation Grant Numbers: EAR-1261681, EAR-1620251; Weston Howland Jr. Postdoctoral Scholarship, 2018-10-25

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Tectonophysics 721 (2017): 143-150, doi:10.1016/j.tecto.2017.10.003., The 2006 Mw 7.8 Java earthquake was a tsunami earthquake, exhibiting frequency-dependent seismic radiation along strike. High-frequency global back-projection results suggest two distinct rupture stages. The first stage lasted ~65 s with a rupture speed of ~1.2 km/s, while the second stage lasted from ~65 to 150 s with a rupture speed of ~2.7 km/s. High-frequency radiators resolved with back-projection during the second stage spatially correlate with splay fault traces mapped from residual free-air gravity anomalies. These splay faults also colocate with a major tsunami source associated with the earthquake inferred from tsunami first-crest back-propagation simulation. These correlations suggest that the splay faults may have been reactivated during the Java earthquake, as has been proposed for other tsunamigenic earthquakes, such as the 1944 Mw 8.1 Tonankai earthquake in the Nankai Trough., W.F. is currently supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Weston Howland Jr. Postdoctoral Scholarship.

The complexity of the earthquake rupture process makes earthquakes inherently unpredictable. Seismic hazard forecasts often presume that the rate of earthquake occurrence can be adequately modeled as a space-time homogenenous or stationary Poisson process and that the relation between the dynamical source properties of small and large earthquakes obey self-similar scaling relations. While these simplified models provide useful approximations and encapsulate the first-order statistical features of the historical seismic record, they are inconsistent with the complexity underlying earthquake occurrence and can lead to misleading assessments of seismic hazard when applied in practice. The six principle chapters of this thesis explore the extent to which the behavior of real earthquakes deviates from these simplified models, and the implications that the observed deviations have for our understanding of earthquake rupture processes and seismic hazard.Chapter 1 provides a brief thematic overview and introduction to the scope of this thesis. Chapter 2 examines the complexity of the 2010 M7.2 El Mayor-Cucapah earthquake, focusing on the relation between its unexpected and unprecedented occurrence and anthropogenic stresses from the nearby Cerro Prieto Geothermal Field. Chapter 3 compares long-term changes in seismicity within California's three largest geothermal fields in an effort to characterize the relative influence of natural and anthropogenic stress transients on local seismic hazard. Chapter 4 describes a hybrid, hierarchical clustering algorithm that can be used to relocate earthquakes using waveform cross-correlation, and applies the new algorithm to study the spatiotemporal evolution of two recent seismic swarms in western Nevada. Chapter 5 describes a new spectral decomposition technique that can be used to analyze the dynamic source properties of large datasets of earthquakes, and applies this approach to revisit the question of self-similar scaling of souther

Earthquakes are the primary source of seismic waves in seismology and understanding the earthquake source is essential for predicting ground motions and detailing the physics of rupture. Earthquake kinematic source imaging describes the whole rupture process during an earthquake. It does not directly require the resolved source model to be physically or dynamically plausible, but can help in understanding the conditions of rupture dynamics. Therefore, accurate earthquake source models are highly desirable.In Chapter 2, we develop a frequency-based approach to earthquake slip inversion that requires no prior information on the rupture velocity or slip-rate functions. In Chapter 3, we characterize the rupture process of the 25 April 2015 Nepal earthquake with globally recorded teleseismic P waves. In Chapter 4, we investigate the 10 January 2012 Mw 7.2 Sumatra earthquake in the Wharton basin and detect dynamically-triggered large early aftershocks occurring on or near the subduction interface. In Chapter 5, we constrain the spatiotemporal evolution of the 2009 Tonga-Samoa earthquake with global P-wave back-projection and a multiple moment-tensor inversion. Our results show that the rupture branches east of the trench axis were controlled by the geometry of bending-related faults on the Pacific plate, and that the rupture branch west of the trench axis may correlate with along-strike fore-arc segmentation.In Chapter 6, we detect and locate 48 previously unidentified large early aftershocks triggered by 7 < M < 8 earthquakes within a few fault lengths, during times that high-amplitude surface waves arrive from the mainshock. The observations indicate that near-to-intermediate-field dynamic triggering commonly exists and fundamentally promotes aftershock occurrence.In Chapter 7, we analyze the 2006 Mw 7.8 Java tsunami earthquake with global P-wave back-projection, tsunami tide-gauge back-propagation, and P-wave source spectra modeling. The results suggest that the