Jeff McGuire is a research geophysicist in the Earthquake Hazards Program.
Science and Products
Fiber Optic Seismology for Earthquake Hazards Research, Monitoring and Early Warning
A revolution is underway in seismology that transforms fiber-optic cables into arrays of thousands of seismic sensors. Compared to the traditional monitoring networks using inertial seismometers, the fiber-optic approach can increase the spatial data density by orders of magnitude and enable data processing methodologies that require a high-fidelity wavefield. The Working Group aims to advance the
External Grants - Overview
The U.S. Geological Survey (USGS) provides support for research that will assist in achieving the goals of the Earthquake Hazards Program. The goal is to mitigate earthquake losses that can occur in many parts of the nation by providing earth science data and assessments essential for land-use planning, engineering design, and emergency preparedness decisions.
What if the ShakeAlert Earthquake Early Warning System Had Been Operating During the M6.9 1989 Loma Prieta Earthquake?
Release Date: OCTOBER 17, 2019 How will ShakeAlert® likely perform now on a large earthquake impacting a major urban area? How much warning will you get? To answer this, let’s do a thought experiment...
Input for assessing the impact of noisy data on earthquake magnitude estimates derived from peak ground displacement measured with real-time Global Navigation Satellite System data
This data release complements Murray et al. (2023) which presents a framework for incorporating earthquake magnitude estimates based on real-time Global Navigation Satellite System (GNSS) data into the ShakeAlert® earthquake early warning system for the west coast of the United States. Murray et al. (2023) assess the impact of time-dependent noise in GNSS real-time position estimates on the re
Data Release for Latency Testing of Wireless Emergency Alerts intended for the ShakeAlert earthquake early warning system for the West Coast of the United States of America
ShakeAlert, the earthquake early warning (EEW) system for the West Coast of the United States, attempts to provides crucial warnings before strong shaking occurs. However, because the alerts are triggered only when an earthquake is already in progress, and the alert latencies and delivery times are platform dependent, the time between these warnings and the arrival of shaking is variable. The Shak
Filter Total Items: 18
Testing the ShakeAlert earthquake early warning system using synthesized earthquake sequences
We test the behavior of the United States (US) West Coast ShakeAlert earthquake early warning (EEW) system during temporally close earthquake pairs to understand current performance and limitations. We consider performance metrics based on source parameter and ground‐motion forecast accuracy, as well as on alerting timeliness. We generate ground‐motion times series for synthesized earthquake seque
Very low frequency earthquakes in between the seismogenic and tremor zones in Cascadia?
Megathrust earthquakes and their associated tsunamis cause some of the worst natural disasters. In addition to earthquakes, a wide range of slip behaviors are present at subduction zones, including slow earthquakes that span multiple orders of spatial and temporal scales. Understanding these events may shed light on the stress or strength conditions of the megathrust fault. Out of all types of slo
Earthquake early warning for estimating floor shaking levels of tall buildings
This article investigates methods to improve earthquake early warning (EEW) predictions of shaking levels for residents of tall buildings. In the current U.S. Geological Survey ShakeAlert EEW system, regions far from an epicenter will not receive alerts due to low predicted ground‐shaking intensities. However, residents of tall buildings in those areas may still experience significant shaking due
Correlation of porosity variations and rheological transitions on the southern Cascadia megathrust
The unknown onshore extent of megathrust earthquake rupture in the Cascadia subduction zone represents a key uncertainty in earthquake hazard for the Pacific Northwest that is governed by the physical state and mechanical properties of the plate interface. The Cascadia plate interface is segmented into an interseismically locked zone located primarily offshore that is expected to rupture in large
Expected warning times from the ShakeAlert earthquake early warning system for earthquakes in the Pacific Northwest
The ShakeAlert® earthquake early warning system has been live since October 2019 for the testing of public alerting to mobile devices in California and will soon begin testing this modality in Oregon and Washington. The Pacific Northwest presents new challenges and opportunities for ShakeAlert owing to the different types of earthquakes that occur in the Cascadia subduction zone. Many locations in
Commentary: The role of geodetic algorithms for earthquake early warning in Cascadia
The ShakeAlert earthquake early warning (EEW) system issues public alerts in California and will soon extend to Oregon and Washington. The Cascadia subduction zone presents significant new challenges and opportunities for EEW. Initial publications suggested that EEW algorithms based on Global Navigation Satellite System (GNSS) data could provide improved warning for intraslab events and dramatical
A long-term geothermal observatory across subseafloor gas hydrates, IODP Hole U1364A, Cascadia accretionary prism
We report 4 years of temperature profiles collected from May 2014 to May 2018 in Integrated Ocean Drilling Program Hole U1364A in the frontal accretionary prism of the Cascadia subduction zone. The temperature data extend to depths of nearly 300 m below seafloor (mbsf), spanning the gas hydrate stability zone at the location and a clear bottom-simulating reflector (BSR) at ∼230 mbsf. When the hole
ShakeAlert Earthquake Early Warning System Performance During the 2019 Ridgecrest Earthquake Sequence
During July 2019, a sequence of earthquakes including a Mw6.4 foreshock and a Mw7.1 mainshock occurred near Ridgecrest, California. ShakeAlert, the U.S. Geological Survey (USGS) ShakeAlert public Earthquake Early Warning (EEW) system being developed for the U.S. West Coast, was operational during this time, though public alerting was only available within LA County. ShakeAlert created alert messag
New opportunities to study earthquake precursors
No abstract available.
Abundant spontaneous and dynamically triggered submarine landslides in the Gulf of Mexico
Submarine landslides that occur offshore are common along the U.S. continental margins. These mass wasting events can trigger tsunamis and hence potentially devastate coastal communities and damage offshore infrastructure. However, the initiation and failure processes of submarine landslides are poorly understood. Here, we identify and locate 85 previously unknown submarine landslides in the Gulf
Aseismic transient slip on the Gofar transform fault, East Pacific Rise
Oceanic transform faults display a unique combination of seismic and aseismic slip behavior, including a large globally averaged seismic deficit, and the local occurrence of repeating magnitude (M) ∼6∼6 earthquakes with abundant foreshocks and seismic swarms, as on the Gofar transform of the East Pacific Rise and the Blanco Ridge in the northeast Pacific Ocean. However, the underlying mechanisms t
Semiautomated estimates of directivity and related source properties of small to moderate southern California earthquakes using second seismic moments
We develop a semiautomated method for estimating with second seismic moments the directivity, rupture area, duration, and centroid velocity of earthquakes. The method is applied to 41 southern California earthquakes with magnitude in the range 3.5–5.2 and provides stable results for 28 events. Apparent source time functions (ASTFs) of P and S phases are derived using deconvolution with three stack
Science and Products
- Science
Fiber Optic Seismology for Earthquake Hazards Research, Monitoring and Early Warning
A revolution is underway in seismology that transforms fiber-optic cables into arrays of thousands of seismic sensors. Compared to the traditional monitoring networks using inertial seismometers, the fiber-optic approach can increase the spatial data density by orders of magnitude and enable data processing methodologies that require a high-fidelity wavefield. The Working Group aims to advance theExternal Grants - Overview
The U.S. Geological Survey (USGS) provides support for research that will assist in achieving the goals of the Earthquake Hazards Program. The goal is to mitigate earthquake losses that can occur in many parts of the nation by providing earth science data and assessments essential for land-use planning, engineering design, and emergency preparedness decisions.What if the ShakeAlert Earthquake Early Warning System Had Been Operating During the M6.9 1989 Loma Prieta Earthquake?
Release Date: OCTOBER 17, 2019 How will ShakeAlert® likely perform now on a large earthquake impacting a major urban area? How much warning will you get? To answer this, let’s do a thought experiment... - Data
Input for assessing the impact of noisy data on earthquake magnitude estimates derived from peak ground displacement measured with real-time Global Navigation Satellite System data
This data release complements Murray et al. (2023) which presents a framework for incorporating earthquake magnitude estimates based on real-time Global Navigation Satellite System (GNSS) data into the ShakeAlert® earthquake early warning system for the west coast of the United States. Murray et al. (2023) assess the impact of time-dependent noise in GNSS real-time position estimates on the reData Release for Latency Testing of Wireless Emergency Alerts intended for the ShakeAlert earthquake early warning system for the West Coast of the United States of America
ShakeAlert, the earthquake early warning (EEW) system for the West Coast of the United States, attempts to provides crucial warnings before strong shaking occurs. However, because the alerts are triggered only when an earthquake is already in progress, and the alert latencies and delivery times are platform dependent, the time between these warnings and the arrival of shaking is variable. The Shak - Publications
Filter Total Items: 18
Testing the ShakeAlert earthquake early warning system using synthesized earthquake sequences
We test the behavior of the United States (US) West Coast ShakeAlert earthquake early warning (EEW) system during temporally close earthquake pairs to understand current performance and limitations. We consider performance metrics based on source parameter and ground‐motion forecast accuracy, as well as on alerting timeliness. We generate ground‐motion times series for synthesized earthquake sequeVery low frequency earthquakes in between the seismogenic and tremor zones in Cascadia?
Megathrust earthquakes and their associated tsunamis cause some of the worst natural disasters. In addition to earthquakes, a wide range of slip behaviors are present at subduction zones, including slow earthquakes that span multiple orders of spatial and temporal scales. Understanding these events may shed light on the stress or strength conditions of the megathrust fault. Out of all types of sloEarthquake early warning for estimating floor shaking levels of tall buildings
This article investigates methods to improve earthquake early warning (EEW) predictions of shaking levels for residents of tall buildings. In the current U.S. Geological Survey ShakeAlert EEW system, regions far from an epicenter will not receive alerts due to low predicted ground‐shaking intensities. However, residents of tall buildings in those areas may still experience significant shaking dueCorrelation of porosity variations and rheological transitions on the southern Cascadia megathrust
The unknown onshore extent of megathrust earthquake rupture in the Cascadia subduction zone represents a key uncertainty in earthquake hazard for the Pacific Northwest that is governed by the physical state and mechanical properties of the plate interface. The Cascadia plate interface is segmented into an interseismically locked zone located primarily offshore that is expected to rupture in largeExpected warning times from the ShakeAlert earthquake early warning system for earthquakes in the Pacific Northwest
The ShakeAlert® earthquake early warning system has been live since October 2019 for the testing of public alerting to mobile devices in California and will soon begin testing this modality in Oregon and Washington. The Pacific Northwest presents new challenges and opportunities for ShakeAlert owing to the different types of earthquakes that occur in the Cascadia subduction zone. Many locations inCommentary: The role of geodetic algorithms for earthquake early warning in Cascadia
The ShakeAlert earthquake early warning (EEW) system issues public alerts in California and will soon extend to Oregon and Washington. The Cascadia subduction zone presents significant new challenges and opportunities for EEW. Initial publications suggested that EEW algorithms based on Global Navigation Satellite System (GNSS) data could provide improved warning for intraslab events and dramaticalA long-term geothermal observatory across subseafloor gas hydrates, IODP Hole U1364A, Cascadia accretionary prism
We report 4 years of temperature profiles collected from May 2014 to May 2018 in Integrated Ocean Drilling Program Hole U1364A in the frontal accretionary prism of the Cascadia subduction zone. The temperature data extend to depths of nearly 300 m below seafloor (mbsf), spanning the gas hydrate stability zone at the location and a clear bottom-simulating reflector (BSR) at ∼230 mbsf. When the holeShakeAlert Earthquake Early Warning System Performance During the 2019 Ridgecrest Earthquake Sequence
During July 2019, a sequence of earthquakes including a Mw6.4 foreshock and a Mw7.1 mainshock occurred near Ridgecrest, California. ShakeAlert, the U.S. Geological Survey (USGS) ShakeAlert public Earthquake Early Warning (EEW) system being developed for the U.S. West Coast, was operational during this time, though public alerting was only available within LA County. ShakeAlert created alert messagNew opportunities to study earthquake precursors
No abstract available.Abundant spontaneous and dynamically triggered submarine landslides in the Gulf of Mexico
Submarine landslides that occur offshore are common along the U.S. continental margins. These mass wasting events can trigger tsunamis and hence potentially devastate coastal communities and damage offshore infrastructure. However, the initiation and failure processes of submarine landslides are poorly understood. Here, we identify and locate 85 previously unknown submarine landslides in the GulfAseismic transient slip on the Gofar transform fault, East Pacific Rise
Oceanic transform faults display a unique combination of seismic and aseismic slip behavior, including a large globally averaged seismic deficit, and the local occurrence of repeating magnitude (M) ∼6∼6 earthquakes with abundant foreshocks and seismic swarms, as on the Gofar transform of the East Pacific Rise and the Blanco Ridge in the northeast Pacific Ocean. However, the underlying mechanisms tSemiautomated estimates of directivity and related source properties of small to moderate southern California earthquakes using second seismic moments
We develop a semiautomated method for estimating with second seismic moments the directivity, rupture area, duration, and centroid velocity of earthquakes. The method is applied to 41 southern California earthquakes with magnitude in the range 3.5–5.2 and provides stable results for 28 events. Apparent source time functions (ASTFs) of P and S phases are derived using deconvolution with three stack - News