Interpolation of 2‐D vector data using constraints from elasticity

Sandwell, David T.; Wessel, Paul

doi:10.1002/2016gl070340

Cited by 59 publications

(78 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A standard value of Poisson's ration of 0.25 is assumed in the following analysis. Sandwell and Wessel (2016) have produced a simplified variant of our method called gpsgridder that is now available as part of the Generic Mapping Tools (Wessel et al, 2013). The two methods handle the tasks differently.…”

Section: Vdohs Methodsmentioning

confidence: 99%

A Preseismic Strain Anomaly Detected Before M6 Earthquakes in the South Iceland Seismic Zone From GPS Station Velocities

et al. 2018

View full text Add to dashboard Cite

The South Iceland Seismic Zone (SISZ) accommodates E‐W translation due to oblique spreading between the North American and the Eurasian plates in South Iceland with ruptures on N‐S faults. Strain is released in earthquake sequences that last days to years, at average intervals of 80–100 years. Two M6.5 earthquakes struck in the SISZ in June 2000, and two M6 earthquakes in May 2008. These events released only half of the strain accumulated since the last earthquake sequence in 1896–1912. GPS station velocities are estimated from annual campaigns and continuous measurements in the SISZ during 2001–2015. The GPS station velocities are used to calculate strain rates from a new method using the vertical derivatives of horizontal stress. Our new strain rates are obtained by integrating vertical derivatives of horizontal stress rates, rather than differentiating interpolated GPS velocities, allowing finer resolution of strain. Estimating the strain rates for eight time intervals, we find high strain rates in the SISZ (0.5–1 microstrain per year) with significant temporal and spatial variation. The strain rates in the SISZ reveal contraction in the Hengill area and dilatation over a large area in eastern SISZ, indicating inflation of the magma system beneath Hekla volcano. A prominent strain anomaly is evident in the epicentral area prior to the May 2008 earthquakes. We suggest that this signal is primarily caused by plate motion and an increase in the rate of contraction in the Hengill area, located ∼10 km west of the epicentral area.

show abstract

Section: Vdohs Methodsmentioning

confidence: 99%

A Preseismic Strain Anomaly Detected Before M6 Earthquakes in the South Iceland Seismic Zone From GPS Station Velocities

et al. 2018

View full text Add to dashboard Cite

show abstract

“…We outline the fundamentals of the method below, although we refer the reader to Haines et al (2015), Dimitrova et al (2016), and Árnadóttir et al (2018) for more detail on application of the method to GPS velocity fields. An analytical approximation for the Haines et al (2015) method has been developed by Sandwell and Wessel (2016) to create gridded 2-D velocity fields in the gpsgridder algorithm in GMT.…”

Section: Deriving a New Zealand Strain And Vdohs Rate Field From Gps mentioning

confidence: 99%

New Zealand‐Wide Geodetic Strain Rates Using a Physics‐Based Approach

Haines

Wallace

2020

Geophysical Research Letters

View full text Add to dashboard Cite

We present a new strain rate map for New Zealand, based on geodetic data acquired from 1995 to 2013. We use a physics‐based approach, which inverts the horizontal GPS velocities for Vertical Derivatives of Horizontal Stress (VDoHS) rates, relying on using elasticity theory and the horizontal force balance equations at the Earth's surface. The VDoHS rates are then integrated to obtain horizontal strain rates. Strain rates derived using this new approach are less spatially smoothed than previous results using conventional methods. In addition to the major plate boundary features in New Zealand, low‐rate zones of deformation are resolved by the strain and VDoHS rates, which bodes well for the utility of this method to reveal processes on hidden or ill‐characterized fault zones. Application of this new method to obtain strain and VDoHS rates provides the highest resolution view to‐date of contemporary deformation in New Zealand.

show abstract

“…Here we examine this coincidence in southern California. The strain rate data are derived from the Community Geodetic Model (CGMl; Sandwell & Wessel, ). Similar to Jin and Aki (), we compute the dilatational strain rate ( e x x + e y y ) (see Figures a and b).…”

Section: Discussionmentioning

confidence: 99%

An Improved Method to Determine Coda‐Q, Earthquake Magnitude, and Site Amplification: Theory and Application to Southern California

Wang

Shearer

2019

JGR Solid Earth

View full text Add to dashboard Cite

Seismic coda waves can be used to constrain attenuation, estimate earthquake magnitudes, and determine site amplification factors. We have developed a new multistation and multievent method to determine these three important seismic parameters simultaneously. We analyze 642 representative local (≤100 km) and shallow (≤20 km) earthquakes with catalog magnitudes between 1.8 and 5.4 in southern California at multiple frequency bands centered at 1.5, 3, 6, and 12 Hz. We find that the length of the moving average time window can affect the measurement of coda attenuation Q C , but our tests indicate that the optimal window length is about 15 times the dominant data period. We use linear regression to fit each coda section and use only those portions that agree with the model decay rate with a correlation coefficient larger than 0.9. For a frequency-dependent coda-Q C model (Q C = Q 0 f n ) at 1-Hz reference frequency, our results yield estimates for Q 0 and n of 107-288 and 0.42-1.14, respectively. Our coda magnitude estimates are linearly correlated with catalog magnitudes, and our observed lateral variations in coda-Q C and our site amplification factors are in general agreement with previous results, although there are notable differences at some locations. This approach provides a unified, accurate, and stable method to measure coda-Q C , earthquake magnitude, and site amplification using coda waves of locally recorded earthquakes. Key Points:• We develop a new coda-Q method to determine coda magnitudes, site amplification factors, and coda attenuation simultaneously • We introduce a sourceside coda attenuation together with the conventional stationside coda attenuation considering complex attenuation • The multiple frequency source terms can be used to study the source spectral models and earthquake scaling relation Supporting Information:• Supporting Information S1

show abstract

Interpolation of 2‐D vector data using constraints from elasticity

Cited by 59 publications

References 16 publications

A Preseismic Strain Anomaly Detected Before M6 Earthquakes in the South Iceland Seismic Zone From GPS Station Velocities

A Preseismic Strain Anomaly Detected Before M6 Earthquakes in the South Iceland Seismic Zone From GPS Station Velocities

New Zealand‐Wide Geodetic Strain Rates Using a Physics‐Based Approach

An Improved Method to Determine Coda‐Q, Earthquake Magnitude, and Site Amplification: Theory and Application to Southern California

Contact Info

Product

Resources

About