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Topographic response to simulated Mw 6.5-7.0 earthquakes on the Seattle Fault

We explore the response of ground motions to topography during large crustal fault earthquakes by simulating several magnitude 6.5–7.0 rupture scenarios on the Seattle fault, Washington State. Kinematic simulations are run using a 3D spectral element code and a detailed seismic velocity model for the Puget Sound region. This model includes realistic surface topography and a near‐surface low‐veloci

Aftershocks preferentially occur in previously active areas

The clearest statistical signal in aftershock locations is that most aftershocks occur close to their mainshocks. More precisely, aftershocks are triggered at distances following a power‐law decay in distance (Felzer and Brodsky, 2006). This distance decay kernel is used in epidemic‐type aftershock sequence (ETAS) modeling and is typically assumed to be isotropic, even though individual sequences

Detection of aseismic slip and poroelastic reservoir deformation at the North Brawley Geothermal Field from 2009 to 2019

The North Brawley Geothermal Field, located within the Brawley Seismic Zone of Southern California, presents a case study for understanding seismic hazards linked to fluid injection and geothermal energy extraction. An earthquake swarm near the geothermal field in 2012 included two earthquakes with magnitudes greater than 5 and was potentially preceded by a years-long aseismic slip transient. To b

Interaction between climate and tectonics in the northern Lesser Antilles inferred from the last interglacial shoreline on Barbuda island

In the context of increasing evidence of plate interface coupling variability in subduction zones, there is a need to extend the short time window given by instrumental data and to gather data over multiple time and spatial scales. We hence investigated the long-term topography on Barbuda island, located in the northern part of the Lesser Antilles, west of the Caribbean subduction zone. Following

Improved resolution across the Global Seismographic Network: A new era in low-frequency seismology

The Global Seismographic Network (GSN)—a global network of ≈150 very broadband stations—is used by researchers to study the free oscillations of the Earth (≈0.3–10 mHz) following large earthquakes. Normal‐mode observations can provide information about the radial density and anisotropic velocity structure of the Earth (including near the core–mantle boundary), but only when signal‐to‐noise ratios

Working with dynamic earthquake rupture models: A practical guide

Dynamic rupture models are physics‐based simulations that couple fracture mechanics to wave propagation and are used to explain specific earthquake observations or to generate a suite of predictions to understand the influence of frictional, geometrical, stress, and material parameters. These simulations can model single earthquakes or multiple earthquake cycles. The objective of this article is t

The potential of using fiber optic distributed acoustic sensing (DAS) in earthquake early warning applications

As the seismological community embraces fiber optic distributed acoustic sensing (DAS), DAS arrays are becoming a logical, scalable option to obtain strain and ground‐motion data for which the installation of seismometers is not easy or cheap, such as in dense offshore arrays. The potential of strain data in earthquake early warning (EEW) applications has been recently demonstrated using records f

Considerations for creating equitable and inclusive communication campaigns associated with ShakeAlert, the earthquake early warning system for the West Coast of the USA

PurposeThe 2019 Global Assessment Report on Disaster Risk Reduction (GAR) cites earthquakes as the most damaging natural hazard globally, causing billions of dollars of damage and killing thousands of people. Earthquakes have the potential to drastically impact physical, social and economic landscapes; to reduce this risk, earthquake early warning (EEW) systems have been developed. However, these

Insights into the geometry and evolution of the southern San Andreas Fault from geophysical data, southern California

Two new joint gravity-magnetic models in northern Coachella Valley provide additional evidence for a steep northeast dip of the Mission Creek strand of the southern San Andreas fault (southern California, USA). Gravity modeling indicates a steep northeast dip of the Banning fault in the upper 1–2 km in northern Coachella Valley. The Mission Creek strand and its continuation to the southeast (Coach

Preliminary geologic map of early Miocene felsic eruptive centers in the Aquarius Mountains, west-central Arizona

The first author, Gary S. Fuis, conducted this mapping in the summer of 1967 in partial fulfillment of the entry requirements into the Ph.D program of the Division of Geological and Planetary Sciences of the California Institute of Technology, Pasadena, Calif. The area mapped lies wholly within the Fort Rock Ranch, a private ranch spanning ~50 square miles in Mohave and Yavapai Counties, Arizona.

Regional-scale liquefaction analyses

Regional-scale liquefaction hazard analyses are necessary for resilience planning and prioritization of seismic upgrades for critical distributed infrastructure such as levees, pipelines, roadways, and electrical transmission facilities. Two approaches are often considered for liquefaction hazard analysis of distributed infrastructure: (1) conventional, site-specific probe or borehole-based analys

A review of the microtremor horizontal-to-vertical spectral ratio (MHVSR) method

The single-station microtremor horizontal-to-vertical spectral ratio (MHVSR) method was initially proposed to retrieve the site amplification function and its resonance frequencies produced by unconsolidated sediments overlying high-velocity bedrock. Presently, MHVSR measurements are predominantly conducted to obtain an estimate of the fundamental site frequency at sites where a strong subsurface